Are you a disruptive physician?

The phrase “disruptive physician” has been bandied about at medical staff meetings lately. Apparently, most hospital medical staffs have provisions in their bylaws for sanctioning physicians deemed to be disruptive irrespective of their clinical competence. I’ve always been a bit uneasy about this, since any behavior or opinion someone else (such as a nurse or an administrator) finds objectionable could be categorized as disruptive.

Of course there are occasional examples of physician behavior clearly detrimental to patient care such as intoxication, sexual impropriety and threatening or intimidating behavior so severe as to preclude an effective working relationship among staff. Such episodes require an organized, explicit institutional response. The notion of a disruptive physician policy to deal with these situations is sound. But how do you define disruptive behavior? Greg Piche in his Health Care Law Blog recently remarked “The definition of what constitutes disruptive behavior in most of these policies is left so inordinately broad and so diaphanously vague as to render them effective tools for silencing responsible criticism….” His examples of behaviors that could be considered disruptive are concerning; having a disagreeable personality or willingness to speak out against the administration could perhaps result in a disciplinary proceeding.

So this concerns me. Although the original notion of a disruptive physician policy may be valid it could have the unintended consequences of stifling original thought and dissent. This editorial from the Journal of American Physicians and Surgeons warns about abuse of the concept. Please read the whole article, particularly the little ditty at the end.

Disclosure: I have occasionally bumped heads by playing the medical staff curmudgeon role.

The list of drugs that prolong the QT interval and cause torsades de pointes

is growing so rapidly that clinicians need help in keeping up. Here’s a useful resource: The Center for Education and Research on Therapeutics at the University of Arizona Health Sciences Center, spearheaded by Raymond L. Woosley, MD, PhD Vice President for Health Sciences there. Dr. Woosley has an extensive background on the clinical pharmacology of antiarrhythmic drugs. The site is a frequently updated listing of drugs that cause or increase the risk of TDP. The lists are categorized according to degree of risk and strength of recommendation.

Under diagnosis of alpha 1 antitrypsin deficiency

A survey in the September issue of Chest reminds us that we are under diagnosing alpha 1antitrypsin deficiency (AATD). The study of 1020 patients with AATD revealed an average of 8.3 years from symptom onset to diagnosis. 20% of patients went through four or more physicians before being diagnosed. Timeliness of diagnosis did not improve between 1968 and 2003.

AATD is easy to diagnose, so why are we doing so poorly? Clinicians under appreciate the fact that AATD can be present in any patient with COPD. It is not, as popularly believed, confined to the rare non-smoker with emphysema or to those patients with primarily lower lobe disease. Moreover, it may not be widely known that current guidelines cast a broad net for screening patients for AATD. In reviewing this topic I was surprised to learn that the World Health Organization, the American Thoracic Society and the European Respiratory Society recommend that ALL patients with COPD be tested for AATD.

The joint statement of the American Thoracic Society/European Respiratory Society was published in the American Journal of Respiratory and Critical Care Medicine in 2003. Here is a partial list of patients for whom screening was definitely recommended (type A recommendation):

1) Symptomatic patients with a diagnosis of emphysema or COPD
2) Patients with asthma whose pulmonary function does not completely normalize after aggressive treatment
3) Individuals with unexplained liver disease
4) Asymptomatic patients with persistent obstruction on pulmonary function tests with known risk factors
5) Adults with necrotizing panniculitis

Panic attacks---not so benign

They may be bad for your heart (American Journal of Cardiology).

COPD and cardiovascular disease

Two recent offerings from the medical literature suggest an association between COPD and cardiovascular disease that may be under-appreciated. In this study from Chest patients with COPD had twice the rate of hospitalization for a composite of cardiovascular outcomes, adjusted for pre-study cardiovascular risk factors. The follow up period was just under three years.

This paper from the European Heart Journal reports unrecognized heart failure in 20% of patients with stable COPD. Approximately half the heart failure cases had systolic left ventricular dysfunction and half had primarily diastolic dysfunction. Surprisingly, none had right sided heart failure. The authors suggest that right sided failure is characteristic of more advanced COPD than was represented in this study. The reasons for the association may be both physiologic (e.g. ventricular interdependence) and epidemiologic (overlapping risk factors, particularly smoking).

The pioglitazone controversy continues

Pioglitazone (Actose) and rosiglitazone (Avandia) are members of the thiazoladinedione (TZD) class of oral medications for type 2 diabetes. These agents have been surrounded by controversy because their predecessor in the TZD class, troglitazone (Rezulin), was withdrawn from the market because of liver toxicity. Although their beneficial effects on metabolic risk factors for macrovascular disease have long been known, outcome based data regarding protection against such events have been lacking until very recently and the Public Citizen Health Research Group has placed TZD drugs on its “do not use” list.

Recently the PROactive Study (PROspective pioglitAzone Clinical Trial In macroVascular Events) demonstrated the efficacy of pioglitazone in preventing macrovascular events. I blogged it here following presentation of the results but shortly after the announcement and before final publication a BMJ opinion piece was harshly critical of the study. My response to the BMJ commentary is here.

Now PROactive has been published in Lancet October 8 along with a commentary by Hannele Yki-Järvinen. Unlike the BMJ editorial the Lancet commentary acknowledges the clinical benefit of pioglitazone in decreasing macrovascular events. The major controversy about the PROactive results concerned the lack of statistical significance for the primary outcome and reliance on the secondary outcome. But Yki-Järvinen points out that inclusion of procedure related endpoints in the primary outcome could have biased the results against pioglitazone and implies (as I said before) that the primary outcome would have reached statistical significance with a longer follow up period, as the curves were diverging at study’s end. The commentary poses questions about the clinical significance of the increase in heart failure and how it might counterbalance the improvement in vascular outcomes.

So is it time for Public Citizen to change its “do not use” recommendation? They defend the recommendation on the basis that the TZDs “may be less effective than other drugs for diabetes and cause liver damage, weight gain, anemia and heart failure.” PROactive and other evidence suggests that this statement may be unfounded. How can the question of effectiveness of TZDs compared to other agents be answered? Because different classes of medication for diabetes have mechanisms of action which are complementary to one another it may be simplistic to ask whether one class of agents is as effective as another. It now appears that pioglitazone can join metformin as another agent capable of improving macrovascular outcomes. As for liver damage, none was found in PROactive. Weight gain (4 kg more than placebo) was seen, but the clinical significance is unknown and anemia was not mentioned. The problem of heart failure remains troubling although no new heart failure concerns were raised by the study.

Why is Alzheimer’s disease getting all the attention?

This study published in Radiology, evaluating structural changes and cerebral blood flow in elderly demented patients compared with age-matched cognitively intact individuals, found reduced cerebral blood flow in the demented patients suggesting that vascular disease is an important factor in dementia in the elderly. We’ve gone through phases in our understanding of dementia. In the nineteenth century dementia was synonymous with general paresis of the insane, later understood to be caused by syphilis. A half century ago dementia was widely believed to be primarily a vascular disease, leading to a proliferation of vasodilators such as ergoloid mesylates, cyclandelate, and papaverine, none of which worked. More recently we’ve better appreciated Alzheimer’s disease. Does the article in Radiology bring us full circle with regard to “vascular dementia?” No, but it suggests that perhaps our emphasis on Alzheimer’s disease has lead to an under appreciation of vascular mechanisms. Here’s info on multi-infarct dementia and Binswanger’s dementia.

Two lessons in the interpretation of medical literature from a fascinating paper in Medscape General Medicine

Anticoagulation Therapy for Venous Thromboembolism, a review in Medscape General Medicine, stunningly concludes: “Anticoagulants have not been shown to be efficacious in reducing morbidity and/or mortality or safe in VTE treatment.”
Lesson one: Evidence based medicine (EBM) doesn’t always give us the answer.
The Medscape review points out that anticoagulant therapy became the standard based on a single small randomized controlled trial published in Lancet in 1960 which would be considered unacceptably flawed by today’s EBM standards. Moreover, subsequent studies in support of anticoagulation for venous thromboembolism (VTE) were of the sort the EBM crowd frowns on (observational studies, comparisons with historical controls, etc.).

But the Lancet study, flawed as it was, had striking results in favor of treatment. Anticoagulation became the standard, and it has since been considered unethical to do any more placebo controlled randomized trials. The totality of the subsequent evidence, although low level by EBM standards, is compelling. For me, the treatment of VTE with anticoagulants is justified even though it will probably never be “evidence based.” This thoughtful and thorough review in the Journal of Internal Medicine makes that point better than I can.
Lesson two: Financial conflicts of interest aren’t the only ones that need to be disclosed.
Note the following author information for the Medscape paper.Disclosure: David K. Cundiff has no significant financial interests or relationships to disclose. Mr. Cundiff has disclosed that he withdrew warfarin from a patient with lower limb deep vein thrombosis on the grounds that the risk of bleeding in this case seemed to be higher than the benefit of anticoagulant treatment. The patient later died of pulmonary embolism and Mr. Cundiff subsequently lost his medical license because of this case.
Kind of makes you want to read the paper a little more carefully, eh?

What’s so special about Up to Date?

Wonders The Krafty Librarian, who reports doctors’ reactions when a local health system decided to restrict Up to Date access to on campus users. (Linked at Grand Rounds by Hospital Impact). Up to Date is expensive and very restrictive in its access options. Institutional subscriptions generally only provide on site access. Apparently it’s prohibitively expensive for many institutions to provide home access for all users. Like the Krafty Librarian I wonder why so many folks swear by it.

She writes: “But is UpToDate's content really that much more superior to FirstConsult and eMedicine that doctors are willing to put up with a product that seems to have extremely restrictiveve access policies and is not rapidly expanding into needed areas like the handheld and EMR market? Or are physicians apathetic? They know about UpToDate, they know it is a good product, but they don't care to learn or be bothered with other products because they are sticking with the one that they are familiar with come hell or high water.”

Hmmm--- I have mixed feelings. Apparently, according to one of the links in the post, emedicine has an institutional edition which requires a paid subscription. This is news to me, and I’m struggling to understand how it differs from the free version of emedicine I was already familiar with. So is Up to Date really that much better than the free version of emedicine? Emedicine seems to be a work in progress, and is getting better and better. However, it doesn’t seem as well organized or as extensively linked as Up to Date. It’s a large and growing collection of stand alone monographs. And, if renowned expertise in the authorship is important, Up to Date has the edge with a list of contributors that reads like a parade of stars. Also, it’s advertising free, and the free version of emedicine is not (if that’s important to you).

But Up to Date may be living largely on reputation. As the Krafty Librarian points out, doctors are familiar with it and trust it. I don’t agree with some of my colleagues who think it’s all they need, or that it’s even the best resource. I use it extensively and have a personal subscription so I can access it at home (very important to me), but I find it complementary to many other resources. Disadvantages include imprecise searching (you usually have to combine searching and browsing) and somewhat limited graphics. I think there may be other resources that provide a better bang for the buck.

Warfarin after acute coronary syndrome?

The pendulum has been swinging on this issue for years. A meta-analysis published in the August 16 issue of Annals of Internal Medicine favors warfarin added to aspirin for patients with ACS. Patients who received coronary stents were excluded. Warfarin was associated with decreases in myocardial infarction, ischemic stroke and need for revascularization. Benefits outweighed the bleeding risks in all but those patients stratified as high risk for bleeding. There was no effect on mortality.

For patients with ACS who do not receive stents we now have two antithrombotic agents to consider adding to aspirin, these being clopidogrel and warfarin. Patient selection for treatment with one agent or the other will be complex, and will need to take into account risk factors, cost, and patient preference.

Statins and clopidogrel together: Do we have the final answer?

Not yet, in spite of the profusion of studies that have been published ever since the first report in Circulation of an in vitro interaction between clopidogrel and atorvastatin. Clopidogrel is a pro-drug which is metabolized to the active drug by CYP3A4, while atorvastatin is metabolized by the same enzyme. Atorvastatin attenuated the anti-platelet action of clopidogrel in vitro, in a dose dependent fashion.

The latest offering is a recent study in the European Journal of Clinical Investigation in which the effect of clopidogrel on platelet function was tested during concomitant administration of several statins in healthy subjects. Simvastatin and fluvastatin, but not atorvastatin, pravastatin or rosuvastatin, attenuated the effect of clopidogrel. The dose of atorvastatin was only 20mg daily.

An earlier study had concluded that none of five statins, including atorvastatin, attenuated the anti-platelet effect of clopidogrel. The range of atorvastatin doses in that study was 10-40mg.

The clinical significance of the interaction is controversial, with this recent outcome based study suggesting no significant clinical effect, but with other evidence suggesting the interaction may indeed be clinically adverse.

Despite several studies and substantial expert opinion pointing to the safety of concomitant use of statins and clopidogrel I remain concerned because of a lack of data concerning statin dosage effects. My specific concern is that the in vitro evidence suggests that the interaction is dose dependent, and the highest atorvastatin dose purportedly shown to be safe with clopidogrel was 40mg. This is particularly important in view of recent recommendations that 80mg atorvastatin be initiated in the early period following acute coronary syndrome.

Government run health agencies would prefer a double standard

And apparently they have been enjoying one for some time, at least when it comes to reporting malpractice awards and settlements to the National Practitioner Data Bank., as reported here in the New York Times. The law requiring reporting to the Data Bank explicitly applies to federal government health services as well as the private sector. However, the new inspector general has found that non-compliance on the part of government health services is routine. The excuses cited by the federal agencies, such as the NIH and the Indian Health Service, are that sometimes the records get lost, or that they just plain don’t think they should have to comply.

What’s being done about it? The Times piece concludes with:
“Betty James Duke, administrator of the health services agency, said she would soon recommend changes to ‘ensure greater compliance’ with the reporting requirements. But in discussions with the inspector general's staff, federal agencies did not make any firm commitments. ‘It was not clear whether they would fully comply,’ Mr. Levinson wrote.”

Non medical

A blog devoted to cool stuff about Google maps.

Intensive glycemic control in critical illness

This is a hot topic in hospital medicine. I’ve discussed the tension between “patient oriented” and “disease oriented” medical literature. In my opinion we need to read both. Here’s a patient oriented review of intensive in patient insulin therapy from last October’s Cleveland Clinic Journal of Medicine. Here is a disease oriented study and an accompanying editorial from a recent issue of the Journal of Clinical Investigation.

For me, empirical evidence is more interesting and meaningful when coupled with pathophysiologic rationale. (I hope the EBM Mafia isn’t watching).

Stephen Barrett takes courageous stand against Institute of Medicine Report

Stephen Barrett wrote this critical review (via Medscape) of the Institute of Medicine (IOM) book on complementary and alternative medicine (CAM). The National Center for Complementary and Alternative Medicine (NCCAM), a subsidiary of the NIH, commissioned the IOM to write the report. Barrett accuses both the NCCAM and the IOM of promoting unsound health claims. The report, Barrett says, uncritically accepts implausible health methods. In my opinion he nails the issue in stating “Methods that are plausible should be tested with well-designed clinical trials. The rest should be discarded” (Italics mine). I have previously argued that it is wasteful to study scientifically implausible treatments. He goes on: “Despite all the alleged experts involved in its preparation, the IOM report does not contain a single word of criticism against methods that are sufficiently irrational to be discarded now. Instead, it makes broad, sweeping generalizations and attempts to set an agenda for the widespread adoption of ‘CAM’ research and teaching.”

And, concerning CAM teaching, Barrett points out the increasing uncritical adoption of unscientific claims in medical school curricula. He cites this paper by Stanford professor of medicine Wallace Sampson, M.D. on medical school teaching of alternative medicine. Sampson’s survey indicates that medical schools often present baseless alternative medicine claims uncritically or, worse, actively promote them. This open access full text article is worth reading in its entirety. Sampson writes “With inadequate approaches that fail to uphold criteria for validity and plausibility, so called ‘evidence-based’ medicine remains fluid and loses its value to help physicians discern what is truly useful.” Bingo! Sampson makes valid suggestions for reform of the medical school curriculum.

The saga of the pulmonary artery catheter

Medpundit posted about this the other day. Here’s my perspective.

Bedside pulmonary artery catheterization, more commonly known as Swan-Ganz catheterization, began life around 1970. As an internal medicine house officer in the late 70s I watched it come into vogue long before the rigors of evidence based medicine. Offered initially as a tool for management of myocardial infarction it soon enjoyed a broader range of use in critically ill medical patients. In the 1980s papers by Shoemaker and colleagues [1] [2] suggested that aggressive protocol driven therapy guided by the pulmonary artery catheter (PAC) improved outcomes in high risk surgical patients.

In the 1990s several papers addressed PAC guided therapy to maximize oxygen delivery in septic patients, with negative results [3] [4]. In 1996 the SUPPORT investigators published a prospective cohort study of outcomes associated with the use of the PAC in a variety of critically ill patients. This oft-quoted and controversial study suggested harmful effects of the PAC and was followed by editorial commentary suggesting that it was time to pull the catheter. Many writers called for prospective randomized trials of PAC and the American College of Cardiology and other professional societies published guidelines for use of the catheter based on the best evidence at the time.

Subsequently, higher level studies have failed to show benefits of the PAC. Finally, in the October 5 issue of JAMA are two studies and an editorial which suggest we may be approaching the final chapter of the PAC saga. The ESCAPE trial, looking at severely ill patients with heart failure, was a bust. In the same JAMA issue this meta-analysis showed no benefit of the PAC across a spectrum of critical illness. An accompanying editorial is linked here.

It’s been a long and interesting ride. If the ongoing FACTT study fails to show benefits of the PAC in patients with ARDS it may indeed be time to pull the catheter.

Should metformin’s contraindications be contraindicated?

The real test of a drug’s safety is to get it out to the market and into the hands of providers who ignore the labeling and contraindications. Some drugs, like cisapride, prove to be unforgiving of such indiscretions and are taken off the market. That’s the situation that gets most of the attention. Metformin may be different. It seems to be a more forgiving drug. The biguanides, of which metformin is a member, are well known to precipitate lactic acidosis, yet the condition has been difficult to attribute to metformin in the post marketing experience despite widespread contraindicated prescribing. Here’s a point- counter point on the question in a recent issue of CMAJ.

Will the labeling be relaxed for metformin? I don’t know. For now I’ll continue to observe the labeling.

Remembering Hemo the Magnificent

Longer ago than I care to admit a popular educational resource for kids was a series of Bell Telephone sponsored films on a variety of science topics. The series was made for TV in the mid to late 50s and later distributed to schools. The one I remember best was Hemo the Magnificent. It combined humorous Disney style animation with human actors to take the student on a virtual tour of the circulatory system. Clever production elements and analogies (such as nervous pathways illustrated by telephone lines and little men operating levers representing pre-capillary sphincters) held us baby boomers in rapt attention and indelibly etched the circulatory system in our minds.

Fast forward to generation X and this paper in Advances in Physiology Education. The survey of undergraduate students found a high rate of misconceptions about circulatory function and offers fascinating insight about how we learn. When asked to trace the flow of blood a student might draw a path around the perimeter of the body. When asked about the principal function of the lungs some students said it was to filter the blood, others said to convert oxygen into carbon dioxide. There was confusion about distinctions between arteries, veins and capillaries. Worse, these college students were pursuing a career in elementary education.

Despite improvements over time major misconceptions persisted through the end of the course. Equally concerning was the fact that one on one interviews with students uncovered many more misconceptions about the circulation than standard tests, suggesting that students can conceal major areas of misunderstanding on routine testing.

The authors point out that faulty preconceptions about course material hinder learning. Learning is a synthesis of new content and what the student thought before. If the student’s prior thoughts are flawed the learning is less effective. The discipline of physiology, the study of how the body works, may be uniquely susceptible to prior thinking. Early on children begin to develop a mental model based on their interpretations of body sensations. Although the model becomes more sophisticated over time it remains flawed. The teaching of physiology might be more effective if teachers could identify student misconceptions, then employ means to help students unlearn or modify them. The authors conclude that new methods of assessment and teaching are needed. I would add that perhaps we should resurrect Hemo the Magnificent.

Dialysis for dummies

Hospitalists are increasingly called on to participate in the care of dialysis patients. Now it’s more important than ever for us to know a little about dialysis. Here’s a nice review from Southern Medical Journal with the basics.

Hepatoadrenal syndrome

This paper in Critical Care Medicine is noteworthy because it demonstrates an unexpectedly high rate of adrenal insufficiency in patients with severe acute and chronic liver failure, and suggests that treatment with hydrocortisone improves outcome in those patients demonstrated to have adrenal insufficiency. Perhaps we should be doing rapid cortrosyn stimulation tests on these patients at hospital admission. This is useful information with the potential to change hospital practice.

Furosemide and albumin administration in acute lung injury

A recent paper in Critical Care Medicine adds another piece to our understanding of the controversy surrounding fluid management in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In patients with ALI/ARDS and low total serum protein (<6g/dl) the investigators compared furosemide with albumin to furosemide with placebo. The albumin group had better outcomes in terms of oxygenation and hemodynamic stability. The use of albumin was associated with less shock, the need for fewer fluid boluses, and consequently better ability to maintain negative fluid balance.

Historically the controversy has centered around two related questions, one being whether it’s better to maintain positive or negative fluid balance in ARDS (the “wet vs. dry” debate) and the other issue being the use of albumin in general.

Evidence to date seems to favor the dry school (patients with negative fluid balance and who lost weight did better in this study and those who dropped their wedge pressure did better in this one). The level of evidence in these studies is somewhat low, and better answers await completion of FACTT, an ARDSnet sponsored study prospectively comparing wet and dry strategies. (The study also has arms comparing central venous catheter vs. pulmonary artery catheter monitoring).

The albumin controversy has an interesting history. Used indiscriminately in the past, it fell into disfavor after this meta-analysis of albumin use in a variety of critical illnesses including ARDS. Survival differences in this analysis were not significantly different but the point estimates suggested harm with albumin administration.

I can remember when it was popular to administer albumin with loop diuretics for ARDS based on little more than physiologic plausibility. People began to decry the use of albumin when evidence based medicine came on the scene. This study in Critical Care Medicine suggests an evidentiary basis for albumin, but the authors caution that more studies, looking at more meaningful outcomes, are needed. I look forward to knowing whether patients have fewer days of mechanical ventillation, shorter ICU stays and better survival.

Hormone replacement hype

A recent issue of The American Journal of Obstetrics and Gynecology reports that doctors have an inflated perception of the risks of hormone replacement therapy (HRT). The survey of Florida physicians found that primary care doctors were more likely to overestimate the risk than Ob-Gyns. The authors felt the respondents were confused between relative risk difference and absolute risk difference.

This is illustrated by data from the Women’s Health Initiative (WHI) study of estrogen and progesterone in which the relative risk numbers, when considered alone, exaggerate the perception of harm from HRT. This may have resulted in distorted media reporting of the study. For example, considering only the relative risks, there was a 29% increase in coronary heart disease events, a 26% increase in breast cancer, a 41% increase in stroke, and a doubling of pulmonary embolism. Unfortunately these figures are deceptive because they ignore the low baseline rate of events. Translated into absolute risk, HRT was associated with only 7 excess coronary heart disease events per 10,000 patient years, 8 more breast cancers, 8 more strokes, and 8 more PEs. These numbers represented the true magnitude of harm but seemed to be buried in the fine print of much of the popular reporting. An editorial in the same issue of JAMA cautioned against taking relative risk out of context, correctly pointing out that absolute risk data provided the true measure of effect. Although the editorial put the study in perspective it was given little notice in popular reporting.

Undue emphasis on relative risk difference is deceptive. Such emphasis can be used not only to exaggerate harm but also to inflate the apparent effectiveness of treatment, as is sometimes done in pharmaceutical company advertisements.

Why aren’t doctors more savvy about this issue? Maybe we should pay less attention to the popular news reports and concentrate more on the primary sources.

Constrictive pericarditis: the great mimicker

The July issue of the Journal of General Internal Medicine has a case report of constrictive pericarditis presenting as protein-losing enteropathy. This is one of many deceptive presentations of constrictive pericarditis which have been reported including liver disease, Budd Chiari Syndrome, refractory pleural effusions, chylous ascites, chylothorax, and lymphopenia with hypogammaglobulinemia. These unusual manifestations are, in one way or another, consequences of systemic venous hypertension.

Clinically, constrictive pericarditis looks a lot like restrictive cardiomyopathy. Differentiation between the two has been difficult, but is crucial, as constrictive pericarditis is surgically treatable if diagnosed early. Recent advances in echocardiography and cardiac doppler have improved the diagnostic approach which is outlined in this review. The distinction can be made with echo-doppler but it is operator dependent, requiring a focused approach with detailed attention to the respiratory cycle. This isn’t the type of information you’re likely to get from a routine echo report unless you tell the technician exactly what you’re looking for.

Beware of dementia bias

All other things being equal, patients with dementia who are admitted to the ICU do just as well as those without dementia according to this study in the June issue of Critical Care Medicine. A higher percentage of patients in the dementia group (46% vs. 11%) were from nursing homes.

Although there may be legitimate reasons to withhold ICU care in some demented patients (such as advance directives) we can’t base the decision on a presumption of poor clinical outcome.

Computers, evidence based medicine and the problem oriented medical record

After blogging about evidence based medicine (EBM) and the problem oriented medical record (POMR) recently I wondered what Lawrence Weed, originator of the POMR, had been up to lately. It turns out he founded Problem-Knowledge Couplers, the PKC Corporation. They have developed software for medical record keeping and decision support. Concerning EBM and the POMR I opined that we haven’t done a very good job at either. It looks like these folks are on to something that may help us do better at both. Here’s an article about Lawrence Weed in Healthcare Informatics.

Disclosure: I have no interest in PKC.

Watch for major changes in emergency cardiac care

Dr. Gordon Ewy and his group at the University of Arizona are quietly marshalling evidence that challenges the current practice of cardio-pulmonary resuscitation (CPR). One of their latest publications is found here in Circulation. The investigators reviewed resuscitation records of patients experiencing out of hospital cardiac arrest in greater Tucson. Standard automated external defibrillator (AED) protocols were used. This resulted in frequent interruption of chest compressions such that compressions were performed only 43% of the time during resuscitation efforts. Initial defibrillation attempts did not restore perfusing rhythm is any patients, and survival was no better than their historical control.

What is the clinical importance of these observations? Over time following the onset of ventricular fibrillation (VF) myocardial ATP rapidly depletes. The result is that rapidly over time the relative effectiveness of electrical defibrillation diminishes in comparison to chest compressions as the initial modality of treatment, culminating in unresponsiveness to defibrillation unless reperfusion via adequate chest compression (and consequent repletion of myocardial ATP) is accomplished first. [1]

This has lead to the concept of the three phases of CPR: the electrical, the hemodynamic and the metabolic phases. These phases correspond to time periods of roughly 0-5 minutes, 5-10 minutes, and longer, respectively. During the electrical phase initial defibrillation is the most important. That’s in keeping with popular teaching. However, during the hemodynamic phase compression becomes the most important initial intervention, because by that time there is little hope that defibrillation will restore spontaneous circulation unless there is pre-treatment with chest compression to replete myocardial energy stores. The hemodynamic phase is the one often encountered by responders to out of hospital cardiac arrest. (The metabolic phase, during which measures to decrease brain metabolism such as therapeutic hypothermia are of importance, will not be discussed here).

The Arizona group has also demonstrated that current practices of rescue breathing may compromise myocardial perfusion due to delays and interruptions in chest compression . This and related evidence, coupled with survey data indicating reluctance of bystanders to perform mouth to mouth rescue breathing has lead these researchers to teach continuous compression CPR to the public and institute local fire department protocol changes in Tucson.

Although the American Heart Association (AHA) and International Liaison Committee on Resuscitation (ILCOR) strive to be evidence based and tend to await high level evidence before recommending changes in emergency cardiac care, expect the following or some semblance thereof to show up eventually in the recommendations: 1) The lay public will be taught compression only CPR; 2) the initial modality for emergency personnel responding to out of hospital cardiac arrest, unless compressions are already in progress, will be a prolonged and continuous series of compressions before defibrillation is attempted.

CAVEATS:

1) For witnessed VT or VF in the health care setting immediate defibrillation remains the initial modality (remember the electrical phase!).

2) This new thinking does NOT apply to pediatric codes or other arrests of suspected respiratory origin. Rescue breathing remains a higher priority in those situations.

Xigris in perspective

The ADDRESS trial of activated protein C (Xigris) was just published in NEJM. Though it was touted in the press as a breaking development it was really nothing new. Maybe September 28 was a slow news day in healthcare. I wouldn’t have bothered posting it here, but now that it’s been hyped some perspective is needed.

ADDRESS is old hat not only because it was announced months ago but also because it merely confirms what we already knew from a subset analysis of the earlier PROWESS trial: that the optimal use of Xigris is exactly according to the way FDA has labeled it and the company (Eli Lilly) has promoted it all along. Specifically, it is indicated as an adjunct to antibiotics and general supportive care in patients with severe sepsis who have an APACHE-2 score of at least 25.

FDA approval of Xigris was based on PROWESS, analysis of which revealed that the benefits of Xigris were confined to the subset of patients with the higher APACHE-2 scores. The FDA restricted its approval to this group of patients and then required Lilly to conduct a randomized controlled trial (ADDRESS) to specifically assess those patients with lower scores. As anticipated from PROWESS, ADDRESS found no overall survival difference. Although there was no overall difference a trend toward increased mortality with Xigris was seen in patients with recent surgery, as had previously been gleaned from PROWESS in the lower risk patients. Increased mortality was also observed with Xigris in the subset of patients who were the first enrollees at their respective research sites, suggesting a learning curve with the drug, and highlighting the importance of experience. This finding bolsters the suggestion of some that the use of Xigris be restricted to intensivists or other designated specialists.

Unfortunately the study was somewhat hyped in the press. Xigris looked like a flop in some reports and like poison in others, not to mention that most of the news reports were just plain confusing.

Finally: Clinical outcome-based data in favor of thiazolidinediones

On September 12 at the 41st European Association for the Study of Diabetes meeting the results of the Prospective Pioglitazone Clinical Trial in Macrovascular Events (PROactive) were announced. As reported by Medscape the study of over 5000 type 2 diabetic patients showed a decrease in macrovascular complications in patients treated with pioglitazone (Actose). The 10% relative risk reduction for the primary composite endpoint of seven macrovascular events did not reach statistical significance. However for the composite of stroke, MI and death the 16% reduction was statistically significant.

Other findings included a highly statistically significant >50% reduction in patients needing to add long term insulin. In addition to a significant fall in HbA1C the pioglitazone group experienced a statistically significant rise in HDL and fall in triglyceride levels confirming a beneficial effect on the “metabolic syndrome”, the principal dyslipidemia of type 2 diabetes. No new safety concerns were noted in the study.

This is a significant advance because it has previously been difficult to demonstrate a beneficial effect on macrovascular disease with insulin or oral agents, with the exception of metformin. Pioglitazone and rosiglitazone were reviewed last year in NEJM.

Now will the Public Citizen Health Research Group finally remove Actose from its black list?

Should we throw the bums (drug reps) out?

The medical blogging about the dispute between No Free Lunch and the American Academy of Family Physicians has been mostly favorable to No Free Lunch. I am glad to see that AAFP has finally decided to allow No Free Lunch (NFL) to exhibit and I hope ACP follows suit next year. I believe in a free market place of ideas, and theirs deserve to see the light of day.

I said before that while I agree with the basic premise of NFL (“that pharmaceutical promotion should not guide clinical practice”) I am concerned that some of their positions are extreme, or are taken to extremes by their supporters. My intention here is to state my specific areas of concern and issue a call for moderation. (Disclaimer: try as I will to avoid the straw man argument, I could be perceived as misstating the NFL position. NFL has eloquently stated its principles, but with the possible exception of the pledge these principles have not been codified in any formal way. As I express my concerns I realize that the opinions of NFL supporters occupy a spectrum. If this shoe doesn’t fit don’t wear it).

One of my differences with NFL lies in the distinction between skepticism and cynicism. At a recent CME conference at McGill Dr. Jerome Hoffman, professor of emergency medicine at UCLA and a supporter of NFL, pointed out the difference between these two approaches to evaluating claims and evidence. The cynic, he said, seeks to knock everything down; the skeptic, by contrast, thinks critically and questions claims, but all the while with an open mind. Webster defines the cynic as “contemptuously distrustful of human nature and motives” (italics mine). My perspective about the pharmaceutical industry is skeptical, while I view the attitude of many NFL supporters as cynical.

The cynic’s position might be that the drug companies care only about their stock holders, never have the public good in mind and that their interests are always in conflict with those of patients. The cynic might feel that the medical profession should have no interaction with the industry and never believe anything they say.

As a skeptic I believe that while there are conflicts of interest, in perception and in fact, the interests of the drug companies are sometimes but not always in conflict with good patient care. (Good patient outcomes can help increase profits). Unlike the cynic I believe win-win situations are possible. My skepticism says not to believe everything they claim and to always check primary sources. However, out of hand rejection of every claim based solely on source (the ad hominem fallacy) is unreasonable.

What about the practical consequences of the NFL objections? Are we ready to give up industry supported CME? I enjoy attending CME meetings. Although I can do without the pharmaceutical company exhibits, were it not for partial industry support the registration fees would be prohibitively expensive for many meetings. Not all physicians are wealthy. Those who attend AAFP and ACP meetings are among the least likely to be wealthy. I dare say many would not be able to attend at all without industry support.

There are other examples. Many of us enjoy (and often link to) emedicine and Medscape. I don’t want those free resources to go away. What about all the open access medical journals which would not survive without pharmaceutical advertising?

So to those who want to “throw the bums out” I urge caution. This highly nuanced issue does not lend itself to simplistic ideas.

Another nail in the coffin of a medical myth

Tradition has it that parenteral therapy is necessary to treat vitamin B-12 malabsorption. In recent years accumulating evidence has suggested the effectiveness of oral treatment. Much of the evidence has been in the form of case control and case series studies. This was the subject of a recent Cochrane review which found two RCTs of oral versus parenteral vitamin replacement, totaling 108 participants. 1000 to 2000 mcg of oral B-12 daily was found equal to a standard parenteral regimen.

Two recent narrative reviews of vitamin B-12 deficiency are linked here. [1] [2] They explain the physiologic rationale for oral replacement and highlight the only recently appreciated and most common cause of B-12 deficiency, known as food-cobalamin malabsorption syndrome. Now believed to be more common than classic pernicious anemia, food-cobalamin malabsorption syndrome is largely a disorder of the elderly. As explained in these reviews a common form of age related gastric atrophy results in deficient secretion of acid and pepsin, which are necessary to strip cobalamin from food protein. Patients with this common disorder can absorb B-12 from pills, but not food. Such patients have a normal Schilling’s test. The disorder is poorly understood, and some cases may be the result of longstanding H. pylori infection.

Food-cobalamin malabsorption is to be distinguished from classic pernicious anemia, an autoimmune disease characterized by antibodies to parietal cells and intrinsic factor. The effectiveness of oral B-12 replacement in such patients is less well understood, but apparently there is an alternate pathway of absorption which is independent of intrinsic factor. The absorptive mechanism is simple diffusion and requires a high concentration gradient, which is provided by the large daily oral doses of 1000-2000 mcg used in the studies.

As suggested in the Cochrane review this evidence, if put into widespread practice, could ease a substantial burden on health care resources. (The clinical effects may be more modest in those patients who derive substantial placebo effect from B-12 shots---anecdotal observation).

A few caveats:
1) The number of patients studied is small. The number with classic PA is smaller still.
2) The effective oral dose is high---1000 to 2000mcg daily.
3) Parenteral therapy has stood the test of time and may be preferable in patients with questionable compliance.
4) If oral treatment is elected the patient should be followed carefully in the short and long term for resolution of neurologic, hematologic and metabolic abnormalities including monitoring of the hemogram, reticulocyte response, homocysteine and methylmalonic acid levels.

Fetal pain round three

Well, we finally got disclosure about the fetal pain article, but wouldn’t it be better if the authors had provided it themselves? We shouldn’t have to rely on the media to do it for us. The National Right to Life Committee (NRLC) did some homework and came up two more items of note about Dr. Eleanor A. Drey, one of the paper’s authors. I previously noted that she is an abortion provider. The NRLC linked to the March 31 2004 issue of the San Fransisco Chronicle which informs us that she was head of San Fransisco’s largest abortion clinic and testified against the Partial-Birth Abortion Ban Act of 2003.

The September 2004 issue of the Physicians for Reproductive Choice and Health newsletter, also linked from the NRLC web site, profiles Dr. Drey as an activist whose passion on the issue is intense. Concerning a woman’s choice, she is quoted “It’s already an emotional decision, and to make it that much more difficult really infuriates me.” It infuriates her. Wow. With such intense emotion driving her opposition to fetal pain legislation could she have been objective in selecting and interpreting studies for a scientific review of the topic? The newsletter goes on to quote “It makes me feel really good that I can do something very immediate to serve women’s medical and emotional welfare while working in a political sense to train future providers, do research, and hopefully broaden women’s access to abortion and reproductive care. I am very lucky because I get to train residents and medical students, and I really do feel that it’s a type of activism.” (Italics mine).

This speaks volumes. There was clearly an agenda surrounding the fetal pain paper, and JAMA readers needed to know.

Heliox for asthma exacerbation

The popularity of heliox has outpaced its evidentiary basis. Here’s some interesting evidence in favor of heliox from this month’s Academic Emergency Medicine.

Another important cause of dilated cardiomyopathy

On July 27 I discussed familial dilated cardiomyopathy (DCM). There is another under-appreciated form of DCM that must not be missed because it can be completely reversible. I’ll start with a case. This is not a real patient, but a composite of some memorable ones I’ve seen.

A 66 yo male presents with dyspnea and leg edema, progressive over three weeks. He had no prior history of heart disease, diabetes or hypertension and had never consumed alcohol. Physical exam revealed bilateral lung crackles, lower extremity edema, ascites, neck vein distension and an S3 gallop. The electrocardiogram revealed rapid atrial fibrillation. The patient was not aware of his irregular cardiac rhythm.

He was admitted and underwent diuresis, rate control and anticoagulation with subsequent clinical improvement. An echocardiogram showed global hypokinesis, an ejection fraction of 15%, and no significant valvular abnormalities. The patient was discharged on digoxin, furosemide, warfarin and potassium supplement. (This was before the era of ACE inhibitors and beta blockers!).

After a few weeks of anticoagulation he returned for cardioversion followed by cardiac catheterization, which showed an ejection fraction of 20% and no significant coronary artery disease. He was diagnosed as “idiopathic dilated cardiomyopathy, possibly due to viral myocarditis.”

During long term follow up he maintained sinus rhythm and clinical improvement, and was able to have his diuretic discontinued. At one year all manifestations of his heart failure seemed to have disappeared and a repeat echo was totally normal, with an ejection fraction of 65%. What’s going on? What is the most likely etiology of his cardiomyopathy?

Answer: chronic tachycardia-induced cardiomyopathy.

Here’s a review of the topic from the American Journal of Medicine (only the abstract linked here is available for free; the full text is well worth the read if you can obtain it). This phenomenon was occasionally reported for decades but remained largely under the radar screen until publication of series like this one from the Mayo Clinic in 1992. (American Journal of Cardiology). These patients, some of whom were on the transplant list, were thought to have atrial fibrillation secondary to idiopathic DCM. The interesting finding in the series was that after rate or rhythm control the patients exhibited striking reversibility. Instead of atrial fibrillation secondary to DCM, the reverse appeared to be true. These patients likely started out with nothing more than “lone” atrial fibrillation. Is there anything unique about certain atrial fibrillation patients that predisposes them to this complication? Perhaps it’s that they lack tachycardia awareness, thus allowing them to maintain the arrhythmia for long periods without seeking medical attention. (That seemed to be a common thread in the Mayo series).

As explained in the American Journal of Medicine review, animal models of this condition produced by prolonged rapid pacing have demonstrated evidence of chronic myocardial energy depletion and numerous ultrastructural changes, all reversible after cessation of pacing.

What are the take home points?
1) When your new case of “idiopathic” DCM happens to have atrial fibrillation don’t be hasty and write it off as irreversible.
2) Chronic tachycardia can be the sole etiology of DCM (which may have originated as merely lone atrial fibrillation in a patient lacking tachycardia awareness) or a contributing etiology (in which case aggressive rate control will improve the patient’s heart failure).

Will the Lancet review be the death knell for homeopathy?

Maybe not. Here’s an article the investigators appear to have overlooked! :-)

The lost art of electrocardiography

Retired Doc recently lamented the lack of skill in ECG interpretation among internal medicine and emergency medicine residents. Perhaps in the present era of high technology electrocardiography has become a lost art much like physical examination. J. Willis Hurst has written extensively about the reasons, and possible remedies, for the decline in skill in electrocardiography. [1] [2]. He cites various weaknesses in postgraduate teaching, as well as the failure to understand basic electrophysiologic principles. Sadly, there is a lack of formal training. Learning by osmosis is not very effective.

There are a few decent web based learning resources. The best I’ve found is ECG Wave-Maven. This site is cased based, somewhat interactive, and has annotations with literature citations. Medscape’s ECG of the Week (free access after registration) is also somewhat helpful. Unfortunately, another of my favorites, the American College of Cardiology ECG of the month, has gone behind access controls.

Opinion writing disguised as medical research

In my recent post about the controversial JAMA article on fetal pain I suggested that financial relationships with pharmaceutical companies are not the only conflicts of interest that need to be disclosed. What else should be disclosed? The fetal pain article raised issues about two of the authors. We learned from the New York times that Dr. Eleanor Drey held opinions against proposed fetal pain legislation which could constitute bias. The Chicago Tribune also reported that she was an abortion provider. Another author, Susan Lee, had worked as an attorney for an abortion rights group. Though some disclosure was clearly needed it is unclear how it should have been accomplished. Readers needed to know about an author’s role as an abortion rights activist and another author’s role (and perhaps opinions) as a provider. But what other questions should be asked? Do we need to know about an author’s religious beliefs, or how an author voted in the last election? Certainly the notion of disclosure could be carried to undesirable extremes.

In the popular news media there is concern that opinion pieces are disguised as objective journalism. I wonder if a disclosure policy would help settle the debate about media bias and increase the credibility of news organizations. In medical literature we now have a similar concern that opinion writing could be disguised as research reporting. While the JAMA paper sparked particularly heated discussion there are many other examples of potential bias in medicine, largely under the radar screen and less emotionally charged.

In my own field of hospital medicine early studies suggested that the hospitalist model was associated with improved outcomes. But the fact that some of the papers were written by leaders in the hospitalist movement [1] [2] raises the possibility of bias. Similarly, papers which showed improved outcomes with a closed ICU model of care were authored by leaders in pulmonary-critical care medicine or published in journals affiliated with the specialty. This paper reported excessive rates of product withdrawal and post-marketing drug labeling changes, implying ineffective FDA procedures. Missing from the disclosure, however, was that one of the authors is an activist whose organization has a long history of lobbying on the issue.

Surprisingly little has been written about conflicts of interest in medical research except as they pertain to the influence of drug companies, although a few writers have acknowledged that there are other biases. Shaughnessy and Slawson for example, recognizing that expertise in a field creates bias, suggested that experts should not write reviews, and that we should not read papers written by experts. Sackett, similarly noting the bias of experts, wrote that as soon as one becomes an expert he or she should retire from teaching or writing in the field of expertise (whereupon he announced his retirement from teaching and writing about his field of evidence based medicine). This article on medical professionalism in NEJM took a broad view of bias and suggested for example that ophthalmologists or dermatologists rather than gastroenterologists should advocate for colon cancer screening.

These solutions seek to eliminate bias and are extreme. We can’t eliminate bias entirely. Disclosure, however, may heighten readers’ skepticism and provide a healthy opportunity for critical appraisal. I hope the debate surrounding the fetal pain article will not be hijacked by hate speech, but rather will broaden our awareness of bias and the importance of disclosure. It’s not just about the drug companies.

Personal reflections on the hospitalist movement

Published in the July/August 2005 issue of The Hospitalist is an abstract from the 2005 Society of Hospital Medicine annual meeting research competition that has received considerable attention around the medical blogosphere. It reports a large study of various outcomes of care by hospitalists compared with non-hospitalists in academic medical centers. In this first ever multi-center study there was no significant difference between hospitalists and non-hospitalists in outcomes. This was somewhat unexpected, since some earlier smaller studies suggested improved outcomes with hospitalist care.

Rather than try to critique the study (that’s been nicely done by DB, California Medicine Man and Clinical Cases and Images) I’ll offer my purely personal views as a hospitalist. First I disagree somewhat with Clinical Cases and Images that a well designed trial would solve the question of whether hospitalists are useful. To me the success of the hospitalist movement is driven by the growing demands and complexities of hospital medicine and a growing niche created by ever increasing numbers of primary care doctors choosing to practice exclusively ambulatory medicine. Personally I’m happy to fill that niche as long as it’s there. Although I’ve experienced more professional satisfaction since becoming a hospitalist I have no desire for the movement to “take over” hospital care.

The results don’t particularly surprise me. In fact they somewhat mirror my personal experience as I compare my numbers with those of my excellent local non-hospitalist peers. Many doctors in traditional primary care maintain excellent hospital skills. Their patients can get quality hospital care and at the same time maintain a measure of continuity---the best of both worlds.

Meanwhile a growing knowledge base in hospital medicine is creating a steep learning curve, and I enjoy ascending that curve. Maintaining this blog disciplines me to stay more abreast of this growing literature. In future posts I hope to accumulate a collection of hospital medicine “bookmarks” which will be useful not only to myself but to other physicians, in practice or training, with an interest in hospital medicine.

More about familial dilated cardiomyopathy

Over a month ago I blogged about this. Here’s another article on the topic from Cardiovascular Reviews and Reports via Medscape (free access after registration). Again the authors make the point that familial DCM is common, and that first degree relatives of patients with “idiopathic” DCM should be screened via echo and ECG.

The politicization of science

I blogged Wednesday that I thought I smelled politics in the JAMA article on fetal pain and suggested that the authors should have disclosed their political leanings as possible conflicts of interest. Yesterday the Chicago Tribune addressed the issue nicely (thanks to Kevin for directing us to the article).

The author information at the end of the paper says “Financial Disclosures: None reported.” Although no political leanings were disclosed to the JAMA readers one of the authors let her views slip in these comments to the New York Times: Dr. Eleanor A. Drey, one of Dr. Rosen's co-authors, said that as an obstetrician who sometimes performs abortions, she would find it troubling to be compelled to bring up the subject of fetal pain with her patients. "I would be forced to drag them through potentially a lot of misinformation," she said.

We’ve heard howls of indignation about conflict of interest in research until we’re numb, but the outrage has been selective, directed primarily at the financial influence of the pharmaceutical companies. Let’s not forget that political influence and advocacy are also forces that can have corrupting effects on scientific inquiry. Although the JAMA paper may not inform us about fetal pain it will have the beneficial unintended consequence of sparking discussion on an under appreciated form of conflict of interest.

It would be unreasonable to summarily reject a scientific paper based on source or affiliation, be it political or financial. However, disclosure of real or potential conflicts of interest is essential as it gives readers information they need for critical appraisal.

Why study homeopathy----

when it has no physiologic or pharmacologic plausibility in the first place? This is a distortion of evidence based medicine which takes empiricism to an extreme. Straight from the Doc, Medpundit and Medicine and Man have already pointed us to the Lancet article on the subject.

This overview from Homeowatch outlines the field’s history and states that homeopathy was harmless compared to prevailing nineteenth century conventional medical practices, a fact which drove its popularity. It points out the utter irrationality of the theory, which is that a “spirit like essence” remains behind in the water even after all molecules of active substance have been diluted out.

Total lack of biologic plausibility is one reason not to bother to study homeopathy. Another reason, as has already been pointed out by the other bloggers, is that the adherents won’t believe the studies. At least some don’t believe a randomized placebo controlled trial is the proper methodology.

If you want to debunk something, rather than spend all that money on studies, why not just call Randi the magician?

Fetal Pain

In the latest issue of JAMA is an article about fetal pain which makes the case that abortion providers should not have to inform women about the possibility of procedural pain in the fetus, and purports to back up the assertion with science. Go read what Medpundit has to say about this. She has summed it up better than I can although I would offer a few observations and questions.

The authors’ major premise is that pain is a psychological construct. Indeed, the premise sets the evidentiary standard for the rest of the paper, because, in the authors’ own words, it “presupposes” the neuroanatomic connections they believe must be proven to make the case for fetal pain. Conveniently enough, the presupposition makes tissue injury irrelevant. (What if physicians start telling patients their pain is psychogenic)?

JCAHCO had some things to say about this in its pain management initiative of a few years ago. 1) Patients have a right to assessment and management of pain (implicitly surrogates have the right to be informed about pain). 2) Observation of vital signs, crying and reflex withdrawal (which have been observed in premature infants of less than 29 weeks gestation, and which the JAMA authors seem to dismiss as non-evidence of fetal pain) are legitimate pain assessment tools in preverbal individuals.

The authors admit that the evidence does not establish at what point in fetal development the thalamo-cortical pain pathways become functional.

The first sentence of the abstract establishes the politics driving this “science.” Perhaps the authors’ conflict of interest disclosure should have included their political affiliations. The issue of interface between scientific publication and politics has surfaced previously in JAMA and caused trouble for an editor.

Medication safety across the continuum of care

Hospitals have long been concerned about medication errors during the flow of in patient care. Until recently, however, relatively little attention has been paid to the problem of errors at the points of transition between in patient and out patient care. Many hospitalized patients are on a large number of chronic medications. The transition points at admission and discharge are especially vulnerable for such patients because of the need to communicate and document complex medication history. At admission the patient may provide faulty or fragmentary information. At discharge the patient may not understand the doctor’s instructions. Hospitalization often results in one or more changes in the patient’s chronic medication. When medication orders are written in the hospital and when the patient is instructed at discharge these orders and instructions must take into account the patient’s pre-hospital medications and dosages. This is what the Joint Commission on Accreditation of Healthcare Organizations in its 2005 patient safety initiatives terms reconciliation of medications across the continuum of care. This issue was reviewed in an article and an accompanying editorial in the current issue of the American Journal of Health-system Pharmacy. (Open access until September 1 05).

It’s good to see this issue getting the attention it deserves. Accurate transfer of information at the transition of care seems to be an elusive quality goal. Deficiencies in the process are what we hospitalists often refer to as the “information voltage drop.”

More about evidence based patient decisions

I blogged about this recently. Among other things I pointed out that an essential component of evidence based medicine (EBM) was involvement of the patient in the decision process by providing quality information. Although this important step is often ignored in discussions of EBM it was emphasized as a defining characteristic in the classic paper of David Sackett et.al. entitled “Evidence based medicine: what it is and what it isn’t.” The authors state that the process, among other things, involves “------the more thoughtful identification and compassionate use of individual patients' predicaments, rights, and preferences in making clinical decisions about their care.”

I discussed the concept of number needed to treat (NNT) as an understandable way to discuss the magnitude of treatment effects with patients. Then I ran across this recent study. It seems patients have difficulty with the concept. Decisions were influenced only marginally, if at all, by the NNT. In addition, 24% of patients who made a decision after being informed of the NNT changed their minds following additional explanation of the meaning of NNT. In almost all cases better understanding of the concept caused patients to reject the treatment in question. Worse, this paper from the August 1 issue of American Family Physician paints a dim picture of patients’ health literacy.

This is sobering. In my previous post I illustrated that the process was time consuming and challenging. These papers suggest that it’s even more challenging than we had thought.

Diagnosis of pulmonary embolism: Are we there yet?

A systematic review in the April 27 issue of JAMA was blogged about by Inner Visions on May 8, and has more recently been given the status of POEM as abstracted in the current issue of Cleveland Clinic Journal of Medicine. The take home message was that a normal CT done with the appropriate technique equals pulmonary angiography (PAG) for the exclusion of pulmonary embolism (PE). This sounds simple enough, but questions remain about how this evidence changes our diagnostic approach. What is the initial test of choice? Does CT replace nuclear ventilation and perfusion (V/Q) scanning?

This paper doesn’t answer these questions. Such questions require a broader perspective which takes into account the results of PIOPED I and PIOPED II. The JAMA review evaluated the performance of CT by the standard of freedom from events over three month follow up and compared those results with similar data previously reported for PAG. PIOPED I evaluated V/Q scanning against the reference standard of PAG. PIOPED II evaluated CT against a multi-dimensional diagnostic strategy using non invasive tests and occasional use of PAG. The multi-dimensional strategy was validated as a reference standard by clinical follow up for freedom from events. PIOPED II has not been published, but its results were presented at the Radiological Society of North America 90th Scientific Assembly and Annual Meeting late last year, abstracted here at Medscape (free registration required).

While consideration of all this evidence together with cost and patient tolerability provides no simple answers, I believe the following statements are supported.

1) Invasive PAG is seldom indicated.
2) A normal V/Q scan has the best negative predictive value (NPV) of all tests (note I said normal, not “low probability”). (In PIOPED I no patients with normal V/Q had PE!).
3) When CT results are discordant with clinical probability the PPV and NPV are poor. This was a significant finding in PIOPED II, similar to the findings for discordant V/Q results in PIOPED I. This means that, just as with V/Q scanning, results of CT must be integrated with other clinical data.
4) A CT scan costs more than a V/Q scan. [1].
5) There is no clear modality of choice for initial testing. Careful clinical assessment determines the choice of the initial test(s) which might include D-dimer, leg compression ultrasonography, V/Q scanning or CT.

This POEM adds to our knowledge of testing for PE but it’s just one piece of the puzzle. Be careful of simplistic interpretations.

Who has time for evidence based medicine?

I recently blogged an ideal description of evidence based medicine. I gave examples to point out that it’s onerous, and I implicitly questioned whether it’s realistic. Truth be told I wonder if many doctors even practice it. A commenter did a better job of making the point. “My goodness. If my physician went to all that trouble for me, I'd require resuscitation from the shock. But to tell you the truth, such extreme conscientiousness -- while I applaud it -- is not only impractical in terms of time (yours!) but also overestimates by a long shot what most patients would expect in terms of empowerment.” (Go read the comment in its entirety).

EBM is indeed rigorous. Formulating a question, translating the question into a search strategy, performing the search and critically appraising what you retrieve is a substantial chore even with the help of the short cuts provided by some medical Internet resources. Of course, your job isn’t finished there. You then must evaluate how well the patient populations represented in the evidence you’ve retrieved match the unique characteristics of your patient and, finally, integrate this evidence with your patient’s preferences, circumstances and values.

Most of us would say we practice EBM but the reality is we often practice only the trappings of EBM. That is, we can quote from randomized controlled trials and talk about meta-analyses, odds ratios and confidence intervals. We can name off a number of things doctors who practice EBM are supposed to do, and to a variable degree, do them. We use Internet resources but often not in a systematic way. With good intentions we put on these appearances and often still don’t really practice EBM as we’re supposed to.

What we have then is a degree of disconnect between the theory and the practice of a revolutionary idea in medicine. This is not unprecedented. It is analogous to another revolution in medical thinking that occurred in the 1960s: the problem oriented medical record, a.k.a. the Weed system. It was the talk of the wards when I was a medical student. Since those days SOAP formatted progress notes have become commonplace, and most medical records have had a problem list, after a fashion. However, this is a far cry from the true practice of the Weed system as it was originally defined and taught. Again, we practiced only the trappings. (In researching for this post I was unable to find any of the original descriptions of the Weed system to provide as links. The articles are old and only the citations are on line. I was able to find a print description in an old copy of Hurst’s The Heart, sixth ed., which contains a description on p. 105. J. Willis Hurst, professor and chairman of the Department of Medicine at Emory, was a champion for the Weed system [1] [2]. Older editions of his text contain elegant descriptions of the problem oriented medical record as applied to clinical practice, which time and space constraints do not permit me to abstract here).

We miss the mark with EBM, in part because we lack time. Reimbursement incentives put doctors under pressure to see large numbers of patients in limited time, and consequently don’t reward the practice of EBM. How then should we regard it? We should embrace it. If the ideal is unattainable it should challenge, not discourage us. It is a challenge I find fascinating, and one that I approach with the hope that as we ascend the learning curve and information resources improve, things will get better and better.

EBM has many dimensions which fascinate me, and I’ll be blogging about it a great deal. Stay tuned.

How and why do doctors read?

It occurs to me that the ways we read medical literature fall into at least two categories. First there’s the type of reading we do to practice evidence based medicine (EBM). That type of reading focuses on the clinical question at hand as it applies to a particular patient. We often use the PICO acronym to help us formulate the question. (In a Population with my patient’s attributes, what is the effect of the Intervention in question versus a Comparison group with respect to Outcomes?). Such a question forms the basis for a search that will retrieve relevant articles. This highly focused and specific type of reading has been variously termed question driven reading, problem based reading and foreground question reading, and often relies on POEMs. It is often done “at the point of care”, e.g. the physician’s office, the exam room or the hospital ward. The reading material might consist of abstracts of randomized controlled trials, a systematic review, or topic summaries from a filtered source such as Bandolier, DARE, TRIP, or Up to Date. This is a relatively new type of reading, not possible before the availability of the Internet and the vast repository of searchable medical databases.

Another type of reading is the more traditional type which, although often patient based, is not as focused. It is sometimes referred to as background question reading. I have recently heard the somewhat derogatory term “reading for the heck of it” to describe this type of reading. Such reading often draws on DOE (disease oriented evidence). It is more likely to take place at home, and the topic might be related to a patient you saw that day, or that week. The source could be a textbook or a narrative review. It would have a broader scope than the former type of reading, and might encompass the clinical features, epidemiology and pathophysiology of a disease.

So why do I make a fuss about this? Well, it seems there’s a ground swell of opinion these days against background reading. This article encourages students to do problem based searching of filtered resources, but not to bother with standard medical journals! This tutorial on EBM warns the reader that DOE is worthless if not dangerous. I’m reading more and more opinions of this sort, many taking aim against narrative reviews, textbooks, experts and the practice of reading about pathophysiology. The purveyors are purportedly doing this to advance the cause of EBM. I would argue that this reflects a narrow view of EBM. The classic paper by Sackett, et. al., which many recognize as a defining article on EBM, clearly points out that expertise and judgment (which I believe derive from background reading) are important components of the process.

I believe both types of reading are essential. Without foreground reading we can’t bring the best and most current evidence to bear on the individual patient’s problem. Without background reading we lack depth of understanding, and can never cultivate the expertise and judgment so essential to the rational and prudent application of evidence.

Now excuse me while I go read a chapter from Harrison’s.

Do drug company promotions impact clinical outcomes? Is there a way to know? Does anybody want to know?

My recent post on the effects of drug industry marketing drew a difficult and insightful question: “RW, how do you propose to measure patient outcomes?”
Can outcome based research be done, or must surrogate evidence suffice? Perhaps patient outcomes in a health care setting (a clinic, an academic medical service, an HMO, or a hospital) could be measured before and after implementation of a “no sample” or a “no drug rep” policy. Is there precedent for this type of study? Yes. There are numerous examples of health system, health care environment, and cultural changes that have been studied for their effects on outcomes including the adoption of heart failure multidisciplinary management programs [2]