Monday, October 24, 2016

Viral infection in community acquired pneumonia

The advent of PCR has improved the identification of viruses in patients with community-acquired pneumonia (CAP). Several studies have used PCR to establish the importance of viruses in the aetiology of CAP.

We performed a systematic review and meta-analysis of the studies that reported the proportion of viral infection detected via PCR in patients with CAP. We excluded studies with paediatric populations. The primary outcome was the proportion of patients with viral infection. The secondary outcome was short-term mortality.

Our review included 31 studies. Most obtained PCR via nasopharyngeal or oropharyngeal swab. The pooled proportion of patients with viral infection was 24.5% (95% CI 21.5–27.5%). In studies that obtained lower respiratory samples in greater than 50% of patients, the proportion was 44.2% (95% CI 35.1–53.3%). The odds of death were higher in patients with dual bacterial and viral infection (OR 2.1, 95% CI 1.32–3.31).

Viral infection is present in a high proportion of patients with CAP. The true proportion of viral infection is probably underestimated because of negative test results from nasopharyngeal or oropharyngeal swab PCR. There is increased mortality in patients with dual bacterial and viral infection.

Sunday, October 23, 2016

PE may be hiding out in patients with COPD exacerbation

Background COPD patients encounter episodes of increased inflammation, so-called acute exacerbations of COPD (AE-COPD). In 30% of AE-COPD no clear etiology is found. Since there is a well-known crosstalk between inflammation and thrombosis, the objectives of this study were to determine the prevalence, embolus localization and clinical relevance, and clinical markers of pulmonary embolism (PE) in unexplained AE-COPD.
Methods A systematic search was performed using MEDLINE and EMBASE platforms from 1974 – October 2015. Prospective- and cross-sectional studies that included patients with an AE-COPD and used pulmonary CT-angiography for diagnosis of PE were included.
Results The systematic search resulted in 1650 records. Main reports of 22 articles were reviewed and 7 studies were included. The pooled prevalence of PE in unexplained AE-COPD was 16.1% (95% confidence-interval 8.3%-25.8%) in a total of 880 patients. Sixty-eight percent of the emboli found were located in the main pulmonary arteries, lobar arteries or inter-lobar arteries. Mortality and length of hospital admission seem to be increased in patients with unexplained AE-COPD and PE. Pleuritic chest pain and cardiac failure were more frequently reported in patients with unexplained AE-COPD and PE. In contrast, signs of respiratory tract infection was less frequently related to PE.
Conclusions PE is frequently seen in unexplained AE-COPD. Two-thirds of emboli are found at localizations that have a clear indication for anticoagulant treatment. These findings merit clinical attention. PE should receive increased awareness in patients with unexplained AE-COPD, especially when pleuritic chest pain and signs of cardiac failure are present and no clear infectious origin can be identified.
The mechanism of the association, as pointed out in the abstract above, may be the association between inflammation and thrombosis.

Other factors were mentioned as possible mechanisms for the association, as pointed out in a review of the paper by ACP Hospitalist Weekly.

This is not the first time such an association has been mentioned, and I have blogged about it several times in the past including here.

Tuesday, September 20, 2016

Wednesday, September 14, 2016

Stress ulcer prophylaxis: an example of a non evidence based “standard of care”

Stress ulcer prophylaxis, generally with a PPI, has long been an in house performance measure in many institutions, but the practice was never evidence based. According to this review there is equipoise for a clinical trial.

Tuesday, September 13, 2016

The emerging link between community acquired pneumonia and cardiac disease

This is a growing concern and was recently reviewed here. From the review:

Recent findings: Recent evidence suggests that a large proportion of deaths from CAP are attributable to cardiovascular disease, including sudden cardiac death, acute myocardial infarction (MI), arrhythmias and cardiac failure. Up to one-third of patients with CAP may experience cardiovascular complications within 30 days of hospital admission, while data also suggest that CAP managed in the community is associated with increased risk of acute MI. The risk is maximal within a few days of hospitalization with CAP and reduces over time. Most studies suggest that risk is still increased at 1 year, and some suggest risk continues to be increased at 10 years post-CAP. This clearly contributes to the well-recognized increased long-term mortality associated with CAP. The mechanism is not entirely clear, but recent published data have better defined the impact of the host response, including systemic inflammation and platelet activation. The contribution of Streptococcus pneumoniae has also been recently investigated, with animal studies suggesting a direct effect of S. pneumoniae on the myocardium, forming microlesions that heal with resulting myocardial fibrosis. Several studies suggest a key role for the pore-forming toxin pneumolysin in S. pneumoniae-induced cardiac toxicity.

Summary: Several therapies have been shown to improve the outcomes in cardiovascular disease, but whether these would be effective in improving outcomes in CAP is unknown. In this review, we argue that cardioprotective treatments may hold the greatest promise in terms of reducing long-term mortality in patients with CAP.

By way of background I have posted extensively about this before [1] [2] [3] [4].

Monday, September 12, 2016

Thrombocytopenia as a prognostic marker in septic shock

This paper was highlighted in ACP Hospitalist Weekly as an important study and although it is the first time thrombocytopenia has been looked at in this way in my view it is not fundamentally new or practice changing. From the paper:

Design: Prospective, multicenter, observational cohort study.

Setting: Fourteen ICUs from 10 French university teaching and nonacademic hospitals.

Patients: Consecutive adult patients with septic shock admitted between November 2009 and September 2011 were eligible.

Intervention: None.

Measurements and Main Results: Of the 1,495 eligible patients, 1,486 (99.4%) were included. Simplified Acute Physiology Score II score of greater than or equal to 56, immunosuppression, age of more than 65 years, cirrhosis, bacteremia (p less than or equal to 0.001 for each), and urinary sepsis (p = 0.005) were globally associated with an increased risk of thrombocytopenia within the first 24 hours following the onset of septic shock. Survival at day 28 estimated by the Kaplan-Meier method was lower in patients with thrombocytopenia and decreased with thrombocytopenia severity. By multivariate Cox regression, a platelet count of less than or equal to 100,000/mm3 was independently associated with a significantly increased risk of death within the 28 days following septic shock onset. The risk of death increased with the severity of thrombocytopenia (hazard ratio, 1.65; 95% CI, 1.31-2.08 for a platelet count below 50,000/mm3 vs greater than 150,000/mm3; p less than 0.0001).

Conclusions: This is the first study to investigate thrombocytopenia within the first 24 hours of septic shock onset as a prognostic marker of survival at day 28 in a large cohort of ICU patients. Measuring platelet count is inexpensive and easily feasible for the physician in routine practice, and thus, it could represent an easy "alert system" among patients in septic shock.

The last statement is not practice changing and almost sounds silly given that all patients with sepsis get at least an automated CBC which routinely includes a platelet count.

Saturday, September 10, 2016

TIMI and GRACE perform poorly in the evaluation of patients presenting with chest pain to the ER


The Thrombolysis in Myocardial Infarction (TIMI) and the Global Registry in Acute Coronary Events (GRACE) scores were largely evaluated and validated in stratifying risk of cardiovascular events in patients with chest pain and acute coronary syndrome. Our objective was to compare these 2 scores in predicting outcome in emergency department (ED) patients with undifferentiated chest pain.

Materials and methods

This was a prospective cohort study including patients presenting to 4 EDs with chest pain with nondiagnostic or normal ECG. For all included patients (n = 3125), TIMI and GRACE scores were calculated. Follow-up was conducted at 30-day and 1-year post-ED index admission...


We reported 285 (9.1%) major adverse events at 30 days and 436 (13.9%) at 1 year. In patients with low TIMI (less than or equal to 2) and GRACE (less than 109) scores, a significant proportion had major adverse events at 30 days (5% and 7.5%, respectively) and 1 year (7.9% and 12.9%, respectively). Area under ROC curve at 30 days was 0.66 (95% confidence interval [CI], 0.62-0.71) vs 0.57 (95% CI, 0.53-0.62), respectively, for TIMI and GRACE scores. At 1 year, the area under ROC was 0.67 (95% CI, 0.62-0.71) and 0.65 (95% CI, 0.60-0.70), respectively, for TIMI and GRACE scores.


The TIMI and GRACE scores are not valid in short- and long-term risk stratification in our chest pain patients.