Unexplained failure to wean? Get to the heart of the matter.

I've blogged before (here, here and here) that occult cardiac ischemia or decompensation can be the cause of failure to liberate from mechanical ventilation. More recently another review has been published on the topic. It states that a rising BNP during a spontaneous breathing trial is predictive of cardiac decompensation leading to weaning failure and makes these additional points:

Ischemic heart disease, valvular heart disease, systolic or diastolic dysfunction contributes to increase in cardiac load and weaning failure.

Extra demand on cardiac working load imposed by SBT may become apparent when transferring patient from positive to spontaneous ventilation.

Diuretic therapy may be considered for excessive preload.

Noninvasive positive pressure ventilation is beneficial for weaning-induced pulmonary edema.

Further cardiac evaluation is necessary if changes in natriuretic peptide levels are detected during SBT.