Progress Toward Weaning

Weaning has been extensively studied, but existing data does not include any large trial where patients with ARDS were the sole or majority of subjects. In the absence of ARDS-specific trials, the consensus view appears to be that the principles applied to weaning with other causes of respiratory failure are valid and that unnecessary prolongation of MV should be avoided by timely recognition of readiness to wean and readiness to extubate [26, 27].

The first step is the reversal of the underlying condition. ARDS is not a disease but is precipitated by a pathological condition; both its severity and duration are dependent upon that condition [23]. As the underlying condition may influence the ability to wean, management of the underlying and comorbid pathologies is crucial but beyond the scope of this review. While it is prudent to consider weaning during early recovery, if the precipitating cause is an ongoing process, such as unresolved sepsis or recurrent pancreatitis, attempts at early weaning may be interrupted by recurrence or by nosocomial complication and may represent backward steps in any weaning program [5]. However, the alternative of waiting until complete resolution of the underlying condition will unduly delay recovery and precipitate increased debilitation. The earliest return to spontaneous respiratory effort is important as even short intervals of complete diaphragmatic inactivity during MV may increase diaphragmatic proteolysis and atrophy of diaphragm muscle [28, 29].