Cough strength, secretions and extubation outcome in burn patients who have passed a spontaneous breathing trial.

The aim of this study was to develop a clinical prediction model to inform decisions about the timing of extubation in burn patients who have passed a spontaneous breathing trial (SBT). Rapid shallow breathing index, voluntary cough peak flow (CPF) and endotracheal secretions were measured after each patient had passed a SBT and just prior to extubation. We used multiple logistic regression analysis to identify variables that predict extubation outcome. Seventeen patients failed their first trials of extubation (14%). CPF and endotracheal secretions are strongly associated with extubation outcome (p<0.0001). Patients with CPF ≤60 L/min are 9 times as likely to fail extubation as those with CPF >60 L/min (risk ratio=9.1). Patients with abundant endotracheal secretions are 8 times as likely to fail extubation compared to those with no, mild and moderate endotracheal secretions (risk ratio=8). Our clinical prediction model combining CPF and endotracheal secretions has strong predictive capacity for extubation outcome (area under receiver operating characteristic curve=0.96, 95% confidence interval 0.91-0.99) and therefore may be useful to predict which patients will succeed or fail extubation after passing a SBT.