Cough peak flow as a predictor of success in orotracheal extubation: a systematic review with meta-analysis

Abstract

Introduction: A considerable proportion of patients who succeed in the spontaneous breathing trial (SBT) are reintubated because of the incapacity to protect their airways. Objective: This systematic review was designed to assess the cough peak flow CPF usefulness to predict the extubation outcome in patients who passed an SBT. Methods: The search covered the databases MEDLINE, EMBASE, LILACS and IBECS scientific databases, CINAHL, SciELO, Cochrane, Scopus, Web of Science, and gray literature. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess the methodological quality and risk of study bias. The statistical heterogeneity of likelihood and diagnostic odds ratios was evaluated using forest plots and the Cochran’s Q statistic, and a crosshair summary receiver operator characteristic (SROC) plot using the multiple cutoffs model was calculated. Results: Many studies presented unclear risk of bias in the “patient selection”, and “flow and time” criteria. Of the 12 included studies, 7 presented “high risk” and 5 a “unclear risk” in the item “Reference Standard”, because of lack of objective clinical criteria for reintubation, use of rescue therapy and non-exclusion of patients who reintubated for laryngospasm. The diagnostic performance of CPF for extubation outcome was low to moderate when considering the results from all included studies. A subgroup analysis including only the studies with a cutoff between 55-65L/min showed a slightly better performance, however, still moderate. Conclusion: The CPF assessment considering a cutoff between 55-65L/min may be useful as a complementary measurement prior to the extubation. More well-designed studies are needed to elucidate the best method and equipment to record CPF, as well as the best cutoff.