Objective To investigate the value of cough peak expiratory flow rate ( PEF) for the prediction of machine with-drawal in children with acute respiratory failure.Methods Eighty-five severe cases of acute respiratory failure in children were admit-ted into our hospital from September, 2010 to September, 2012, including 48 male and 37 female cases, with an age range of 2-6 years.In accordance with the necessity of endotracheal intubation 48 hours after removal of the ventilator, the patients were designated as the success group (71 cases) and the failure group (14 cases) .Differences in general clinical data, pulmonary function, blood-gas analysis results and PEF values before removal of the ventilator were compared between the 2 groups.The ROC curve was used to calcu-late Az value and evaluate the predicative value of PEF in the removal of the ventilator.Results With respect to the general medical data of the success and failure groups before removal of the ventilator, there was no statistical significance in age, gender, pediatric ill-ness scores, causes of illness, rate of lower respiratory tract infection and mechanical ventilation time, when comparisons were made be-tween the 2 groups(P>0.05).No statistical significance could be noted in respiratory rate (RR), heart rate (HR), tidal volume ( Vt) , minute ventilation( MV) , mean airway pressure( MAP) , pH value, PaO2 , PaCO2 and PaO2/FiO2 , before removal of the venti-lator, when comparisons were made between the 2 group(P>0.05).Before removal of the ventilator, PEF value of the success group was(46.3 ±8.2)L/min, which was significantly higher than that of the failure group(37.6 ±7.4)L/min, with statistical significance (P<0.05).Az value used to predict the results of ventilator removal was 0.890, and the optimal PEF value used for the prediction of ventilator removal was 40.6 L/min.Conclusion PEF value used for the prediction of ventilator removal was accurate to some extent
and could be used as a clinical evidence for ventilator removal.