Efficacy of spontaneous breathing trial in process of weaning and extubation

Abstract

Objective To evaluate the efficacy of spontaneous breathing trial(SBT) as a step of protocols-directed weaning and extubation.Methods Protocols-directed weaning and extubation were studIed prospectively and no-protocols-directed weaning and extubation were evaluated retrospectively.Duration of ventilation,the incidence of ventilator-associated pneumonia(VAP),intubation rate within 48hours,duration of ICU,mortality in ICU were compared between two groups.As for protocols-directed weaning and extubation group,the variations of monitoring index before and after SBT corresponding to SBT success and SBT failure groups,as well as extubation success and extubation failure groups,were compared.Results Duration of ventilation hours and duration of ICU days(data tranformed by Ln)were shorter in protocols-directed weaning and extuhation group than those in no-protocols-directed weaning and extubation group(4.01±0.71 vs 4.51±0.85;1.86±0.82 vs 2.48±0.92,P<0.05).The incidence of VAP and intubation rate within 48 hours were no significant difference between two groups.The change of heart rate,respiratory rate,rapid shallow breathing index(f/Vt)and PaCO_2 were significantly different between SBT success and SBT failure groups.Those parameters had no significance between extubation success and extubation failure groups.Among 5 extubation failure patients,3 patients were intubation because of sputum drainage failure.Conclusions Protocols-directed weaning and extuhation shorten the time of mechanical ventilation and average ICU stay time,while the intubation rate was not increased.The change of heart rate,respiratory rate,f/Vt and PaCO_2 were more important to judge the SBT result.To patients with excessive mucinoid sputum and without effective drainage,the extubation should be eonducted prudentiy. Key words: Spontaneohs breathing trial; Mechanical ventilation; Extubation