The predictive value of breathing variability for weaning outcome in patients with chronic obstructive pulmonary diseases

SANG Ling; LIU Xiao-qing; HE Wei-qun; CHEN Si-bei; XU Yong-hao; YANG Chun; YU Yu-heng; LIU Xue-song; LIU Dong-dong; LI Yi-min

Abstract：Objective To investigate the value of breathing variability in predicting the weaning outcome in pa-tients with chronic obstructive pulmonary diseases ( COPD) .Methods A single-center prospective observational study was conducted .Ventilated AECOPD patients , who successfully passed spontaneous breathing trials ( SBT) and extubated finally in ICU were enrolled .According to the outcome of weaning , they were divided into success group and failure group.Before extubation, gender, age, APACHEⅡscore, ventilation duration, body mass index (BMI), RSBI, MIP, P0.1, and the breathing variability during SBT , including coefficient of variation of Vt (CV of Vt), CV of Ti, CV of TTOT, CV of Ti/TTOT and CV of Vt/Ti of each patient were recorded and analyzed .Results A total of 57 patients were enrolled , among whom 46 cases were assigned into success group and 11 cases into failure group.The gender, age, APACHE Ⅱscore, BMI, and ventilation duration were similar between the two groups .In success group, the P0.1 and RSBI were sig-nificantly lower, and the MIP, CV of Vt, CV of Ti, CV of TTOT, CV of Ti/TTOT and CV of Vt/Ti were significantly higher than those in failure group(P<0.05).The ROC curves of all indexes were created for predicting successfully weaning . The area under the ROC curve (AUC) of CV of Vt/Ti was revealed as the largest area among above (0.962, 95%CI:0.917-1.000); and with threshold >15.5, its sensitivity and specificity were 93.5% and 90.9%, respectively, in predicting successful weaning .Meanwhile, P0.1 had the smallest AUC(0.748, 95%CI:0.713-0.784);and with P0.1 <4.05 cmH2 O, its sensitivity and specificity were 53.5% and 87.4%, respectively , in predicting successful weaning . Conclusion Increased breathing variability is a good predictor of successful weaning in AECOPD patient receiving me -chanical ventilation , and CV of Vt/Ti has the most valuable sensitivity and specificity in predicting the successful weaning outcome when it is above 15.5.