Application of diaphragm index based on ultrasonic evaluation in weaning of patients with severe pneumonia undergo-ing mechanical ventilation

ZHONG Lin; WANG Min; ZHANG Jie

Abstract：Objective To evaluate the predictive value of diaphragmatic muscle and its derived indicators based on ultra-sonic evaluation in weaning of mechanical ventilation patients with severe pneumonia.Methods The patients with severe pneu-monia admitted who received invasive mechanical ventilation were selected as the study objects.All patients reached the offline standard.After passing the SBT screening,they were given offline decannulation.Their respiratory and oxygenation status within 48 hours of offline were observed.They were divided into offline success group and offline failure group according to the offline outcome.The basic data and monitoring indexes before offline were compared between the two groups;Compared with RSBI,the predictive value of DD,DTF and D-RSBI on the success of weaning was evaluated by using the ROC curve.Results In wean-ing group,mechanical ventilation time was(210.40±92.28)h,RR was(15.62±3.34)times/min,DD was(16.41±3.23)mm,DTF was(32.98±7.03)%,and D-RSBI was(1.19±0.26)times/min·mm.In offline failure group,mechanical ventilation time was(339.90±126.13)h,RR was(18.43±4.86)times/min,DD was(14.14±3.10)mm,DTF was(24.00±5.53)%,and D-RSBI was(1.69±0.34)times/min·mm.There was a statistical difference(P<0.05).Using the ROC curve,taking the largest Youden index as the optimal critical value,the optimal critical value of RSBI was 60.69 times/(min·L),AUCROCwas 0.79;The optimal critical value of DD was 12.60mm,AUCROCwas 0.70;The optimal critical value of DTF was 30.00%,AUCROCwas 0.84;The optimal critical value of D-RSBI was 1.36 times/min·mm,AUCROCwas 0.87.Among them,D-RSBI had the largest area un-der the ROC curve for offline successful prediction and the best prediction value.Conclusion DD,DTF and D-RSBI have good predictive value for weaning from mechanical ventilation in severe pneumonia,of which D-RSBI is the best.