Effect of Respiratory Muscle Performance on Ventilatory Weaning

呼吸肌功能對呼吸器脫離之影響

李昭賢(Chao-Hsien Lee) ； 吳健樑(Chien-Liang Wu) ； 陳培然(Pei-Jan Chen)

《胸腔醫學》 20卷5期 (2005/10) Pp. 371-379

https://doi.org/10.29806/TM.200510.0003

摘要

研究背景：自發性呼吸用於脫離呼吸器為有效且普遍應用的呼吸器脫離方法，然而當自發性呼吸脫離方式失敗時，接著使用壓力支持型脫離方法是否仍如一開始即用自發性呼吸脫離方法一樣有效且其對呼吸肌力之影響為何。
方法：本研究探討103位於加護病房符合脫離呼吸器條件之患者，每日記錄受試者3次最大吸氣力量並採最大值，潮氣容積及每分鐘呼吸次數，當患者整體狀況回穩且符合脫離條件，第一階段我們採用自發性呼吸方式脫離，患者經三次自發性呼吸方式嘗試脫離而無法脫離成功者即改採第二階段之壓力支持型方式脫離，當支持壓力下降至12公分水柱即可改採自發性呼吸方式。患者如無呼吸窘迫或心跳血壓之改變，於2小時後拔管且沒有於48小時內再接回機器即視為脫離成功；如於嘗試脫離呼吸器兩週後仍無法脫離呼吸器即為第二階段脫離失敗。
結果：一開始即用自發性呼吸方法脫離之103位患者，66位患者(64%)成功脫離，而脫離失敗之37位患者改採壓力支持型脫離方式者有23位患者(62%)成功脫離，整體成功率為86%(89/103)而脫離時間約為78±37小時。比較一開始即用自發性呼吸脫離方法之位患者，成功者有較高之最大吸氣力量、較大的最大吸氣力量增強百分率(△PImax%)及較低之呼吸率潮氣容積比(f/VT)。改採壓力支持型脫離方式者成功者有較大的最大吸氣力量增強(△PImax%)。
結論：最大吸氣力量，最大吸氣力量增強百分率(△PImax%)及呼吸率潮氣容積比(f/VT)可預測早期脫離呼吸器之成功率，但無法預測早期脫離呼吸器失敗者再嘗試脫離之成功率。使用壓力支持型脫離方式於早期脫離呼吸器失敗者大約有62%的成功率，但對於呼吸肌之增強無法達到顯著差異，此有賴更多病人更長時間之隨機自由分配研究以釐清呼吸器脫離方式對於呼吸肌力之長期影響。

關鍵字

壓力支持型呼吸 ； 呼吸肌肉力量 ； 自發性呼吸 ； 呼吸器脫離

並列摘要

Background: In order to determine whether the use of pressure-support ventilation (PSV) could retrain the respiratory muscles and enhance the success rate after patients had failed a spontaneous breathing trial (SBT), we developed sequential weaning protocols and monitored the changes in respiratory muscle performance during the weaning process.
Methods: A total of 103 patients requiring mechanical ventilation and admitted to a tertiary hospital were enrolled. Weaning was first attempted with a once-daily spontaneous breathing trial (OSBT). For patients who failed this trial, PSV was used until a pressure of 12 cmH2O was reached, followed by SBT.
Results: Sixty-six (64%) patients were successfully weaned with the OSBT. Twenty-three (62%) of the remaining 37 patients managed with PSV were successfully weaned, yielding an 86% (89/103) success rate for those who were weaned within 78±37 hours. Compared with those who failed the OSBT, the patients who succeeded with the OSBT had a significantly higher maximal inspiratory pressure (Pimax), higher percentage of change in Plmax (△Plmax%), and lower frequency-to-tidal volume ratio (f/VT). Those who succeeded with PSV also had a significantly higher △Plmax% than those who failed.
Conclusions: Initial respiratory muscle performance is predictive of early successful weaning by OSBT, but not later weaning by PSV. PSV was able to help wean those patients who failed OSBT, with a success rate comparable to that of early weaning by OSBT. PSV might not produce significant augmentation of respiratory muscle strength, but was able to delay the decrease of respiratory muscle strength in the weaning process.

並列關鍵字

pressure-support ventilation ； respiratory muscle performance ； spontaneous breathing trial ； ventilatory weaning