压力支持通气与同步间歇指令通气压力支持水平两种脱机方式的比较

Comparison of two weaning modes in patients with pressure support ventilation and synchronized intermittent mandatory ventilationpressure support level

目的：比较压力支持通气（ＰＳＶ）与同步间歇指令通气压力支持水平（ＳＩＭＶＰＳ）两种机械通气方式的脱机效果。方法：对照观察两种通气方式患者在脱机时间、ＰＳ、潮气量（ＶＴ）、呼吸频率（ｆ）、气道闭合压（Ｐ０．１）以及脱机步骤方面的差异。结果：ＰＳＶ脱机成功２５例，ＳＩＭＶＰＳ脱机成功１３例。两种脱机方式的脱机时间、ＰＳ水平、ＶＴ、ｆ和Ｐ０．１比较均无显著性差异（Ｐ均＞０．０５）。ＰＳＶ脱机：短期带机（＜７日）的ＰＳ应≤０．６９ｋＰａ（１ｋＰａ＝１０．２０ｃｍＨ２Ｏ）；长期带机（＞７日）的ＰＳ应达０．４９～０．５９ｋＰａ，并应动态观察Ｐ０．１通气、氧合变化可成功实现脱机。ＳＩＭＶＰＳ脱机：短期带机（＜７日）的ＰＳ应置于０．５９～０．６９ｋＰａ，ＳＩＭＶ的ｆ可逐渐减至６次／ｍｉｎ；长期带机（＞７日）ＳＩＭＶ的ｆ减至４次／ｍｉｎ，并根据患者的耐受情况，同时调整ＰＳ达０．４９ｋＰａ，结合常规参数变化及Ｐ０．１的变化可完成脱机过程。结论：ＳＩＭＶＰＳ脱机优于ＰＳＶ脱机，尤其对不能耐受ＰＳＶ脱机患者采用ＳＩＭＶＰＳ方式可成功实现脱机。ＳＩＭＶＰＳ是一种较佳的脱机方式。

Objective:To compare two weaning modes in patients with pressure support ventilation (PSV) and synchronized intermittent mandatory ventilation(SIMV)pressure support level (PS).Methods:There were 2 groups in this study:PSV successful weaning group (n=25) and SIMVPS successful weaning group (n=13).During mechanical ventilation (MV),weaning duration,PS,tidal volume (VT),respiratory frequency (f),airway occlusion pressure (P01) as well as weaning steps were compared between the two weaning modes.Results:Weaning duration,PS,VT,f and P01 showed no significant differences between the two weaning modes (all P>005).When PSV was used for weaning mode,PS level was less than 069 kPa(1 kPa=1020 cmH2O) in patients with short time of MV (<7 days),and was at 049～059 kPa in patients with long time of MV (>7 days),and dynamic changes in P01 and ventilationoxygenation were considerd.When SIMVPS was used for weaning mode,PS level was at 059～069 kPa in patients with short time of MV (<7 days) and its rate of SIMV was progressively decreased (6 cycles per minute),but when the rate of SIMV was progressively decreased (4 cycles per minute) in patients with long time of MV (>7 days),and PS level was lower than 049 kPa according to patient′s tolerance.The conventional parameters combined with the changes in P01 could serve as satisfactory guides for weaning processes.Conclusions:Weaning of SIMVPS modality is better than that of PSV alone,particularly in patients without tolerance of PSV modality.Therefore,SIMVPS mode is one of the best ventilated modalities used for weaning.