Liang Guopeng, Liu Tingting, Zeng Yihua, Shi Yunfeng, Yang Wei, Yang Yunqin, Kang Yan
Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China.
Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China.
Respir Care. 2018 Apr;63(4):388-394. doi: 10.4187/respcare.05820. Epub 2018 Feb 6.
The objective of this work was to identify the unique characteristics of patients who experienced success in a 30-min spontaneous breathing trial (SBT) but failed at 120 min.
Patients who had received mechanical ventilation for >24 h were eligible for inclusion in this study. The SBT was performed by 7 cm HO of pressure support with zero PEEP. After a successful 120-min SBT, weaning from mechanical ventilation was performed. Data were collected at 30 and 120 min or at the failure of the SBT. All patients who successfully completed a 30-min SBT were enrolled.
We enrolled 352 subjects in this study. Of these, 311 subjects (88.4%) directly completed a 120-min SBT (success group), and 41 subjects (11.6%) passed the test for at least 30 min but failed before 120 min (failure group). In data collected before the SBT, presence of chronic cardiopulmonary disease, number of previous SBT attempts before 30-min SBT success, age, and P were independently associated with 120-min SBT failure. A scale was developed that used these 4 variables. The failure rate was low in subjects with ≤2 points (3%) but significantly higher in subjects with >2 points (46%). In data collected at the 30-min SBT, P , rapid shallow breathing index, ΔP /F , Δbreathing frequency, and ΔpH were independently associated with 120-min SBT failure. These 5 variables were then used to develop another scale to predict SBT success. Similar to the previous score, the failure rate was low in subjects with ≤2 points (1%) and significantly higher in subjects with >2 points (55%).
This study highlights differences between subjects who completed a 120-min SBT and those who succeeded at 30 min but failed by 120 min. In subjects with a score >2 points, reflecting a greater risk of SBT failure, a 120-min SBT may be required.
本研究的目的是确定在30分钟自主呼吸试验（SBT）中成功但在120分钟时失败的患者的独特特征。
接受机械通气超过24小时的患者符合纳入本研究的条件。SBT通过7cm H₂O的压力支持和零呼气末正压（PEEP）进行。在120分钟的SBT成功后，进行机械通气撤机。在30分钟和120分钟或SBT失败时收集数据。所有成功完成30分钟SBT的患者均被纳入。
本研究共纳入352名受试者。其中，311名受试者（88.4%）直接完成了120分钟的SBT（成功组），41名受试者（11.6%）通过了至少30分钟的测试但在120分钟前失败（失败组）。在SBT前收集的数据中，慢性心肺疾病的存在、30分钟SBT成功前先前SBT尝试的次数、年龄和P与120分钟SBT失败独立相关。开发了一个使用这4个变量的量表。得分≤2分的受试者失败率较低（3%），但得分>2分的受试者失败率显著较高（46%）。在30分钟SBT时收集的数据中，P、快速浅呼吸指数、ΔP/F、Δ呼吸频率和ΔpH与120分钟SBT失败独立相关。然后使用这5个变量开发了另一个量表来预测SBT成功。与先前的评分相似，得分≤2分的受试者失败率较低（1%），得分>2分的受试者失败率显著较高（55%）。
本研究突出了完成120分钟SBT的受试者与在30分钟时成功但在120分钟时失败的受试者之间的差异。在得分>2分的受试者中，反映出SBT失败风险更大，可能需要进行120分钟的SBT。
