Bai Linfu, Duan Jun
Department of Respiratory Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Respir Care. 2017 May;62(5):566-571. doi: 10.4187/respcare.05260. Epub 2017 Feb 28.
A ventilator includes the function to measure flow velocity. We aimed to compare the predictive accuracy for re-intubation diagnosed by cough peak flow (CPF) measured by a spirometer and a ventilator.
Endotracheally intubated subjects who passed a spontaneous breathing trial were enrolled. Before extubation, CPF was measured by a spirometer and a ventilator, respectively. Re-intubation was recorded at 72 h after extubation.
A total of 126 subjects were enrolled. Among them, 15 subjects (12%) experienced re-intubation. CPF was lower in re-intubated subjects than those without re-intubation (measured by a spirometer: 54 ± 30 L/min vs 86 ± 37 L/min, < .001; and measured by a ventilator: 50 ± 22 L/min vs 80 ± 26 L/min, < .001). CPF measured by a spirometer and a ventilator had similar area under the curve of receiver operating characteristic (0.79 vs 0.83, = .26). When a CPF of 56.4 L/min was measured by a spirometer as cutoff value, the sensitivity and specificity to distinguish re-intubation was 73 and 87%, respectively. When it was measured by a ventilator, the cutoff value, sensitivity, and specificity were 56 L/min, 73%, and 85%, respectively.
CPF measurement by a ventilator was convenient, affordable, and safe. It had a predictive accuracy for re-intubation similar to that of a spirometer.
呼吸机具备测量流速的功能。我们旨在比较通过肺活量计和呼吸机测量的咳嗽峰值流速（CPF）对再插管诊断的预测准确性。
纳入通过自主呼吸试验的气管插管受试者。在拔管前，分别用肺活量计和呼吸机测量CPF。记录拔管后72小时内的再插管情况。
共纳入126名受试者。其中，15名受试者（12%）经历了再插管。再插管受试者的CPF低于未再插管者（用肺活量计测量：54±30升/分钟对86±37升/分钟，P<.001；用呼吸机测量：50±22升/分钟对80±26升/分钟，P<.001）。用肺活量计和呼吸机测量的CPF在受试者工作特征曲线下面积相似（0.79对0.83，P=.26）。当用肺活量计测量的CPF以56.4升/分钟为截断值时，区分再插管的敏感性和特异性分别为73%和87%。当用呼吸机测量时，截断值、敏感性和特异性分别为56升/分钟、73%和85%。
用呼吸机测量CPF方便、经济且安全。其对再插管的预测准确性与肺活量计相似。
