Author/Authors :
Lee, Chung-Shu Department of Thoracic Medicine - Chang Gung Memorial Hospital, Linkou, Kueishan Dist, Taoyuan City, Taiwan , Chen, Ning-Hung Department of Thoracic Medicine - Chang Gung Memorial Hospital, Linkou, Kueishan Dist, Taoyuan City, Taiwan , Chuang, Li-Pang Department of Thoracic Medicine - Chang Gung Memorial Hospital, Linkou, Kueishan Dist, Taoyuan City, Taiwan , Chang, Chih-Hao Department of Thoracic Medicine - Chang Gung Memorial Hospital, Linkou, Kueishan Dist, Taoyuan City, Taiwan , Li, Li-Fu Department of Thoracic Medicine - Chang Gung Memorial Hospital, Linkou, Kueishan Dist, Taoyuan City, Taiwan , Lin, Shih-Wei Department of Thoracic Medicine - Chang Gung Memorial Hospital, Linkou, Kueishan Dist, Taoyuan City, Taiwan , Huang, Hsiung-Ying Department of Pulmonary and Critical Care Medicine - Xiamen Chang Gung Hospital, Xiamen City, China
Abstract :
Objective. To investigate whether hypercapnic ventilatory response (defined as the ratio of the change in minute ventilation [Δ𝑉̇
𝐸] to
the change in end-tidal partial pressure of carbon dioxide [Δ𝑃ETCO2
]) is a predictor of successful weaning in patients with prolonged
mechanical ventilation (PMV) and to determine a reference value for clinical use. Methods. A hypercapnic challenge test was
performed on 32 PMV subjects (average age: 74.3 years ± 14.9 years). The subjects were divided into two groups (i.e., weaning
successes and weaning failures) and their hypercapnic ventilatory responses were compared. Results. PMV subjects had an overall
weaning rate of 68.8%. The weaning-success and weaning-failure groups had hypercapnic ventilatory responses (Δ𝑉̇ 𝐸/Δ𝑃ETCO2 ) of 0.40±0.16 and 0.28±0.12 L/min/mmHg, respectively (𝑃 = .036).The area under the receiver operating characteristic curve was 0.716
of the hypercapnic ventilatory response, and the practical hypercapnic ventilatory response cut-off point for successful weaning was
0.265 with 86.4% sensitivity and 50% specificity. Conclusions. PMV subjects who failed weaning had a lower hypercapnic ventilatory
response than successfully weaned subjects. However, the prediction capacity of this test, assessed by the area under the receiver
operating characteristic (ROC) curve, poorly predicted weaning outcome.
