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Canadian Respiratory Journal
Volume 2017 (2017), Article ID 7381424, 7 pages
Research Article

Hypercapnic Ventilatory Response in the Weaning of Patients with Prolonged Mechanical Ventilation

1Department of Thoracic Medicine, Chang Gung Memorial Hospital, Linkou, No. 5, Fu-Hsing St., Kueishan Dist., Taoyuan City, Taiwan
2Department of Respiratory Therapy, Chang Gung University, Taoyuan City, Taiwan
3Department of Pulmonary and Critical Care Medicine, Xiamen Chang Gung Hospital, Xiamen City, China

Correspondence should be addressed to Shih-Wei Lin

Received 13 April 2017; Revised 8 August 2017; Accepted 17 September 2017; Published 30 October 2017

Academic Editor: Alice M. Turner

Copyright © 2017 Chung-Shu Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objective. To investigate whether hypercapnic ventilatory response (defined as the ratio of the change in minute ventilation [] to the change in end-tidal partial pressure of carbon dioxide []) 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 () of and  L/min/mmHg, respectively (). 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.