• P E Huygen, I Gültuna, C Ince, A Zwart, J M Bogaard, B W Feenstra, and H A Bruining.
• Department of Surgery, University Hospital Rotterdam, The Netherlands.
• Crit. Care Med. 1993 Aug 1;21(8):1149-58.

Objectivesa) To determine the validity of a new method to analyze indicator gas washout tests on mechanically ventilated patients. This method takes into account the difference between the end-expiratory gas fraction and the mean gas fraction in the lung and provides the end-expiratory lung volume and a new index of ventilation inhomogeneity called volumes regression index. b) To determine the validity of this index as a predictor of chronic obstructive pulmonary disease. c) To compare this index with the moment ratio index and Becklake index.DesignProspective study of diagnostic test. Criterium standards: Closed-circuit indicator gas dilution technique and Tiffeneau index.SettingSurgical intensive care unit of a university hospital.PatientsA total of 38 mechanically ventilated postoperative patients, divided into two groups: the obstructive group (n = 21) and the nonobstructive group (n = 17), based on their preoperative lung function.InterventionsNone.Measurements And Main Resultsa) The mean coefficient of variation of all lung volume measurements in a group of nine healthy volunteers was 5%, and the difference between this technique and the closed-circuit helium dilution measurements was -2 +/- 5%. In patients, the mean coefficient of variation of the lung volume measurements was 3.5%. The volumes regression index was measured as 0.02 +/- 0.04 in a dummy lung, 0.37 +/- 0.08 in the healthy volunteers, 0.64 +/- 0.23 in the nonobstructive patients, and 1.1 +/- 0.3 in the obstructive patients. The volumes regression index provided a better correlation (r2 = .46) with preoperatively determined Tiffeneau index than the Becklake index (r2 = .11) or the moment ratio index (r2 = .18).ConclusionThe proposed technique provides a means for accurate measurement of the end-expiratory lung volume and the amount of ventilation inhomogeneity in mechanically ventilated intensive care unit patients.

29 keywords...

hide…