The effects of prolonged inspiratory time during one‐lung ventilation: a randomised controlled trial

• Published in: Anaesthesia 2013-09, Vol.68 (9), p.908-916
• Main Authors: Lee, S. M., Kim, W. H., Ahn, H. J., Kim, J. A., Yang, M. K., Lee, C. H., Lee, J. H., Kim, Y. R., Choi, J. W.
• Format: Article
• Language: English
• Subjects: Anesthesia; Blood Gas Analysis - methods; Carbon Dioxide - blood; Female; Humans; Inhalation - physiology; Lungs; Male; Middle Aged; One-Lung Ventilation - methods; Oxygen - blood; Pulmonary Gas Exchange; Respiratory Mechanics - physiology; Thoracic surgery; Thoracic Surgical Procedures; Tidal Volume; Time Factors; Ventilation
• ISSN: 0003-2409; 1365-2044
• DOI: 10.1111/anae.12318

Summary We evaluated the effects of a prolonged inspiratory time on gas exchange in subjects undergoing one‐lung ventilation for thoracic surgery. One hundred patients were randomly assigned to Group I:E = 1:2 or Group I:E = 1:1. Arterial blood gas analysis and respiratory mechanics measurements were performed 10 min after anaesthesia induction, 30 and 60 min after initiation of one‐lung ventilation, and 15 min after restoration of conventional two‐lung ventilation. The mean (SD) ratio of the partial pressure of arterial oxygen to fraction of inspired oxygen after 60 min of one‐lung ventilation was significantly lower in Group I:E = 1:2 compared with Group I:E = 1:1 (27.7 (13.2) kPa vs 35.2 (22.1) kPa, respectively, p = 0.043). Mean (SD) physiological dead space‐to‐tidal volume ratio after 60 min of one‐lung ventilation was significantly higher in Group I:E = 1:2 compared with Group I:E = 1:1 (0.46 (0.04) vs 0.43 (0.04), respectively, p = 0.008). Median (IQR [range]) peak inspiratory pressure was higher in Group I:E = 1:2 compared with Group I:E = 1:1 after 60 min of one‐lung ventilation (23 (22–25 [18–29]) cmH2O vs 20 (18–21 [16–27]) cmH2O, respectively, p