High-Tidal-Volume Mechanical Ventilation and Lung Inflammation in Intensive Care Patients With Normal Lungs

摘要

Background This study was conducted to investigate whether high-tidal-volume mechanical ventilation is associated with increased lung inflammation compared with low-tidal-volume mechanical ventilation in critically ill patients with no evidence of lung injury. Methods In this prospective, single-blind, randomized (1:1), parallel-group study, 18 critically ill patients with normal lungs were randomly assigned to receive mechanical ventilation with a tidal volume of either 6 mL/kg (low tidal volume) or 12 mL/kg (high tidal volume) during the first 4 days in the intensive care unit. Results At baseline and at 24, 48, and 96 hours, exhaled breath condensate was collected to measure interleukin 1 beta, interleukin 10, tumor necrosis factor alpha, and total nitric oxide metabolites. Interleukin 1beta levels in exhaled breath condensate were significantly increased at 24 hours compared with baseline in the high-tidal-volume group but not in the low-tidal-volume group. The interleukin 1 beta increase in the high-tidal-volume group was transient. Exhaled breath condensate levels of interleukin 1beta, interleukin 10, tumor necrosis factor alpha, and total nitric oxide metabolftes did not differ significantly between the high-tidal-volume and low-tidal-volume groups at any time point. Conclusion Short-term mechanical ventilation with a tidal volume of 12 mL/kg may trigger inflammatory responses in the lungs of intensive care unit patients without preexisting lung injury.