Saturday December 3, 2005
Low tidal volume (TV) anyway?
From ARMA trial of ARDSNET we learned about benefits of low TV in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) but reports and studies have shown benefit of low TV (or harm of high TV) in non-ALI/ARDS too. See this retrospective cohort study of 332 patients who did not have acute lung injury but required mechanical ventilation - 80 patients developed ALI within the first 5 days of mechanical ventilation. One of the main risk factors in developing ALI was the use of large tidal volume in dose-dependent manner (odds ratio 1.3 for each ml above 6 ml/kg predicted body weight). 2 lessons learned:
1) We still tend to ignore the “ideal” body weight depending on height and gender and are using “actual” body weight for initial TV setup.
2) We still don’t know the “optimum” TV on non-ALI patients.
References: click to get abstract/article
1. Ventilator-associated lung injury in patients without acute lung injury at the onset of mechanical ventilation Critical Care Medicine. 32(9):1817-1824, September 2004