Adequacy of ventilation with low and conventional tidal volumes in overweight and obese patients undergoing elective general surgical procedures� a prospective, single�blinded, randomised controlled trial

Justin P James; Sarah Ninan

Volume : VI, Issue : VII, July - 2016

Adequacy of ventilation with low and conventional tidal volumes in overweight and obese patients undergoing elective general surgical procedures� a prospective, single�blinded, randomised controlled trial

Justin P James, Sarah Ninan

Abstract :

INTRODUCTION: Low tidal volume (TV) ventilation has become popular due to its benefits in patients with lung injury. The effects of low TV in patients with normal lung function are unclear. METHODOLOGY: 36 patients with BMI of 25 or more with normal lung function were randomised to receive TV of either 6 mL/kg or 10 mL/kg of ideal body weight for 2 hours during elective general anaesthesia. Primary outcome was End–tidal Carbon Dioxide (ETCO2)going beyond defined limits of 24–40 mm Hg. A suggested starting TV was also derived, such that the ETCO2 was likely to have remained within the defined limits if that TV had been used from the start. RESULTS: 74% of patients receiving 6 mL/kg and 6% of patients receiving 10 mL/kg TV had inadequate ventilation. None of the patients receiving 6 mL/kg but 90% of patients receiving 10 mL/kg TV had excessive ventilation. The difference were statistically significant. In both groups, a TV of 8 mL/kg was derived as most likely to maintain ETCO2 within accepted limits.