BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.
OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.
DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.
MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.
RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.
CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.
TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223.
}}, author = {{Nijbroek, Sunny G and Hol, Liselotte and Swart, Pien and Hemmes, Sabrine N T and Serpa Neto, Ary and Binnekade, Jan M and Hedenstierna, Goran and Jaber, Samir and Hiesmayr, Michael and Hollmann, Markus W and Mills, Gary H and Vidal Melo, Marcos F and Putensen, Christian and Schmid, Werner and Severgnini, Paolo and Wrigge, Hermann and Gama de Abreu, Marcelo and Pelosi, Paolo and Schultz, Marcus J}}, issn = {{1365-2346}}, keywords = {{Adult; Critical Illness; Female; Humans; Lung; Male; Respiration, Artificial; Sex Characteristics; Tidal Volume}}, language = {{eng}}, month = {{10}}, number = {{10}}, pages = {{1034--1041}}, publisher = {{European Society of Anaesthesiology}}, series = {{European Journal of Anaesthesiology}}, title = {{Sex difference and intra-operative tidal volume : Insights from the LAS VEGAS study}}, url = {{http://dx.doi.org/10.1097/EJA.0000000000001476}}, doi = {{10.1097/EJA.0000000000001476}}, volume = {{38}}, year = {{2021}}, }