The Effect of Mechanical Ventilation With Low Tidal Volume on Blood Loss During Laparoscopic Liver Resection: A Randomized Controlled Trial

BACKGROUND: Control of bleeding during laparoscopic liver resection (LLR) is important for patient safety. It remains unknown what the effects of mechanical ventilation with varying tidal volumes on bleeding during LLR. Thus, this study aims to investigate whether mechanical ventilation with low tidal volume (LTV) reduces surgical bleeding during LLR. METHODS: In this prospective, randomized, and controlled clinical study, 82 patients who underwent scheduled LLR were enrolled and randomly received either mechanical ventilation with LTV group (6–8 mL/kg) along with recruitment maneuver (once/30 min) without positive end-expiratory pressure (PEEP) or conventional tidal volume (CTV; 10–12 mL/kg) during parenchymal resection. The estimated volume of blood loss during parenchymal resection and the incidence of postoperative respiratory complications were compared between 2 groups. RESULT: The estimated volume of blood loss (median [interquartile range {IQR}]) was decreased in the LTV group compared to the CTV group (301 [148, 402] vs 394 [244, 672] mL, P = .009); blood loss per cm 2 of transected surface of liver (5.5 [4.1, 7.7] vs 12.2 [9.8, 14.4] mL/cm 2 , P < .001) and the risk of clinically significant estimated blood loss (>800 mL) were reduced in the LTV group compared to the CTV group (0/40 vs 8/40, P = .003). Blood transfusion was decreased in the LTV group compared to the CTV group (5% vs 20% of patients, P = .043). No patient in the LTV group but 2 patients in the CTV group were switched from LLR to open hepatectomy. Airway plateau pressure was lower in the LTV group compared to the CTV group (mean ± standard deviation [SD]) (12.7 ± 2.4 vs 17.5 ± 3.5 cm H 2 O, P = .002). CONCLUSIONS: Mechanical ventilation with LTV may reduce bleeding during laparoscopic liver surgery.