Intraoperative Blood Loss Under Standard Versus Low Pneumoperitoneum Pressure During Laparoscopic Liver Resection.

Intraoperative Blood Loss Under Standard Versus Low Pneumoperitoneum Pressure During Laparoscopic Liver Resection.

Intraoperative Blood Loss Under Standard Versus Low Pneumoperitoneum Pressure During Laparoscopic Liver Resection: Study Protocol for a Randomized Controlled Trial

Commonly the pressure of about 14 mmHg is applied during laparoscopic liver resection (LLR) with moderate neuromuscular blockade. Lowering the pneumoperitoneum pressure combined with deep neuromuscular blockade may sustain optimal operating space with providing better short-term postoperative results. It has been proved in randomized controlled trials in colorectal or bariatric patients, however there is lack of similar data for laparoscopic liver resection. Doubts about lowering the pneumoperitoneum pressure too hasty are supported by apprehension of worse bleeding control during liver parenchyma transection and its impact on postoperative results. The aim of the trial is to assess the impact of standard (14 mmHg) versus low (10 mmHg) pneumoperitoneum pressure on intraoperative blood loss, what will be the primary outcome. As secondary endpoints following outcomes will be measured: quality of operating space, intraoperative adverse events, quality of recovery, postoperative renal function, 30-day postoperative complications rate, length of hospital stay. The investigators assume that lower pneumoperitoneum provides non-inferior blood loss control during laparoscopic liver resection with better postoperative results.

After signing the informed consent patients will be randomized into 2 groups.This stratification is aimed to reduce a strong risk factor for intraoperative blood loss which is the difficulty of performed procedure. Applied classification is simple to use and contains blood loos as one of the three main classifiers to determine the difficulty (beside operative time and conversion rate). Stratified randomization will be conducted by investigators via drawing a sealed envelope with computer-generated intervention code at the Department just before patient transfer to the operating theatre. There will be two study arms with 1:1 fashion For both trial arms additional routine elements of perioperative anesthesia care will be defined: low central vein pressure, aimed for 5 ± 2 mmHg with restrictive fluid therapy ventilation in a volume-controlled mode without intraoperative high positive end-expiratory pressure (PEEP) invasive arterial blood pressure monitoring with maintaining mean arterial pressure ≥ 60 mmHg maintaining hemoglobin concentration > 8g/dl maintaining normothermia and normoglycemia maintaining oxygenation >94%, in case of hypercapnia with respiratory acidosis, the respiratory rate and tidal volume will be stepwise increased The surgeon will be blinded to the study arm and level of pneumoperitoneum pressure. The blood loss during liver parenchyma transection and total procedure blood loss will be reported based on the amount of sucked outside intraperitoneal fluids after liver transection and after procedure without volume inserted for intraperitoneal irrigation. The estimated blood loss will be measured in milliliters. During the procedure, the surgeon will be asked for rating the quality of operating space in accordance to the Leiden Surgical Rating Scale every 60 minutes. In case of inadequate operating space, pneumoperitoneum pressure may be increased by 2 mmHg (with maximum of 16 mmHg in arm 1. and 12 mmHg in arm 2.). Intraoperative adverse events will be assessed in accordance to ClassIntra classification. Quality of recovery (QoR) will be measured on postoperative day 1, 3 and 5 with patient reported QoR-40 questionnaire, 30-day postoperative complication rate will be assessed in accordance to Clavien-Dindo classification. Length of hospital stay will be counted from the date of surgery to the discharge day. All patients will be followed up by researchers who are blinded to the intraoperative grouping.

Expressed in accordance to Leiden scale (L-SRS) and the rate of need for increase of pneumoperitoneum pressure Score 1-5 (where 1 means extremely poor conditions; 5- optimal conditions) From multiple measurements, value submitted for analysis will be the lowest reported during the surgery.

Expressed in accordance to ClassIntra scale Grades 0-V (where 0 means no deviation; V- intraoperative death of the patient)

Expressed in accordance to questionaire QoR-40 40 questions with 1-5 points each (total score minimum 40 points; maximum 200 points)

From date of surgery until the date of disscharge or date of death from any cause, whichever came first, assessed up to 100 days

Inclusion Criteria: Patients scheduled to perform elective laparoscopic major liver resection Age of 18 years or older Body mass index (BMI) between 18.5 kg/m2 and 35 kg/m2 Signed informed consent Exclusion Criteria: Severe cardiopulmonary disease Severe renal disease Emergency surgery Pregnancy Patient's refusal of participation