Intraoperative Protective Ventilation for Obese Patients Undergoing Gynaecological Laparoscopic Surgery

Catholic University of the Sacred Heart60 enrolled

Overview

Background. The use of a comprehensive strategy providing low tidal volumes, peep and recruiting maneuvers in patients undergoing open abdominal surgery improves postoperative respiratory function and clinical outcome. It is unknown whether such ventilatory approach may be feasible and/or beneficial in patients undergoing laparoscopy, as pneumoperitoneum and Trendelenburg position may alter lung volumes and chest-wall elastance. Objective. The investigators designed a randomized, controlled trial to assess the effect of a lung-protective ventilation strategy on postoperative oxygenation in obese patients undergoing laparoscopic surgery.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Anesthesia Surgery--Complications

Interventions

Anaesthesia induction will be obtained with i.v. 2-3 mg/kg propofol, 0,6-0,8 mcg/kg fentanyl, and 0.9-1,2 mg/kg rocuronium. Anaesthesia will be maintained with i.v. propofol continuous infusion, with a dose titrated to achieve a bi-spectral index value between 40 and 50

Crystalloid SolutionsDRUG

Balanced crystalloids will be administered to patients in both groups as a standard rate of 3-5 ml/kg/h. Treatment of eventual hemodynamic instability will be left to the attending physician

Esophageal pressure measurementDIAGNOSTIC_TEST

A nasogastric polyfunctional tube (Nutrivent, Sidam, Italy) will be placed after anaesthesia induction in all enrolled patients to measure esophageal pressure, estimate pleural pressure and compute transpulmonary pressure

Lung volume measurement with the nitrogen washin-washout techniqueDIAGNOSTIC_TEST

Lung volume will be measured through nitrogen wash-in wash-out technique and low-flow Pressure-volume curve will be recorded to estimate differences in alveolar recruitment between the two study groups.

Eligibility

Sex: FEMALEMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * scheduled for gynaecological laparoscopic surgery in the Trendelenburg position * Obesity with body mass index\>35 kg/m\^2 * written informed consent Exclusion Criteria: * Clinical history or signs of chronic heart failure * history of neuromuscular disease * history of thoracic surgery * pregnancy * chronic respiratory failure requiring long-term oxygen administration

Locations (1)

General surgery OR, A. Gemelli hospital

Rome, Italy

Outcomes

Primary Outcomes

Postoperative oxygenation

PaO2/FiO2 ratio 1 hour after extubation, while the patient is receiving oxygen through VenturiMask 40%

Time frame: One hour after extubation

Secondary Outcomes

Postoperative forced expiratory volume in 1 second (FEV1)

volume exhaled during the first second of a forced expiratory maneuver started from the level of total lung capacity

Time frame: 48 hours after the end of surgery

Postoperative forced vital capacity (FVC)

the total amount of air exhaled during a forced expiratory maneuver started from the level of total lung capacity

Time frame: 48 hours after the end of surgery

Postoperative Tiffeneau index

computed as FEV1/FVC

Time frame: 48 hours after the end of surgery

Postoperative Dyspnea

Dyspnea assessed by Borg dyspnea scale

Time frame: 1 hour after surgery

Pulmonary infection

modified clinical pulmonary infection score (mCPIS)

Time frame: 24 hours after the end of surgery

Postoperative pulmonary infiltrates

Evaluated with the chest x-ray by two independent clinicians blinded to treatment assignment

Time frame: 24 hours after the end of surgery

Intraoperative driving pressure

driving pressure, computed as Plateau pressure-PEEP