Intraoperative Protective Ventilation for Obese Patients Undergoing Gynaecological Laparoscopic Surgery (Inprove4large)

Intraoperative Protective Ventilation for Obese Patients Undergoing Gynaecological Laparoscopic Surgery. A Single-centre Randomized, Controlled Trial

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 Overview

• Status: Completed
• Conditions: Surgery--Complications; Anesthesia
• Intervention / Treatment: Drug: Intravenous anesthetic; Drug: Crystalloid Solutions; Diagnostic test: Esophageal pressure measurement; Diagnostic test: Lung volume measurement with the nitrogen washin-washout technique

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Italy
  • Rome, Italy, 00100
    • General surgery OR, A. Gemelli hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Protective ventilation; Volume controlled ventilation with tidal volume 6-7 ml/kg of predicted body weight (45.5 + 0.91 (height [cm] -152.4)), FiO2 0.4 and PEEP 10 cmH2O during the whole study period. Respiratory rate will be titrated to keep end-tidal CO2 values between 30 and 40 mmHg. I:E ratio will be set in order to obtain an inspiratory time of 0.8 seconds and an inspiratory pause of 0.3 seconds and FiO2 will be kept unchanged during the whole study period. In patients in this group, recruiting maneuvers will be performed throughout a stepwise 5 cmH2O PEEP increase every 30 seconds to achieve a PEEP of 35 cmH2O during Pressure Controlled Ventilation (10 cmH2O of inspiratory pressure while keeping respiratory rate unmodified), followed by a stepwise 5 cmH2O PEEP reduction every 30 seconds until the baseline set peep is reached.	Drug: Intravenous anesthetic; 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; Drug: Crystalloid Solutions; 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; Diagnostic test: Esophageal pressure measurement; 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; Diagnostic test: Lung volume measurement with the nitrogen washin-washout technique; 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.
Active Comparator: Standard Ventilation; Volume controlled ventilation with tidal volume 10 ml/kg of PBW (45.5 + 0.91 (height [cm] -152.4)), FiO2 0.4 and PEEP 5 cmH2O during the whole study period. Respiratory rate will be titrated to keep end-tidal CO2 values between 30 mmHg and 40 mmHg. I:E ratio will be set in order to obtain an inspiratory time of 0.8-1 seconds and an inspiratory pause of 0.3 second	Drug: Intravenous anesthetic; 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; Drug: Crystalloid Solutions; 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; Diagnostic test: Esophageal pressure measurement; 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; Diagnostic test: Lung volume measurement with the nitrogen washin-washout technique; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative oxygenation	PaO2/FiO2 ratio 1 hour after extubation, while the patient is receiving oxygen through VenturiMask 40%	One hour after extubation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	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	48 hours after the end of surgery
Postoperative Tiffeneau index	computed as FEV1/FVC	48 hours after the end of surgery
Postoperative Dyspnea	Dyspnea assessed by Borg dyspnea scale	1 hour after surgery
Pulmonary infection	modified clinical pulmonary infection score (mCPIS)	24 hours after the end of surgery
Postoperative pulmonary infiltrates	Evaluated with the chest x-ray by two independent clinicians blinded to treatment assignment	24 hours after the end of surgery
Intraoperative driving pressure	driving pressure, computed as Plateau pressure-PEEP	during surgery, recorded on a 60-minute basis
Intraoperative lung driving pressure	transpulmonary driving pressure, computed as Transpulmonary end-inspiratory pressure-transpulmonary total end-expiratory pressure	during surgery, recorded on a 60-minute basis
Intraoperative oxygenation	PaO2/FiO2	during surgery, recorded on a 60-minute basis
Intraoperative dead space	Approximated as the difference between End-tidal CO2 and PaCO2 divided by PaCO2	during surgery, recorded on a 60-minute basis
Lung recruitment	lung recruitment/changes in end expiratory lung volume between the two groups	during surgery, recorded on a 60-minute basis
Intraoperative blood pressure	Arterial blood pressure	during surgery, recorded on a 60-minute basis
Intraoperative respiratory system compliance	computed as Tidal volume/airway driving pressure	during surgery, recorded on a 60-minute basis
Intraoperative lung compliance	computed as Tidal volume/lung driving pressure	during surgery, recorded on a 60-minute basis

Collaborators and Investigators

• Sponsor: Catholic University of the Sacred Heart

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2017
• Primary Completion (Actual): March 31, 2019
• Study Completion (Actual): March 31, 2019

Study Registration Dates

• First Submitted: May 12, 2017
• First Submitted That Met QC Criteria: May 15, 2017
• First Posted (Actual): May 17, 2017

Study Record Updates

• Last Update Posted (Actual): May 20, 2019
• Last Update Submitted That Met QC Criteria: May 16, 2019
• Last Verified: May 1, 2019

More Information

Terms related to this study

• Keywords: Mechanical ventilation
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics, General; Anesthetics; Anesthetics, Intravenous
• Other Study ID Numbers: InproveForLarge

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No