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

Catholic University of the Sacred Heart

Status: Completed

Conditions: Surgery--Complications; Anesthesia

Treatments: Drug: Crystalloid Solutions; Diagnostic Test: Esophageal pressure measurement; Drug: Intravenous anesthetic; Diagnostic Test: Lung volume measurement with the nitrogen washin-washout technique

Study type: Interventional

Funder types: Other

Identifiers

NCT03157479

InproveForLarge

Details and patient eligibility

About

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.

Enrollment: 60 patients

Sex: Female

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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60 participants in 2 patient groups

Protective ventilation

Experimental group

Description:

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.

Treatment:

Diagnostic Test: Esophageal pressure measurement

Drug: Crystalloid Solutions

Diagnostic Test: Lung volume measurement with the nitrogen washin-washout technique

Drug: Intravenous anesthetic

Standard Ventilation

Active Comparator group

Description:

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

Treatment:

Diagnostic Test: Esophageal pressure measurement

Drug: Crystalloid Solutions

Diagnostic Test: Lung volume measurement with the nitrogen washin-washout technique

Drug: Intravenous anesthetic