Driving Pressure Guided Mechanical Ventilation Versus Lung Protective Ventilation Among Patients Undergoing Elective Surgeries

Rawalpindi Medical College70 enrolled

Overview

Patient undergoing surgeries in general anesthesia require support of their breathing by ventilator. Different strategies can be used to manage breathing of the patient. Lung protective ventilation provides breathing at a set volume determined by patient ideal body weight, along with a set rate to maintain adequate breathing. The pressures in the lower airway are kept less than 30 cm of H20 while a pressure of 5cm of H20 is applied to prevent lung collapse. Recently to above mentioned regimen a driving pressure is added which is a difference between lower airway pressure and pressure applied to prevent lung collapse. Ventilatory settings are adjusted to keep this driving pressure less than 15 cm of H2O.

Lung protective ventilation provides tidal volume at 6-8 ml/kg along with a set respiratory while keeping plateau pressure less than 30cm of H2O and Peak pressure less than 35cm of H2O and PEEP of 5cm of H20 is applied. The aim is to prevent volutrauma, barotrauma and atelectrauma. To above mentioned regimen another parameter is added that is driving pressure. It is manipulated by adjusting PEEP level so that difference between Plateau Pressure and PEEP is less than equal to 15cm of water.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

OTHER

Masking

DOUBLE

Enrollment

Conditions

Mechanical Ventilation Lung Protective Ventilation

Interventions

Lung protective ventilationDEVICE

The patient in this group will receive tidal volume at 6-8 ml/kg of ideal body weight with PEEP of 5 cm of H2O and plateau pressure will be kept less than 30cm of H2O.

Driving pressure guided ventilationDEVICE

They will receive tidal volume of 6-8 ml/kg of ideal body weight and initial PEEP of 5 cm of water. Principal investigator will then incrementally increase PEEP by 2 cm of water till a value 15 cm of water PEEP is reached or Plateau pressure becomes equal to 30 cm of water or driving pressure starts to increase or there is change in any hemodynamics. Each incremental PEEP will last for 3 respiratory cycles before moving on to next value. PEEP value with lowest driving pressure will then be selected for the duration of surgical procedure

Eligibility

Sex: ALLMin age: 16 YearsMax age: 80 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * American Society of Anesthesiologists (ASA) class: I and II. * Elective laparoscopic surgeries requiring General Anesthesia and Mechanical ventilation * Patients receiving neuromuscular blockade during surgery. * Receiving Mechanical ventilation for at least 1h. Exclusion Criteria: * Pregnancy * Patients who had received mechanical ventilation of more than 1h in the previous 2 weeks. * Body mass index \>35 kg/m2 * Smokers and ASA class III and above. * Thoracic and Cardiac surgery

Outcomes

Primary Outcomes

Intra-operative pulmonary compliance

Time frame: This will be measured at 10 minutes interval in the intraoperative period and then mean will be calculated.

Secondary Outcomes

Oxygenation index

Time frame: This will be the ratio of PaO2/FiO2 and this will be measured during surgery (at time of skin closure)

PEtCO2-PaCO2 gradient

Time frame: This will be the PEtCO2-PaCO2 gradient and this will be measured during surgery (at time of skin closure)

Intra-operative blood pressure

Time frame: This will be Systolic, Diastolic and Mean Blood pressure measured at baseline and then 10 minutes interval in the intraoperative period. Mean will be calculated for comparison across groupss.

Post operative pulmonary complications

Time frame: This will be the need for prolonged ventilatory support, need for re-intubation ,need for supplemental oxygenation and its duration, PaO2/FiO2 ratio less than 300, pneumothroax. These will be observed in first 24hours after surgery.