Optimal Positive End-expiratory Pressure (PEEP) in Prone Position During Spine Surgery

Optimal Positive End-expiratory Pressure (PEEP) in Prone Position During Spine Surgery. A Prospective Observational Study

Background:

There is a lack of studies regarding Optimal (best) positive end-expiratory pressure (PEEP) in prone position during surgery, and its relation with optimal PEEP in supine position.

Hypothesis:

In patients undergoing scheduled spinal surgery, optimal PEEP in the prone position is lower than optimal PEEP in the supine position.

Aims:

To assess the difference optimal PEEP in supine vs. prone positions in patients undergoing spine surgery.

To evaluate the changes in optimal PEEP in prone position throughout the surgical procedure.

Methods:

Observational study, one center. Main variable: optimal PEEP. Secondary variables: PaO2, pCO2 and dynamic compliance (Crd) in prone and supine position.

Recruitment: Patients scheduled for spine surgery were Main outcome: Optimal PEEP determined after a pulmonary recruitment manoeuvre in supine and in prone position and every hour during the surgery in prone position.

Secondary outcomes: Pulmonary compliance, blood gas analysis and hemodynamic parameters

Inclusion Criteria:

• Age ≥18 years.
• Spine prone surgery lasting ≥2 hours.
• Absence of known pulmonary pathology.

Exclusion Criteria:

• Pregnancy or lactation.
• Contraindication to alveolar recruitment maneuvers (risk of barotrauma, hemodynamic instability).
• Body mass index (BMI) >35.
• Heart failure defined as IC <2.5 L/min/m2 and/or inotropic support requirements prior to surgery.
• Diagnosis or suspicion of intracranial hypertension (intracranial pressure >15 mmHg).