Stepwise PEEP vs Sustained Inflation in Bariatric Surgery Patients

In the SI group:, the anesthesiologist adjust the ventilator to manual ventilation mode and ad¬just The ventilator will be switched to manual mode, and the airway pressure-limiting valve will be set to 30 cmH₂O. A sustained manual inflation was then applied by gradually squeezing the anesthesia reservoir bag over 3-5 seconds until a peak airway pressure (Ppeak) of 30 cmH₂O was achieved. This pressure was maintained continuously for 30 seconds. Following the maneuver, mechanical ventilation was resumed with positive end-expiratory pressure (PEEP) back to 5 cmho In the IP group:, alveolar recruitment will be performed as follows: ventilation will be set to pressure control mode and the driving pressure maintained at 10 cmH2O with an initial PEEP of 5 cmH2O, respiratory rate 8-10, I:E 1-1PEEP will be then increased by 5 cmH2O ev¬ery 30 s until the Ppeak reached 30 cmH2O (so peep will reach 20), held for 30 s , then PEEP will be gradually reduced at intervals of 5 cmH2O down to 5 cmH2O, when initial volume control ventilation will be resumed. In the incremental PEEP group, PEEP was increased stepwise by 5 cmH₂O every 3-5 breaths until a peak airway pressure of 30 cmH₂O was achieved, after which mechanical ventilation was resumed with maintenance PEEP. The total duration of the recruitment maneuver was approximately 60-90 seconds.

receive 30 cmH₂O sustained inflation for 30seconds

Procedure: sustained inflation recruitement

receive PEEP was increased stepwise by 5 cmH₂O every 5 breaths until a peak airway pressure of 30 cmH₂O

Procedure: Stepwise PEEP

anesthesiologist adjust the ventilator to manual ventilation mode and ad¬just The ventilator was switched to manual mode, and the airway pressure-limiting valve was set to 30 cmH₂O. A sustained manual inflation was then applied by gradually squeezing the anesthesia reservoir bag over 3-5 seconds until a peak airway pressure (Ppeak) of 30 cmH₂O

: ventilation will be set to pressure control mode and the driving pressure maintained at 10 cmH2O with an initial PEEP of 5 cmH2O, respiratory rate 8-10, I:E 1-1PEEP will be then increased by 5 cmH2O ev¬ery 30 s until the Ppeak reached 30 cmH2O

Plazo: Postoperative upon admission to the post-anesthesia care unit approximately within first 15 minutes after extubation

lung ultrasound scoring system

Plazo: Postoperative upon admission to the post-anesthesia care unit Approximately within first 15 minutes after extubation and repeated before discharge

SpO₂

Plazo: in the post-anesthesia care unit 15 minutes after extubation

to maintain SpO₂ ≥94%.

Plazo: from beginning till end of the recruitment maneauver

Intraprocedural significant desaturation was defined as SPO2 \< 90% or a decrease of more than 5% from the pre-maneuver baseline.

Plazo: postprocedural; Immediately after the end maneauver

a systolic blood pressure \< 80 mmHg, diastolic blood pressure \< 50 mmHg, or a reduction in mean blood pressure \> 20% from baseline.

Comparison of Stepwise PEEP vs Sustained Inflation Recruitment Maneuvers on Postoperative Oxygenation and Atelectasis in Bariatric Surgery Patients