Effect of Intraoperative Salbutamol Administration on Mechanical Power and Respiratory Mechanics in Obese Patients Undergoing Laparoscopic Bariatric Surgery

Effect of Intraoperative Salbutamol Administration on Mechanical Power and Respiratory Mechanics in Obese Patients Undergoing Laparoscopic Bariatric Surgery

The primary objective of this study is to evaluate the effect of intraoperative salbutamol administration on mechanical power in obese patients undergoing laparoscopic bariatric surgery under general anesthesia. Mechanical power will be measured at predefined intraoperative time points (T0, T1, and T2), and changes over time will be compared to determine the impact of salbutamol on the overall energy delivered to the respiratory system during mechanical ventilation.

Secondary objectives include the assessment of intraoperative respiratory mechanics, including peak airway pressure (Ppeak), plateau pressure (Pplat), driving pressure (Pdrive), airway resistance (Raw), and lung compliance, as well as gas exchange parameters (SpO₂, EtCO₂) and hemodynamic variables (mean arterial pressure). Postoperative pulmonary outcomes will be evaluated using the Melbourne Group Scale (MGS), with a score greater than 4 indicating the presence of postoperative pulmonary complications. The study aims to investigate whether improvement in intraoperative mechanical power and respiratory mechanics is associated with a reduction in postoperative pulmonary complications in this high-risk population.

Inclusion Criteria:

• Age: 18-65 years

BMI ≥35 kg/m² (candidates for obesity surgery)

Scheduled for elective laparoscopic bariatric surgery

ASA physical status I-III

Signed informed consent

Exclusion Criteria:

Known allergy or contraindication to salbutamol

Severe cardiovascular disease (e.g., recent MI, uncontrolled arrhythmia)

Pre-existing severe pulmonary disease (e.g., severe COPD, asthma exacerbation)

Pregnancy or lactation

Emergency surgery

Use of β-agonists or bronchodilators within 24 hours prior to surgery

Patients with inability to provide informed consent

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