Low-flow anesthesia has been used for years with positive results, but its effects on hemodynamic parameters and oxygenation are not clearly known in high-risk morbidly obese patients who are prone to pulmonary dysfunction related to the obesity. Therefore, this prospective randomized study aimed to compare the effects of low-flow (0.75 L/min) and normal-flow (1.5 L/min) anesthesia on hemodynamic parameters and oxygenation in morbidly obese patients undergoing laparoscopic bariatric surgery.

Low-flow anesthesia has several potential benefits. It improves the flow dynamics of the inhaled air, increase mucociliary clearance, maintain body temperature, reduce fluid loss, result in savings of up to 75% and reduce greenhouse gas emissions and reduce treatment costs (10 - 13). However, it is necessary to examine whether the reduction of fresh gas flow affects the quality and safety of anesthesia management, especially during high-risk operations such as laparoscopic bariatric surgery.

Low-flow anesthesia has been used for years with positive results, but its effects on hemodynamic parameters and oxygenation are not clearly known in high-risk morbidly obese patients who are prone to pulmonary dysfunction related to the obesity. Therefore, this prospective randomized study aimed to compare the effects of low-flow (0.75 L/min) and normal-flow (1.5 L/min) anesthesia on hemodynamic parameters and oxygenation in morbidly obese patients undergoing laparoscopic bariatric surgery.

Inclusion Criteria:

• Morbidly obese patients with American Society of Anesthesiology (ASA) scores of III-IV,
• Aged 18-65 years old,
• BMI>40

Exclusion Criteria:

• Pregnant
• Uncontrolled diabetes mellitus,
• Cardiovascular disease,
• Pulmonary disease,
• Cerebrovascular disease,
• Drug and alcohol addiction.