PCV vs VCV in Low-Flow Anesthesia

Pressure-Controlled Versus Volume-Controlled Ventilation in Low-Flow Anesthesia: A Randomized Controlled Trial on Intraoperative Respiratory Mechanics and Postoperative Pulmonary Function

The aim of this observational study is to investigate the effects of ventilation modes on intraoperative and postoperative lung functions in patients under general anesthesia.

This study aimed to compare the effects of low-flow anesthesia on intraoperative respiratory mechanics and early postoperative pulmonary function between PCV and VCV in ASA I-II adult patients.

Studies comparing the effects of pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV) on lung function under low-flow conditions are limited. In this study, the effects of PCV and VCV on intraoperative respiratory mechanics and early postoperative pulmonary function were investigated during low-flow anesthesia in ASA I-II adult patients undergoing routine anesthesia procedures.

Inclusion Criteria:

- age 18-65 years and American Society of Anesthesiologists (ASA) physical status I-II.

Exclusion Criteria:

• morbid obesity (BMI > 35 kg/m²),
• scoliosis or thoracic deformity,
• restrictive or obstructive lung disease,
• prior thoracic or upper abdominal surgery,
• history of major thoracic trauma or congenital chest wall anomaly,
• active smoking or chronic use of corticosteroids,
• β-agonists, bronchodilators, or antihistamines,
• anticipated difficult airway
• severe hypoxemia (SpO₂ < 90%) during induction.