Comparison of Low vs. High Tidal Volumes in One-Lung Ventilation: Impacts on Respiratory Function and Clinical Outcomes during Thoracic Surgery

Abstract

respiratory function.

Objective: To evaluate the impact of low vs. high tidal volumes during one-lung ventilation on postoperative pulmonary complications, respiratory function, length of ICU and hospital stay, and mortality in thoracic surgery patients.

Methods: A prospective observational cohort study was conducted at Fatima Jinnah Institute of Chest Diseases Quetta from April 2024 to April 2025 with 245 adult patients undergoing elective thoracic surgery requiring OLV. Patients were divided into two groups: Group A (low tidal volume) and Group B (high tidal volume). Postoperative outcomes, including pulmonary complications, arterial blood gas (ABG) measurements, lung compliance, ICU and hospital stay duration, and 30-day mortality were assessed.

Results: The incidence of postoperative complications, including atelectasis (21% vs. 34%), pneumonia (12% vs. 20%), and ARDS (6% vs. 10%), was significantly lower in Group A (low tidal volume). PaO2/FiO2 ratios at 24 hours were higher in Group A (275 ± 48) compared to Group B (245 ± 55, p = 0.01), indicating better oxygenation. Lung compliance at 24 hours was better in Group A (42.3 ± 7.8) compared to Group B (39.1 ± 6.5). The length of ICU stay and total hospital stay were significantly shorter in Group A (2.4 days and 7.6 days, respectively) compared to Group B (3.1 days and 8.2 days, respectively). Mortality rates were low in both groups (0.8% in Group A vs. 1.6% in Group B), with no significant difference (p = 0.47).

Conclusion: It is concluded that low tidal volume ventilation during one-lung ventilation in thoracic surgery patients is associated with reduced postoperative pulmonary complications, better respiratory function, and shorter ICU and hospital stays..