To Breathe or Not to Breathe: Spontaneous Ventilation During Thoracic Surgery in High-Risk COPD Patients-A...

Background: Spontaneous ventilation with intubation (SVI) during video-assisted thoracoscopic surgery (VATS) has been introduced as a hybrid technique that combines the physiological benefits of spontaneous breathing with the safety of a secured airway. However, its application in patients with chronic obstructive pulmonary disease (COPD) remains controversial due to concerns about hypercapnia, hypoxemia, and dynamic hyperinflation. To date, no study has directly compared COPD and non-COPD patients undergoing VATS lobectomy under SVI using identical anesthetic and surgical protocols. Methods: A prospective observational study was conducted between January 2022 and December 2024 at a single tertiary thoracic surgery center. A total of 36 patients undergoing elective VATS lobectomy with SVI were included and divided into two groups: COPD (n = 17) and non-COPD (n = 19), based on GOLD criteria. All patients were intubated with a double-lumen tube and allowed to maintain spontaneous ventilation during one-lung ventilation (OLV) after recovery from neuromuscular blockade. Arterial blood gas (ABG) samples were collected at four predefined time points (T1-T4), and intraoperative respiratory parameters, hemodynamics, spontaneous ventilation time, and spontaneous ventilation fraction (SpVent%) were recorded. Postoperative outcomes, including ICU stay, complications, and conversion to controlled ventilation, were analyzed. Statistical comparisons were performed using t-test, Mann-Whitney U test, chi-square test, and ANCOVA with adjustment for age, sex, BMI, and FEV₁%. Results: All 36 procedures were successfully completed under SVI without conversion to controlled mechanical ventilation or thoracotomy. Baseline demographics were comparable between COPD and non-COPD patients regarding age (68.4 ± 6.9 vs. 67.8 ± 7.1 years; p = 0.78) and BMI (27.1 ± 4.6 vs. 26.3 ± 4.2 kg/m²; p = 0.56), while pulmonary function was significantly lower in COPD patients (FEV₁/FVC 53.8% (IQR 47.5-59.9) vs. 82.4% (78.5-85.2); p < 0.001). The duration of spontaneous ventilation was significantly longer in the COPD group (82 ± 14 min vs. 58 ± 16 min; p < 0.001), and remained significant after ANCOVA adjustment (β = +23.7 min; p = 0.001). The SpontVent% was higher in COPD patients (80% [70-90] vs. 60% [45-80]), showing a trend toward significance (p = 0.11). Intraoperative permissive hypercapnia was well tolerated: peak PaCO₂ levels at T3 were higher in COPD (52 ± 6 mmHg) than in non-COPD patients (47 ± 5 mmHg; p = 0.06), without pH dropping below 7.25 in either group. No significant differences were observed in mean arterial pressure, oxygen saturation, ICU stay (1.1 ± 0.4 vs. 1.0 ± 0.5 days; p = 0.48), or postoperative complication rates (p = 0.67). All patients were extubated in the operating room. Conclusions: Intubated spontaneous ventilation during VATS lobectomy is feasible and safe in both COPD and non-COPD patients when performed by experienced teams. COPD patients, despite impaired baseline lung function, were able to maintain spontaneous breathing for significantly longer periods without developing severe hypercapnia, acidosis, or hemodynamic instability. These findings suggest that SVI may represent a lung-protective alternative to fully controlled one-lung ventilation, particularly in hypercapnia-adapted COPD patients. Further multicenter studies are warranted to validate these results and define standardized thresholds for CO₂ tolerance, patient selection, and intraoperative monitoring during SVI.