Assessing Permissive Hypercapnia's Role in Cerebral Oxygenation and Recovery Quality in Elderly Cerebrovascular Patients During Thoracoscopic Procedures: A Research Framework

Abstract Background One-lung ventilation (OLV) can disrupt the respiratory cycle and lead to changes in oxygenation and local cerebral oxygen saturation (rSO²), which may predispose elderly patients to an imbalance in the ventilation/perfusion ratio and an increased risk of hypoxemia. Permissive hypercapnia has been gradually recommended as a lung-protective mechanical ventilation strategy in recent years, in theory could enhance cerebral blood perfusion and oxygen supply. However, the actual clinical benefits of this physiological response remain uncertain. Our study hypothesizes that permissive hypercapnia during OLV may have a beneficial effect on the cerebral oxygen supply and demand balance in elderly patients with a history of cerebrovascular disease undergoing thoracoscopic lung surgery. Methods This is a prospective, single-center, randomized controlled, double-blind clinical study. 270 participants(≥65years) scheduled for thoracoscopic surgery will be included in this study. Participants in the treatment group will use protective lung ventilation strategy during operation, maintain end-tidal partial pressure of carbon dioxide at 50-65mmHg; Participants in the placebo group will not use protective lung ventilation strategy during operation, maintain end-tidal partial pressure of carbon dioxide at 35-45mmHg. Discussion The primary hypothesis of the forthcoming study is that permissive hypercapnia during OLV might have a beneficial effect on the cerebral oxygen supply-demand balance in elderly patients with a history of cerebrovascular disease who are undergoing thoracoscopic lung surgery, in term of reducing the incidence of event rate of cerebral desaturation. Trial registration: This trial is registered at www.chictr.org.cn with a registration number of ChiCTR2200064832.