EXAMINING THE IMPACT OF PERMISSIBILITY HYPERCAPNIA ON POSTOPERATIVE DELIRIUM AMONG ELDERLY PATIENTS UNDERGOING THORACOSCOPIC-LAPAROSCOPIC ESOPHAGECTOMY: A SINGLE-CENTER INVESTIGATIVE STUDY

Abstract

ABSTRACT Objective: This study explores how permissive hypercapnia, a key aspect of lung-protective ventilation, impacts postoperative delirium in elderly patients following thoracic surgery. Methods: A single-center trial at The Second Hospital of Anhui Medical University involved 136 elderly patients undergoing thoracoscopic esophageal cancer resection. Randomly assigned to maintain PaCO2 35–45 mm Hg (group N) or 46–55 mm Hg (group H). Primary outcome: postoperative delirium (POD) incidence 1–3 days post-surgery. Secondary endpoints included monitoring rSO2, cardiovascular parameters (MAP, HR), pH, OI, and respiratory parameters (VT, RR, Cdyn, PIP) at specific time points. Perioperative tests assessed CRP/ALB ratio (CAR) and systemic inflammatory index (SII). VAS scores were documented for 3 postoperative days. Results: Postoperatively, group H showed significantly lower POD incidence than group N (7.4% vs. 19.1%, P = 0.043). Group H exhibited higher PaCO2 and rSO2 during surgery (P < 0.05). Patients in group H maintained better cardiovascular stability with higher blood pressure and lower heart rate on T2–4 (P < 0.05). Respiratory parameters were more stable in group H with lower TV, RR, and PIP, and higher Cdyn during OLV (P < 0.05). Group H had lower pH and higher OI at T2–4 (P < 0.05). CRP and CAR levels rose less in group H on the first day and 1 week later (P < 0.05). Conclusions: Maintaining PaCO2 at 46–55 mm Hg reduces POD incidence, possibly by enhancing rSO2 levels and stabilizing intraoperative respiration/circulation.