Effects of multiple low-dose intranasal dexmedetomidine administration on postoperative pulmonary complications in elderly patients undergoing thoracoscopic radical resection of lung cancer: a single-center randomized controlled trial

Background Postoperative pulmonary complications (PPCs) ranging from 30% to 50% have been recognized as a major threat to postoperative recovery. Current conventional interventions cannot effectively reduce the occurrence of PPCs. Objective In this study, we aimed to investigate the effects of multiple low-dose intranasal dexmedetomidine administration on PPCs in elderly patients. Methods In this double-blind, randomized, controlled trial, elderly patients were randomly assigned at a 1:1 ratio to receive multiple low-dose intranasal dexmedetomidine administration (MD group) or normal saline nasal spray (NS group). The primary outcome was the incidence of PPCs within 7 days after surgery. Key secondary outcomes included the severity grading and classification of PPCs. Other secondary outcomes included serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels, Richards-Campbell sleep questionnaire (RCSQ) scores at predefined time points, and adverse reactions. Results A total of 190 patients were screened, and 186 completed the study. The incidence of PPCs was significantly lower in the MD group than in the NS group (9.68% vs. 22.58%, P = 0.017), with a risk ratio (RR) of 2.333 [95% confidence interval (CI): 1.173–6.317], absolute risk reduction (ARR) of 12.90%, and number needed to treat (NNT) of 7.75. Sensitivity analyses using the per-protocol population (PP) dataset yielded consistent results, confirming the stability and reliability of the primary outcome. The distribution of severity grading of PPCs also differed significantly between the groups ( P = 0.036). After Bonferroni correction, the between-group difference in PPCs severity grading was not statistically significant (corrected P = 0.072). The distribution of pneumonia also differed significantly between the groups ( P = 0.029). There were significant group effects, time effects, and interaction effects for IL-6, TNF-α, and RCSQ in the two groups after surgery (all P < 0.05). No significant between-group differences were observed in drug-related adverse events. Conclusion Multiple low-dose intranasal dexmedetomidine administration significantly reduces the incidence of PPCs in elderly patients undergoing radical thoracoscopic lung-cancer resection with a favorable safety profile. Clinical Trial Registration https://www.chictr.org.cn/showproj.html?proj=243165 ; identifier ChiCTR2400090593.