Abstract: Objective To investigate the analgesic effect and safety of patient-controlled intravenous analgesia (PCIA) of 2 μg/kg sufentanil in the patients with different body mass index (BMI) undergoing thoracoscopic radical resection of lung cancer during the perioperative period. Methods A total of 168 patients who underwent thoracoscopic radical resection of lung cancer were enrolled in this study. The patients with BMI<18.5 were divided into group A (n=45), the patients with BMI of 18.5～<24.0 divided into group B (n=71), and those with BMI>24.0 divided into group C (n=52). The analgesic effect, number of analgesic pump compressions and adverse analgesic reactions in the three groups were recorded and compared. Results At the time of 24 and 48 hours after surgery, the score of resting pain in group A was significantly higher than that during postoperative wakefulness, and significantly higher than that in group B and group C at the same time point (P<0.05). Forty-eight hours after surgery, the cough pain score in group A was higher than that in group B and group C (P<0.05). There were statistically significant differences in the number of analgesic pump compressions among the three groups 24 and 48 hours after surgery (P<0.05). There were no statistically significant differences in the incidence rate of adverse reactions such as nausea, vomiting, skin itching, and excessive sedation among the three groups (P>0.05). Conclusions BMI may affect the individualized analgesic effect of sufentanil in the elderly patients undergoing thoracoscopic radical resection of lung cancer. For the elderly patients with BMI<18.5, the dosage of sufentanil by PCIA calculated according to body mass can be appropriately increased.

Key words: body mass index, thoracoscopic surgery, sufentanil, postoperative analgesia, lung cancer