[Effects of S(+)-ketamine combined with sufentanil for patient-controlled intravenous analgesia on the early recovery in elderly patients undergoing laparoscopic radical resection of rectal cancer].

To observe the efficacy and safety of S(+)-ketamine combined with sufentanil for patient-controlled intravenous analgesia (PCIA) in elderly patients undergoing laparoscopic radical resection of rectal cancer and explore its impact on patients' early recovery. One hundred and ten patients undergoing laparoscopic radical resection of rectal cancer in Affiliated Cancer Hospital of Zhengzhou University from December 2020 to March 2021, were divided into two groups (=55) using a random number table: group S received PCIA, with continuous infusion of S(+)-ketamine combined with sufentanil, while group C received PCIA, with continuous infusion of sufentanil. PCIA was initiated at the end of the surgery, and the formulations were as follows: group S, S(+)-ketamine (1.44 mg/kg), sufentanil (1.05 μg/kg), ketorolac tromethamine (2.0 mg/kg) and tropisetron (5 mg), in 100 ml of normal saline; group C: sufentanil (1.50 μg/kg), ketorolac tromethamine (2.0 mg/kg) and tropisetron (5 mg), in 100 ml of normal saline. Postoperative visual analogue scale (VAS) and Ramsay sedation scale were recorded at 6, 12, 24, 36, 48 h after the surgery. The incidence of remedial analgesia, the effective compressions number of PCI during 48 h after the operation. Time to first ambulation, time to first anal exhaust, time to resume oral feeding were recorded. The occurrence of adverse effects was compared between the two groups. A total of 10 patients were excluded during the study, including 4 cases of conversion to laparotomy, 3 cases of dropping out of the study, and 3 cases with operation time more than 4 hours. Finally, 50 cases in group S and 50 cases in group C completed the study. There were no significant differences in VAS scores and Ramsay sedation sores at all time points between two groups (all >0.05). Likewise, there were also no significant differences in the number of remedial analgesia and effective compressions of PCIA during 48 h after the operation between the two groups (both >0.05). The total dosage of sufentanil consumption in group S [(64±9) μg] was lower than that in group C [(95±12) μg] within 48 h of PCIA, with a statistically significant difference (<0.001). Time to first ambulation in group S was (1.1±0.2) d, which was shorter than that in group C [(1.6±0.5) d], and the difference was statistically significant (<0.001). Likewise, time to first anal exhaust in group S [(1.3±0.4) d] was shorter than that in group C [(1.8±0.6) d], with a statistically significant difference (<0.001). Additionally, time to resume oral feeding in group S was (2.5±0.6) d, which was shorter than that in group C [(3.1±0.7) d], and there was a statistically significant difference (<0.001). The incidence of nausea, vomiting and pruritus in group S were 4.0%, 2.0% and 0, which were lower than that in group C (16.0%, 10% and 8.0%, respectively), with statistically significant differences (all <0.05). No case with psychiatric symptoms was found in both groups. When used for postoperative intravenous analgesia in elderly patients undergoing laparoscopic radical resection of rectal cancer, S(+)-ketamine combined with sufentanil can provide satisfactory analgesic effects, decrease total consumption of sufentanil and the incidence of adverse effects, and thus facilitate patients' early recovery.