Discussion
postoperative pain, GI disturbance, nausea and vomiting, hallucinations, dizziness, pain
CAVITY
Our preliminary experiment found that the use of S-ketamine shortened patients’ first occurrence of flatus time after surgery by about 0.5 days. This interesting phenomenon has not been previously reported and thus we set the time of first postoperative flatus as the primary outcome in our current study. The randomized controlled trial during open gynecological surgery and the use of a PCIA pump after surgery showed that S-ketamine enhanced recovery of postoperative GI function. The first flatus time in the S-ketamine group was nearly 6 h earlier than in the control group.The side effects of opioids on the GI tract via the central nervous system and the enteric nervous system have been widely investigated [There are also some studies showed that ketamine on the gastro-intestinal motility was mixed and controversial. One clinical trial of patients undergoing elective surgery of the lower extremities, the use of ketamine-midazolam (250 mg/25 mg; dosage 0.1 ml/kg/h) anesthesia showed no inhibition of intestinal motility compared with fentanyl/midazolam (1 mg/25 mg; dosage 0.1 ml/kg/h) anesthesia [Previous studies mentioned that ketamine with large dose (> 2 mg/kg, iv) and rapid iv administration (> 40 mg/min) can cause hallucinations, unpleasant reactions and nightmares in adults [Opioids often cause nausea and vomiting, dizziness, and GI disturbance, which are symptoms of chemoreceptor stimulation [Previous reports have shown that females are more sensitive to postoperative pain [In our study, all patients received preoperative education and were encouraged to control pain by using PCIA pump. A total of 4 patients received the additional requirement of analgesic drugs, 2 patients in each group. Although, the assumption of sufentanil in the first postoperative 24 h were similar in two groups, our study showed that additional use of S-ketamine reduced the VAS pain score 24 h postoperatively in gynecological abdominal surgery patients. Because of the addition of S-ketamine, the effect of reducing pain becomes reasonable. Previous studies showed that S-ketamine enhanced analgesic efficacy [Our findings indicating no significant difference in sufentanil use in the first postoperative 24 h between the two groups are also consistent with previous studies [Contrary to that, several studies have indicated that S-ketamine reduces postoperative opioid consumption [In addition, although we selected open abdomen gynecological surgeries with no intestinal lesions for this study, the gentle touching of the intestine and returning the viscera into the abdominal cavity may have affected the normal physiological morphology of the intestine. Further studies are warranted to confirm the efficacy of S-ketamine to enhance intestinal recovery in patients undergoing intestinal resection surgery.