Effects of preincisional analgesia with surgical site infiltration of ketamine or levobupivacaine in patients undergoing abdominal hysterectomy under general anesthesia; A randomized double blind study.

CONTEXT: Postoperative pain management remains a cornerstone in patient's management to ensure a better quality of life. Preemptive analgesia is reported to inhibit the persistence of postoperative pain.

AIMS: The aim of this study is to assess the analgesic effectiveness of preincisional infiltration of ketamine following elective abdominal hysterectomy as compared to levobupivacaine.

SETTINGS AND DESIGN: This was a prospective, randomized, double-blind study.

SUBJECTS AND METHODS: This study included 48 patients undergoing abdominal hysterectomy under general anesthesia. They were randomized into two equal groups; Group K received subcutaneous infiltration of 20 ml containing ketamine 2 mg/kg and Group L received subcutaneous infiltration of 20 ml of levobupivacaine 0.25% along the Pfannenstiel incision 5 min before incision. Postoperative pain was assessed using visual analog scale (VAS) at rest and on coughing with evaluation of additional opioid analgesic requirements.

STATISTICAL ANALYSIS USED: Numerical variables were presented as mean and standard deviation or median and range as appropriate. The intergroup differences were compared using the independent-sample Student's t -test or Mann-Whitney test for numerical variables.

RESULTS: VAS score decreased significantly in Group L from 10 to 24 h and in Group K from 8 to 24 h as compared to the immediate postoperative reading. VAS score in ketamine group was significantly lower than that in the levobupivacaine group 8, 10, and 24 h postoperatively. Ketamine group showed delayed request of additional opioid analgesia ( P < 0.001) with significantly less opioid consumption ( P < 0.001) as compared to levobupivacaine. The total dose of meperidine consumed during the 24 postoperative h was significantly smaller in ketamine group ( P < 0.001).

CONCLUSION: Surgical site infiltration of ketamine is a promising preemptive analgesic method in the lower abdominal surgery with minimal sedation and adverse effects.