2021, Vol. 3, Issue 2, Part I

Aim: Levobupivacaine alone versus levobupivacaine with ketamine in subcutaneous infiltration for postoperative analgesia in lower segment cesarean section.

Material and Methods: A randomized double blind controlled study conducted in the Department of Anaesthesia, RVM institute of medical sciences & research centre, India for the period of 1 year. A total of 60 adult parturients of Physical status II or III as per the American society of anaesthesiologists (ASA) without any medical or obstetrical problems, and scheduled for cesarean section under spinal anesthesia were included in this study. Parturients were randomized to one of the two groups (30 each) according to computer-generated random numbers kept in separate, sealed, and numbered envelopes. Group A parturients received subcutaneous surgical wound infiltration with a solution of 0.5% levobupivacaine at 2 mg/kg body weight (rounded to nearest multiple of 10) to a maximum of 150 mg (maximum safe dose) diluted with normal saline to a total of 32 ml. Group B parturients received subcutaneous surgical wound infiltration with a solution of 0.5% levobupivacaine 2 mg/kg body weight (rounded to nearest multiple of 10) to a maximum of 150 mg plus ketamine 1 mg/kg body weight diluted with normal saline to a total volume of 32 ml. The primary outcome, postoperative pain relief was measured using the VAS scale and the total analgesic consumption during the 24 hours postoperative period. The secondary outcome, that is, patient satisfaction score (PSS) was assessed postoperatively at 24 hours and was subjectively graded as: Excellent (4), Good (3), Moderate (2), Poor (1).

Results: The zero hour (baseline) mean heart rates were comparable between groups A and B (P=0.891). The mean heart rate of group A was higher than that of group B which was statistically insignificant at majority of the time points except at 4th and 6th hour post-operative. The intra group comparison of mean heart rate showed a gradual decrease in values across time in both the groups but was more prominent in group B. Correspondingly, parturients in group A had higher mean VAS scores than those in group B at all-time intervals and statistically significant difference were observed at 1, 4, 6, and 12 hours. The mean time to FRA of group A was at 3.43 ± 2.35 hours (188 mins) while that of group B was at 5.02±2.42 hours (279 mins). This difference was statistically significant (P=0.041). Thus, parturients in Group B complained of pain 1.8 hours later than the parturients in group A. In group B with ketamine as an adjuvant to levobupivacaine, only 45.83% of the parturients demanded rescue analgesia, whereas nearly 95.83% of the parturients needed rescue analgesia in group A which received levobupivacaine alone. Parturients in group A consumed a mean total opioid dose of 96.22±39.11 mg in 24 hours compared to 60.72±20.77 mg in group B. Thus, statistically significant higher opioid consumption was observed in group A than in group B (P=0.002). There were 6.67% parturient in Group A compared to 21.67% in Group B in whom the PSS was of excellent quality and 23.33% in Group A and 40% in Group B graded the PSS with good quality. Thus, the difference in patient satisfaction score was statistically significant between the two groups (P=0.009).

Conclusion: We concluded that the ketamine is an effective adjunct modality to levobupivacaine for local wound infiltration in terms of superior pain relief, lesser need for rescue opioid analgesia, and no major side effects.