Abstract

Background: This study investigated the effect of low-dose ketamine on neonatal and maternal well-being with a view to assessing neonatal and maternal safety profile of low-dose ketamine-induced analgesia as an adjuvant to subarachnoid block in caesarean section.

Methods: After obtaining ethical approval, spinal anaesthesia was performed in 120 healthy pregnant women scheduled for caesarean section delivery using 10 mg hyperbaric bupivacaine. Parturient mothers were randomly selected into four groups (n = 30) consisting of K1, K2, NK1 and NK2. K1 received 0.3 mg/kg intravenous ketamine diluted with sterile water to 5 mL, as a bolus dose 2 minutes before surgical incision, K2 received 0.3 mg/kg ketamine also made up to 5 mL with sterile water, as a bolus dose 2 minutes after delivery of baby, while groups NK1 and NK2 received equivalent volumes of normal saline (5 mL) 2 minutes before surgical incision and 2 minutes after baby extraction respectively. Incidence of maternal side effects and neonatal well-being were assessed after surgery. Results were analysed using ANOVA, and chi-square statistics. Student Newman-Keuls tests was used for post hoc analysis as appropriate. P value of < 0.05 was considered statistically significant.

Results: The demographic characteristics and The American Society of Anaesthesiologists (ASA) Score of Physical Health Status of the participants were comparable across all groups. The indices of maternal well-being including pulse rate, incidence of chest pain and shivering were not significantly different in low-dose ketamine group relative to the nonketamine group. Similarly, the incidence of hypertension was not significantly affected by low-dose ketamine, however incidence of hypotension was significantly elevated in the non-ketamine group relative to the ketamine group (p = 0.047). There was no incidence of hallucination, nightmares and confusion among the mothers across all groups. The duration of surgery was significantly increased in K1 relative to NK1, but was not when K2 was compared to NK2. The neonatal Apgar score at 1 minute after birth was not significantly different across all groups.

Conclusion: This study indicated that the administration of intravenous low dose (0.3 mg/kg) ketamine during caesarean did not result in statistically significant maternal and neonatal adverse effects, suggestive that low-dose ketamine has a good safety profile for use perioperatively as an analgesic adjuvant to subarachnoid block in caesarean section.