• MATTHEW OMUYA ONIPE National Postgraduate Medical College of Nigeria



Background: Peri-operative nausea and vomiting have been found to increase morbidity and mortality in surgical patients. The use of different antiemetics that act at different receptor sites have proven to reduce these complications. As such, this study was designed to compare the effectiveness and safety of two antiemetics, iv metoclopramide 10mg (antidopaminergic) and iv granisetron 0.04mg/kg (antiserotonergic), in the prevention of nausea and vomiting in parturients who had elective caesarean section under subarachnoid block.

Materials and methods: One hundred and thirty five consenting parturients were randomized into three equal groups of 45 patients each. The patients in the first group (MT) were given iv metoclopramide 10mg, another group (G) had iv granisetron 0.04mg/kg, while iv normal saline 5mls was administered to all the patients in the placebo group (NS). All the study drugs were given slowly over 2 minutes before subarachnoid block was established. With patients in sitting position, the L3- L4 interspace was identified. Using size 26G spinal needle, 2.5mls of 0.5% heavy bupivacaine was injected intrathecally when free flow of cerebrospinal fluid (CSF) was observed. The incidence of nausea and emesis, the drugs side effects on the mother, the effects of the study drugs on parturients’ haemodynamics  as well as the drugs effects on the neonatal Apgar scores were assessed and documented intra-operatively and at specific intervals for 24 hours post-operatively.Influence of some risk factors for PONV were also assessed  during the study period

Results: There was no significant statistical difference in the patients’ demographic distribution and pre-operative basic vital signs among the groups. More patients 24.4% experienced  nausea intra-operatively in group NS, compared with 6.67% and 13.3% of the patients in groups G and MT respectively, p=0.046 for Groups NS vs MT; p=0.002 for Groups NS vs G; and p=0.346 for Groups G vs MT. In the early (0-2 hours) post- operative periods, 8.8%, 20% and 15.5% of patients in groups G, NS and MT had nausea respectively, p=0.04 for groups G vs NS, p=0.473 for groups MT vs NS, and p=0.251 for groups G vs MT. In the late postoperative (2-24 hours) period, 2.22% of patients in group G versus 13.3% and 15.5% of patients in groups MT and NS respectively had nausea, p=0.039 for groups G vs MT, p=0.018 for groups G vs NS and p=0.702 for groups MT vs NS. Furthermore, 15.5% of patients in group NS compared with  2.2% of patients in group G and 8.88% of patients in group MT  vomitted intra-operatively, p= 0.012 for groups G  vs NS, p=0.201 for groups MT  and NS, p=0.206 for groups G and MT. Throughout the study period, 6.66%, 17.7% and 33.3% of patients in groups G, MT and NS respectively vomited, p= 0.004. No statistical significant differences were found between the groups with respect to the side effects of study drugs, changes in haemodynamic parameters of the parturient and the neonatal Apgar scores.

Conclusion: Intravenous granisetron 0.04mg/kg was found to be more effective against intra-operative and post- operative nausea and vomiting compared to intravenous metoclopramide 10mg  and placebo. There were no statistical signifant differences between the groups with respect to the side effect profiles of the study drugs, APGAR scores of  the  neonates as well as the maternal haemodynamic variables.There were no recognized influences of  the assessed risk factors on the prevalences  of  intra-operative and post- operative nausea and vomiting.