A Randomised Comparative Study on the Effect of Pre-Emptive Intravenous Acetaminophen on Intraoperative Opioid Requirement in Superficial Oncological Surgeries

Abstract

Background- Balanced anaesthesia for any surgery is usually achieved with the usage of Opioids peri and post-operatively for maintenance of good analgesia. Opioid-free anaesthesia (OFA) is a ground-breaking approach in the field of anaesthesia that aims to minimize or completely eliminate the use of Opioids during surgical procedures and post-operative pain management. There are limited studies related to intravenous Acetaminophen as a part of OFA. In this study, a comparison was made on the effect of pre-emptive analgesia with intravenous Acetaminophen given before the surgical stimulus versus pre-medication of intravenous Fentanyl on peri-operative and total intra-operative Fentanyl consumption in superficial oncological surgeries.

Materials and Methods- This was a randomised double-blinded study. 60 ASA physical status class I, II or III patients posted for elective thyroid and breast surgeries under general anaesthesia were recruited and randomly divided into 2 groups of 30 each with group A receiving intravenous Paracetamol 15mg/kg (1 gram/100 ml) 15 minutes before shifting to operation theatre and group B receiving 100 ml of 0.9 % normal saline with Fentanyl 1 mcg/kg. In the operating room, baseline heart rate (HR), mean arterial pressure (MAP) and surgical pleth index (SPI) were recorded. All the patients were then given standard general anaesthesia. HR, MAP and SPI was monitored until the end of surgery. Patients in both the groups received 0.5 mcg/kg bolus doses of Fentanyl if SPI value was above 50 and HR or MAP were more than 20% of baseline. A time interval of 20 minutes was maintained between the boluses and the number of doses were noted. Total amount of Fentanyl administered intra and peri-operatively, emergence time and extubation time were the parameters observed.

Results- Intra-operative requirement of Fentanyl was higher in group A, total consumption of Fentanyl was significantly higher in group B, the emergence time and extubation time were lesser in group A.

Conclusion- Intravenous Acetaminophen given to patients as pre-emptive analgesia did require intra-operative dose of intravenous Fentanyl but the total consumption of Fentanyl was significantly low, the patients had lesser emergence and extubation time when compared to intravenous Fentanyl as pre-medication.