EFFICACY OF INTRAVENOUS PARACETAMOL INFUSION FOR PROLONGATION OF ANALGESIA UNDER SPINAL ANAESTHESIA FOR MYOMECTOMY

Abstract

Acute pain is an unpleasant perioperative experience in patients undergoing
surgeries such as myomectomy under spinal anaesthesia. Combinations of various drugs
and techniques have been employed in prolonging the duration of analgesia with different
success rates. Paracetamol which is easily accessible with relatively mild side effects was
used for this study.
The aim of this study was to determine the effectiveness of intravenous
paracetamol infusion in prolonging analgesia under spinal anaesthesia when compared
with placebo.
The study was a prospective randomized double blind study with 126 patients of
ASA 1 and 11 aged 18 to 45 years undergoing elective myomectomy under spinal
anaesthesia. Patients were allocated to receive paracetamol (group P) or normal saline
(group N). Data collection with the aid of a proforma included age, height weight, ASA
physical status. Also documented was time to first analgesic demand, pain assessment
using the numerical rating scale and patient satisfaction with pain management.
The results were analyzed using Statistical Package for Social Sciences (SPSS)
version 17 and represented in tables and figures. The results showed that 37.1% of the
patients in group P needed additional analgesia between 90 and 150 minutes after spinal
anaesthesia when compared to 87.1% of patients in group N within the same period,
P<0.001, (Table III). Also 62.9% of patients in group P had pain score <4, six hours after
intravenous paracetamol infusion while none in group N had pain score <4 within the
same period after intravenous normal saline (Table 111). Mean time to first analgesic
demand was 4.75±1.59 hours and 2.23±0.15 hours for group P and group N respectively,
P<0.001), (Table IV), while the mean dose of additional analgesic was 11.81±2.50mcg
and 255.49±140.80mcg for group P and group N, respectively (Table V). The incident of
satisfaction with pain control was 0% poor, 24.2% good and 75.8% excellent in group P
when compared to group N with 62.9% poor, 37.1% good and 0% excellent (Table
V111).
In conclusion intravenous paracetamol infusion provided a better analgesia under
spinal anaesthesia as evidenced by increase in the time to first analgesic demand,
decreased Numerical Rating Scale (NRS) scores and it has a good margin of safety and
good patient satisfaction.