ASSESSMENT OF OPTIMAL DOSE OF METOCLOPRAMIDE FOR PREVENTING PAIN ON INJECTION OF PROPOFOL IN THE UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN

Abstract

BACKGROUND: Injection pain is a well-known adverse effect of propofol which
distresses patients. None of the commonly used methods completely attenuate
the pain. Metoclopramide has been shown to be effective for reducing the
incidence and severity of this pain, probably because of its local anaesthetic
effect. However the optimal dose of metoclopramide required for this purpose
has not been properly defined as different researchers have used different
doses ranging from 2.5mg to 20mg. This study is performed to compare four
different doses of intravenous metoclopramide premixed with propofol for
mitigating the incidence and severity of propofol injection pain.
METHODS: Following the approval of the institution ethical review committee,
a prospective randomized double-blind study was conducted on 125 ASA
physical status I and II adult patients scheduled for elective surgery. The patients
were randomized into 5 groups. Group A (Control group) received 40mg of
lidocaine premixed with 200mg of propofol. Group B, C, D and E received 5mg,
10mg, 15mg and 20mg of metoclopramide premixed with 200mg of propofol
respectively. The pain perception was assessed after administering 50mg of
propofol over 15seconds through the largest vein on the dorsum of the hand
xi

and responses were scored on a 4-point verbal rating scale (graded as none,
mild, moderate or severe).
RESULTS: Demographic variables were similar between the groups. The
incidences of propofol injection pain were significantly higher in group B (60%)
and group C (52%) compared with group A (control group, 24%) (p< 0.05). There
was no statistically significant difference in the incidence of injection pain in
group D (44%) and group E (36%) compared with the control group (24%) (p>
0.05). The severity of injection pain also showed statistically significant benefit
for the control group A over group B and group C (p< 0.05), but not over group
D and E (p > 0.05) .The median pain score were higher in group B (1, range 0-3)
and C (1, range 0-3) compared with other groups (0, range 0-2).
CONCLUSION: Intravenous administration of more than 10mg of
metoclopramide premixed with propofol effectively decreases the incidence
and severity of propofol injection pain. The analgesic efficacy of 15mg and 20mg
of metoclopramide premixed with propofol were similar to that of 40mg of
lidocaine premixed with propofol.