The main purpose of this study was to assess the effect of intramuscular
midazolam on postoperative pain and to test our hypothesis that the patients
are more comfortable and suffering less pain after operation. Eighty male
patients with ASA class (I, II), aged 15-60 years whom were scheduled
for elective inguinal herniorraphy, were enrolled in this study in a double
blind fashion. Patients were randomly assigned to two groups of forty,
whom were randomly allocated for this study. Group A the test group received
0.1 mg kg -1 midazolam and group B the control group received
0.02 cc kg -1 saline, intramuscularly, just after inducing anesthesia
with fentanyl 3 μg kg -1 , thiopental 5 mg kg -1
as well as atracurium 0.5 mg kg -1 . Popular McGill questionnaires
were filled for pain severity assessment in four stages (1, 2, 3 and 8
h after operation) and the patients` vital signs were charted in five
stages (preoperative and 1, 2, 3 and 8 h after operation). The data so
obtained was analyzed statistically using Student t-test and Chi-square.
First hour after operation, pain score average in group A was 2.3 in comparison
with 6.6 in group B (p<0.05). After second and 3rd h of operation scores
of 3.6 and 3.8 in comparison with 6.4 and 6.2 were related to group A
and group B, respectively (p<0.05). Vital signs of the patients in
group A were more stable than group B during the first hour of recovery
period (p<0.05). Moreover, the need of intravenous opiate for relieving
pain during recovery period in group A was less than group B (p<0.05).
Intramuscular midazolam just after inducing anesthesia appears to cause
pain relief after herniorraphy, particularly during early recovery period.