Journal of Research in Pharmacy Practice

Abstract Objective: Shivering is an unpleasant sensation for patients who undergoing spinal 
anesthesia. This randomized double‑blind clinical trial study was designed to compare the 
effect of intrathecal fentanyl with intrathecal meperidine for prevention of shivering in lower 
limb orthopedic surgeries under spinal anesthesia.
Methods: Ninety patients were randomly recruited to receive either 3 ml of 0.5% hyperbaric 
bupivacaine plus 20 μg of fentanyl (Group F), or 3 ml of 0.5% hyperbaric bupivacaine plus 
0.2 mg/kg of meperidine (Group M), or 3 ml of 0.5% hyperbaric bupivacaine plus normal saline 
(Group S). The incidence and intensity of shivering were compared in three groups. Data 
were analyzed by analysis of variances, Mann–Whitney U‑test followed by Chi‑square test.
Findings: There were not statistically differences in complications and side‑effects between 
three groups. Total incidence of shivering was similar between Groups F and M (16.7% 
vs. 13.3% respectively, P = 0.72) whereas it was significantly different to Group S (43.3%) 
(P = 0.025 for Group F vs. S, and P = 0.011 for Group M vs. S). Also the intensity of 
shivering between Groups F and M was similar (P = 0.66), while it was significantly less in 
these groups compared to Group S (P = 0.013 and P = 0.004, respectively).
Conclusion: Addition of fentanyl 20 µg or meperidine 0.2 mg/kg to 0.5% bupivacaine 
intrathecally significantly decreased the incidence of shivering in lower limb orthopedic 
surgeries. There was no significant difference between two drugs with this respect.

Abstract Objective: Intraoperative hypothermia is a common problem with anesthesia. Spinal 
anesthesia, the same as general anesthesia, affects the process of temperature regulation. The 
aim of this study was to compare the prophylactic effect of intravenous(IV) ondansetron with 
intrathecal (IT) meperidine on prevention of shivering during spinal anesthesia in patients 
underwent orthopedic surgery of the lower limb.
Methods: In this study, 120 patients with American Society of Anesthesiologists physical 
status I to II, between the ages 16 and 65 were randomized into three groups. Group O 
and Group M were given IV ondansetron 8 mg and IT meperidine 0.2 mg/kg, before spinal 
anesthesia, respectively. Group C received IV saline 0.9%. The core and ambient temperatures, 
the incidence and intensity of shivering, blood pressure, heart rate, and maximum level of 
sensory block were recorded.
Findings: Shivering was observed in 15%, 2.5%, and 37.5% of patients in Groups O, M, and 
C, respectively. There was a significant difference between Group O and M compared to 
Group C (P = 0.023 for Group O vs. Group C, P < 0.001 for Group M vs. Group C, P = 0.049 
for Group M vs. Group O). Shivering incidence and intensity in Group M was significantly 
lower than Group O (P = 0.049 and P = 0.047, respectively). Twenty‑two patients required 
additional IV meperidine among which 15 patients were from Group C (37.5%), six patients 
from Group O (15%) and one patient from Group M (2.5%).
Conclusion: We concluded that IT meperidine and IV ondansetron comparably can 
decrease intensity and incidence of shivering compared to control group as well as decreasing 
the requirement to additional doses of meperidine for shivering the control without any 
hemodynamic side effect.