The effect of transdermal nitroglycerine on intrathecal fentanyl with bupivacaine
for postoperative analgesia following gynaecological surgery.
Author(s): Garg A, Ahmed F, Khandelwal M, Chawla V, Verma AP.
Affiliation(s): Department of Anaesthesia and Critical Care, Sawai Man Singh Medical College and
Hospital, Jaipur, Rajasthan, India.
Publication date & source: 2010, Anaesth Intensive Care. , 38(2):285-90
Fentanyl is a short-acting synthetic opioid with spinal analgesic properties and
dose-dependent side-effects. The analgesic effect of opioids is mediated in part
through activation of inhibitory descending pain pathways involving nitric oxide
(as a central neurotransmitter) through the NO-cGMP system. This NO-cGMP pathway
plays an important role in spinal nociception. The aim of the study was to
evaluate the effect of transdermal nitroglycerine on the analgesic action of
intrathecal fentanyl in patients undergoing abdominal hysterectomy. Patients
(n=120) were randomised into one of four groups. All received 3 ml bupivacaine
0.5% plus 0.5 ml of an intrathecal test drug. Twenty minutes after lumbar
puncture, a transdermal patch of either nitroglycerine or placebo was applied.
Group B received spinal bupivacaine plus saline 0.5 ml and a placebo patch. Group
B-N received bupivacaine plus saline 0.5 ml and a nitroglycerine patch. Group F
received bupivacaine plus fentanyl 25 microg and a placebo patch. Group F-N
received bupivacaine plus fentanyl 25 microg and a nitroglycerine patch. The
duration of effective analgesia was longer in group FN (363.53 +/- 34.09 min)
compared from the other groups (P < 0.001). The times to two-segment regression
in group F-N and group F were 132.87 +/- 31.2 min and 126.40 +/- 26.81 min
respectively. The visual analog scale pain score at the time of the first rescue
analgesic was similar in all groups. We conclude that nitroglycerine does not
result in postoperative analgesia but enhances the analgesic effect of
intrathecal fentanyl.
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