COMPARISON OF HEIGHT – WEIGHT ADJUSTED DOSE OF HEAVY BUPIVACAINE TO A STANDARD DOSE FOR SPINAL ANAESTHESIA FOR ELECTIVE CAESAREAN SECTION

  • M. A. Ozoagu National Postgrduate Medical College of Nigeria (NPMCN)

Abstract

Hypotension after spinal anaesthesia for caesarean section remains a
common and potentially serious complication, despite the use of left uterine
displacement, leg elevation and wrapping, fluid loading with crystalloids or
colloids, prophylactic and therapeutic use of pharmacological drugs.
Hypotension is defined as a decrease in baseline systolic blood pressure of
more than 30% or systolic blood pressure of less than 100 mmHg. The clinical
importance of this side effect was shown in a study by Bernd 2002, who proved
that hypotensive episodes detected by an automated record-keeping system
clearly correlate with mortality. Other complications such as shivering, nausea,
and peritoneal discomfort also occur.
In this prospective, randomised, double-blind study, the effects of two
dosage regimens were compared. Pregnant patients at term were randomly
assigned to two groups to be given 0.5% hyperbaric bupivacaine 2.4 ml or
hyperbaric bupivacaine 0.5% adjusted according to the patient's height and
weight. Adequate anaesthesia was provided in all patients in fixed dose group
while six patients in the adjusted group required supplemental analgesia. The time
to loss of cotton wool sensation to maximum block height was faster with the
fixed dose regimen (p = 0.001) Hypotension occurred in 62.9% vs. 28.6% of patients in the fixed dose and adjusted dose groups respectively (p = 0.001). In
the fixed dose group, more patients required ephedrine to treat hypotension
(62.9% vs. 28.6%, p = 0.001) and a larger median dose was administered (6 mg
vs. 3 mg, p = 0.001). The decrease in mean (SD) arterial pressure was less in the
adjusted dose group (18-71 mmHg vs. 23-71 mmHg, p = 0.001) compared to the
fixed dose group.
This study shows that satisfactory anaesthesia for elective caesarean section can
be provided with adjusted doses of 0.5% of hyperbaric bupivacaine, and
complications minimized. 

Published
2019-04-01
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Section
Articles