THE EFFICACY OF PROPHYLACTIC INTRAVENOUS TRAMADOL IN THE PREVENTION OF POSTANAESTHETIC SHIVERING FOLLOWING SUB-ARACHNOID BLOCK FOR LOWER LIMB TRAUMA/ORTHOPAEDIC SURGERIES

Abstract

BACKGROUND
One of the common complications of regional technique is shivering with an incidence of
around 40-60%1. Although shivering may have beneficial thermoregulatory effects, it places the
patient under increased physiological stress.
AIMS AND OBJECTIVE
The objective of the study was to evaluate the efficacy of prophylactic intravenous tramadol in
the prevention of post-anaesthetic shivering following subarachnoid block for lower limb
trauma/orthopaedic procedures.
PATIENTS AND METHODS
This was a prospective, double-blind, randomized controlled trial of prophylactic intravenous
tramadol for the prevention of post-spinal shivering. The study was conducted at the University
of Benin Teaching Hospital, Benin City. In this study, ninety-five ASA physical status 1 or 2
eligible patients aged between 16 and 65 years were randomly allocated to either the tramadol
group or the saline group. A randomization schedule with sealed envelopes was used.
Each patient received 10mg diazepam the night before and morning of surgery. Spinal
anaesthesia was induced in the sitting position with 15mg hyperbaric bupivacaine. The tramadol
group received 0.5mg/kg IV while the control group was given saline IV. Both drugs and
placebo were made up to 2ml with saline to ensure blinding.
The primary outcome variable- post-spinal shivering was observed from induction of SAB to
discharge from the recovery room using a study questionnaire. This was done using a three-point
ordinal scale with 0=no shivering, 1=mild fasciculation of the face or neck, 2=visible tremors
involving more than one group of muscles. The degree of sedation was also assessed on a three
point scale as 0=no sedation, 1=mild sedation (easily arousable) and 2=heavy sedation (not
easily arousable).
RESULTS
Patients in both the tramadol and saline groups were found to have the same incidence of
shivering (six each) which was not statistically significant (P=1.000)
However, severity of shivering was higher in the saline group. Furthermore, tramadol abolished
shivering promptly when employed as a rescue medication with no recurrence.
CONCLUSION
The use of tramadol resulted in low but tolerated side effects. Therefore, tramadol at a dose of
0.5mg/kg could be considered for prophylaxis for post-spinal shivering particularly in
orthopaedic patients under subarachnoid block.

THE EFFICACY OF PROPHYLACTIC INTRAVENOUS TRAMADOL IN THE PREVENTION OF POSTANAESTHETIC SHIVERING FOLLOWING SUB-ARACHNOID BLOCK FOR LOWER LIMB TRAUMA/ORTHOPAEDIC SURGERIES