SUBARACHNOID BLOCK FOR TRANSURETHRAL RESECTION OF THE PROSTATE: A COMPARISON OF THE BLOCK CHARACTERISTICS BETWEEN 0.5% ISOBARIC BUPIVACAINE WITH FENTANYL AND 0.5% ISOBARIC BUPIVACAINE ALONE

  • Chimaobi Tim Nnaji National Postgrduate Medical College of Nigeria (NPMCN)

Abstract

Spinal anaesthesia is commonly administered for transurethral resection of prostate (TURP). It
is known to have a better outcome by enhancing early diagnosis and prompt treatment of
complications associated with TURP in this group of patients with increased prevalence of co
morbid and degenerative diseases like hypertension, diabetes mellitus and osteoarthritis. This
study was aimed at comparing the block characteristics of 0.5% isobaric bupivacaine with
fentanyl versus 0.5% isobaric bupivacaine alone during spinal anaesthesia for TURP
operations.

After obtaining the approval of the Ethics and Research Committee of the University of Port
Harcourt Teaching Hospital, Port Harcourt, 60 male patients aged 40 - 90 years with American
Society of Anesthesiologists physical status class I or II scheduled for elective TURP were
recruited into the prospective randomized double blind comparative study and allocated into 2
groups (A and B) using coded papers in an envelope. Following a spinal tap, intrathecal
injection in Group A (n = 30), 2.0 ml of 0.5% isobaric bupivacaine with fentanyl 25 µg (0.5
ml), and in Group B (n = 30), 2.0 ml of 0.5% isobaric bupivacaine with 0.9% saline solution
0.5 ml was administered. The sensory and motor block characteristics, quality of analgesia
during and after the surgery, haemodynamic data, and side effects were assessed and recorded.
The patients were observed until the level of sensory block was S1 dermatome and the Bromage
score was 0.

The differences in the mean age, weight, height, BMI distributions were not statistically
significant in Group A and Group B and the p values were p=0.78, p=0.43, p=0.42 and p=0.67.
The median maximal sensory block height was statistically significant in the two groups of
patients, p=0.02. Group A had a median maximum sensory block height of T4, while Group B 
had a median maximum sensory block height of T6. The number of patients requesting for
postoperative analgesia in Group A were 21 (80%), compared to Group B 28 (100%), and the
difference was statistically significant (p=0.04) in both groups.

The mean heart rate, mean systolic blood pressure, and mean diastolic blood pressure were
observed to be lower at 35 min in Group B (74.74±5.91 bpm, 121.23±6.65 mmHg, and
68.89±3.92 mmHg) compared to Group A (82.08±5.45 bpm, 131.39±4.19 mmHg and
83.08±3.51 mmHg). The changes were statistically significant, and the p values were p=0.03,
p=0.01, and p=0.00 respectively. However, the change in the mean mean arterial blood pressure
at 35 min in Group A (93.69±3.39 mmHg) and Group B (95.86±5.65 mmHg) was not
statistically significant (p=0.25).

Bradycardia and hypotension were more in Group B (17.85% and 14.28%) compared to Group
A (11.53% and 7.69%) patients and they were satisfactorily treated with intravenous atropine
0.6mg and saline solution respectively.

It was thus concluded that isobaric bupivacaine with fentanyl for spinal anaesthesia in TURP
patients provides adequate sensory block, and more stable haemodynamic profile, but with
prolongation of motor block compared with isobaric bupivacaine alone.

Published
2019-04-01
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