ANALGESIC EFFICACY OF ULTRASOUND GUIDED UNILATERAL TRANSVERSUS ABDOMINIS PLANE BLOCK FOR MANAGEMENT OF POSTAPPENDICECTOMY PAIN.

Abstract

This study compared the quality of postoperative analgesia achieved with ultrasound
guided unilateral TAP block using bupivacaine and saline in patients scheduled for
appendicectomy. Approval was sought and received from the Research and Ethics Committee
of the Hospital and patients consent was obtained. Seventy two patients aged between 18 and
50 years scheduled for appendicectomy were recruited and randomized into two groups (36
in each group). Baseline haemodynamic parameters were obtained and patients’ circulation
was preloaded with 15ml/kg normal saline before establishing subarachnoid block under
aseptic condition using a combination of 3ml (15mg) of 0.5% hyperbaric bupivacaine and
10mg of preservative free pethidine (0.2ml). Vital signs were monitored continuously and
recorded.
At the end of appendicectomy, an ultrasound guided unilateral TAP block was
performed using 20ml of 0.25% plain bupivacaine and 20ml of sterile saline for group I and
II respectively.
Pain was assessed using VAS scores while time to first analgesic request was
recorded. Haemodynamics parameters were monitored after establishing TAP block,
postoperative pain was assessed using VAS score until first analgesic request.
The proportion of patients with VAS scores of ≤ 3, at the 4th hour postoperatively was the
primary outcome. Continuous data were compared using t-test while categorical data were
compared using Fisher’s exact test. P value< 0.05 was considered significant.
There was significant difference in the proportion of patients who required analgesic;
none in group 1 had experienced pain at the second hour postoperatively while 12 patients
(33.3%) in group 2 had pain (P < 0.0002). At the fourth hour, no patients in group 1 requested
for analgesic as against 36(100%) in group 2 (p < 0.0001). This was statistically significant.
At the sixth hour, 15 (41.6%) patients requested for analgesic in group I (P < 0.0001)
while all group 2 had earlier requested for analgesia prior to the sixth hour. The time to first
analgesia request was 477.14±216.33 minutes in group I and 160.17 ±37.42 minutes in group
II (P < 0.0001). The mean paracetamol consumption in 24 hours was significantly higher in
group II (2350 ±168.18mg) compared to 1250 ±363.147mg in group I (P < 0.0001), while the
mean tramadol consumption in 24 hours postoperatively was significantly higher too in group
II (363.89±48.71mg) compared to 216.67±65.47mg in group I (P < 0.0001). Changes in the
postoperative haemodynamic parameters were comparably similar in both groups. The
incidence of complications was also similar in both groups (P < 1.0000).
Ultrasound guided unilateral TAP blocks with bupivacaine resulted in decreased VAS
scores, prolonged time to first analgesic request and decreased analgesics consumption
compared to saline. It is suggested that TAP block should be added to the postoperative
analgesic regime following appendicectomy in a multimodal analgesia strategy.