THE EFFECT OF PRE-INCISION FIELD BLOCK VERSUS POST-INCISION INGUINAL WOUND INFILTRATION ON POST OPERATIVE PAIN AFTER HERNIOTOMY

Abstract

Background
Adequate analgesia after inguinal herniotomy in children is essential and may be obtained
through various techniques. These methods include the administration of non-steroidal
anti-inflammatory drugs, caudal block and opioids. The use of opioid analgesics has been
associated with untoward gastrointestinal side effects which may delay recovery from ambulatory
surgery. This has stimulated a search for alternative methods of pain relief. The
Ilioinguinal/iliohypogastric nerve block procedure is a widely used technique for post operative
pain relief after inguinal herniotomy which has been shown to significantly decrease opioid
analgesic requirements and side effects.
The study aimed to compare the effect of preemptive anaesthesia pre-incisional field block
with 0.25% bupivacaine and post-incisional wound infiltration with 0.25% bupivacaine for
postoperative pain control during inguinal herniotomy.
Patients & Methods
After institution of general anaesthesia, sixty-two healthy ASA I and II patients aged 1-7
years were randomly assigned by blind balloting into two groups of 31, to receive pre-incision
field block (group I) or post-incision wound infiltration at the time of wound closure (group II).
The pain score was assessed in the recovery room using mCHEOPS score and VAS/FLACC score
at home by the parents for 24 hours.
Results
The mean age of the two groups were similar, group I (3.50 ± 1.71) years versus group II
(3.06 ± 1.94) years, p = 0.687. The mean weight, BMI, duration of surgery, time of first analgesic
requirement, total dose of paracetamol and the time of first micturition were also similar, p >0.05.
The ‘’mean pain scores’’ during the 2 hour stay in the recovery room were similar in both groups,
group I (0) versus group II (0), p>0.05. However, the mean pain scores were significantly lower at
6 hours at home in group I (1.22 ±0.57) than in group II (1.58 ±0.90), p <0.001, but
significantly higher at 24 hours at home in group I (3.29 ±0.46) than in group II (2.32 ± 0.24), p =
0.040. The ‘mean pain scores’ at other time intervals at home were similar: at 12hours; group I
(1.83±0.94cm) versus group II (1.78±0.94cm) p=0.871, and at 18 hours; group I (1.62 ±0.11)
versus group II (1.64 ±0.15cm), p = 0.588. There was no difference in mean paracetamol
requirement in both groups; group I (316.07 ± 99.15) versus group II (318.52 ±
115.28) mg, p = 0.479. Similarly, there was no significant difference in the number of patients
who required paracetamol for pain relief at home groups I (28) versus group II (24), p=
0.167.
Conclusion- This study has demonstrated that both preincisional ilioinguinal/iliohypogastric field
block and post incisional wound infiltration provided adequate postoperative analgesia for 24
hours as the mean pain scores were less than 4 during the study period