INTRATHECAL TRAMADOL VERSUS INTRATHECAL FENTANYL FOR VISCERAL PAIN CONTROL DURING BUPIVACAINE SUBARACHNOID BLOCK FOR APPENDICECTOMY.

Abstract

Background
Traditionally, appendicectomy is performed under general anaesthesia. Recently,
addition of opioids to heavy bupivacaine for sub-arachnoid block is taking the centre
stage of anaesthetic practice. The reliable measurement and treatment of pain intensity
have assumed an important dimension in the face of recent knowledge demonstrating the
detrimental effects of untreated pain. Any untreated pain intra-operatively during
appendicectomy may not only be distressing to the patients, it will also be distressing to
both the anaesthetist and the surgeon. Although it has been shown that addition of
fentanyl to hyperbaric bupivacaine could produce profound intra-operative and
immediate post-operative analgesia, its effectiveness with equipotent dose of intrathecal
tramadol has not been compared. In this study, the effectiveness and duration of intra
operative and post-operative analgesia produced by intrathecal fentanyl were compared
with that of intrathecal tramadol during bupivacaine spinal anaesthesia for
appendicectomy.

Study Design
This was a prospective, randomized, double blinded, controlled trial. Approval
was obtained from the University of Benin Teaching Hospital research and ethics
committee. One hundred and ninety five ASA 1 or 11 patients aged between 18 and 60
years scheduled for emergency appendicectomy at the University of Benin Teaching
Hospital were recruited into this study. Informed written consent was obtained.
The patients were randomized into three groups. Group A received intrathecal
fentanyl 25µg plus 3ml of 0.5% hyperbaric bupivacaine, Group B received 0.5ml normal
saline plus 3ml of 0.5% hyperbaric bupivacaine and Group C received intrathecal
tramadol 25mg plus 3ml of 0.5% hyperbaric bupivacaine. The preoperative vital signs
(pulse rate, systolic blood pressure, diastolic blood pressure, arterial oxygen saturation
and respiratory rate) were obtained and recorded.
Intravenous access was secured using a 16 or 18G cannula and normal saline 15
ml/kg was administered for preloading. Visual Analogue Scale (VAS) score was used to
assess both intraoperative and post-operative pain score. Visual Analogue Scale 0mm
indicated no pain, 100mm showed worst pain, 1mm to 39mm showed mild pain, 40mm
to 69mm showed moderate pain, 70 and above showed severe pain. Visual Analogue
Scale scores and frequency of subjective symptoms of chest tightness, dragging sensation,
vomiting, nausea and retching from manipulation of peritoneum or abdominal viscera
recorded for patients in the three groups formed the measurement of primary outcome of
this study.

The data obtained were analyzed using statistical package for social sciences
(SPSS) 16.0 software (Chicago Illinois, USA.) All parametric data were analyzed with one
way ANOVA. Non-prametric data were analyzed with chi square, Fisher’s exact, Kruskal
Wallis or Mann-Whitney test where applicable. Probability values <0.05 were considered
significant.
Results
Effective intraoperative sensory block was achieved in 100% of patients in group
A and C. Thirty three patients (53.2%) had effective sensory block in group B while 29
(46.8%) others in the group had ineffective sensory block. The incidence of ineffective
sensory block in Group B was significant statistically (P-value=0.0001) when compared
with Groups A and C. The difference between Groups A and C was not significant.
The pain free period was significantly longer in patients in Group A than Group B
and C. Mean time for Group A with regard to first analgesic request was 304+67.91min,
Group B was 146.59+36.62 and Group C was 238.39+61.8min. Intergroup comparison of
time to first analgesic request showed that the difference was statistically significant
between Groups B and C (P-value=0.001); between Groups B and A (P-value=0.001) and
between Groups A and C (P-value=0.001.)
Incidence of complications were comparable among the three groups. Fifteen
(24.2%), 13 (20.9%) and 15 (24.5%) patients in Groups A, B, and C respectively had
hypotension. The difference in incidence of hypotension was not significant (P
value=0.88.) No patient in Groups A and C had any complaint of pain, chest tightness,
vomiting, retching or nausea, but 5 patients (8.1%), 7 patients (11.1%), and 3 patients
(4.8%) in Group B reported pain, chest tightness and vomiting respectively. Three
patients (4.8%) had episodes of nausea and another three (4.8%) had retching.
Shivering occurred in 3 patients (4.8%) in Group B none in Group A or C which was
not significant (P-value=0.108.) Itching was significantly higher in Group A compared
with Groups B and C (P-value=0.035.) Four patients (6.5%) had pruritus in Group A, none
in the other groups. One (1.6%) had headache in Group A but none in the other groups,
the difference did not achieve any statistical significance (P-value=1.000.) The difference
in the incidence of post-operative vomiting was significant statistically (P-value=0.016)
when vomiting episode (16.1%) in Group C was compared with Groups B and A.
The degree of both surgeon’s and doctor’s satisfactions were comparable. They
were more satisfied with the anaesthesia administered to fentanyl and tramadol groups
than that administerd to placebo group (P-values=0.0001and 0.0001 respectively.
Conclusion
This study showed that intrathecal tramadol can safely replace intrathecal
fentanyl in the management of visceral pain and discomfort during subarachnoid block
for appendicectomy. Tramadol (25mg) is equipotent with intrathecal fentanyl (25µg) and
like intrathecal fentanyl, it has profound and prolonged post operative analgesia.

INTRATHECAL TRAMADOL VERSUS INTRATHECAL FENTANYL FOR VISCERAL PAIN CONTROL DURING BUPIVACAINE SUBARACHNOID BLOCK FOR APPENDICECTOMY.