^1,2Associate Professor, ³Sr. Resident, Department of Anaesthesiology, Osmania Medical College and Hospital, Hyderabad, Telangana, India.

Email: sarithachandapet@gmail.com

Comparison of the MODIFIED RAMSAYSEDATION SCORE 30 mins, 60 mins and 90 mins between the two groups shows that MODIFIED RAMSAYSEDATION SCORE 30 mins is higher in GROUP B group and is statistically significant with a p-value.

Figure 4: Comparison of VAS among the two groups studied

Comparison of the VISUAL ANALOGUE SCALE 6Hrs, 12 hrs, 18 hrs and 24 hrs between the two groups shows that VISUALAN ALOGUE SCALE 6Hrs is higher in Group-T and is statistically significant with a p value of <0.001

0

Table 4: Distribution of side effects in study groups

Nausea and vomiting are significantly higher in group T, with p-value < 0.001. Hypotension and bradycardia are more in group B which is statistically in significant.

DISCUSSION

Hyperbaric bupivacaine is the most commonly used intrathecal local aesthetic. Various adjuvants have been added to bupivacaine to shorten the onset of block and prolong the duration of block. Opioid administration has been demonstrated to provide postoperative analgesia after a variety of surgical procedures, at the cost of increased risk of respiratory depression. Buprenorphine is a mixed agonist-antagonist type of opioid with along duration of action. The high lipid solubility, high affinity for opioid receptors and prolonged duration of action makes buprenorphine a suitable choice for intrathecal and peripheral nerve site administration. Tramadol is a centrally acting analgesic that has moderate affinity for mu receptors1 and weak kappa and delta opioid receptor affinity. It has less respiratory depressant effect because it has 6000 fold less affinity for mu receptors compared to morphine.³ It also inhibits serotonin and norepinephrine reuptake in the spinalcord and has no reported neurotoxicity. Therefore tramadol has the potential to provide effective postoperative analgesia, with no risk of respiratory depression after central neuraxial administration. However pruritus, nausea, vomiting, urinary retention and risk of unpredictable respiratory depression⁴ have directed the clinicians to use a lower dose of tramadol that can be used intrathecally to produce effective and prolonged analgesia with out such complications. Lower abdominal and lower limb surgeries may be performed under local, regional (spinal or epidural) or general anaesthesia. Spinal block is still the first choice because of its rapid onset, superior blockade, low risk of infection as from catheter in situ, less failure rates and cost-effectiveness, but has the drawbacks of shorter duration of block and lack of adequate post operative analgesia. Therefore, the present study was performed to compare Buprenorphine and Tramadol in their efficacy as adjuvants to spinal anaesthesia. This study comprised of 80 cases of ASA grade I and II, of both sexes and age ranging between18 to 60years, posted for routine surgeries of lower abdomen and lower limb. These 80 patients were given either of the two sets of intrathecal drugs randomly so that each group comprised 40 patients. In our study design Group-B received 0.5% of hyperbaric Bupivacaine 3 ml with Buprenorphine (60mcg) and Group-T received 0.5% hyperbaric Bupivacaine 3 ml with Tramadol (25mg) injected intrathecally .J.A.Alhashemi.et.al (2003)⁵ used Bupivacaine 0.5% heavy 3ml with 25mg Tramadol for postoperative pain relief in patients undergoing transurethral resection of prostate (TURP). Dr G.Prathap Rao.et.al (2015)⁶ used Bupivacaine heavy 3ml with 60mcg of Buprenorphine in subarachnoid block for patients undergoing transurethral resection of prostate (TURP).

Demographic profile: The demographic data compared between two groups were Age, Sex, Height, Weight. Both sexes are equally distributed (25 each) among two groups. Patients included in this study, were between 18 – 60 yrs. of age and the mean age in our study groups were similar in terms of age, height, weight (Table-1 and sex. Similar age, weight and height distribution was also seen in the study of Torres et al⁷, Susmita Chakraborty et al (2008)⁸and B.N. Biswas et al (2002).⁹

Sensory Block

1. Onset of sensory block: In the present study, the onset of sensory block was tested by pin-prick method, this has been the commonest method of testing the onset of sensory block. The mean time of onset of sensory block seen in different groups was found (p>0.05) (Table 4) statistically not significant. This showed that there is no effect of Tramadol or Buprenorphine on onset of sensory block. Dr Alok Pratap Singh (2015)⁶ in his comparative study of intrathecal bupivacaine with bupivacaine-tramadol and bupivacaine-fentanyl for post-operative pain relief in lower abdominal and lower limb surgeries found no statistical difference in onset of sensory block with addition of tramadol or fentanyl to bupivacaine intrathecally. Khan FA, Hamdani GA¹⁰(2006) in their study of Comparison of intrathecal fentanyl and buprenorphine in urological Surgery also found no difference in time of onset of sensory blockade.
2. Time of sensory regression to S1: The mean time of sensory regression to S1 in group B was statistically highly significant with p<0.0001 (Table 4). It implied that sensory block is prolonged more with buprenorphine than with tramadol. Dr Alok Pratap Singh (2015)⁶in his comparative study of intrathecal bupivacaine with bupivacaine-tramadol and bupivacaine-fentanyl for post-operative pain relief in lower abdominal and lower limb surgeries found prolonged sensory block with both fentanyl and tramadol which is more with fentanyl (6.86 + 0.75) than tramadol (4.58 + 0.46). Khan FA, Hamdani GA¹⁰(2006) in their study of Comparison of intrathecal fentanyl and buprenorphine in urological Surgery also found significant prolongation of sensory block with both fentanyl and buprenorphine with 70% of pts in fentanyl group showed sensory regression to L1 60 min postoperatively compared to 35% pts in buprenorphine group. Dalvi NP, Patil N¹¹ in their study “Comparison of Effect of Intrathecal Fentanyl-bupivacaine and Tramadol-bupivacaine Combination on Postoperative Analgesia in Lower Abdominal Surgeries” found the duration of sensory blockade was to be longer with intrathecal fentanyl than intrathecal tramadol. Biswas et al⁹ found that the duration of sensory blockade was longer in the patients who received intrathecal bupivacaine with fentanyl than the patients who received intrathecal bupivacaine alone. Torres et al (1993)⁷ compared the analgesic efficacy of intrathecal Tramadol and Bupivacaine with Fentanyl and Bupivacaine in moderate to severe postoperative pain. They concluded that intrathecal administration of Bupivacaine with Tramadol or Fentanyl prolongs the duration of sensory block was more prolonged in Fentanyl group as compared to the Tramadol group. M. Ravishankar et al (2002)¹² in their respective studies concluded that when Tramadol was added to Bupivacaine it increases the analgesic effect of the spinal block. All these studies showed when compared between fentanyl and tramadol sensory block is more prolonged in fentanyl group, between buprenorphine and fentanyl it is more prolonged in buprenorphine group. In our present study, sensory block is more prolonged with buprenorphine than tramadol.

Motor Block

• Onset of motor block: In our present study mean time of onset of motor block (Table 4). On intergroup comparison p<0.0001 is statistically highly significant. Onset of motor block is earlier in buprenorphine group than tramadol group. Dr Alok Pratap Singh (2015)⁶in his comparative study of intrathecal bupivacaine with bupivacaine-tramadol and bupivacaine-fentanyl for post-operative pain relief in lower abdominal and lower limb surgeries found no significant difference in onset of motor block among tramadol, fentanyl and plain bupivacaine groups. Khan FA (2006)¹⁰ in their study of Comparison of intrathecal fentanyl and buprenorphine in urological Surgery also found no significant difference in time of onset of motor block among plain bupivacaine group (4.35 min), buprenorphine (5.1 min) and fentanyl group (4.95 min) Dalvi NP, Patil N¹¹ in their study “ Comparison of Effect of Intrathecal Fentanyl-bupivacaine and Tramadol-bupivacaine Combination on Postoperative Analgesia in Lower Abdominal Surgeries”, it was found that patients receiving fentanyl and tramadol had nearly the same onset of motor block (2.47 ± 0.777 vs 2.6 ± 0.62 minutes)
• Mean time of regression to Bromage-0: In our present study mean time of regression to bromage-0 is statically highly significant with p<0.0001. It concluded that duration of motor block is more in buprenorphine group than tramadol group. Dalvi NP, Patil N¹¹ in their study “Comparison of Effect of Intrathecal Fentanyl-bupivacaine and Tramadol-bupivacaine Combination on Postoperative Analgesia in Lower Abdominal Surgeries” found the duration of motor block was longer in group Fentanyl as compared to group Tramadol and was statistically highly significant (263.66 ± 40.97 vs 214.66 ± 26.61 minutes, p< 0.001). It implies that the motor recovery and street fitness was delayed in fentanyl group as compared to the tramadol group. In our study also motor recovery was earlier with tramadol.

Khan FA, (2006) in their study of Comparison of intrathecal fentanyl and buprenorphine in urological Surgery found no significant differences among fentanyl and buprenorphine groups in state of motor block at 4 hrs, which implied that fentanyl and buprenorphine are comparable in terms of motor blockade. In our study, also buprenorphine group had prolonged motor blockade like fentanyl group in Khan FA et. al study.10 Duration of Analgesia:
In our present study Mean duration of analgesia in group B was is statistically highly significant with p <0.0001. Dalvi NP, Patil N11 in their study “Comparison of Effect of Intrathecal Fentanyl-bupivacaine and Tramadol-bupivacaine Combination on Postoperative Analgesia in Lower Abdominal Surgeries” found the duration of postoperative analgesia to be significantly prolonged in fentanyl group as compared to the tramadol group. Chakraborty et al8 found that the duration of postoperative analgesia was longer in the patients receiving intrathecal bupivacaine- tramadol than the patients receiving only bupivacaine. Ravishankar12 found that the duration of postoperative analgesia was significantly longer in the patients receiving intrathecal lignocaine-tramadol than in the patients receiving lignocaine only. Capogna G, Celleno D13. “Intrathecal buprenorphine for postoperative analgesia in the elderly patients” A study on 90 patients aged 56-85 years scheduled for suprapubic prostatectomy randomly received intrathecally either bupivacaine 30mg (group A), bupivacaine 30mg plus buprenorphine 0.03 mg (group B) or bupivacaine 30mg plus buprenorphine 0.045 mg (group C). They concluded that prolonged postoperative analgesia in the groups that received buprenorphine and as the dose of buprenorphine was increased the duration of analgesia also more. Above studies showed that duration of analgesia was prolonged when opioids were added to intrathecal bupivacaine and is more so with buprenorphine, fentanyl than tramadol, in our present study also the results were similar.
These results were consistent with experimental evidence of a synergistic interaction between spinal opioids and local anaesthetics. This is due to separate mechanisms of action of both the drugs. Intrathecal opioids inhibit nociceptive afferent synaptic transmission via A delta and C fibbers by opening presynaptic potassium channels to inhibit transmitter release and thus reduce calcium influx. There is also a direct postsynaptic effect with hyperpolarization and reduced neuronal activity. Local anaesthetics work primarily by causing blockade of voltage-gated sodium channels in the axonal membrane and, possibly, a further effect on presynaptic inhibition of calcium channels. Hemodynamic Parameters: In the present study there was no significant difference between both the groups with respect to intraoperative and postoperative mean heart rates and mean arterial blood pressures(MAP) with p>0.05 Dalvi NP, Patil N11 in their study “ Comparison of Effect of Intrathecal Fentanyl-bupivacaine and Tramadol-bupivacaine Combination on Postoperative Analgesia in Lower Abdominal Surgeries” also found no significant difference between fentanyl and tramadol groups with respect to heart rates and systolic and diastolic blood pressures. Dr Alok Pratap Singh (2015)6in his comparative study of intrathecal bupivacaine with bupivacaine-tramadol and bupivacaine-fentanyl for post-operative pain relief in lower abdominal and lower limb surgeries found no significant difference in mean heart rates, mean arterial pressures among control, fentanyl and tramadol groups. Torres et al (1993)7, M. Ravishankar et al (2002)12, Sushmita Chakraborty et al (2008)8 found no significant change in pulse rate and blood pressure in their respective studies. Khan FA, Hamdani GA (2006)10 in their study of Comparison of intrathecal fentanyl and buprenorphine in urological Surgery found no significant differences among fentanyl and buprenorphine groups with respect to systolic, diastolic blood pressures and mean heart rates. Similar results were also found in other studies. Hypotension is anticipated sequelae after neuraxial block but the addition of either Tramadol or Fentanyl to bupivacaine has not produced significant difference from the control group. As all the patients in the present study were of ASA grade I and II and were properly preloaded with 15ml/kg of Ringer’s Lactate, no episode of moderate or severe hypotension was encountered. Respiratory parameters
There was no significant difference between both the groups (P>0.05) in respiratory rate and oxygen saturation, there was no episode of any respiratory depression in both groups
M.Ravishankar et al (2002)12, and Susmita Chakraborty et al (2008)8 found that intrathecal Tramadol with hyperbaric Bupivacaine does not cause respiratory depression. Similar results were also found in other studies. Sedation: In the present study sedation was assessed by MRSS, the scores were higher at 30 min in group B which was statistically insignificant with p=0.04, and again at 60 min and 90 min which statistically significant. At 120 min, 150 min, 180 min it is higher in group T but statistically insignificant with p values 0.68, 1, 1 respectively. Sedation is more with buprenorphine than tramadol in our study. Dalvi NP, Patil N11 in their study “Comparison of Effect of Intrathecal Fentanyl-bupivacaine and Tramadol-bupivacaine Combination on Postoperative Analgesia in Lower Abdominal Surgeries” found that Patients from fentanyl group were more sedated than the patients from tramadol group. No patient had any evidence of delayed respiratory depression or hypoxia in both the groups
Postoperative Analgesia: In our study, postoperative analgesia was assessed by VAS at 6hr, 12hr, 18hr, 24hr. The scores were lower in buprenorphine group than tramadol group which was statistically highly significant with p values < 0.001. Khan FA, Hamdani GA10 (2006) in their study of Comparison of intrathecal fentanyl and buprenorphine in urological Surgery found the mean time for the spinal injection to the first requirement of postoperative analgesia was significant with p <0.001. these results explain the lower VAS scores in buprenorphine group. Dalvi NP, Patil N11 in their study “Comparison of Effect of Intrathecal Fentanyl-bupivacaine and Tramadol-bupivacaine Combination on Postoperative Analgesia in Lower Abdominal Surgeries” found low VAS scores in fentanyl than tramadol and Total analgesic requirement during the observation period of 24 hours was noted. Group F patients required fewer doses of analgesics as compared to group T. So, between fentanyl and tramadol VAS was lower in fentanyl group, between fentanyl and buprenorphine VAS was lower in buprenorphine group, in our study VAS scores were lower in buprenorphine group compared to tramadol group.
Side effects: Nausea and vomiting were significantly higher in group T, with p value <0.001. Hypotension and bradycardia were more in group B which is statistically insignificant. Dalvi NP, Patil N11 in their study found 14 pts experienced nausea, 11 pts experienced vomiting in tramadol group. Dr Alok Pratap Singh(2015)6 in his comparative study of intrathecal bupivacaine with bupivacaine-tramadol and bupivacaine-fentanyl for post-operative pain relief in lower abdominal and lower limb surgeries found that one patient in control group 2 pts each in fentanyl and tramadol group had bradycardia. There were 2, 3, 3 patients in Group control, tramadol and fentanyl groups respectively, who had hypotension. Although incidence of hypotension was more with Tramadol and Fentanyl group, none of the patient had moderate to severe hypotension. Nausea and Vomiting was most common in tramadol group (5 patients), followed by fentanyl group (2 patients) and control group (1 patient). There were no incidences of headache, respiratory depression, pruritus or constipation intra-operatively and post-operatively. These results were supporting our study
After spinal administration opioids undergo redistribution by rostral spread, which explains the occurrence of side effects due to intrathecal opioids. Opioids reach the cisterns of brain 3-6 hrs after the intrathecal administration and then the respiratory centre through ventral pons 85,86. A lipid soluble nonionised drug like buprenorphine passes rapidly via the arachnoid granulations into venous and lymphatic vessels which allows minimal increase in csf concentration with very low risk of respiratory depression. The effect of lipophilic opioids is brief due to rapid clearance from spinal cord sites.
CONCLUSION
Addition of Buprenorphine (60mcg) with hyperbaric bupivacaine significantly prolongs both sensory and motor block. Intraoperatively, there was less incidence of side effects with Intrathecal Buprenorphine when compared to Intrathecal tramadol with hyperbaric bupivacaine. The postoperative 24 hours analgesic requirements were significantly less in the Buprenorphine group than tramadol group. To conclude, Buprenorphine (60mcg) seems to be an attractive alternative to tramadol(25mg) as an adjuvant to spinal bupivacaine in surgical procedures. It provides good quality of intraoperative analgesia, haemodynamically stable conditions, and excellent quality of postoperative analgesia. Hence, Buprenorphine seems to be a better choice as Intrathecal adjuvant with Bupivacaine when compared with Tramadol.



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