Abstract

Man has experienced pain since ages. Pain is subjective experience comprising both physical and emotional components. For surgical analgesia opiod is always preferred over other analgesic agents because of potency. Epidural route of drug administration is very safe and gives good haemodynamic stability. Sufentanil, the newer generation opiod is potent with fewer side effects.

Prospective randomized study of 50 female patients (ASA II/III) with cardiac diseases scheduled for abdominal gynaecological surgeries done in Seth GS Medical College and KEM Hospital in the year of 2005-2006. After optimization cases were divided into two groups of 25 patients each. Group I received plain Bupivacaine 12 ml of 25% while group II received Sufentanil 25 mg with Bupivacaine in the same dose. After confirming the sensory level 20 minutes later general anaesthesia was given to all patients. Vitals were monitored, post procedure visual analogue score and rescue analgesia required time was noted. Data was analyzed. Duration of analgesia in group I was 154 min ± 25.67 min while in group II, it was 360 ± 86.45 min. Haemodynamic stability was better in group II compared to group I.

Introduction

Pre-emptive analgesia prevents the initiation of the physiological and neuroendocrinal responses of the body to intense noxious stimuli.5 Inadequate pain relief can cause an increase in sympathetic activity i.e. heart rate, stroke volume, cardiac work which all lead to increase in myocardial oxygen demand which can adversely affect the myocardial oxygen supply/demand ratio.7,10

Amongst the methods of pain relief epidural opioid analgesia is considered the best because of fewer incidences of hypotension and good quality of analgesia. Sufentanil is the newer synthetic opioid and more cardio stable.9 Onset of action after epidural administration is 5-10 minutes.3 The study was undertaken to know the efficacy of epidural sufentanil for perioperative analgesia in cardiac patients, compare the total duration of analgesia and assess the haemodynamic stability and side effects.

Material and Methods

After obtaining approval from the local ethics committee and written informed consent from the patients, we studied 50 female patients in the age group of 33-74 years (ASA group II/III) scheduled for abdominal gynaecological surgery. This was a prospective randomized study done in Seth GS Medical College and KEM Hospital in the year of 2005-2006.

After optimization of cardiac conditions cases were divided into two groups of 25 patients each.

Group I : Received Bupivacaine 12 ml of 25% epidural.

Group II : Received Sufentanil 25 mg along with Bupivacaine 12 ml of 25% epidurally.

Starvation and necessary medication was confirmed.

Patients were premedicated with injectable glycopyrrolate 4 mg/kg intramuscularly ½ hour before induction of anaesthesia and Midazolam 0.03 to 0.04 mg/kg IV. Monitoring consisted of cardioscope, pulse oximetry, end tidal CO2, blood pressure and central venous pressure.

Base line vitals were noted. Under all aseptic precautions epidural needle 18 gauge was introduced in L2-3 space and after confirming the epidural space with loss of resistance technique 12 ml of 0.25% Bupivacaine given to group I and 25 mg Sufentanil is added to the above drug and given to group II.

After confirming the sensory level, 20 minutes later general anaesthesia was induced with propofol 1-2 mg/kg and vecuronium as muscle relaxant 0.08 to 0.1 mg/kg and intubated with appropriate sized endotracheal tube. No. IV analgesia was given. Intra operative continuous haemodynamics and saturation were monitored. Any intraoperative complications, total blood loss were noted. Post procedure patients were extubated. Visual analogue score was noted on a scale from 0-10 (0=no pain, 10=worst pain imaginable). Rescue analgesia required time and side effects were noted.

Statistical analysis was done by student’s ‘t’ test and ‘z’ test.

A p value of < 0.05 was considered significant.

Results

Demographic data was comparable. There were no significant differences in two groups regarding age, sex, operative procedure, type of cardiac disease (Hypertension, IHD, Valvular heart disease). Level of sensory analgesia was comparable, mean - 8.5.

Duration of analgesia in group I was 154 min ± 25.67 min while in group II it was 360 ± 86.45 min which shows significant difference. Similarly VAS score in group 2 was significantly lower than in group I suggesting patient in group II were pain free upto 6 ± 1½ hour as compared to group 1 where they had analgesia for 2½ hours ± ½ hour.

Baseline mean pulse rate in group I and II were comparable. It decreased in group II 20 minutes after epidural and decrease persisted for 5 hours showing statistically significant difference. To begin with mean systolic blood pressure were comparable in both the groups, significant difference was observed 10 minutes after general anaesthesia. Mean systolic blood pressure in group I was significantly higher in group II. This observation was constant for 5 hours post epidural after which mean systolic pressure in group II also increases.

Mean diastolic blood pressure were also comparable. The values in group II decreased 20 minutes after epidural and remained so for seven hours post epidurally compared to group I.

Side effects

We looked for adverse events such as nausea, vomiting, pruritus, respiratory depression and any cardiac complications in the form of bradycardia, hypotension and ECG changes. None of these were observed in group I while in group II 8% had nausea relieved with IV ondensetron. 8% reported mild pruritus, subsided on its own.

Only one patient in group II had respiratory depression after 5 minutes of epidural sufentanil and intubated immediately but was not accompanied with hypotension and bradycardia.

Discussion

Pain relief improves surgical outcome with reduced morbidity, need for hospitalization and convalescence by reduction in surgical stress response.10 Opioids can reduce central neuron activation by presynaptically inhibiting neurotransmitter release or by post synaptically fixing of dorsal horn nociresponsive neurons.5

Our study shows that the combination of sufentanil and bupivacaine as an epidural injection improved both quality and duration of analgesia when compared with only bupivacaine.8 The duration of analgesia was fairly prolonged in group II i.e. 6 ± 1½ hour as compared to group I i.e. 2½ hours ± ½ hours. George Graf, et al,1 who studied four different epidural doses of sufentanil for post operative analgesia found analgesia duration of 3.5 to 4.5 hours with doses of 40-55 mg (Fig. 1).

Medej et al compared the duration of analgesia with epidural fenatnyl and sufentanil and concluded that sufentanil was superior to fentanyl having duration of 4 ± ½ hour with similar doses.4

We found greater haemodynamic stability in group II, where mean pulse rate, systolic and diastolic blood pressure remained significantly lower compared to group I but clinically not significant from baseline (Figs. 2-4).

Similar results of cardiovascular stability were documented by Peter et al,6 Raza et al,7 with IV sufentanil in cardiac patients undergoing cardiac surgery.

Fig. 1 : Mean duration of Analgesia for two groups	Fig. 2 : Mean Pulse rate at different time intervals for two groups.
Fig. 3 : Mean Systolic BP at different time intervals for two groups.	Fig. 4 : Mean Diastolic BP at different time intervals for two groups.
Fig. 5 : Side effects

Incidence of side effects was minimal. Only one patient in group II i.e. 4% had respiratory depression (RR < 12/min, SaO2 - 90%) five minutes after epidural who was intubated immediately.

George et al1 reported single case of respiratory depression with epidural sufentanil. Two patients in group II had mild nausea (8%). George et al1 observed nausea in 1, 2, 2 and 3 patients with sufentanil 25, 40, 55 and 70 mg respectively. Pruritus was mild in nature, did not require any treatment. Similar results were quoted in the study conducted by George et al1 and Coda et al10 (Fig. 5).

No cardiac problems in the form of hypotension, bradycardia or ECG changes were noticed.

Conclusion

We conclude that epidural sufentanil 25 mg with bupivacaine 12 ml of .25% significantly improves the quality and duration of analgesia, provides haemodynamic stability specially in patients with cardiac diseases as no hypo or hypertension, bradycardia or fresh ECG changes were noticed with minimal serious side effects.

Acknowledgement

We are thankful to Dr. N Kshirsagar and Dr. S Parulekar for their cooperation for the study.

References

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6. Peter S Sebel, James Bovil, et al. Cardiovascular effects of Sufentanil anaesthesia. Anesth Analg 1982;61:115-9.
7. Raza SM, Martis RW, et al. Department of anaesthesiology university of illinosis college of medicine Chicago 606-12: Haemodunamic stability with Midazolam, sufentanil analgesia in cardiac patients. 1986.
8. Hansdottir V, Bake B, Nodberge G. The analgesic efficacy and adverse effects of continuous epidural sufentanil and Bupivacaine infusion after thoracotomy. Anaesthesia and Analgesia 1996; 83 : 394-400.
9. Kehlet H, Holte K. Effect of post operative analgesia on surgical outcome. Br Journal of Anaesthesia 2001; 87 : 62-72.
10. Coda A. Mary Cleveland Brown, et al. Pharmacology of epidural fentanyl, alfentanyl and sufentanil in volunteers. Anaesthesiology 1994 : 81.

*Associate Professor, **Lecturer, ***Professor and Head, Department of Anaesthesiology, KEM Hospital, Seth GS Medical College, Mumbai.