Epidural verapamil reduces analgesic consumption after lower abdominal surgery

Effect of Verapamil as an Adjuvant to Levobupivacaine in Supraclavicular Brachial Plexus Block

BACKGROUND

Many adjuvants have been used with local anesthetics to reduce the time of onset and prolong the duration of analgesia in brachial plexus blocks. However, few studies are there using verapamil as an adjuvant with levobupivacaine.

AIMS

This study aims to study the effects of verapamil as adjuvant to levobupivacaine in supraclavicular block for upper extremity surgery.

METHODS

In this double-blinded clinical trial, 60 American Society of Anesthesiologist Class I and II patients posted to undergo upper extremity surgery were divided into 2 different groups randomly. In Group A, the patients received 30 ml levobupivacaine 0.5% plus 2 ml normal saline and Group B patients received 30 ml levobupivacaine 0.5% plus 5 mg verapamil diluted to 2 ml normal saline for supraclavicular block. Time of request for rescue analgesia, onset and duration of sensory motor blocks and changes in hemodynamic parameters were studied and analyzed. P < 0.001 was considered statistically significant.

RESULTS

Time for a request for rescue analgesia was 425.80 ± 90.46 min in Group B and 366.13 ± 70.42 min in Group A which was clinically significant. The mean of sensory and motor block onset time in Group B was less than in Group A, the difference between the two groups being statistically significant (P < 0.001). In Group A, mean duration of sensory block was 316.13 ± 91.08 min and in Group B was 375.83 ± 114.48 min, which was statistically significant (P < 0.001).

CONCLUSION

The addition of verapamil as an adjuvant to levobupivacaine in brachial plexus blockade delayed the requirement of rescue analgesia with decreased onset time and prolonged duration of sensory and motor block characteristics.

Verapamil as an Adjunct to Local Anaesthetic for Brachial Plexus Blocks

BACKGROUND

Calcium channel blockers potentiate the effects of local anaesthetics. We examined the effect of adding verapamil to local anaesthetic solution on anaesthetic duration in patients undergoing surgery under brachial plexus block.

METHODS

This study was a prospective, randomized, controlled, double blind study. Sixty patients undergoing elective upper limb surgery were divided into two groups of 30 each. Group A received 40 ml of 1% lignocaine with 0.25% bupivacaine, while Group B patients had 2.5 mg verapamil added.

RESULT

Onset of sensory blockade time was marginally faster in Group B (23.2 ± 3.94 minutes) as compared to Group A (23.9 ± 4.13 minutes). However this difference was statistically not significant. The increase in duration of sensory blockade in Group B (185 ± 46.52 minutes) as compared to Group A (157 ± 44.28 minutes) was statistically significant (p= 0.011). Increase in duration of motor blockade in Group B (161 ± 46.14 minutes) as compared to Group A (149 ± 42,76 minutes) was statistically not significant (p = 0.15). Similarly prolongation of analgesic duration in Group B (318 ± 69.54minutes) as compared to Group A (302 ± 0.69 minutes) was statistically not significant (p=0.18).

CONCLUSION

We conclude that adding verapamil to brachial plexus block can prolong sensory anaesthesia without any effect on analgesic duration.

Effects of a calcium channel blocker on electrical activity in myofascial trigger spots of rabbits

OBJECTIVE

This study investigated the effect of a calcium channel blocking agent, verapamil, on the spontaneous electrical activity (SEA) in a myofascial trigger spot of biceps femoris muscles of rabbits.

DESIGN

Left and right legs of eight adult New Zealand rabbits were randomly assigned into either experimental or control groups to assess the effect of verapamil on SEA. Verapamil and normal saline were injected into the external iliac artery for experimental and control groups, respectively. The experiment was divided into two phases: Phase A investigated the immediate effect of verapamil on SEA of one active locus, and phase B studied the effect of verapamil on SEA of 25 different active loci. The average integrated value of SEA was used to statistically analyze the effect of verapamil on myofascial trigger-spot sensitivity.

RESULTS

In phase A, conducted on one active locus, the regression analysis results showed that the average integrated value in the verapamil group linearly decreased with time, but the average integrated value did not significantly change with time in the control group. In phase B, which analyzed 25 different active loci, the results indicated that the mean average integrated values in the verapamil group was significantly lower than that of the control group.

CONCLUSIONS

Calcium channel blockers can effectively inhibit the SEA of myofascial trigger spots.