A RANDOMISED CONTROLLED TRIAL TO STUDY THE EFFECT OF ADDITION OF LIGNOCAINE VERSUS DEXMEDITOMIDINE ON BLOCK CHARACTERISTICS WITH BUPIVACAINE IN ULTRASOUND GUIDED INFRACLAVICULAR BLOCK

Dr. Ruhi Sharma, Dr. Saru Singh, *Dr. Shibu Sasidharan, Dr. Meenu Agrawal and Dr. Meena Singh

ABSTRACT

Background: A randomised, double blinded trial was designed to study the effect of addition of dexmedetomidine versus lignocaine to bupivacaine for infraclavicular block with the primary objective of comparing onset time of block and duration of post operative analgesia as secondary objective. Materials & Methods: Under ultrasonic guidance, the point of needle puncture was identified and 2 ml of Inj. Lidocaine 2% was infiltrated in the proposed needle tract. The nerve bundle was identified and drug infiltrated in aliquots around each nerve bundle9 according to the groups as proposed in the study. Group B: 35 ml bupivacaine 0.375% + 1 ml Normal Saline Group BL: 25 ml bupivacaine 0.375%+ 10 ml lignocaine 2% + 1 ml Normal Saline Group BD: 35 ml bupivacaine 0.375% + 1 mcg/ kg dexmedetomidine in 1 ml Normal Saline. Onset of sensory and motor blockade, haemodynamic parameters and side effects were monitored. Time of completion of block was taken as time 0 and all durations were measured thereon. Patients were assessed for loss of sensation to blunt pin prick over C5-T1 dermatomes at every 1 minute for 15 minutes and motor block every 1 minute for 15 minutes. Sensory block was measured by Modified Hollmen score and motor block was assessed using the modified Bromage Scale. Time of onset of sensory block (grade 1) and motor block (Bromage 2) were noted. Results: The demographic parameters and preoperative haemodynamics were statistically comparable. The systolic and diastolic blood pressures were statistically lower in group containing dexmedetomidine (BD).The mean heart rate in these groups was also statistically lower. The addition of dexmedetomidine to bupivacaine (BD) provides a statistically significant increase in the duration of analgesia as compared to the addition of lidocaine (BL) (p<0.001). The bupivacaine and lidocaine group (BL) had similar duration of analgesia as plain bupivacaine (9.24±3.6 hrs vs 10.22±3.29 hrs.) (p-0.831). Conclusion: With a longer duration of analgesia in post operative period. There should be minimum risk of toxicity and haemodynamic alterations. A prolonged motor blockade is undesirable. Addition of dexmedetomidine to bupivacaine provides similar reduction in onset time as addition of lidocaine with a superior duration of post operative analgesia.

Keywords: USG Guided Block, Regional Anaesthesia, Dexmeditomidine, Lignocaine, Bupivacaine.