Vasanthageethan, R (2007) A Comparative study of Bupivacaine with Clonidine and Bupivacaine alone in Nerve Locator Assisted Brachial Plexus Blockade: Supraclavicular Approach. Masters thesis, Stanley Medical College, Chennai.
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Abstract
INTRODUCTION: Ever since Koller’s original work, the popularity of local anaesthetic has waxed & waned, like that of many other medical developments. There were many positive influences after Lofgren synthesized lignocaine in 1943. Bupivacaine is particularly important, since its long duration of action avoids repeated injection with relatively little risk of cumulative toxicity. Today regional anaesthesia is well established as equal to general anaesthesia in effectiveness & patient acceptability. Regional anaesthesia is the blocking of peripheral nerve conduction in a reversible way by using local anaesthetic agents thereby one region of the body is made insensitive to pain and is devoid of reflex response to surgical stimuli. In this the CNS is spared, so that the patient is conscious, fully awake during the surgical procedure without recognizing pain. For surgeries on upper extremities particularly in emergency surgeries regional anaesthesia has many advantages over general anaesthesia. The frequent use of pneumatic tourniquet33 to provide a bloodless field during surgery makes individual nerve blocks impractical. Brachial plexus block28 is the answer in such a situation. There are different approaches but the ones frequently employed for blocking the brachial plexus29 include; a) Supraclavicular approach, b) Infraclavicular approach, c) Axillary approach, d) Interscalene approach. Axillary approach30 has the lowest incidence of serious complications and can be performed with ease. But there are limitations associated with axillary approach like; • It is inadequate for operations on the arm and shoulder. • It is difficult to block the musculocutaneous nerve predictably with resultant sparing of the radial aspect of forearm and dorsum of hand. • Tourniquet pain is not well tolerated. • Also abducting the arm by 90 degrees for giving the block may be painful and even dangerous in traumatic lesions of the upper extremity. The brachial plexus is approached at the level of trunks and the compact arrangement of trunks at supraclavicular level gives a high success rate with minimum local anaesthetic drug volume and a dense & fast onset of block. Hence the supraclavicular approach is the method of choice for blocking the brachial plexus. William Steward Halsted first performed brachial plexus block in 1885. In 1911, Kulenkampff and Hirshel described the first percutaneous brachial plexus block by supraclavicular and axillary routes respectively. Since then several techniques of brachial plexus block have been described with the purpose of improving the efficacy and success rate and minimizing the risk and rate of complications. Of the various techniques29 the most widely practiced methods are the classical technique described by Patrick (1940), Vertical plumb bob approach described by Brown, 1st rib walk over technique described by Bonica and Moore and the Subclavian perivascular technique described by Winnie and Collins (1964). Of the several local anaesthetic drugs used for brachial plexus block, bupivacaine is used most frequently in our set up as it has a long duration of action varying from 3 – 8 hours. To prolong the duration of analgesia various drugs have been studied as adjuvant to the local anaesthetic solution and techniques like the continuous catheter placement in the plexus have evolved. These adjuvant drugs ideally are expected to prolong the analgesic effect without causing any systemic side effects or prolonging motor blockade. Nerve locators are now widely seen as useful aids in nerve blocks. Its use avoids paraesthesia, decreases the chance of nerve injury and gives high success rate. Clonidine is an α2 agonist has an anti-nociceptive effect on a wide dynamic range of neurons and receptors. In animal studies, Clonidine depressed impulse conduction in isolated nerve fibre with some preference for C-fibres. Used as the sole analgesic, it produced analgesia after intrathecal, epidural and intra articular administration. Clonidine can be safely administered along the neuroaxis and is being used as an adjunct to local anaesthetics to increase the duration of analgesia. It produces analgesia by interacting with α2- adrenergic receptors. These receptors are located on superficial laminae of spinal cord and brain stem nuclei implicated in pain. So analgesia may be produced at peripheral, spinal and brain steam sites. This study is intended to determine the effects of adding Clonidine to Bupivacaine in brachial plexus blockade by Nerve locator assisted supraclavicular approach, with regard to the onset, intensity and duration of blockade along with its analgesic efficacy. AIM OF THE STUDY: The aim of the present study is to evaluate the effect of addition of 100μg of Clonidine to 0.375% Bupivacaine solution in Supraclavicular brachial plexus block with regard to following parameters. 1. Onset of blockade, 2. Duration of blockade, 3. Intensity of blockade, 4. Sedation, 5. Quality of analgesia, 6. Haemodynamic changes, 7. Complications if any. MATERIALS AND METHODOLOGY: Forty adult patients of both sexes in the age group of 20-60 years belonging to ASA I/II category and their weight ranging between 50-70 kgs posted for various types of upper limb surgeries at the Department of plastic surgery, Institute of Research and rehabilitation of Hand, Government Stanley Hospital, formed the study group. This study was designed as a prospective randomized comparative study. After receiving the institutional ethical committee approval and informed consent, the patients were randomly allocated into two groups. Supraclavicular brachial plexus block was performed via peripheral nerve locator assisted subclavian perivascular technique. Groups: 1. Group – B (Bupivacaine alone) – 20 patients received 30 ml of 0.375% Bupivacaine with 2 ml of 0.9% sodium chloride solution. 2. Group – BC (Bupivacaine + Clonidine) – 20 patients received 30 ml of 0.375% Bupivacaine with Clonidine hydrochloride 100 μg (1 ml of 150μg diluted with 2ml 0.9% Nacl solution. From that 2ml used for study). Inclusion Criteria: 1. ASA PS I & II, 2. Age group 20-60 years, 3. Weight 50 – 70 kilograms, 4. Surgeries on forearm and hand. Exclusion Criteria 1. Patient refusal, 2. Local infection at needle insertion site, 3. Coagulopathy, 4. Patient on anticoagulants, 5. Pneumothorax or previous pneumonectomy on the opposite side. SUMMARY: 1. Onset time for both motor and sensory block was quicker in the Bupivacaine with clonidine group. 2. Time taken for completion of both motor and sensory blockade was significantly lesser in clonidine group. 3. There was no difference between the groups in the intensity of blockade. 4. The mean duration of both sensory & motor blockade was significantly prolonged in clonidine group. 5. Sedation was statistically significant with Bupivacaine-clonidine group in the intraoperative period. 6. Heart rate significantly decreased in clonidine group during intraoperative period. 7. There was no haemodynamic instability in both the groups in the study period. 8. There was no complication due to the addition of 100μg clonidine to Bupivacaine. CONCLUSION: In conclusion, clonidine 100μg (in 2ml) when used as an additive to 0.375% Bupivacaine (30ml) solution for Supraclavicular brachial plexus block, quickens the onset of sensory & motor blockade and prolongs the duration of sensory & motor blockade. It also improves the quality of post operative analgesia with mild intraoperative sedation and decreases the heart rate without any haemodynamic instability. Hence, clonidine can be considered as a safe additive to local anaesthetic solution for brachial plexus blocks.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Bupivacaine ; Clonidine ; Bupivacaine ; Nerve Locator Assisted Brachial Plexus Blockade ; Supraclavicular Approach ; Comparative study. |
| Subjects: | MEDICAL > Anaesthesiology |
| Depositing User: | Subramani R |
| Date Deposited: | 22 Apr 2018 15:40 |
| Last Modified: | 28 Apr 2018 05:30 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/7234 |
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