RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE,

KARNATAKA.

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

1. / NAME OF THE CANDIDATE
AND ADDRESS / DR. JITHENDRA.C
S/O CHINNAPPA.M.R
#147, 12TH CROSS, 6TH MAIN, N.G.E.F LAYOUT, NAGARABHAVI,
BANGALORE-560072
ADDRESS FOR CORRESPONDENCE / DR. JITHENDRA.C
POST-GRADUATE IN ANAESTHESIA,
DEPT OF ANAESTHESIOLOGY
M.S.RAMAIAH MEDICAL COLLEGE
BANGALORE. 560054.
2. / NAME OF THE INSTITUTION / M.S.RAMAIAH MEDICAL COLLEGE. BANGALORE. 560054.
3. / COURSE OF THE STUDY AND SUBJECT / M.D ANAESTHESIOLOGY
4. / DATE OF ADMISSION TO THE COURSE / 30/05/2011
5. / TITLE OF THE TOPIC / EFFECT OF ADDITION OF DEXMEDETOMIDINE TO ROPIVACAINE FOR SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK

6. Brief resume of intended work.

6.1 Introduction and need for the study:

Brachial plexus block is a popular and widely employed regional nerve block of upper extremity which avoids the unwanted effect of anesthetic drugs used during general anesthesia and the stress of laryngoscopy and tracheal intubation. Patients can also enjoy a post operative period free from nausea, vomiting, cerebral depression and immediate post operative pain.

Ropivacaine, a long acting amide local anesthetic causes differential sensory nerve block, with a dose-dependent motor blockade and a safer cardiac profile1. Hand strength returned more quickly and there was less paresthesia of the fingers in patients receiving ropivacaine than in those receiving bupivacaine.

Adjuvants with local anaesthetics in brachial plexus block are being used to achieve quick, dense and prolonged block. One among these being dexmedetomidine, a selective alpha 2 adrenoceptor agonist, which has higher affinity to alpha 2 receptors compared to clonidine2. Dexmedetomidine added to local anesthetics shortens the onset time and prolongs the duration of block and postoperative analgesia in brachial plexus block2. Addition of dexmedetomidine in clinically relevant doses to ropivacaine results in a dose dependent increase in the duration of sensory and motor block3. However their combination in supraclavicular brachial plexus block has not been tried till now, hence the need for the study.

6.2 Review of literature:

Previous studies have found that Dexmedetomidine added to Levobupivacaine for Axillary brachial plexus block shortens the sensory and motor block onset times, prolongs the duration of the block and also the duration of the postoperative analgesia2. In other study it was found that combination of Dexmedetomidine and Bupivacaine used for Greater palatine nerve Block increased the duration of analgesia after repair of cleft palate by 50% with no clinically relevant side effects4. Ropivacaine alone has been extensively used in various nerve block procedures and has been proven to be advantageous over other local anesthetics. A study on rats where ropivacaine was used in combination with dexmedetomidine for sciatic nerve block found that there was a dose dependent increase in the duration of thermal antinociception5.

6.3 Objectives of the study:

To compare the effects of combination of Dexmedetomidine and Ropivacaine with Ropivacaine alone for Supraclavicular brachial plexus block. The effects will be studied in terms of

·  Onset of sensory blockade and motor blockade

·  Duration of analgesia / first request for analgesic

·  Duration of motor blockade

·  Complications / side effects if any

7. Material and methods:

7.1 Source of data:

A minimum of 50 patients admitted to M.S Ramaiah Medical Teaching and Memorial hospitals satisfying the inclusion and exclusion criteria undergoing elective upper limb surgery will be included in the study, after obtaining the ethical committee clearance.

7.2 Method of collection of data:

As there are no studies available where ropivacaine has been used in combination with dexmedetomidine for supraclavicular brachial plexus block a pilot study is being conducted to arrive at the actual mean differences. 25 cases in each group will be recruited for the study and will be randomized to receive Ropivacaine alone or Ropivacaine with Dexmedetomidine to arrive at the actual mean differences, and the outcome parameters being studied with the visual analogue scale (VAS), Modified Bromage score and mean time for first analgesic. Subsequently using this data the actual numbers to achieve the requisite precision shall be arrived over and above the current sample size.

7.3 Type of study: A prospective study will be conducted in patients of either sex requiring elective upper limb surgeries after obtaining an informed consent.

Inclusion criteria:

1) Age: 18 – 70 years

2) American society of anaesthesiologists (ASA) physical status I – III

3) Elective upper limb surgeries

Exclusion criteria:

1) Patient refusal for procedure

2) Any bleeding disorder or patient on anticoagulants

3) Neurological deficits involving brachial plexus

4) Patients with allergy to local anaesthetics

5) Local infection at the injection site

6) Patients on any sedatives or antipsychotics

7) Body mass index >35

Fifty patients scheduled for Elective upper limb surgery will be randomized and divided into two equal groups. Brachial plexus will be approached by Supraclavicular route using a 22gauge 55 millimeters (mm) insulated needle (Stimuplex B`Braun) connected to a peripheral nerve stimulator (B`Braun). Patients will be assigned randomly into one of the two groups. In group A (n=25) 30millilitres (ml) of 0.5% Ropivacaine +1ml saline and in group B (n=25) 30ml of 0.5% Ropivacaine +1microgram (mcg)/kilogram (kg) Dexmedetomidine will be given. Intraoperative sedation will be maintained with intravenous Midazolam 1 mg and intravenous Fentanyl 0.5 mcg/kg given prior to starting the procedure. Motor and Sensory block onset times; block durations and the time of first request for analgesic will be recorded. Pain will be assessed using a standard 100 mm Visual Analogue Scale (VAS) and Motor block by Modified Bromage Scale by an independent anesthesiologist.

A VAS consists of a line, often 10 cm long, with verbal anchors at either end. In the numerical scale, 0 corresponds to no pain and 10 designate the worst possible pain. Patients are asked to choose a point on the line that represents the intensity of their current state.

Modified Bromage scale:

0-  normal motor function,

1- Ability to move only fingers,

2- Complete motor block with inability to move elbow, wrist and finger

During the intraoperative period heart rate, systolic and mean arterial pressures will be noted every 5minutes (mins) during the first 15mins, then every 15mins throughout the surgery. Intravenous paracetamol 1gram will be given 6th hourly for the first 24 hours. Intramuscular tramadol 50mg will be given as rescue analgesic if VAS > 3. Inadequate sensory and motor blockade beyond 30mins following the infiltration will be considered as unsuccessful block.

Management of unsuccessful block:

In the circumstance of inadequate or patchy action of the block, the block would be supplemented with general anesthesia.

If in case surgery was unduly prolonged and the effect of the block wore off, rescue analgesia will be given in the form of intravenous Fentanyl 1 mcg/kg and infusion of Propofol 50-100 mcg/kg/min

Other variables that will be recorded are:

1)  Age

2)  Gender

3)  Coexisting diseases

4)  Medications patient is receiving

5)  Duration of surgery

6)  Post operative infection

7)  Adverse perioperative event

Statistical analysis:

The independent‘t’ test shall be employed to compare the means of the VAS score, Modified bromage score and time of first request of analgesic

7.3 Does the study require any investigation or interventions to be conducted on Patients or other humans or animals?

Yes. The patients will undergo the investigations recommended by the ASA guidelines for the age prior to surgery

7.4 Has ethical clearance been obtained from your institution?

Yes.

8. List of references:

1) Misiolek HD, Kucia HJ, Knapik P, Werszner MM, Karpe JW, Gumprecht J. Brachial plexus block with ropivacaine and bupivacaine for the formation of arteriovenous fistula in patients with end-stage renal failure. European Journal of Anesthesiology-2005; 22:471–484

2) Aliye E, Fusun Y, Aynur A, Cemil Y. Dexmedetomidine Added to Levobupivacaine Prolongs Axillary Brachial Plexus Block. Anesth Analg-2010, Dec; 111(6):1548-51

3) Grewal A. Dexmedetomidine: New avenues. J Anaesthesiol Clin Pharmacol-2011, Sep, 19; 27:297-302

4) Obayah GM, Refaie A, Aboushanab O, Ibraheem N, Abdelazees M. Addition of Dexmedetomidine to Bupivacaine for Greater Palatine nerve block prolongs postoperative analgesia after cleft palate repair. European Journal of Anesthesiology: March 2010; 27(3):280–284

5) Chad MB, Mary AN, John MP, Ralph L. Perineural Administration of Dexmedetomidine in Combination with Bupivacaine Enhances Sensory and Motor Blockade in Sciatic Nerve Block without Inducing Neurotoxicity in Rat. Anesthesiology-2009; 111(5):1111-9.

9. / SIGNATURE OF THE CANDIDATE
10. / REMARKS OF THE GUIDE / SEVERAL STUDIES HAVE PROVED THE ADVANTAGE OF INTRATHECAL AND EPIDURAL ADMINISTRATION OF DEXMEDETOMIDINE, WHILE THERE ARE LIMITED STUDIES ON ITS USAGE IN PLEXUS BLOCKS, HENCE THE NEED OF OUR STUDY.
11.1 / NAME AND DESIGNATION OF THE GUIDE / DR. SANDHYA.K, M.D
ASSISTANT PROFESSOR
DEPARTMENT OF ANAESTHESIOLOGY
M.S.RAMAIAH MEDICAL COLLEGE
BANGALORE-560054
11.2 / SIGNATURE
11.3 / CO-GUIDE / DR.GEETHA.L, M.D., P. D. F (NEUROANAESTHESIA)
ASSISTANT PROFESSOR,
DEPARTMENT OF ANAESTHESIOLOGY
M.S. RAMAIAH MEDICAL COLLEGE.
BANGALORE-560054
11.4 / SIGNATURE
11.5 / HEAD OF THE DEPARTMENT / DR. RATHNA, M.D, D.A, DNB
PROFESSOR AND HEAD OF DEPT.,
DEPARTMENT OF ANAESTHESIOLOGY
M.S.RAMAIAH MEDICAL COLLEGE.
BANGALORE. 560054.
11.6 / SIGNATURE
12. / DEAN AND PRINCIPAL / DR. SARASWATHI RAO. M.D.
PRINCIPAL AND DEAN.
M.S. RAMAIAH MEDICAL COLLEGE.
BANGALORE. 560054.
12.1 / REMARKS OF THE DEAN AND PRINCIPAL
12.2 / SIGNATURE

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