Plasma Glucose Levels With Dexamethasone as Adjuvant to Interscalene Block

The purpose of this study is to determine the Finger Blood Glucose (sugar) when dexamethasone is added to a local anesthetic for a shoulder nerve block procedure. The investigators hypothesize that there is no increase in plasma glucose when 8 mg of dexamethasone is used as an adjuvant with local anesthetic to interscalene regional anesthesia. By performing finger stick blood glucose measures pre/peri and post operatively the investigators will be able to determine if any such increase exists.

Patients receiving regional anesthesia for orthopedic surgeries are provided with significant pain relief in the post-operative period. Dexamethasone as an adjuvant to local anesthetic has been shown to provide increased duration of block without adverse effects. Use of steroids as adjuvants are restricted to non-diabetics due to concern for increased plasma glucose from systemic absorption. The investigators hypothesize that there will be no difference(increase) from patient baseline(preoperative plasma glucose) in plasma glucose levels up to 4 hours post nerve block in patients who receive 8 mg of dexamethasone used as an adjuvant with local anesthetic to interscalene regional anesthesia. Research has demonstrated the safety and efficacy of dexamethasone as an adjuvant to local anesthetic in peripheral nerve block. Currently there are no studies which document any plasma glucose effects(or lack of effects) from dexamethasone used as an adjuvant to regional anesthesia. Currently dexamethasone is used clinically off label by anesthesiologists as an adjuvant in association with local anesthetic for nerve block anesthesia. Once studies are completed, the investigators hope to allow diabetics to also receive the prolongation of pain relief associated with the use of steroid as an adjuvant. In addition, the increased educational and pharmacological data gleamed from the data can potentially be utilized for future studies with dexamethasone utilized perineurally.

Shoulder Pain, Injury of Shoulder Region, Disorder of Shoulder, Disorder of Rotator Cuff, Disorder of Tendon of Biceps

Blood Glucose, Bupivacaine, Interscalene Nerve Block, Regional Anesthesia, Pain Blockade, Arthroscopic Surgery, Arthroscopic rotator cuff repair, Dexamethasone, Anti-Inflammatory Agents, Therapeutic Uses, Physiological Effects of Drugs, Glucocorticoids, Anesthetics, Local, Anesthetics, Sensory System Agents, Adjuvants, Anesthesia, Anesthesiology, Injections, Adult, Analgesia/methods, Brachial Plexus/drug effects, Brachial Plexus/surgery, Brachial Plexus/ultrasonography, Bupivacaine/administration & dosage, Dexamethasone/administration & dosage, Drug Therapy, Combination, Female, Humans, Male, Nerve Block/methods, Pain, Postoperative/etiology, Pain, Postoperative/prevention & control, Prospective Studies, Time Factors

50 randomized participants in group receive 20cc 0.25% bupivacaine injected perineurally for interscalene nerve block.

50 randomized participants in group will 8 mg(2cc of 4mg/cc solution) Dexamethasone added to 20 cc 0.25% bupivacaine in one syringe resulting in 364 µgm/cc for injection. Injected perineurally for interscalene nerve block pre-operatively.

8mg (2cc 4mg/cc Solution) mixed with 20 cc 0.25% bupivacaine in one syringe resulting in 364 µgm/cc for injection in perineural space. One time dose during nerve block preoperatively.

Normal fasting blood glucose is defined by investigators as less than 100mg/dL.(current literature suggests normal is 70-100 so investigators have chosen to utilize high normal.) Any increase greater than 10%(or 10mg/dL ) would be considered a response to the dexamethasone.

Investigators will document patient pain in post-anesthesia care unit (both at rest and with movement)utilizing the VAS scale.

Patients will be called for follow-up days 1, 2 and 14 and provided with a pain diary to document first narcotic usage.

Patients will be called for follow up on days 1, 2 and 14 and provided with a pain diary to document the quality and duration of the motor block.

Patients will be called for follow up on days 1, 2 and 14 and provided with a pain diary to document the quality and duration of the sensory block.

Inclusion Criteria: ASA 1 or ASA 2 male or female non pregnant patients undergoing elective shoulder arthroscopy for surgical repair. Exclusion Criteria: severe lung disease contralateral diaphragmatic paralysis coagulopathy pregnancy pre-existing neuropathy involving the surgical limb systemic use of corticosteroids for 2 weeks or longer within 6 months of surgery chronic opioid use (30 mg oral oxycodone equivalent per day) diabetes I or II diagnosis of "pre-diabetes" currently prescribed any of the oral glucose medications :sulfonylureas, meglitinides, biguanides, thiazolidinediones, alpha-glucosidase inhibitors, or DPP-4 inhibitors.

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