Plasma Glucose Levels With Dexamethasone as Adjuvant to Interscalene Block

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.

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.