If the patient is willing to participate and signs the consent, he/she will be randomized to one of the two treatment groups:
1. Single shot block
2. Local Infiltration
In the institution investigators usually advocate for regional anesthesia and intravenous sedation for the repair of open fracture of the distal radius.
Patients will be monitored during block performance with standard ASA monitors. All patients will receive 2 L of oxygen via a nasal cannula. Sedatives will be titrated to effect. Midazolam 1-2 mg, and fentanyl 50-100 mcg will be used for sedation.
Block time out will be preformed according to standard operating procedure. All blocks will be done under ultrasound guidance. Sonosite S nerve machine will be used with a low frequency curvilinear (C5) US probe with 2-5 MHZ frequency. Both single shot and local infiltration will be performed according to the SOP in the department. Ultrasound survey of the deltopectoral groove below the clavicle will take place. The axillary artery and the three cords (posterior, medial and lateral) of the brachial plexus will be identified in short axis view deeper to the pectoralis minor muscle.
For single shot blocks: A 4 inch 21 gauge single shot (B-Braun) needle will be introduced in-plane towards the posterior cord of the brachial plexus and 1-2 mL of dextrose 5% (D5%) bolus will be used to verify correct placement of the needle in the vicinity of the posterior cord and adequate spread pattern to both lateral and medical cord. 20 ml of of Ropivicaine 0.5% will be injected through the needle with intermittent aspiration after each 5 ml bolus injection.
For local infiltration: At the end of surgery, surgeon will inject 10 ml of Ropivacaine 0.5% into the arthroscopy portals and the wrist. Specifically, 1 ml to 2 ml of Ropivacaine 0.5% will be injected into each portal with the remainder of the volume injected into the joint space itself.
Block success will be defined as a change in cutaneous sensation to touch with an alcohol pad in the posterior, medial and lateral cord distribution over the forearm and the hand within 30min after injection. Subjects with successful catheter placement per protocol and nerve block onset will be retained in the study. Subjects with a failed catheter insertion or misplaced catheter indicated by a lack of sensory changes will have their catheter replaced or will be single shot blocked and withdrawn from the study.
Intraoperative sedation will consist of intermittent boluses of midazolam (1-2 mg), fentanyl (50-100 mcg) and propofol infusion, titrates to sedation and patient comfort (25-50 mcg/kg/min).
All patients will receive prophylaxis for postoperative nausea and vomiting (PONV) during surgery. The protocol for prophylaxis against PONV includes administration of 4 mg of dexamethasone after induction of anesthesia and 4 mg of ondansetron 20 minutes before recovery from anesthesia. Dexamethasone is withheld if the patient has poorly controlled diabetes mellitus (DM). Uncontrolled DM will be defined as random blood glucose above 250 mg/dl.
