Comparison of Pain Relief After US Guided Non Stimulating Interscalene Catheter Placement vs Stimulating Catheter Placement in Total Shoulder Arthroplasty;a Randomized Study

After consent patients will be randomized to one of the two groups: Control Group or the Experimental Group. Patients will be blinded to the group assignment. As both catheters are placed using almost the same technique, the subjects will be unable to tell type of catheter they will be getting..

Every procedure will be done after starting intravenous access and placing standard anesthesia monitors (EKG, Blood Pressure Cuff and Pulse-Ox) on the patients. For comfort care sedation will be titrated using accepted American Society of Anesthesiology and American society of Regional Anesthesia Guidelines.

In the Control Group the patient will have interscalene catheter placed using nerve stimulation technique. Initially ultrasound guidance will be used to visualize brachial plexus at the cricoid level with the intent to visualize upper trunks or roots. Then following established guidelines a nerve stimulating catheter will be placed. This will be done using an ARROW NERVE KIT. The kit is FAD approved for this purpose.. Following accepted aseptic guidelines the nerves will be visualized at the base of the neck using ultrasound machine. Once proper nerve roots or trunks visualized, kit provided 17gauge insulated Touhy needle will be used to access the brachial plexus. Once twitches elicited in Deltoid, biceps or triceps muscles at 0.5 mamp, catheter will be threaded via the needle while maintaining twitch at 0.5 mamp or less. Once catheter is threaded 3 cm beyond the tip, Touhy needle will be removed. Catheter will be tested for proper placement using lidocaine and epinephrine as is recommended by Regional Anesthesia Society guidelines. Thereafter 3 mg/kg of 0.5 % bupivacaine will be injected in small blouses via the catheter.

In the Experimental Group, after placement of monitors, the nerves will be visualized using ultrasound machine. Once nerve visualized at the cricoids level, proper tip of Touhy needle will be guided using hydro-dissection technique. Once in good place, catheter will be threaded 3 cm into the space. They subjects will be dosed using 0.5% bupivacaine 3 mg/kg for the surgery via the catheter. Adequacy of catheter placement will be judged by examining the spread of local anesthetics around the plexus.

The extent of block before the surgery will be evaluated at 30 minutes post injection. Surgery will be done with sedation. Conversion of anesthetic technique to general anesthesia will be considered failure of the technique to provide adequate surgical anesthesia.