MGH Orthopaedic Ambulatory Surgery Center Anesthesia Interscalene Block

Regional Anesthestic Techniques

INTERSCALENE BLOCK

The interscalene block is a regional anesthetic technique used for surgeries of the shoulder and upper arm. It is a safe and effective block that provides both safe and excellent surgical anesthesia and post-operative pain control.

During a preoperative phone interview the procedure and its risks and benefits will be discussed with you. On arrival to the ASC prep area you will be asked to sign a consent for the procedure. You will then be attached to the usual monitors: a blood pressure cuff, a light sensor to measure your blood oxygen level will be attached to your finger, and EKG leads will be placed on your chest. You will receive some sedation through your intravenous prior to placement of the block, which both relaxes you and will likely cause you to have little or no recollection of the block placement.

Next, the anesthesiologist will cleanse your neck on the operative side with an antiseptic solution. He or she may ask you to lift your head off the bed or sniff with your nose while examining your neck. These maneuvers help the anesthesiologist to locate landmarks on the side of your neck that aid in the correct placement of the block needle. He or she will also use an ultrasound machine to help find the desired location for the needle placement.

Once the optimum location is found, the anesthesiologist will numb the skin with local anesthetic. Next he or she will slowly insert a needle the size of a paper clip into that location. Your anesthesiologist will utilize the ultrasound to guide the needle to a location near the nerves. Occasionally, a very small amount of electrical current will be put through the needle as the needle is advanced to assist in locating the nerves to your shoulder and arm and optimizing the needle placement. You will feel the sensation of involuntary twitches or movements in your shoulder and arm. Don't try to stop these movements because they tell us if we are in the right location with the needle. When the location and/or response is optimal the anesthesiologist will inject the long acting Novocain like medicine to numb your shoulder and arm. This procedure usually takes only a few minutes to perform.

The block takes approximately 15-20 minutes to work. You will notice shoulder and arm weakness and numbness. Once in the operating room, you will once again be attached to the usual monitors and positioned by the surgeon. You will receive relatively deep levels of sedation or a light general anesthetic because it allows for better blood pressure control, and ultimately more patient comfort.

After the surgery and transport to the recovery room, the sedation will begin to wear off. You may notice a few things. First you will have little or no pain. You won't be able to move or feel your shoulder, arm, and sometimes your hand. Rarely, your voice may be hoarse and you may feel like you're not taking as deep a breath as you did before the surgery. These are normal expected side effects from the interscalene block and are relatively short lived.

The numbness from the block usually lasts from 6-18 hrs. As it begins to wear off you should start your pain medicine that was prescribed by the surgeon.