Interscalene Block Side Effects

An interscalene nerve block is a regional anesthetic commonly used for shoulder and upper-arm surgery as an alternative to general anesthesia. Some sedation is also provided. The patient stays conscious but does not experience pain. Side effects generally are mild.

Procedure

• To provide an interscalene block, an anesthesiologist uses a numbing solution such as bupivacaine on the skin as a local anesthetic, then inserts a needle and guides it to a location near the nerves. He then administers the numbing solution to function as a nerve block.

Time Frame

• The direct effect of numbing can last for up to 18 hours after surgery, as noted by Massachusetts General Hospital, and the patient may not be able to use her shoulder, arm and hand during that time. She should wear a sling to protect the arm.

Cause

• Most interscalene block side effects are caused by the local anesthetic spreading to nerves near the shoulder and arm. It may affect the diaphragm, throat and face.

Side Effects

• Interscalene block side effects may include a hoarse voice, mild difficulty swallowing, mild shortness of breath and drooping eyelids with blurred vision. These effects usually do not last long, according to Massachusetts General Hospital.

Complications

• Extremely rare complications include a punctured lung if the needle pierces the lung lining, and nerve damage causing seizures and long-term nerve dysfunction.