This was covered in the opening of the February EMRAP however not something that I was at all familiar with.  Here are the basics and something that is probably rare but worth knowing about:

 In the episode they presented a case of  70 year old female that was brought in with a complaint of shortness of breath. RR = 28 and SA02 – 88%. The patient presented three hours after a right shoulder arthroscopy.  

ECG : normal

CXR: elevation of the right hemidiaphragm

 Dx:  paralysis of right hemidiaphram after intrascalene nerve block

There are two major complications associated with intrascalene nerve blocks: 1. pneumothorax

2. unilateral phrenic nerve paralysis.

The patient likely had a transient phrenic nerve dysfunction causing unilateral diaphragmatic paralysis.  Younger patients can compensate, older patients with co-morbid conditions may not be able to tolerate this as only one lung is effectively ventilating.

The patient in this case was managed with supplemental 02 until the buvipicane wore off.  Some patients with underlying lung disease and this complication may require BiPAP/CPAP or intubation.  

Things that I took away:

•  be aware of this procedure and this complication
• this may be done for patients with same days surgeries to the upper extremity and this is important history to have from Pt or family.
• It may be missed prior to d/c.  This was an example of one that was missed by Anesthesia prior to d/c of the patient. 
• May look clinically like PE (tachypnea, tachycardia, post-op patient), however,  history will help make the dx as well as CXR.

A little more about the block:

Interscalene nerve block is typically performed to provide analgesia for upper extremity surgeries and may or may not be combined with mild general anesthesia.

 Example of Surgeries this may be used for:

-Shoulder surgery, such as rotator cuff repair, acromioplasty, hemiarthroplasty, and total shoulder replacement

– Humerus fracture