Do you utilize phrenic nerve EMG in patients with diaphragmatic issues?

Diaphragm muscle needle EMG is definitely a useful tool to assess patients with suspected respiratory muscle weakness/paralysis. It can differentiate neurogenic from myopathic disorders and it can help with prognostication. However, many providers, including myself, are not very comfortable with "blind" needle insertion in the diaphragm based on palpation of anatomic landmarks, because there is always a small (~5%) risk of pneumothorax, and even a small pneumothorax in a patient with underlying diaphragm paralysis and supine hypoxemia could be risky. That said, nowadays there is the option of ultrasound-guided needle insertion which is safe even in more challenging situations, such as obese patients or those taking anticoagulation.

What I wa...

We do phrenic nerve conduction studies on all prospective lung transplant patients so we are very comfortable with this although there are times this can be difficult. The transplant team needs to know about each hemi-diaphragm which spirometry won't tell you. Ultrasound is probably the best approach to see if functional diaphragm but a SNIFF test with fluoroscopy is an option if you don't have an ultrasound. I don't do diaphragmatic EMG for all the reasons Dr. @Dr. First Last mentioned. You need to do this a lot to feel secure.