Brachial plexus injuries due to improper positioning

[stevierae]

Just want to validate something. From my own understanding of what I have learned about proper positioning over the years, a brachial plexus injury to an adult patient (I don't want to get into Erb's palsy of the newborn) is either from prolonged stretch (such as prolonged or exaggerated hyperextension, prolonged or exaggerated lateral extension, or prolonged or exaggerated rotation of the head) or from improper or no arm padding, or excessive abduction of the arm, such as from angling the armboard in excess of 90 degrees, or even allowing the arm to fall off the armboard (such as might occur with fasciculation during induction if the arm isn't restrained at the wrist, thus sustaining an acute stretch injury.)

Am I correct so far?

So, this is what I wonder about. I always thought the brachial plexus began at C-5. If a patient has limited ROM (frozen shoulder; can't lift arm, but no rotator cuff or other orthopedic injury present) and documented atrophy of one arm post-op (with no previous history of arm or shoulder impingement and normal ROM pre-op) it seems pretty clear to me that this must be a brachial plexus injury, and that this would be confirmed by EMG or other nerve conduction studies.

But, what if the EMG or other nerve conduction studies show involvement at C-4 as well? If C-4 is not technically part of the brachial plexus, is this, then, a separate and distinct injury, perhaps caused by surgical trauma, not due to positioning? And if C4 is not part of the brachial plexus, what, then, is it? Is there an area specifically innervated by nerves at the C4 level? Isn't the diaphragm innervated by nerves at C4? There are no problems with spontaneous respirations in this situation.

Or would you simply lump an injury to both C4 and C-5 (and C6-7) inot the category of "upper trunk neuropathy?" I just don't see how it can be called a brachioplexopathy given that C4 is involved. I am doing some Q.A. and simply want to call things by their proper names, and I suspect these are two separate and distinct inuries--and that the one at C4 can't be blamed on stretch or improper positioning, but instead surgical insult to a nerve at C-4.

Thanks for your input and sharing your experience and expertise.

[TraumaNurse]

C-4 can be part of the brachial plexus and is referred to as pre-fixed. The brachial plexus may also include down to T2 which is post-fixed. In general, the brachial plexus range is from C5-T1 but may also include C4 and T2. Hope this helps.

[stevierae]

C-4 can be part of the brachial plexus and is referred to as pre-fixed. The brachial plexus may also include down to T2 which is post-fixed. In general, the brachial plexus range is from C5-T1 but may also include C4 and T2. Hope this helps.

It does help, very much. Thank you for clearing up my confusion. I have never heard the terms pre-or post-fixed before.