Complications and emergencies: brachial plexus injury from positioning: practice question

A Anaesthesia question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Anaesthesia · Complications and emergencies: brachial plexus injury from positioning

Sample item

During a 5-hour supine operation, the left arm lay abducted well beyond 90 degrees on an arm board while the head was turned to the right. Afterwards the arm is weak with patchy sensory loss. What is the usual mechanism of this injury?

ACervical root compression from a disc prolapseBNeedle trauma during an axillary blockCCompression of the ulnar nerve at the elbowDTraction on the brachial plexus

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Traction on the brachial plexus

Hyperabduction of the arm with contralateral head rotation stretches the brachial plexus between its fixed points at the cervical roots and the axillary fascia. Arm abduction should be kept at 90 degrees or less, with the head in a neutral position.

Option by option

A. Cervical root compression from a disc prolapse
A disc prolapse is a spontaneous event with neck and root pain, and it is not linked to the intraoperative posture described.
B. Needle trauma during an axillary block
No regional block is mentioned in the history, and needle injury would be localised to the injected nerve.
C. Compression of the ulnar nerve at the elbow
Elbow compression of the ulnar nerve affects only the ulnar distribution and does not cause global arm weakness.
D. Traction on the brachial plexus (correct)
Correct. Stretching the plexus by abducting the arm while turning the head away is the classic positional mechanism.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is D, Traction on the brachial plexus. Hyperabduction of the arm with contralateral head rotation stretches the brachial plexus between its fixed points at the cervical roots and the axillary fascia.

Why is "Cervical root compression from a disc prolapse" not the answer?

A disc prolapse is a spontaneous event with neck and root pain, and it is not linked to the intraoperative posture described.

Why is "Needle trauma during an axillary block" not the answer?

No regional block is mentioned in the history, and needle injury would be localised to the injected nerve.

Why is "Compression of the ulnar nerve at the elbow" not the answer?

Elbow compression of the ulnar nerve affects only the ulnar distribution and does not cause global arm weakness.

What concept does this question test?

It tests Complications and emergencies: brachial plexus injury from positioning in Anaesthesia. Arm abduction should be kept at 90 degrees or less, with the head in a neutral position.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Complications and emergencies: brachial plexus injury from positioning?

Make a table of each agent, its key advantage and its main side effect. Then use the flashcards and the other Anaesthesia questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.