Trauma and burns: venous air embolism: practice question

A General Surgery 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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General Surgery · Trauma and burns: venous air embolism

Sample item

A man with a stab wound to the base of the neck suddenly becomes hypotensive, cyanosed and breathless. A hissing sound is heard from the wound and a mill-wheel murmur is audible over the precordium. What is the immediate action?

AStart a heparin infusionBPerform urgent pericardiocentesisCOcclude the wound, place him head-down in the left lateral position and aspirate air from the right heartDPerform needle decompression of the chest

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

The answer and the reasoning

C. Occlude the wound, place him head-down in the left lateral position and aspirate air from the right heart

Air entering an open neck vein can lodge in the right ventricle and cause an air lock. The wound is occluded, and the patient is positioned head-down on the left side so air collects at the apex of the right ventricle away from the outflow. Air can then be aspirated through a central catheter.

Option by option

A. Start a heparin infusion
Heparin does not treat an air embolus and could increase bleeding.
B. Perform urgent pericardiocentesis
Pericardiocentesis treats tamponade, which does not produce a hissing wound.
C. Occlude the wound, place him head-down in the left lateral position and aspirate air from the right heart (correct)
Correct. Positioning to trap air in the right ventricle apex and aspirating it relieves the air lock.
D. Perform needle decompression of the chest
Needle decompression treats tension pneumothorax, which does not cause a mill-wheel murmur.

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 General Surgery question

What is the answer to this General Surgery question?

The best answer is C, Occlude the wound, place him head-down in the left lateral position and aspirate air from the right heart. Air entering an open neck vein can lodge in the right ventricle and cause an air lock.

Why is "Start a heparin infusion" not the answer?

Heparin does not treat an air embolus and could increase bleeding.

Why is "Perform urgent pericardiocentesis" not the answer?

Pericardiocentesis treats tamponade, which does not produce a hissing wound.

Why is "Perform needle decompression of the chest" not the answer?

Needle decompression treats tension pneumothorax, which does not cause a mill-wheel murmur.

What concept does this question test?

It tests Trauma and burns: venous air embolism in General Surgery. The wound is occluded, and the patient is positioned head-down on the left side so air collects at the apex of the right ventricle away from the outflow. Air can then be aspirated through a central catheter.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Trauma and burns: venous air embolism?

Learn classic signs and eponyms alongside what they diagnose. Then use the flashcards and the other General Surgery 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.