Regional anaesthesia: retrobulbar block complication: 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 · Regional anaesthesia: retrobulbar block complication

Sample item

Minutes after a retrobulbar block for cataract surgery, a patient becomes drowsy, apnoeic and bradycardic with contralateral pupil dilation. What is the likely cause?

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

The answer and the reasoning

B. Brainstem anaesthesia from spread along the optic nerve sheath

Local anaesthetic can enter the subarachnoid space around the optic nerve and reach the brainstem, causing apnoea, loss of consciousness and cardiovascular instability. Treatment is supportive with airway management, ventilation and circulatory support until the effect resolves. Other complications include globe perforation and retrobulbar haemorrhage.

Option by option

  • A. Oculocardiac reflex only

    The oculocardiac reflex causes bradycardia but not apnoea and altered consciousness.

  • B. Brainstem anaesthesia from spread along the optic nerve sheath (correct)

    Correct. Spread to the brainstem gives this characteristic early picture.

  • C. Anaphylaxis to latex

    Anaphylaxis would produce rash, bronchospasm and hypotension.

  • D. Malignant hyperthermia

    Malignant hyperthermia presents with rising temperature and ETCO2.

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.

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Questions about this Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is B, Brainstem anaesthesia from spread along the optic nerve sheath. Local anaesthetic can enter the subarachnoid space around the optic nerve and reach the brainstem, causing apnoea, loss of consciousness and cardiovascular instability.

Why is "Oculocardiac reflex only" not the answer?

The oculocardiac reflex causes bradycardia but not apnoea and altered consciousness.

Why is "Anaphylaxis to latex" not the answer?

Anaphylaxis would produce rash, bronchospasm and hypotension.

Why is "Malignant hyperthermia" not the answer?

Malignant hyperthermia presents with rising temperature and ETCO2.

What concept does this question test?

It tests Regional anaesthesia: retrobulbar block complication in Anaesthesia. Treatment is supportive with airway management, ventilation and circulatory support until the effect resolves. Other complications include globe perforation and retrobulbar haemorrhage.

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 Regional anaesthesia: retrobulbar block complication?

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.