Discuss AACN CCRN-Adult Exam Topic 2 Question 23

A caloric irrigation test of the oculovestibular reflex is performed on a patient who is comatose following a hypoxic brain injury. When cold water is introduced into the left ear, nystagmus occurs with slow deviation of the eyes toward the left, followed by faster eye deviation to the right. This pattern is indicative of a

Apersistent vegetative state.

Bbrain-stem infarction.

Cnormal response.

Dthird cranial nerve palsy.

Suggested Answer: C

The caloric irrigation test, also known as the oculovestibular reflex test, is used to assess brainstem function in patients, especially those who are comatose. In this test, cold water is introduced into the ear canal, which should induce a predictable response if the brainstem is intact. The normal response to cold water irrigation is nystagmus with slow deviation of the eyes toward the side of the cold water (in this case, the left) and a fast phase of eye movement (nystagmus) away from the side of the cold water (to the right). This indicates that the brainstem pathways are functioning properly. Reference: =

American Association of Critical-Care Nurses (AACN). (2024). CCRN Exam Handbook. Retrieved from AACN CCRN Exam Handbook

Adult CCRN/CCRN-E/CCRN-K Certification Review Course Online. AACN

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22 comments · newest first

Isadora 2 days ago

I disagree. It could indicate a brain-stem infarction. The pattern is concerning.

Izetta 7 days ago

I think it's a normal response. The eyes moving right after cold water makes sense.

Cary 12 days ago

I still think A) is the best choice. No awareness means it's not normal.

Karon 17 days ago

But what about D) third cranial nerve palsy? It could explain the eye movement.

Elly 22 days ago

C) normal response makes sense. The eyes moving right is typical.

Kristel 28 days ago

I lean towards B) brain-stem infarction. The pattern suggests brain damage.

Gregg 1 month ago

I disagree, it could be A) persistent vegetative state. No higher function.

Albina 1 month ago

I think it's C) normal response. It shows the reflex is intact.

Kayleigh 1 month ago

So, does this mean the brain is still somewhat functioning?

Cherri 2 months ago

Definitely not a third cranial nerve palsy.

Carole 2 months ago

Wait, are we sure it’s not a brain-stem issue?

Karon 2 months ago

Totally agree, classic nystagmus pattern!

Vallie 2 months ago

This is a normal response to caloric testing.

Cathern 2 months ago

I thought third cranial nerve palsy could show similar signs?

Denny 2 months ago

Definitely not a vegetative state, that’s for sure!

Lavonne 3 months ago

Wait, are we sure it’s normal? Seems a bit off for a comatose patient.

Alfreda 3 months ago

Totally agree, classic nystagmus pattern!

Anjelica 3 months ago

This is a normal response to caloric testing.

Lauryn 3 months ago

I’m a bit confused about the options. I thought a response like this could indicate a third cranial nerve issue, but I’m not confident.

Martina 3 months ago

I practiced a similar question where nystagmus was involved, and I believe it pointed to brain-stem function. Maybe B is the right answer?

Mendy 4 months ago

I'm not entirely sure, but I remember something about cold water irrigation and how it can help differentiate between brain states. Could it be A?

Wilburn 5 months ago

I think the nystagmus response indicates a normal functioning vestibular system, so it might be C.

AACN CCRN-Adult Exam - Topic 2 Question 23 Discussion