Oculovestibular reflex (cold caloric test) is performed by trauma surgeons and surgical intensivists must sometimes assess the patient for brain death. One clinical test that is often performed in these situations is the oculovestibular reflex or cold caloric test. One protocol is as follows:
1. Place the patient’s head in 30-degree up position either by using reverse Trendelenburg or raising the head of the bed.
2. Place 200 cc of tap water into ice. Stay in the good graces of the nursing staff by placing a kidney basin or multiple chucks under each ear.
3. Inspect each ear canal for cerumen and if present, remove with Q-tip.
4. Have an assistant open both eyelids and retract open with fingers if needed.
5. With a Toomey syringe, slowly inject 50 cc into one of the external auditory canals.
Toomey syringe
6. Continuously monitor over a 5 minute period for tonic eye movements toward the side of the cold water stimulus.
7. If no movement is detected, repeat the injection in the same ear and observe for 5 minutes.
8. If no movement is detected, wait 5 minutes and repeat the above steps in the other ear canal.
9. If no movement is detected in any of the above steps, the cold caloric test is considered to be abnormal and likely is consistent with brainstem death if other confounding variables precluding the determination of brain death are absent (e.g., not hypothermic, absence of certain medications, etc.)
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