How to Do a Caloric Test

A caloric test is used to diagnose nerve damage to the ears. Typically, the test involves stimulating the inner ear by delivering cold and warm water to the ear canal at different times. It is recommended for patients with dizziness or vertigo, hearing loss associated with certain antibiotics, and certain types of anemia. The test may feel a little uncomfortable and can induce vertigo in some patients. For accurate results, make sure to follow the proper procedure for doing a caloric test.

Instructions

• 1

  Prepare the patient for the caloric test before they come in. They should avoid caffeine, alcohol, allergy medication, and sedatives for at least 24 hours prior to undergoing the test.

• 2

  Hook the patient up to the system of electrodes that will measure their responses. Caloric tests measure eye movements as water is placed in the ear canal. The tests are typically performed on a computerized system for accurate recording of the eye movements during the test.

• 3

  Have the patient recline in a chair with their head inclined 30 degrees so that the lateral ear canal is horizontal.

• 4

  Place the cold water into one ear canal. The water should be about 86 degrees Fahrenheit. Test one ear at a time. Track the patient's eye movements as the computer records them. You should observe rapid, side-to-side eye movements called nystagmus. The patient's eyes should move away from the cold water and slowly back. Nystagmus usually builds for about 30 seconds, then fades over a period of about two minutes. Let the patient rest at least 5 minutes before proceeding to the other ear.

• 5

  Distract the patient during the recording period. This helps ensure accurate results. If the patient is not distracted, he or she may suppress their response, invalidating the test results. Ask basic questions such as "What is your favorite color?", or ask them to perform basic math problems such as addition or subtraction.

• 6

  Repeat the testing process with the warm water, one ear at a time. The water should be about 112 degrees Fahrenheit. The rapid, side-to-side movements should occur again in the opposite direction, as the patient's eyes move toward the warm water and slowly back. Distract the patient as before to ensure accurate results.