Bacterial culture, middle ear fluid

This test detects and identifies bacteria from fluid or discharge found in the middle ear. It is used to help treat acute otitis media (inflammation of the middle ear) and chronic purulent otitis media. A sample of fluid or discharge from the middle ear may be collected by sterile swab, tympanocentesis or myringotomy.

Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:

• Acute middle ear infection
• Chronic middle ear infections with pus
• Mastoiditis

Ask the healthcare worker for information about how to prepare for this test.

If tympanocentesis or myringotomy will be done, a written consent may be required. Review the consent form with the healthcare worker and ask any questions that you have before signing the consent form. Before either of these procedures are done, healthcare workers may remove earwax and other material from your ear.

Methods used to obtain a sample for culture vary and will depend on the healthcare worker. For perforated (burst) eardrums, fluid or pus may be collected from your ear canal. The sample may be obtained using a sterile cotton-tipped swab. The sample is placed in a sterile container, and sent to the laboratory for testing.

For intact eardrums, a tympanocentesis may be done. An ear speculum and a special magnifying tool called an operative otoscope are used to locate and inspect your eardrum. The healthcare worker will puncture your eardrum with a needle, and remove the fluid using a syringe. The fluid sample from the middle ear is collected using a sterile swab, and placed in a container to be tested.

If a myringotomy is done, an ear speculum and a special magnifying tool called an operative otoscope are used to locate and inspect your eardrum. The healthcare worker will make a small cut on your eardrum. The fluid sample from the middle ear is collected into a sterile suction trap or device. It is gathered using a sterile swab, and placed in a container for testing.

The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.

There is usually no pain experienced when a sample from the middle ear is collected by a sterile swab. This method of collection is usually done for perforated eardrums when fluid or pus is already draining from the ear.

If tympanocentesis or myringotomy will be done, general or local anesthesia may be used. General anesthesia is done by an anesthesiologist. During general anesthesia, you receive medication that puts you into a deep sleep where you are unable to feel pain.

During local anesthesia, a topical anesthetic (numbing medicine) is instilled into the eardrum. You may feel some discomfort when tools are used to inspect the eardrum. There could be pain or discomfort when the eardrum is punctured or cut. Once the fluid has been drained, there will be a feeling of relief from the pain or pressure caused by the fluid that had gathered in the middle ear.

Depending on the procedure used to obtain the sample of middle ear fluid, ask the healthcare worker for any special instructions for you to follow.

You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.