PTA & Masking OSCE

Hand Hygiene and Equipment Cleaning Procedures

Hand Hygiene Protocols

  • Perform hand hygiene using the clinical method, washing hands for at least 20-40 seconds before and after every patient interaction, and after glove removal.

  • If washing facilities are unavailable, use an alcohol-based hand rub as an alternative.

  • The NHS recommends that arms be bare below the elbow to facilitate effective hand washing, minimizing the risk of contamination.

  • Jewelry should not be worn during procedures to prevent harboring bacteria and to ensure thorough cleaning of hands.

Cleaning Work Areas and Equipment

  • Use disinfectant wipes to clean all surfaces in the work area, including desks, keyboards, and chairs, to maintain a hygienic environment.

  • Clean all equipment that will be used on patients, such as AC and BC transducers and response buttons, using disinfectant wipes.

  • Ensure that cleaned equipment is placed on a clean tissue to avoid recontamination before use.

  • Electrical equipment, including audiometers and tympanometers, must be kept clean and dust-free to ensure accurate functioning.

Equipment Function Checks and Maintenance

Daily and Weekly Equipment Checks

  • Daily checks include untangling leads, ensuring they are plugged into the correct sockets, and switching on equipment to allow it to warm up for 5 minutes.

  • Verify calibration dates and ensure serial numbers match on equipment to maintain compliance and accuracy.

  • Weekly checks involve listening for unwanted sounds at soft levels, checking the tension of transducer headbands, and performing audiograms on known subjects to detect deviations from previous results.

Yearly Calibration and Functionality Checks

  • Yearly checks are conducted by an external company to calibrate all equipment, ensuring compliance with industry standards.

  • The date of the last calibration check is typically found on the audiometer, serving as a reference for maintenance schedules.

  • Regular calibration is crucial as transducers must be calibrated to specific audiometers to ensure accurate sound delivery and measurement.

Pre-Test Procedures and Patient Interaction

Pre-Test Preparations

  • Review the patient's medical history and previous test results to understand their clinical needs before conducting any procedures.

  • Obtain relevant history from the patient regarding their suitability for PTA/masking testing and identify any contraindications, such as excessive pain or infection.

  • Perform otoscopy to check for any issues like occluding wax that may affect the test results.

Patient Communication and Instruction

  • Clearly instruct the patient on the testing procedure, using appropriate communication strategies tailored to their needs.

  • Reinforce instructions as necessary, ensuring the patient understands how to respond during the hearing test, such as pressing the response button when they hear a sound.

  • Position the patient so they cannot see the audiometer screen or hear the testing procedure, maintaining the integrity of the test.

Transducer Positioning and Patient Comfort

Correct Positioning of Transducers

  • Ensure transducers are positioned correctly throughout the procedure to maximize patient comfort and test accuracy.

  • For air conduction (AC) testing, ensure ears are fully covered and the headband is secure; check that foam inserts are used appropriately after otoscopy.

  • For bone conduction (BC) testing, place the transducer on the mastoid of the worse ear, ensuring it is close to the pinna without touching the hair.

Importance of Proper Transducer Positioning

  • Correct positioning of transducers is crucial for accurate audiometric testing, ensuring that sound is delivered effectively to the patient's ears.

  • Transducers must be placed comfortably to avoid discomfort, which can affect the patient's responses during testing.

  • Prior to testing, patients should be asked to remove glasses, hearing aids, and any headgear to facilitate proper placement of transducers.

Guidelines for Air Conduction (AC) Testing

  • Ensure that the ears are fully covered by the headphones, and the headband is secure to prevent sound leakage.

  • If foam inserts are used, otoscopy should be performed before and after to check for any obstructions or issues in the ear canal.

  • The testing should start with the better ear, if applicable, to establish a baseline for comparison.

Guidelines for Bone Conduction (BC) Testing

  • The bone conductor should be placed on the mastoid of the worse ear, ensuring it does not touch any hair to avoid interference with sound transmission.

  • The placement should be near the pinna to maximize sound delivery while maintaining patient comfort.

Summary of Key Procedures and Best Practices

Best Practices for Audiology Testing

  • Always prioritize hand hygiene and equipment cleanliness to prevent cross-contamination and ensure patient safety.

  • Regularly check and maintain equipment functionality to ensure accurate testing results and compliance with health standards.

  • Adapt testing methods to suit individual patient needs, considering factors such as age, physical condition, and specific hearing issues.

Audiometric Testing Procedures

Initial Setup and Tone Presentation

  • Begin testing at 1KHz with a starting level of 40dB, adjusting as necessary based on patient responses.

  • Vary the intervals and duration of tones presented (1-3 seconds) to prevent the patient from guessing the pattern of tones, which could skew results.

  • Use appropriate symbols on the audiogram to accurately represent the patient's hearing thresholds throughout the testing process.

Air Conduction Testing Methodology

  • Use the ascending method: increase the tone level by 10dB if not heard, and then decrease by 10dB until no response is given, marking the threshold level.

  • Follow the correct frequency order: 1KHz, 2KHz, 4KHz, 8KHz, 500Hz, and 250Hz, with additional frequencies as needed based on the audiogram shape.

  • Repeat the 1000Hz test for the first ear to confirm consistency in results, and take appropriate action if discrepancies arise.

Bone Conduction Testing Methodology

  • Initially test BC on the worst ear, using the ascending method similar to AC testing.

  • Follow the correct frequency order, ideally starting with 1KHz, 2KHz, and 500Hz, but also including other frequencies as necessary based on local policies.

  • Identify the need for masking based on the differences between AC and BC thresholds, applying the appropriate rules to ensure accurate results.

Masking Procedures and Clinical Considerations

Masking Guidelines and Techniques

  • Provide clear masking instructions to the patient, ensuring they understand when to respond during the test, even for faint sounds.

  • Use a masking grid or chart to document tone thresholds versus masking levels, ensuring a minimum of four levels of masking are covered unless limited by equipment.

  • Be cautious with masking noise levels above 80dB EML or tones above 100dB HL, especially in patients with tinnitus, as this can exacerbate their condition.

Clinical Need for Audiometric Testing

  • The primary goal of audiometric testing is to determine the quietest tones a patient can hear across various frequencies, confirming the presence and severity of hearing loss.

  • Masking is essential to prevent transcranial transmission, ensuring that the test ear is not aided by the non-test ear during testing.

  • Regular equipment checks are necessary to maintain testing accuracy, including checking for unwanted sounds and ensuring all components function properly.

Contraindications and Special Care Considerations

  • Contraindications for testing include occluding wax, foreign objects, discharge, or any conditions that may cause excessive pain or discomfort to the patient.

  • Special care should be taken in cases of collapsed ear canals or swelling around the pinna, as these can affect the accuracy of the test results.

  • Understanding the different types of hearing loss (conductive, mixed, sensorineural) is crucial for interpreting results and determining appropriate follow-up actions.

Factors Influencing Test Accuracy

Common Influences on Test Results

  • Poor patient communication can lead to misunderstandings about the testing process, affecting the accuracy of responses.

  • Patient fatigue can impact performance, making it essential to ensure the patient is comfortable and alert during testing.

  • Equipment calibration is critical; uncalibrated or faulty equipment can yield inaccurate results, necessitating regular checks and maintenance.

Types of Hearing Loss and Their Implications

  • Conductive hearing loss is characterized by a blockage in the outer or middle ear, leading to a significant air-bone gap (20+ dB) across specific frequencies.

  • Mixed hearing loss involves both conductive and sensorineural components, indicated by a gap of more than 10dB between AC and BC thresholds.

  • Sensorineural hearing loss results from damage to the cochlea or auditory nerve, typically indicated when BC thresholds are within 5dB of AC thresholds.