PAM Treatment Protocols & Procedures 2 — Questions and Answers
Question 1: When applying moist heat packs, what is the standard layering guideline to prevent burns?
- Direct skin contact for maximum heat transfer
- 6–8 layers of toweling between pack and skin (Correct answer)
- 1–2 layers of toweling with a plastic barrier
- Ice pack placed on top to regulate temperature
Correct answer: 6–8 layers of toweling between pack and skin
Six to eight layers of toweling (or equivalent insulation) are placed between the hydrocollator pack and skin to prevent thermal burns.
Question 2: A patient with Raynaud's phenomenon is referred for upper extremity pain. Which thermal modality is contraindicated?
- Moist heat pack to the shoulder
- Ultrasound to the forearm
- Cold pack to the hand (Correct answer)
- Paraffin bath to the fingers
Correct answer: Cold pack to the hand
Cold application is contraindicated in Raynaud's phenomenon because it triggers vasospasm and can worsen ischemia.
Question 3: During iontophoresis with dexamethasone, under which electrode is the medication placed?
- Positive electrode (anode), because dexamethasone carries a negative charge
- Negative electrode (cathode), because dexamethasone carries a negative charge (Correct answer)
- Dispersive electrode, regardless of drug charge
- Either electrode; polarity does not matter for corticosteroids
Correct answer: Negative electrode (cathode), because dexamethasone carries a negative charge
Dexamethasone sodium phosphate carries a negative charge and is placed under the cathode (negative electrode) to be driven into tissue by like-charge repulsion.
Question 4: The recommended duty cycle for pulsed ultrasound intended to produce non-thermal (mechanical) effects is:
- 100%
- 50% or less (Correct answer)
- 75%
- Any duty cycle above 75%
Correct answer: 50% or less
A duty cycle of 50% or less (commonly 20%) allows tissue to cool between pulses, minimizing thermal effects and promoting non-thermal cavitation and streaming.
Question 5: Which parameter determines the depth of penetration for therapeutic ultrasound?
- Intensity (W/cm²)
- Duty cycle
- Frequency (MHz) (Correct answer)
- Treatment duration
Correct answer: Frequency (MHz)
Frequency determines penetration depth: 1 MHz penetrates to 3–5 cm, while 3 MHz penetrates only 1–2 cm into tissue.
Question 6: A therapist is applying TENS for chronic low back pain. Which mode is most appropriate for long-duration pain modulation via endorphin release?
- Conventional (high-frequency, low-intensity) TENS
- Acupuncture-like (low-frequency, high-intensity) TENS (Correct answer)
- Brief-intense TENS
- Burst-mode TENS at high frequency
Correct answer: Acupuncture-like (low-frequency, high-intensity) TENS
Acupuncture-like TENS uses low frequency (1–4 Hz) and high intensity to stimulate A-delta fibers and promote endorphin-mediated analgesia for chronic pain.
Question 7: What is the primary reason a coupling medium (gel or water) is required during therapeutic ultrasound?
- To increase the temperature of the transducer head
- To prevent electrical shock to the patient
- To eliminate the air interface that would reflect ultrasound waves (Correct answer)
- To lower the frequency of the sound waves
Correct answer: To eliminate the air interface that would reflect ultrasound waves
Ultrasound cannot travel through air; coupling gel or water eliminates the air-tissue interface so acoustic energy is transmitted efficiently into tissue.
PAM Treatment Protocols & Procedures 2
When applying moist heat packs, what is the standard layering guideline to prevent burns?