CHS Patient Assessment & Evaluation 3 — Questions and Answers
Question 1: Which patient scenario represents an ABSOLUTE contraindication to hyperbaric oxygen therapy?
- Untreated pneumothorax (Correct answer)
- Controlled hypertension on medication
- History of myringotomy with current patent tubes
- Claustrophobia managed with benzodiazepines
Correct answer: Untreated pneumothorax
Untreated pneumothorax is an absolute contraindication because pressurization can convert it to a life-threatening tension pneumothorax.
Question 2: When assessing a wound for HBO therapy candidacy, which wound characteristic indicates the BEST potential response?
- Eschar-covered wound with no periwound erythema
- Wound with transcutaneous oxygen measurement (TCOM) of 40 mmHg on room air that rises to >200 mmHg with normobaric oxygen (Correct answer)
- Wound with TCOM of 10 mmHg unresponsive to oxygen challenge
- Gangrenous wound with absent pedal pulses and no Doppler signal
Correct answer: Wound with transcutaneous oxygen measurement (TCOM) of 40 mmHg on room air that rises to >200 mmHg with normobaric oxygen
A TCOM that responds robustly to oxygen challenge indicates viable tissue with potentially reversible ischemia, predicting good HBO response.
Question 3: A patient scheduled for HBO is found to have a fever of 38.9°C (102°F). What is the most appropriate action?
- Proceed with treatment; fever is not a contraindication
- Postpone treatment and notify the physician (Correct answer)
- Lower chamber pressure to 1.5 ATA only
- Administer antipyretics and treat immediately
Correct answer: Postpone treatment and notify the physician
Fever lowers the seizure threshold, increasing CNS oxygen toxicity risk, so treatment should be postponed until the patient is afebrile.
Question 4: During the initial patient assessment for HBO therapy, the technologist notes the patient has a pacemaker. What is the next step?
- Cancel treatment; pacemakers are an absolute contraindication
- Verify with the cardiologist that the device is rated as pressure-proof (Correct answer)
- Proceed with monoplace chamber treatment only
- Use multiplace chamber so the device can be removed externally
Correct answer: Verify with the cardiologist that the device is rated as pressure-proof
Most modern pacemakers are pressure-safe, but confirmation from the manufacturer and cardiologist is required before proceeding.
Question 5: Which pulmonary function finding would be MOST concerning when evaluating a patient for HBO therapy?
- FEV1/FVC ratio of 0.70
- Presence of bullae on chest X-ray (Correct answer)
- FVC of 85% predicted
- Mild obstructive pattern with bronchodilator response
Correct answer: Presence of bullae on chest X-ray
Pulmonary bullae can trap gas and rupture during decompression, creating a pneumothorax, making this a significant contraindication concern.
Question 6: What is the purpose of performing a TCOM (transcutaneous oxygen measurement) prior to initiating HBO therapy for a diabetic foot wound?
- To measure blood glucose levels transdermally
- To quantify tissue oxygen delivery and predict healing potential (Correct answer)
- To assess peripheral neuropathy severity
- To screen for deep vein thrombosis
Correct answer: To quantify tissue oxygen delivery and predict healing potential
TCOM measures tissue oxygenation at wound margins to determine ischemia severity and predict whether HBO will enhance healing.
Question 7: A patient being assessed for HBO therapy mentions recent use of doxorubicin (Adriamycin). This is clinically relevant because:
- It causes Eustachian tube dysfunction
- It may potentiate cardiac oxygen toxicity
- It blocks mitochondrial electron transport, increasing pulmonary toxicity risk (Correct answer)
- It increases risk of hypoglycemia during treatment
Correct answer: It blocks mitochondrial electron transport, increasing pulmonary toxicity risk
Doxorubicin interferes with mitochondrial function and may potentiate pulmonary oxygen toxicity, making it a relative contraindication for HBO.
CHS Patient Assessment & Evaluation 3
Which patient scenario represents an ABSOLUTE contraindication to hyperbaric oxygen therapy?