LATEST UNDERSEA & HYPERBARIC MEDICINE
CERTIFICATION EXAM OFFERED BY
AMERICAN BOARD OF PREVENTIVE MEDICINE
| COMPLETE EXAM Q&A WITH RATIONALES
1. A 45-year-old male diver surfaces after a 30-minute
dive to 30 meters (99 feet). He immediately develops
severe right shoulder pain and itching over his
abdomen. Which is the most appropriate next step?
A) Observation with oral hydration
B) 100% oxygen via non-rebreather mask
C) Immediate referral to a hyperbaric chamber
D) Aspirin and NSAIDs
Correct answer: C
Rationale: Neurologic symptoms or severe pain after
diving indicate decompression sickness (DCS).
Immediate hyperbaric oxygen (HBO2) therapy is
indicated.
2. A 35-year-old female diver presents 6 hours after a
dive with progressive numbness in both legs and
difficulty urinating. She is unable to walk. Which is the
most appropriate next step?
A) Computed tomography (CT) of the spine
,B) Magnetic resonance imaging (MRI) of the spine
C) Hyperbaric oxygen therapy (HBO2) immediately
D) Lumbar puncture
Correct answer: C
Rationale: Spinal cord decompression sickness is a
medical emergency requiring immediate HBO2.
Imaging should not delay treatment.
3. A 55-year-old male with a chronic, non-healing
diabetic foot ulcer (Wagner grade 3) has failed 6
weeks of standard wound care. Which is the most
appropriate next step?
A) Surgical debridement alone
B) Hyperbaric oxygen therapy (HBO2) as adjunctive
treatment
C) Amputation
D) Topical growth factors only
Correct answer: B
Rationale: HBO2 is indicated for Wagner grade 3 or
higher diabetic foot ulcers that have failed standard
wound care (non-healing for ≥4-6 weeks).
,4. A 25-year-old male diver surfaces rapidly from a
20-meter dive. He develops confusion, ataxia, and
aphasia. Which is the most appropriate initial
treatment before transport to a hyperbaric chamber?
A) 100% oxygen via tight-fitting mask
B) IV fluids (normal saline)
C) Aspirin
D) Dexamethasone
Correct answer: A
Rationale: 100% oxygen (high-flow) reduces nitrogen
washout and symptom severity. IV fluids and
positioning are adjunctive.
5. A 60-year-old male with radiation cystitis
(hemorrhagic) after prostate cancer treatment has
failed multiple interventions. Which is an FDA-
approved indication for HBO2?
A) Radiation cystitis
B) Radiation proctitis
C) Both A and B
D) Neither A nor B
Correct answer: C
, Rationale: Radiation cystitis and radiation proctitis
are FDA-approved indications for HBO2 for
refractory hemorrhagic cystitis/proctitis.
6. A 40-year-old male undergoes a dive to 40 meters
(132 feet) for 25 minutes. He surfaces and complains
of severe fatigue, chest pain, and dry cough.
Neurologic exam is normal. Which is the most likely
diagnosis?
A) Decompression sickness (DCS) type I (skin bends)
B) Decompression sickness (DCS) type II (pulmonary
manifestations - "the chokes")
C) Arterial gas embolism (AGE)
D) Nitrogen narcosis
Correct answer: B
Rationale: Pulmonary DCS ("the chokes") presents
with chest pain, dry cough, dyspnea, and substernal
burning. It is a serious manifestation requiring HBO2.
7. A 30-year-old male presents with sudden-onset
left-sided weakness and aphasia immediately after
surfacing from a 15-meter dive. He had no preceding
symptoms. Which is the most likely diagnosis?
A) Decompression sickness (DCS)
CERTIFICATION EXAM OFFERED BY
AMERICAN BOARD OF PREVENTIVE MEDICINE
| COMPLETE EXAM Q&A WITH RATIONALES
1. A 45-year-old male diver surfaces after a 30-minute
dive to 30 meters (99 feet). He immediately develops
severe right shoulder pain and itching over his
abdomen. Which is the most appropriate next step?
A) Observation with oral hydration
B) 100% oxygen via non-rebreather mask
C) Immediate referral to a hyperbaric chamber
D) Aspirin and NSAIDs
Correct answer: C
Rationale: Neurologic symptoms or severe pain after
diving indicate decompression sickness (DCS).
Immediate hyperbaric oxygen (HBO2) therapy is
indicated.
2. A 35-year-old female diver presents 6 hours after a
dive with progressive numbness in both legs and
difficulty urinating. She is unable to walk. Which is the
most appropriate next step?
A) Computed tomography (CT) of the spine
,B) Magnetic resonance imaging (MRI) of the spine
C) Hyperbaric oxygen therapy (HBO2) immediately
D) Lumbar puncture
Correct answer: C
Rationale: Spinal cord decompression sickness is a
medical emergency requiring immediate HBO2.
Imaging should not delay treatment.
3. A 55-year-old male with a chronic, non-healing
diabetic foot ulcer (Wagner grade 3) has failed 6
weeks of standard wound care. Which is the most
appropriate next step?
A) Surgical debridement alone
B) Hyperbaric oxygen therapy (HBO2) as adjunctive
treatment
C) Amputation
D) Topical growth factors only
Correct answer: B
Rationale: HBO2 is indicated for Wagner grade 3 or
higher diabetic foot ulcers that have failed standard
wound care (non-healing for ≥4-6 weeks).
,4. A 25-year-old male diver surfaces rapidly from a
20-meter dive. He develops confusion, ataxia, and
aphasia. Which is the most appropriate initial
treatment before transport to a hyperbaric chamber?
A) 100% oxygen via tight-fitting mask
B) IV fluids (normal saline)
C) Aspirin
D) Dexamethasone
Correct answer: A
Rationale: 100% oxygen (high-flow) reduces nitrogen
washout and symptom severity. IV fluids and
positioning are adjunctive.
5. A 60-year-old male with radiation cystitis
(hemorrhagic) after prostate cancer treatment has
failed multiple interventions. Which is an FDA-
approved indication for HBO2?
A) Radiation cystitis
B) Radiation proctitis
C) Both A and B
D) Neither A nor B
Correct answer: C
, Rationale: Radiation cystitis and radiation proctitis
are FDA-approved indications for HBO2 for
refractory hemorrhagic cystitis/proctitis.
6. A 40-year-old male undergoes a dive to 40 meters
(132 feet) for 25 minutes. He surfaces and complains
of severe fatigue, chest pain, and dry cough.
Neurologic exam is normal. Which is the most likely
diagnosis?
A) Decompression sickness (DCS) type I (skin bends)
B) Decompression sickness (DCS) type II (pulmonary
manifestations - "the chokes")
C) Arterial gas embolism (AGE)
D) Nitrogen narcosis
Correct answer: B
Rationale: Pulmonary DCS ("the chokes") presents
with chest pain, dry cough, dyspnea, and substernal
burning. It is a serious manifestation requiring HBO2.
7. A 30-year-old male presents with sudden-onset
left-sided weakness and aphasia immediately after
surfacing from a 15-meter dive. He had no preceding
symptoms. Which is the most likely diagnosis?
A) Decompression sickness (DCS)
