NEWEST UNDERSEA & HYPERBARIC
MEDICINE CERTIFICATION EXAM FOR
THE AMERICAN BOARD OF EMERGENCY
MEDICINE (ABMS) | Q&A WITH
RATIONALES
1. According to Henry’s Law, the amount of gas
dissolved in a liquid is:
A) Inversely proportional to the partial pressure of
the gas
B) Directly proportional to the partial pressure of the
gas
C) Independent of the partial pressure of the gas
D) Proportional to the square root of the partial
pressure
Correct answer: B
Rationale: Henry’s Law states that the concentration
of a gas in a liquid is directly proportional to its partial
pressure at equilibrium.
2. The most common symptom of decompression
sickness (DCS) in recreational divers is:
A) Neurological symptoms (paresthesias, weakness)
,B) Joint pain (the bends, type I DCS)
C) Cutaneous manifestations (mottling, pruritus)
D) Pulmonary symptoms (chokes)
Correct answer: B
Rationale: Type I DCS (musculoskeletal) presents
with joint pain (the bends) in 70-80% of cases;
neurological symptoms are also common (type II).
3. The gold standard treatment for decompression
sickness (DCS) and arterial gas embolism (AGE) is:
A) High-flow oxygen at normobaric pressure
B) Hyperbaric oxygen therapy (HBOT) at 2.8
atmospheres absolute (ATA) or per U.S. Navy
treatment tables
C) Intravenous fluids and aspirin
D) Corticosteroids
Correct answer: B
Rationale: Hyperbaric oxygen therapy (HBOT) is the
definitive treatment for DCS and AGE, reducing
bubble size and providing high tissue oxygen.
,4. The U.S. Navy Treatment Table 6 (TT6) for
decompression sickness includes which of the
following pressure profile?
A) Compression to 2.8 ATA (60 feet) for 60 minutes,
then slow decompression with oxygen/air breaks
B) Compression to 6 ATA (165 feet) for 30 minutes
C) Compression to 1.5 ATA (16 feet) for 120 minutes
D) No compression (normobaric oxygen only)
Correct answer: A
Rationale: TT6 involves compression to 2.8 ATA (60
fsw), oxygen breathing periods, and air breaks;
duration approximately 4-5 hours.
5. The primary mechanism by which hyperbaric
oxygen (HBO) reduces bubble size in decompression
sickness is:
A) Vasoconstriction
B) Boyle's Law (increased pressure reduces bubble
volume)
C) Oxygen free radical production
D) Anti-inflammatory effects
Correct answer: B
, Rationale: Increased ambient pressure (Boyle’s Law)
compresses existing gas bubbles, reducing their
volume and tissue distortion.
6. A diver surfaces after a deep dive and immediately
loses consciousness, then regains consciousness
but remains confused and has right-sided weakness.
The most likely diagnosis is:
A) Decompression sickness (type II, neurological)
B) Arterial gas embolism (AGE) – often from
pulmonary barotrauma
C) Nitrogen narcosis
D) Hypothermia
Correct answer: B
Rationale: Rapid onset (immediately after surfacing)
of neurological deficits suggests arterial gas
embolism, often from pulmonary barotrauma.
7. The most common mechanism of arterial gas
embolism (AGE) in divers is:
A) Decompression sickness with venous bubbles
B) Pulmonary barotrauma of ascent (overexpansion
of lungs) forcing air into pulmonary veins
MEDICINE CERTIFICATION EXAM FOR
THE AMERICAN BOARD OF EMERGENCY
MEDICINE (ABMS) | Q&A WITH
RATIONALES
1. According to Henry’s Law, the amount of gas
dissolved in a liquid is:
A) Inversely proportional to the partial pressure of
the gas
B) Directly proportional to the partial pressure of the
gas
C) Independent of the partial pressure of the gas
D) Proportional to the square root of the partial
pressure
Correct answer: B
Rationale: Henry’s Law states that the concentration
of a gas in a liquid is directly proportional to its partial
pressure at equilibrium.
2. The most common symptom of decompression
sickness (DCS) in recreational divers is:
A) Neurological symptoms (paresthesias, weakness)
,B) Joint pain (the bends, type I DCS)
C) Cutaneous manifestations (mottling, pruritus)
D) Pulmonary symptoms (chokes)
Correct answer: B
Rationale: Type I DCS (musculoskeletal) presents
with joint pain (the bends) in 70-80% of cases;
neurological symptoms are also common (type II).
3. The gold standard treatment for decompression
sickness (DCS) and arterial gas embolism (AGE) is:
A) High-flow oxygen at normobaric pressure
B) Hyperbaric oxygen therapy (HBOT) at 2.8
atmospheres absolute (ATA) or per U.S. Navy
treatment tables
C) Intravenous fluids and aspirin
D) Corticosteroids
Correct answer: B
Rationale: Hyperbaric oxygen therapy (HBOT) is the
definitive treatment for DCS and AGE, reducing
bubble size and providing high tissue oxygen.
,4. The U.S. Navy Treatment Table 6 (TT6) for
decompression sickness includes which of the
following pressure profile?
A) Compression to 2.8 ATA (60 feet) for 60 minutes,
then slow decompression with oxygen/air breaks
B) Compression to 6 ATA (165 feet) for 30 minutes
C) Compression to 1.5 ATA (16 feet) for 120 minutes
D) No compression (normobaric oxygen only)
Correct answer: A
Rationale: TT6 involves compression to 2.8 ATA (60
fsw), oxygen breathing periods, and air breaks;
duration approximately 4-5 hours.
5. The primary mechanism by which hyperbaric
oxygen (HBO) reduces bubble size in decompression
sickness is:
A) Vasoconstriction
B) Boyle's Law (increased pressure reduces bubble
volume)
C) Oxygen free radical production
D) Anti-inflammatory effects
Correct answer: B
, Rationale: Increased ambient pressure (Boyle’s Law)
compresses existing gas bubbles, reducing their
volume and tissue distortion.
6. A diver surfaces after a deep dive and immediately
loses consciousness, then regains consciousness
but remains confused and has right-sided weakness.
The most likely diagnosis is:
A) Decompression sickness (type II, neurological)
B) Arterial gas embolism (AGE) – often from
pulmonary barotrauma
C) Nitrogen narcosis
D) Hypothermia
Correct answer: B
Rationale: Rapid onset (immediately after surfacing)
of neurological deficits suggests arterial gas
embolism, often from pulmonary barotrauma.
7. The most common mechanism of arterial gas
embolism (AGE) in divers is:
A) Decompression sickness with venous bubbles
B) Pulmonary barotrauma of ascent (overexpansion
of lungs) forcing air into pulmonary veins
