CHS CHS Decompression Sickness & Diving Medicine

Question 1

What is the primary pathophysiological mechanism of decompression sickness (DCS)?

Accepted Answer

Formation of nitrogen gas bubbles in tissues and blood during rapid ascent

Answer

Oxygen toxicity from excessive O2 partial pressure during ascent

Answer

Carbon dioxide retention from inadequate ventilation underwater

Answer

Nitrogen narcosis progressing to tissue injury

Question 2

Type II (serious) DCS most commonly affects which body system, making early treatment with HBOT critical?

Accepted Answer

Spinal cord and central nervous system

Answer

Gastrointestinal system

Answer

Renal system

Answer

Hepatic system

Question 3

The US Navy Treatment Table 6 (TT6) is the standard HBOT protocol for serious DCS. At what pressure is the majority of the treatment conducted?

Accepted Answer

3.0 ATA (66 fsw)

Answer

1.5 ATA (15 fsw)

Answer

2.4 ATA (60 fsw)

Answer

6.0 ATA (165 fsw)

Question 4

Which clinical finding is most consistent with arterial gas embolism (AGE) in a SCUBA diver?

Accepted Answer

Sudden loss of consciousness immediately upon or within minutes of surfacing

Answer

Joint pain appearing 12 hours after surfacing

Answer

Mild skin rash appearing 6 hours post-dive

Answer

Fatigue developing 24 hours after a dive

Question 5

When a diver with suspected AGE presents for HBOT, what is the recommended immediate positioning during transport?

Accepted Answer

Supine with head at the same level as the body

Answer

Steep Trendelenburg (head down) position

Answer

Sitting upright at 90 degrees

Answer

Left lateral decubitus (Durant's maneuver) for all cases

Question 6

What is the term for the 'chokes' presentation in DCS, and which body system does it affect?

Accepted Answer

Pulmonary DCS causing chest pain, dyspnea, and coughing from bubbles in pulmonary vasculature

Answer

Cutaneous DCS affecting the skin with marbling

Answer

Inner ear DCS causing vertigo and hearing loss

Answer

Type I DCS causing only joint pain