6-10
Subjective: Symptoms
Pulmonary: Non-productive cough and difficulty breathing, usually exacerbated on inspiration, progressing to
substernal burning and severe pain on inspiration.
Objective: Signs
Using Basic Tools: Pulmonary: Dyspnea, non-productive cough, diminished air exchange (cannot blow out
a match or candle 12-14 inches away).
CNS: “VENTID-C” is the mnemonic for oxygen toxicity. There is no specific order in which these signs and
symptoms appear. The first sign may be convulsions. Only one sign may present or several of the signs may
present: V- Visual disturbances (blurred or tunnel vision), E- Ears (tinnitus), N- Nausea, T- Twitching/tingling
(often seen around the eyes and mouth), I- Irritability, D- Dizziness, C- Convulsions (tonic-clonic), often without
warning.
Using Advanced Tools: CXR may reveal thickening of alveolar and interlobular septa and lung edema.
Assessment:
Differential Diagnosis - decompression sickness (DCS), Arterial Gas Embolism, Pulmonary DCS
("Chokes"), Pulmonary Over Inflation Syndrome
Plan:
Treatment
Pulmonary: Wean patient from oxygen source while maintaining normal respiratory function (pulse-ox above
92%.)
CNS: Remove patient from oxygen source and return to room air at sea level. If convulsions occur at depth,
slowly bring patient to surface with regulator in mouth while compressing the abdomen.
Patient Education
General: Oxygen can be toxic for prolonged exposure and at high partial pressures. When diving with oxygen
rigs a diver needs to stay within the limits established in the Navy Dive Manual.
Diet: Normal
Prevention and Hygiene: Do not return to diving for at least 24 hours and until DMO has cleared the diver.
No Improvement/Deterioration: Consult Diving Medical Officer, pulmonolgist or neurologist.
Follow-up Actions
Return evaluation: Follow patient daily to ensure improvement.
Consultation Criteria: If breathing or neurological problems persist, consult DMO, pulmonologist or neurolo-
gist.
Single Depth Oxygen Exposure Limits (from US Navy Dive Manual Revision 4)
Depth Maximum Oxygen Time
25 FSW 240 minutes
30 FSW 80 minutes
35 FSW 25 minutes
40 FSW 15 minutes
50 FSW 10 minutes
A diver should never be on 100% oxygen for more than 4 hours at any depth in any 24-hour period during
normal diving operations.