Pathogenic effect of environmental factors

2. Diving Emergencies
 Pathophysiology of Diving
Emergencies
 Increased dissolution of gases during descent due to
Henry’s law.
 Boyle’s law dictates that these gases have a smaller
volume.
 In a controlled ascent, the process is reversed and the
gases escape through respiration.
 A rapid ascent causes gases to come out of solution
quickly, forming gas bubbles in the blood, brain,
spinal cord, skin, inner ear, muscles, and joints.

3. Diving Emergencies
 Classification of Diving Emergencies
 Injuries on the Surface
 Injuries During Descent
 Barotrauma
 Injuries on the Bottom
 Nitrogen narcosis
 Injuries During Ascent
 Decompression illness
 Pulmonary overpressure and subsequent arterial gas
embolism, pneumomediastinum, or pneumothorax

4. Diving Emergencies
 General Assessment of Diving
Emergencies
 Time at Which Signs and Symptoms
Appeared
 Type of Breathing Apparatus Used
 Type of Hypothermia-Protective Garment
Worn
 Parameters of the Dive
 Number of dives, depth, and duration
 Aircraft Travel following a Dive

5. Diving Emergencies
 Factors to Assess
 Rate of Ascent
 Associated with panic forcing a rapid ascent
 Inexperience of the Diver
 Improper Functioning of Depth Gauge
 Previous Medical Diseases
 Old Injuries
 Previous Episodes of Decompression Illness
 Use of Alcohol or Medications

6. Pressure Disorders
 Decompression Illness
 May occur with dives of 33’ or
more.
 Signs & Symptoms
 Occur within
36 hours.
 Joint/abdominal
pain.
 Fatigue,
paresthesias,
and CNS
disturbances.
 Treatment
 Recompression.

7. Pressure Disorders
 Treatment
 Assess ABCs and begin CPR if required.
 Administer high-flow oxygen and intubate if indicated.
 Maintain supine position.
 Protect the patient from heat, cold, wetness, or noxious
fumes.
 Transport and establish IV access.
 Consult with medical direction regarding administration
of dexamethasone, heparin, or diazepam if CNS is
involved.
 If aeromedical evacuation is used, maintain cabin
pressure at sea level or fly at the lowest possible altitude.
 Send diving equipment with the patient for analysis if
possible.

8. Pressure Disorders
 Pulmonary Overpressure
Accidents
 Can occur in depths as shallow as 6’.
 Signs & Symptoms
 Substernal chest pain with associated respiratory
distress and diminished breath sounds
 Treatment
 Treat as a pneumothorax.
 Provide rest and supplemental oxygen.

9. Pressure Disorders
 Arterial Gas Embolism
 Signs & Symptoms
 Onset is within 2–10 minutes of ascent .
 There is dramatic onset of sharp, tearing pain.
 Common presentation mimics a stroke; suspect AGE in
any patient with neurological deficits immediately after
ascent.
 Treatment
 Assess ABCs, provide high-flow oxygen.
 Maintain a supine position; monitor vital signs frequently.
 Establish IV access and consider administering
corticosteroids.
 Rapidly transport to a recompression chamber.

10. Pressure Disorders
 Pneumomediastinum
 Signs & Symptoms
 Substernal chest pain, irregular pulse, abnormal
heart sounds, hypotension with a narrow pulse
pressure, and a change in voice
 Treatment
 Provide high-flow oxygen.
 Establish IV access.
 Transport for further evaluation.

11. Pressure Disorders
 Nitrogen Narcosis
 Occurs during a dive.
 Can contribute to accidents during the dive.
 Signs & Symptoms
 Altered levels of consciousness and impaired
judgment.
 Treatment
 Return to shallow depth.
 Use oxygen/helium mix during dive.

12. Diving Emergencies
 Other Diving-Related
Emergencies
 Oxygen Toxicity
 Hypercapnia
 Diver’s Alert Network
 Consultation and Referrals
 (919) 684-8111

13. High-Altitude Illness
 Manifestation
 Altitudes above 8,000’
 Prevention
 Ascend gradually.
 Limit exertion.
 Descend for sleep.
 Eat a high-carbohydrate diet.
 Medications
 Acetazolamide and nifedipine

14. High-Altitude Illness
 Types of High-Altitude Illness
 Acute Mountain Sickness
 Mild cases include lightheadedness,
breathlessness, weakness, headache, nausea, and
vomiting.
 Severe cases include weakness, severe vomiting,
decreased urine output, shortness of breath, and
an altered level of consciousness.
 Treatment includes halting of ascent or descent,
use of acetazolamide and antinausea drugs and
supplemental oxygen.

15. High-Altitude Illness
 High-Altitude Pulmonary Edema
 Mild symptoms include dry cough, shortness of
breath, and slight crackles in the lungs.
 Severe cases develop cyanosis, dyspnea, frothy
sputum, weakness, and possibly coma or death.
 Treatment includes descent and supplemental
oxygen, or portable hyperbaric bag; medications
such as acetazolamide, nifedipine, and lasix may be
useful also.

16. High-Altitude Illness
 High-Altitude Cerebral Edema
 Usually occurs as progression of AMS or HAPE.
 Symptoms include altered mental status, ataxia,
decreased level of consciousness, and coma.
 Treatment includes descent and supplemental
oxygen, or portable hyperbaric bag.