This document defines and describes various altitude illnesses including acute mountain sickness (AMS), high altitude cerebral edema (HACE), and high altitude pulmonary edema (HAPE). It lists signs and symptoms of each condition and outlines emergency care, situations requiring evacuation, and prevention techniques. Prevention focuses on gradual ascent, limiting exertion, descending for sleep, diet, and potential medications.

1. ALTITUDE &
DECOMPRESSION
SICKNESS

2. OBJECTIVES
• Define altitude illnesses, include Acute Mountain
Sickness (AMS), High Altitude Cerebral Edema
(HACE) & High Altitude Pulmonary Edema (HAPE)
• List signs & symptoms of AMS, HACE, HAPE
• Describe emergency care for AMS, HACE, HAPE
• Describe situations that require evacuation
• Describe prevention techniques

3. ALTITUDE ILLNESS OVERVIEW
• Altitude illness occurs when people at high elevation do not get
enough oxygen
• As you gain altitude air grows thinner (less air pressure) &
less oxygen is inhaled
• Most common altitude illness is Acute Mountain Sickness (AMS)
• AMS commonly occurs when person recently has reached heights of
6500 – 8000 feet

4. ALTITUDE ILLNESS OVERVIEW
(CONT’D.)
• Symptoms similar to dehydration & heat illness. (If at lower
altitude < 6500 feet suspect those first)
• High Altitude Cerebral Edema (HACE) is cause by fluid collecting in
the brain tissues. If untreated can lead to death
• High Altitude pulmonary edema (HAPE) is caused when fluid collects
in air spaces in the lungs. HAPE can be life threatening.

5. CHECKING FOR ACUTE MOUNTAIN
SICKNESS (AMS)
• Acute Mountain Sickness Signs & Symptoms:
• Headache
• Loss of normal appetite
• Nausea, with/without vomiting
• Insomnia
• Unusual weariness & exhaustion, called “lassitude”

6. CARING FOR AMS
• Descend or stop ascent & wait for improvement. If
illness progresses, descent is mandatory
• Administer oxygen, if available & trained to do so.
Especially helpful during sleep
• Give aspirin or acetaminophen for headaches, if
patient is able to swallow & has no known
contraindication
• If prescribed & recommended by patient’s health care
provider, help patient self-administer medication for
altitude illness

7. SIGNS & SYMPTOMS FOR HIGH
ALTITUDE CEREBRAL EDEMA
• Loss of coordination or “ataxia” (e.g. can’t walk in a strain
line or stand straight with feet together)
• Severe headache not relieved by rest/medication
• Bizarre changes in personality
• Seizures or coma

8. CARE FOR HACE
• Severely ill patients must descend as soon as
possible
• Provide oxygen, if available & trained to do so
• Keep patient from becoming chilled or
overheated
• If prescribed & recommended, help patient self-
administer medications for altitude illness
• Use portable hyperbaric chamber (caution: do not
use in lieu of descending)

9. SIGNS & SYMPTOMS OF HIGH
ALTITUDE PULMONARY EDEMA
• Dry cough, shortness of breath (at rest)
• Shortness of breath becomes more pronounced
• Possible chest pain
• Cough that becomes productive, first frothy sputum, later reddish
sputum

10. CARE FOR HAPE
• Severely ill patients must descend ASAP
• In addition to descent, provide oxygen, if available &
trained to do so
• Keep patient from becoming chilled or overheated.
Especially important for HAPE, since cold weather
increases pulmonary artery pressures & makes HAPE
worse
• Use portable hyperbaric chamber if available, not a
substitute for descending

11. GUIDELINES FOR EVACUATION
• Patient with AMS should stop ascending until
symptoms resolve themselves
• Patient with AMS does not require evac
unless condition worsens, then descent is
mandatory
• GO FAST for any patient with HACE or HAPE.
Descend at least 1000-1500 feet of elevation.
• Anyone with HACE or HAPE MUST be
evaluated by health care provider ASAP

12. PREVENTING ALTITUDE ILLNESSES
• Most High Altitude Illnesses are preventable
• Make a stage ascent, Allow body to adjust
• Increase altitude of overnight camps gradually
• If possible camp no higher than 8000 ft first
night, no more than 1000’ - 1500’ increase per
night
• If trip starts > 9000’, spend 2 nights acclimating
• Proceed higher during the day, but return to
lower altitude during day during acclimation
period

13. PREVENTING ALTITUDE
ILLNESSES (CONT’D.)
• Eat high carb diet:
• >70% diet of carbs reduces symptoms of AMS
• Start high carb diet 1-2 days before starting trip
• Maintain appropriate exercise level until
acclimated. Avoid excessive shortness of breath
• Stay well hydrated (higher loss of fluids at high
elevations)
• Talk to your health care provider about possible
prescription medication

14. • Near-Drowning vs. Drowning
• Pathophysiology of Drowning and Near-Drowning
• Dry vs. Wet Drowning
• Fresh-Water vs. Saltwater Drowning
• Fresh water causes the alveoli to collapse from a lack of surfactant.
• Salt water causes pulmonary edema and eventual hypoxemia due to its
hypertonic nature.
NEAR-DROWNING
AND DROWNING

15. NEAR-DROWNING
AND DROWNING

16. • Factors Affecting Survival
• Cleanliness of Water
• Length of Time Submerged
• Victim’s Age and General Health
• Water Temperature
• Cold-water drowning.
• Mammalian diving reflex.
• The cold-water drowning patient is not dead until he is warm and dead.
NEAR-DROWNING
AND DROWNING

17. • Treatment for Near-Drowning
• Remove the patient from the water.
• Attempt rescue only if properly trained and equipped.
• Initiate ventilation while the patient is still in the water.
• Suspect head and neck injury if the patient experienced a fall
or was diving. Place the victim on a long spine board and use
c-spine precautions throughout care.
• Protect the patient from heat loss.
• Evaluate ABCs. Begin CPR and defibrillation if indicated.
NEAR-DROWNING
AND DROWNING

18. • Manage the airway using proper suctioning and airway
adjuncts.
• Administer oxygen at 100% concentration.
• Use respiratory rewarming, if available.
• Establish IV of lactated Ringer’s or normal saline at
75 mL/hr.
• Follow ACLS protocols if the patient is normothermic. Treat
hypothermic patients according to hypothermia guidelines.
• Adult Respiratory Distress Syndrome
NEAR-DROWNING
AND DROWNING

19. DIVING EMERGENCIES
• Scuba
• The Effects of Air Pressure on Gases
• Boyle’s Law
• The volume of a gas is inversely proportional to its pressure if
the temperature is kept constant.
• Dalton’s Law
• The total pressure of a mixture of gases is equal to the sum of
the partial pressures of the individual gases.
• Henry’s Law
• The amount of gas dissolved in a given volume of liquid is
proportional to the pressure of the gas above it.

20. 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.

21. 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

22. 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

23. 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

24. 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.

25. 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.

26. 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.

27. 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.

28. 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.

29. 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.

30. DIVING EMERGENCIES
• Other Diving-Related Emergencies
• Oxygen Toxicity
• Hypercapnia
• Diver’s Alert Network
• Consultation and Referrals
• (919) 684-8111

31. 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