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lssah2025 · 03-06-2012, 14:56

Lecture notes from teaching HAPE and HACE

XXXI. Problems related to altitude
A. High-altitude pulmonary edema (HAPE)
1. Pulmonary edema following ascent to altitude—frequent in mountaineering, not aviation
2. Current theory
a) Intracapillary pressure increases with altitude
b) Increased intracapillary pressure disrupts basement membrane of capillary
c) Plasma and protein leakage occurs across capillary membrane, into alveoli and interstitial space
d) Following descent, pulmonary artery pressure decreases, basement membrane repairs itself, edema corrected—recovery often dramatic with descent from altitude
3. Most common cause of death from high altitude illness
a) Usually occurs after 48–96 hours at altitude
b) Associated with rapid ascents to altitudes over 8,000 feet— lack of acclimatization
4. Signs and symptoms include
a) Rales in at least one lung field
b) Orthopnea
c) Pink/frothy sputum
d) High-altitude cough
e) Central cyanosis
f) Tachycardia
g) Tachypnea
h) Fever
5. Treatment priorities include
a) Supplemental oxygen
b) Airway control
c) Breathing assistance—BiPAP, CPAP
d) Immediate descent
e) Pharmacological support–(Hyperbarics) Morphine 2-5 mg IV, acetazolamide (Diamox) 125 mg PO BID, Lasix 40-80mg, Viagra 40 mg PO TID (may also be useful) nifedipine 10 mg PO reduces pulmonary artery pressure by 30-50% and increases O2 sat. nifedipine extended release 30 mg PO q8hrs may prophylax against HAPE.

XXXII. High-altitude cerebral edema (HACE)
A. Cerebral edema following ascent to altitude
B. Current theory
1. Hypoxia-induced changes in blood-brain barrier permeability
2. Increased cerebral blood flow—Increased ICP
3. Vasogenic brain edema
C. HACE considered to be end-stage presentation of acute mountain sickness
1. “High altitude” generally described as anything over 5,280 feet
a) Every person above this altitude effected to some degree
b) Severity varies with individuals
D. Signs and symptoms include
1. Headache—“High-altitude headache” most common symptom
2. Insomnia
3. Anorexia
4. Nausea
5. Dizziness/weakness
6. Altered mental status
7. Decreasing level of consciousness
E. Treatment priorities include
1. Rapid descent from altitude
2. Supplemental oxygen
3. Airway/breathing control
4. Pharmacological
a) Steroids
1) Dexamethasone 8mg PO, IM or IV then 4mg q6h
(a) Possibly decreases fluid leaks from microvasculature
(b) Profound euphoric effect
b) Antiemetics
1) Prochlorperazine (Compazine)
2) Promethazine (Phenergan)
c) Diuretics
1) Lasix 40-80mg IV (avoid dehydration and decrease in BP)
5. Prophylactic treatment—Acetazolamide (Diamox)125 mg PO
a) Enhances renal excretion of bicarbonate, producing mild acidosis—balances the effects of hyperventilation that occurs at altitude
b) Mild acidosis also acts as respiratory stimulant, reducing or eliminating the periodic breathing commonly seen at altitude
c) May also lower cerebral spinal fluid volume and pressure

03-06-2012, 14:56	#14
lssah2025 Asset Join Date: Nov 2008 Location: Roaming the world Posts: 16	Lecture notes from teaching HAPE and HACE XXXI. Problems related to altitude A. High-altitude pulmonary edema (HAPE) 1. Pulmonary edema following ascent to altitude—frequent in mountaineering, not aviation 2. Current theory a) Intracapillary pressure increases with altitude b) Increased intracapillary pressure disrupts basement membrane of capillary c) Plasma and protein leakage occurs across capillary membrane, into alveoli and interstitial space d) Following descent, pulmonary artery pressure decreases, basement membrane repairs itself, edema corrected—recovery often dramatic with descent from altitude 3. Most common cause of death from high altitude illness a) Usually occurs after 48–96 hours at altitude b) Associated with rapid ascents to altitudes over 8,000 feet— lack of acclimatization 4. Signs and symptoms include a) Rales in at least one lung field b) Orthopnea c) Pink/frothy sputum d) High-altitude cough e) Central cyanosis f) Tachycardia g) Tachypnea h) Fever 5. Treatment priorities include a) Supplemental oxygen b) Airway control c) Breathing assistance—BiPAP, CPAP d) Immediate descent e) Pharmacological support–(Hyperbarics) Morphine 2-5 mg IV, acetazolamide (Diamox) 125 mg PO BID, Lasix 40-80mg, Viagra 40 mg PO TID (may also be useful) nifedipine 10 mg PO reduces pulmonary artery pressure by 30-50% and increases O2 sat. nifedipine extended release 30 mg PO q8hrs may prophylax against HAPE. XXXII. High-altitude cerebral edema (HACE) A. Cerebral edema following ascent to altitude B. Current theory 1. Hypoxia-induced changes in blood-brain barrier permeability 2. Increased cerebral blood flow—Increased ICP 3. Vasogenic brain edema C. HACE considered to be end-stage presentation of acute mountain sickness 1. “High altitude” generally described as anything over 5,280 feet a) Every person above this altitude effected to some degree b) Severity varies with individuals D. Signs and symptoms include 1. Headache—“High-altitude headache” most common symptom 2. Insomnia 3. Anorexia 4. Nausea 5. Dizziness/weakness 6. Altered mental status 7. Decreasing level of consciousness E. Treatment priorities include 1. Rapid descent from altitude 2. Supplemental oxygen 3. Airway/breathing control 4. Pharmacological a) Steroids 1) Dexamethasone 8mg PO, IM or IV then 4mg q6h (a) Possibly decreases fluid leaks from microvasculature (b) Profound euphoric effect b) Antiemetics 1) Prochlorperazine (Compazine) 2) Promethazine (Phenergan) c) Diuretics 1) Lasix 40-80mg IV (avoid dehydration and decrease in BP) 5. Prophylactic treatment—Acetazolamide (Diamox)125 mg PO a) Enhances renal excretion of bicarbonate, producing mild acidosis—balances the effects of hyperventilation that occurs at altitude b) Mild acidosis also acts as respiratory stimulant, reducing or eliminating the periodic breathing commonly seen at altitude c) May also lower cerebral spinal fluid volume and pressure Last edited by lssah2025; 03-06-2012 at 14:59.
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