High Altitude and Diving Flashcards
What is chronic mountain sickness (CMS)?
polycythemia with PHTN due to high altitude resistance
In ______, the feature is exuberant pulmonary hypertension (PHTN) in response to acute hypoxia.
High Altitude Pulmonary Edema (HAPE)
Atmospheric (or barometric) pressure increases by 1 atm for every ____ meters of depth in sea water.
10
What is the tx for decompression sickness/the bends?
recompression in a hyperbaric chamber
What is adaptation?
- a genetic event that increases tolerance
- occurs only in populations over generations
What are the s/s of Acute Mountain Sickness (AMS)?
- headache
- nausea
- malaise
- insomnia
- anorexia
What is pulmonary barotrauma?
pneumomediastinum or pneumothorax caused by gas pushed into the interstitium
What are the s/s of High Altitude Cerebral Edema (HACE)?
- ataxia
- confusion/combativeness
- hallucinations
- coma
- (presents similarly to intoxication)
This is the most extreme form of acute mountain sickness and is a medical emergency.
High Altitude Cerebral Edema (HACE)
What are the s/s of pneumomediastinum?
- substernal chest pain
- cough
One of the earliest physiological changes that occurs when humans are exposed to acute hypoxia is to ____.
increase blood flow (cardiac output)
What is the value of water vapor pressure?
47
In High Altitude Pulmonary Edema (HAPE) a main feature is _____ in response to acute hypoxia.
pulmonary hypertension (PHTN)
An increase in HR occurs within _____ of hypoxia exposure.
minutes
Increased VE can last for _____, and is thus the most useful short term adaptive response to high altitude exposure.
days and weeks
This is a non-cardiogenic pulmonary edema- a life threatening complication of altitude exposure.
High Altitude Pulmonary Edema (HAPE)
What are the s/s of pneumothorax?
- dyspnea
- unilateral chest pain
- cough
_____ can last for days and weeks, and is thus the most useful short term adaptive response to high altitude exposure.
Increased VE
What is dexamethasone?
a steroid used to treat HACE
This is pneumomediastinum or pneumothorax caused by gas pushed into the interstitium.
pulmonary barotrauma
What is the best mechanism for long-term adaptation to high altitude?
- to increase hemoglobin and red cell mass
- decrease plasma volume
What underlying disease increases the risk of barotrauma?
asthma
The longer and deeper the dive, the more concern for _____.
decompression sickness/the bends
What is shallow water blackout?
breath holding dives that result in loss of consciousness
What is the barometric pressure in Denver?
630
What is High Altitude Pulmonary Edema (HAPE)?
- a non-cardiogenic pulmonary edema
- a life threatening complication of altitude exposure
______ is caused by an increase in brain volume in response to hypoxia that may be due to cerebral edema and/or increased cerebral blood flow/intravascular volume.
Acute Mountain Sickness (AMS)
______ is a genetic event to increase tolerance and thus occurs only in populations over generations.
Adaptation
What is VE?
minute ventilation
What is nitrogen narcosis?
- clumsiness
- bizarre behavior
- euphoria
- unconsciousness
- **** caused by breathing compressed air (>75% N) at depths >100 feet
If acute hypoxia is severe in the unacclimatized, the person rapidly becomes ______.
unconscious
The diffusion of O2 across the alveolar-capillary membrane is dependent on ______ and _______.
its thickness; the concentration of Hb
The _______ across the alveolar-capillary membrane is dependent on its thickness and the concentration of Hb.
diffusion of O2
What are the s/s of nitrogen narcosis?
- clumsiness
- bizarre behavior
- euphoria
- unconsciousness
What are the s/s of decompression sickness/the bends?
- confusion
- musculoskeletal pain
- dyspnea
- stroke
- coma
- seizures
- paralysis
- death
What is acclimatization?
a subacute to chronic physiologic process that permits more efficient function at altitude
In persons that have _____, the ventilatory responses to both hypoxia and to higher PaCO2 are exaggerated.
acclimatized to high altitude
In persons that have acclimatized to high altitude, the ventilatory responses to both hypoxia and to higher PaCO2 are _____.
exaggerated
What is the tx for High Altitude Cerebral Edema (HACE)?
- supportive
- IV dexamethasone
Acute mountain sickness (AMS) is caused by ______ in response to hypoxia that may be due to cerebral edema and/or increased cerebral blood flow/intravascular volume.
an increase in brain volume
What causes decompression sickness/the bends?
inert gases supersaturate the tissues and then the diver ascends too rapidly
The best initial way to increase hemoglobin saturation (and thus tissue oxygen delivery) is to _____.
hyperventilate
Acute mountain sickness (AMS) is caused by an increase in brain volume in response to hypoxia that may be due to ______ and/or _____.
cerebral edema; increased cerebral blood flow/intravascular volume
A “left shift” in the O2-Hb dissociation curve occurs due to _____.
respiratory alkalosis (hyperventilation/decreased PaCO2)
A “____ shift” in the O2-Hb dissociation curve occurs due to respiratory alkalosis (hyperventilation/decreased PaCO2).
left
What is High Altitude Cerebral Edema (HACE)?
the most extreme form of acute mountain sickness- a medical emergency
What is the tx for Acute Mountain Sickness (AMS)?
- analgesics
- oral dexamethasone (a corticosteroid) OR oral acetazolamide
What is the tx for High Altitude Pulmonary Edema (HAPE)?
- decent to lower altitude
- supplemental O2
- vasodilators (nifedipine, tadalafil)
- salmeterol
This is clumsiness, bizarre behavior, euphoria, and unconsciousness caused by breathing compressed air (>75% N) at depths >100 feet.
nitrogen narcosis
This is caused by breath holding dives that result in loss of consciousness.
shallow water blackout
______ is a subacute to chronic physiologic process that permits more efficient function at altitude.
Acclimatization
This is polycythemia with PHTN due to high altitude resistance.
chronic mountain sickness (CMS)
