Don’t give me that altitude
100
The adaptive responses to altitude shown are called____________
Acclimatization?
200
After ascending to 2000m, 4200m and 5900m, approximately 25%, 50%, and 70% of individuals will experience this.
What is Acute mountain Sickness?
Central sleep apnea/Cheyne stokes respirations also noted to be about as common or more common
•Chemoprevention with acetazolamide, possibly dexamethasone
–Pathophysiology of AMS likely 2/2 hypoxia mediated cerebral vasodilatation, edema, and microhemorrhage
–Thought to be a mild form of HACE (high altitude cerebral edema)
300
2 accepted medications for chemoprevention of high-altitude pulmonary edema (HAPE)
Nifedipine and Tadalafil.
HAPE is thought to be 2/2 excessive hypoxic pulmonary vasoconstriction, though heterogenous nature results in edema in the regions with less vasoconstriction
400
In patients with COPD (and likely other respiratory disorders) who are planning air travel, appropriate actions for those with resting sea level SaO2 of 1. >95%, 2. <92%, and 3. 92-95%
1. >95%: fly without O2
–Unless rare instance of pt with 6MWT and 6MWT SaO2 <84%, then HAST
•2. <92%: prescribe supplemental O2 (1-2L/min)
–If already on O2 up to 4L/day, increase by 1-2L/min
•3. 92-95%: 6MWT
–If SaO2 <84% on 6MWT, prescribe O2
–If SaO2 >84%, consider HAST (hypoxia altitude simulation test)/HCT (hypoxia challenge test)
•***multiple published algorithms; BTS has guidelines though no firm conclusions in regards to when to perform HAST
–Cite multiple studies on lack of predictive power of resting SaO2 and in-flight O2
500
2 scientists of history whose laws are responsible for the vast majority of the medical diagnoses specific to medical conditions specific to diving and flight
Boyle‘s law: P1V1 = P2V2; if the pressure drops, the volume of gas will expand in proportion to the pressure drop (in a closed system)
Henry‘s law: amount of gas dissolved in liquid is proportional to the partial pressure of that gas above the liquid