Altitude Emergencies Flashcards
at what altitude do we start to see issues?
> 8000 ft
can occur at > 5000 ft
altitude emergencies are influenced by
rate of ascent
final altitude
sleeping altitude
duration of altitude
RF of altitude emergencies
young males
PHYSICAL FITNESS FOES NOT PROCTECT
smoking, alcohol, overexertion, previous incident
asymptomatic hypoxia (COPD, CHF)
hypoxia
inability to reach tissue
decrease in barometric pressure causes less arterial oxygen tension and less diffusion of inspired air
hypoxemia
low oxygenation of blood
low arterial oxygen in blood due to decreased O2 in air
acclimatization in altitude emergencies
ventilation (increase)
increased CO and pulmonary perfusion
increased cerebral blood flow
increase in HG and erythropoietin (weeks)
acute mountain signess
HA + 1 or more of:
anorexia, N/v, fatigue, difficulty sleeping, light headedness
6-10 hrs after ascent
tx of AMS
slow/halt ascent
analgesics
Diamox prophylaxis (1-2 days earlier)
Dex if unable to descend
diamox and AMS
speeds up acclimatization
1-2 days before
HACE
severe AMS with ATAXIA or altered mental status
may progress to coma or death
typically occurs at >12,000 feet
first sign of HACE
ataxia
tx of HACE
immediate descent or evacuation
oxygen
dexamethasone
HAPE
non-cardiogenic pulmonary edema 2-4 days after ascent above 8000 ft
MC cause of altitude emergencies death
HAPE clinical features
persistent dry cough –> tachycardia and tachypnea at rest + cyanosis –> nocturnal ones and worsening symptoms at night –> dyspnea at rest and crackles in chest
pharm tx HAPE
nifedipine (should still descent)
Gamow bag
altitude emergencies summary of tx
medications + supplemental o2
stop ascent and attempt acclimatization
acetazolamide/diamox altitude emergencies
acclimatization 1-2 days before
little benefit in acute tx and NO HAPE
dexamethasone altitude emergencies
AMS and HACE
no HAPE
HAPE pharm
B-agonists
nifedipine
hyperbaric oxygen and altitude emergencies
BEST in HAVE
beneficial in HAPE
submersion injuries
common in toddlers and children, adolescents, elderly
second leading COD <15
wet drowning
atelectasis
v/q mismatch
breath holding and swallowing water
breathing water
dry drowingin
laryngospasm and glottis closure causing hypoxia
final common pathway of submersion injury
HYPOEXMIA
fresh water drowning
hypotonic solution
inactivates surfactant = hemodilution and hemolysis of cells
hyopnatremia + hyperkalemia
salt water drowning
osmotic gradients pulls fluid into alveoli from cells
suffocates after 8-10 minutes due to inability to exchange O2
drowning pts are at risk for
ARDS and PNA
categories of submersion injury
Asymptomatic
Symptomatic
cardiopulmonary arrest
obviously dead
tx of drowning
CPR
intubation and rewarming
antibiotics
Boyle’s law
pressure and volume inversely proportional
pressure increase = volume decrease (diving)
henry’s law
gas enters liquid in proportion to partial pressure
descent = increased partial pressure
boddy tissue absorbs N faster and diver descends
ascend too quick = nitrogen gas bubble in body tissue = severe pain
descent barotrauma
middle ear squeeze
hemorrhage and edema
influx of water may cause extreme vertigo and disaster
MC medical problem associated with diving
grade of descent barotrauma
0 = pain only
2= erthemia and mild hemorrhage
4= free blood
5= free blood + perforation
sinus barotrauma
air trapped in sinuses
can cause epistaxis
tx with decongestants
mask squeeze
descend without equalizing pressure - negative air pressure in mask and rupture of capillary beds = conjunctival hemorrhage and skin ecchymosis
nitrogen narcosis
increased nitrogen solubility causes intoxication at high partial pressure
DESCENT dz list
- barotrauma
- sinus squeeze
- mask squeeze
- nitrogen narcosis
ascent injury
gas expansion
- barodontalgia
- GI barotrauma
- pulmonary/AGE
- decompression sickness
barodontalgia
when descending air fills cavities then ascent causes air to expand and can’t escape = pain
GI barotrauma
air trapped in GI tract
limited to when you resurface and release air
pulmonary barotrauma
air not released = expand in rupture to surrounding tissue
can have AGE
AGE
air gets into pulmonary veins = gets into left heart = systemic cirulcatoin
CAN CAUSE STROKE
immediate decompression and oxygenation
decompression sickness
nitrogen forms bubbles I ascent too rapid
direct and indirect effect
direct effect DCS
indirect effect
net effect
bubbles in joints, SC, pulmonary and vascular system
indirect: inflammatory response, clotting, inflammatory cascade
net: decreased tissue perfusion, ischemic injury
type 1 DCS
nigges
skin bends
lymphatic involvement
the bands - shoulder joint MC affected
type 2 DCS
staggers - N gets in spinal cord sheath
the chokes
differentiating AGS and DCS
time of onset
AGE – rapid
DCS - over hours
Lightning injuries clinical symptoms
cardiac arrhythmia, nruologic abnormalities, cardiopulmonary arrest
tympanic membrane rupture
cataracts
DIC
feathering burns
pathognomonic lighting injury sign
featuring burns
due to electron showers
pearls of Lightning injuries
damage to exterior does not predict interior damage
respiratory arrest is prolonged, ventilate
HoTN and Lightning injuries
not an expected finding
if seen, look for hemorrhage
cardiac manifestations Lightning injuries
spontaneous circulation, HTN, tachycardia
specific tx not nee. bc BP and pulse spontaneously return
MI unusual and prolonged rescucitative effort often successful
neuro injury Lightning injuries
victims are unconscious and have temporary paralysis
seizure due to injury or hypoxia
ALWAYS CT
Lethal neuro injuries Lightning injuries
heat induced coagulation of cerebral cortex
development of epidural or subdural hematoma
hemorrhage
ocular injury
opthalmic injuries common in lightening strike victims
common to get cataracts
MSK manifestations of Lightning injuries
shoulder dislocation
spinal fracture
RHABDO uncommon
cutaneous injuries Lightning injuries list (6)
- Lichtenberg figures
- flat burns
- punctuate burns
- contact burns
- superficial erythma
- contact wound
lichtenberg figures
pathognomonic
superficial feathering or fern pattern burns
disappear within 24 hrs
contact burns
occur when metal close to skin is heated from lightening current
