Carbon Monoxide Poisoning Flashcards
Risk times for CO
Winter/fall from space heaters, wood burning stoves, charcoal, portable generators.
Common CO sources
AC, motorboats, zambonis, riding in the back of pickups, exhaust pipe occluded by snow, all fires.
Methylene chloride
A source of CO, found in varnishes, paint strippers, christmas ornaments (as bubbling fluid)
It can be inhaled or ingested and is converted in the liver to CO
Time to peak CO levels after exposure
May be 8 hours or longer
CO levels
Normal is 10. Acceptable is up to 50ppm over 8 hours, and occurs naturally in the body during breakdown of heme. 1% is normal, up to 10% in smokers.
Binding of CO
200X higher affinity than O2, and even higher in fetal hb
CO bound to hb is carboxyhemoglobin
Half life
250-320 minutes, 74-80 on 100% O2.
Methylene chloride may be 13 hours due to ongoing metabolic production
Myoglobin CO
CO binds 60 times better than O2
CO in the cell
Interferes with cytochrome oxidase, therefore decreasing ATP production.
Aside from O2 what does CO disrupt
ATP synthesis and therefore creates lactic acid.
Endothelial dysfunction and vasodilation (release of guanylate cyclase and nitric oxide) (NO might be one factor in CO poisoning)
Hypoxia + hypotension can cause damage to cardiac and neuronal tissue.
Damaged endothelial tissue attracts neutrophils and triggers inflam cascade.
CO can cause rhabdo, actue MI, neuronal cell death (basal ganglia particularly sensitive)
Protean definition
Versitile, quickly changing
Clues for CO
Unexplained coma, elevated anion gap, metabolic acidosis or lactic acidosis. Other members affected. History of pt. MI, seizure, syncope
Physical findings CO
Cherry red oral mucosa is only when they ded.
Mild fever, tachycardia, tachypnea, hypertension or hypotension.
Resp or cardiac arrest
Headache, confusion, irritability, seizures, focal neuro deficits, coma.
Retinal hemorrhages
Bullous lesions (more likely for prolonged exposure from being bed ridden)
Bloods for CO poisoning
Elevated anion gap, elevated CK, elevated troponin, metabolic acidosis
Severe poisoning imaging in CO
Lesions to the globus pallidus generally bilateral and symmetric
