Carbon Monoxide Poisoning

Question 1

Risk times for CO

Answer 1

Winter/fall from space heaters, wood burning stoves, charcoal, portable generators.

Question 2

Common CO sources

Answer 2

AC, motorboats, zambonis, riding in the back of pickups, exhaust pipe occluded by snow, all fires.

Question 3

Methylene chloride

Answer 3

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

Question 4

Time to peak CO levels after exposure

Answer 4

May be 8 hours or longer

Question 5

CO levels

Answer 5

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.

Question 6

Binding of CO

Answer 6

200X higher affinity than O2, and even higher in fetal hb

CO bound to hb is carboxyhemoglobin

Question 7

Half life

Answer 7

250-320 minutes, 74-80 on 100% O2.

Methylene chloride may be 13 hours due to ongoing metabolic production

Question 8

Myoglobin CO

Answer 8

CO binds 60 times better than O2

Question 9

CO in the cell

Answer 9

Interferes with cytochrome oxidase, therefore decreasing ATP production.

Question 10

Aside from O2 what does CO disrupt

Answer 10

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)

Question 11

Protean definition

Answer 11

Versitile, quickly changing

Question 12

Clues for CO

Answer 12

Unexplained coma, elevated anion gap, metabolic acidosis or lactic acidosis. Other members affected. History of pt. MI, seizure, syncope

Question 13

Physical findings CO

Answer 13

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)

Question 14

Bloods for CO poisoning

Answer 14

Elevated anion gap, elevated CK, elevated troponin, metabolic acidosis

Question 15

Severe poisoning imaging in CO

Answer 15

Lesions to the globus pallidus generally bilateral and symmetric

Question 16

TX CO

Answer 16

Immediate provide high flow O2

HBO for >25% or >15% preggos

Question 17

Toxicity begins at

Answer 17

100ppm

Question 18

Children

Answer 18

More susceptible from higher metabolic rates and higher % of fetal hB