Dyshemoglobinemias

Question 1

Hyperbaric oxygen

Answer 1

Uses: Prevents lipid peroxidation and delayed neurologic sequelae in CO poisoning

Question 2

Nitrites

Answer 2

MOA: Turns RBC hemoglobin to methemoglobin; CN moves from Fe(3+) on cytochromes to those in RBCs creating cyanomethemoglobin

Misc: Dangerous in concurrent CO poisoning

Question 3

Sodium thiosulfate

Answer 3

MOA: Enhances normal metabolism of cyanide via rhodanase

Question 4

Hydroxycobalamin (Cyanokit)

Answer 4

MOA: Binds with cyanide –> cyanocobalamin (B12)
Uses: Smoke inhalation victims not improving with supportive care, cyanide exposure, nitroprusside at risk patients

Misc: Give concurrently with sodium thiosulfate

Question 5

Methylene blue (Urolene Blue)

Answer 5

MOA: Cofactor of NADPH reductase; gains electron, donates directly to reduce methemoglobin
Uses: Methemoglobinemia >20-30%, or with symptoms
SE: Hemolytic anemia (weak oxidizing capability)