Adult Emergency Medicine
HAP1 - 17 Summaries
HAP18 - 34 Summaries
Wednesday, 27 January 2016
- Oxidisation of the haem of haemoglobin by free radicals or things like hydrogen peroxide and nitric oxide.
- Shifts O2 dissociation curve to the left.
- Hereditary / Congenital
: Hb and NADH-MetHb reductase deficiency
* Medications eg. Amyl nitrite, Benzocaine, Dapsone, Lidocaine, Nitroglycerin, Nitroprusside, Phenacetin, Phenazopyridine, Prilocaine, Quinones, Sulfonamides (eg. sulfamethoxazole). Chloroquine.
* Chemical agents eg. Aniline dye derivatives (shoe dyes, inks) Butyl nitrite, Chlorobenzene, Nitrate-containing foods, Isobutyl nitrite, Naphthalene, Nitrophenol, Nitrous gases, Silver nitrate, and Trinitrotoluene. Sodium nitrite - used in food preservation.
Signs & Symptoms
- chocolate brown discoloration of the blood.
- SaO2 readings go crazy
Blue-grey ‘apparent’ central cyanosis, fatigue, dizziness, headaches
Moderate effects – weakness, tachypnoea, tachycardia
stupor, coma, convulsions, respiratory depression, cardiac arrhythmias, acidosis
> 70% -
<20% - nothing
20 - 30% - oxygen therapy
>30% - methylene blue
1-2 mg/kg IV over 5 minutes - 1% (10mg/ml solution)
repeat up to 7 mg/kg
SpO2 normally dives as you give the methylene blue.
Recheck levels after an hour
Hydrogen sulfide poisoning is
similar to cyanide poisoning and
can be treated by inducing metHb.
Share to Twitter
Share to Facebook
Share to Pinterest
Post a comment
Post Comments (Atom)