Hydrogen sulfide toxicity: Difference between revisions
Neil.m.young (talk | contribs) No edit summary |
Neil.m.young (talk | contribs) No edit summary |
||
| Line 1: | Line 1: | ||
==General Information== | ==Background== | ||
===General Information=== | |||
*Colorless, flammable gas | *Colorless, flammable gas | ||
*Encountered in following industries: oil, gas, organic decomposition (sewer and manure), roofing asphalt tanks | *Encountered in following industries: oil, gas, organic decomposition (sewer and manure), roofing asphalt tanks | ||
*Most common fatal gas exposure | *Most common fatal gas exposure | ||
*“Rotten egg” smell which diminishes with high concentrations or prolonged low concentration exposure | *“Rotten egg” smell which diminishes with high concentrations or prolonged low concentration exposure | ||
*Often used in suicide attempts: acidic detergent (toilet bowl cleaner) is mixed with bath salts or pesticides< | *Often used in suicide attempts: acidic detergent (toilet bowl cleaner) is mixed with bath salts or pesticides<ref>Tintinalli et. al. Hydrogen Sulfide. In: Tintinalli et. al. Emergency Medicine A Comprehensive Study Guide. New York, NY: McGraw Hill. 2011. 1320.</ref> | ||
===Mechanisms of toxicity=== | |||
==Mechanisms of toxicity== | |||
*Highly lipid soluble | *Highly lipid soluble | ||
*Disrupts oxidative phosphorylation by inhibiting cytochrome oxidase aa3 (toxicity through cellular asphyxia and impairs ATP production) => lactate accumulation and metabolic acidosis | *Disrupts oxidative phosphorylation by inhibiting cytochrome oxidase aa3 (toxicity through cellular asphyxia and impairs ATP production) => lactate accumulation and metabolic acidosis | ||
| Line 13: | Line 13: | ||
*Alters brain neurotransmitter content and release | *Alters brain neurotransmitter content and release | ||
== | ==Clinical Features== | ||
*Respiratory: dyspnea, cyanosis, hemoptysis, rales, delayed pulmonary edema | *Respiratory: dyspnea, cyanosis, hemoptysis, rales, delayed pulmonary edema | ||
*Ophthalmic: conjunctivitis, corneal ulceration, corneal scarring | *Ophthalmic: conjunctivitis, corneal ulceration, corneal scarring | ||
| Line 22: | Line 22: | ||
*Death | *Death | ||
==Differential Diagnosis | ==Differential Diagnosis== | ||
*[[Carbon Monoxide]] Toxicity | *[[Carbon Monoxide]] Toxicity | ||
*[[Cyanide]] Toxicity | *[[Cyanide]] Toxicity | ||
Revision as of 17:26, 6 March 2016
Background
General Information
- Colorless, flammable gas
- Encountered in following industries: oil, gas, organic decomposition (sewer and manure), roofing asphalt tanks
- Most common fatal gas exposure
- “Rotten egg” smell which diminishes with high concentrations or prolonged low concentration exposure
- Often used in suicide attempts: acidic detergent (toilet bowl cleaner) is mixed with bath salts or pesticides[1]
Mechanisms of toxicity
- Highly lipid soluble
- Disrupts oxidative phosphorylation by inhibiting cytochrome oxidase aa3 (toxicity through cellular asphyxia and impairs ATP production) => lactate accumulation and metabolic acidosis
- Causes hyperpolarization of potassium-mediated channels in neurons
- Potentiates neuronal inhibitory mechanisms
- Alters brain neurotransmitter content and release
Clinical Features
- Respiratory: dyspnea, cyanosis, hemoptysis, rales, delayed pulmonary edema
- Ophthalmic: conjunctivitis, corneal ulceration, corneal scarring
- Central nervous system: headache, weakness, disequilibrium, intention tremor, muscle rigidity, loss of consciousness, seizures, coma
- Gastrointestinal: green-gray line on gingiva, nausea, vomiting
- Cardiovascular: chest pain, bradycardia
- Neuropsychiatric: amnesia, lack of insight, disorientation, delirium, dementia
- Death
Differential Diagnosis
- Carbon Monoxide Toxicity
- Cyanide Toxicity
- Hydrocarbons Toxicity
- Smoke Inhalation Injury
Diagnosis
- No single test to verify exposure or levels
- ABG Interpretation: metabolic acidosis and normal oxygen saturation (unless pulmonary edema present)
- Elevated lactate
- Discolored copper coins found on patient may be helpful in diagnosis
Management
- Removal from source
- 100% oxygen
- Can give nitrite component of cyanide antidote kit (do NOT give the thiosulfate portion):
- Theoretically increasing methemoglobin formation in blood will cause conversion of sulfide to sulfmethemoglonin (less toxic)
- Amyl nitrite
- Sodium nitrite (3% NaNO2) IV over 2-4 minutes; adult dose 10 mL
- Obtain methemoglobin level 30 minutes after dose (desired level < 30%)
- Hyperbaric oxygen therapy (though not proven to have any benefit)[2]
Disposition
- Admission, likely to MICU
- Toxicology consult