Hydrazine toxicity: Difference between revisions
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** functional B6 deficiency results | ** functional B6 deficiency results | ||
* Metabolism of hydrazine produces free radical intermediates | * Metabolism of hydrazine produces free radical intermediates | ||
* Inhibits | * Inhibits pyridoxine kinase as well as glutamic acid decarboxylase which results in decrease production of GABA neurotransmitter | ||
==Clinical Features== | ==Clinical Features== | ||
*Short term inhalation exposure may cause: | |||
* Short term inhalation exposure may cause | **[[Cough]], oropharyngeal/pulmonary irritation | ||
* Long term inhalation exposure may cause liver and kidney damage | **[[Pulmonary edema]] | ||
* Ingestion | **[[CNS Depression]], [[seizure]], [[tremor]] | ||
* | *Long term inhalation exposure: | ||
**Above, plus may cause [[hepatic failure|liver]] and [[renal failure|kidney damage]] | |||
*Ingestion | |||
**[[Nausea/vomiting]] | |||
**Uncontrollable shaking, [[seizure]], nerve inflammation/polyneuritis, [[coma]] | |||
*Contact exposure | |||
**[[rash|Dermatitis]], [[chemical burns]] | |||
**If absorbed systemically, can -> [[hemolytic anemia]], [[methemoglobinemia]] | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
==Evaluation== | ==Evaluation== | ||
* | *BMP | ||
* | *[[LFTs]] | ||
* | *CBC | ||
* | *[[UA]] | ||
*[[VBG]], MetHb | |||
*[[Lactate]] | |||
*[[CXR]] if inhalational exposure or pulmonary symptoms | |||
==Management== | ==Management== | ||
| Line 53: | Line 60: | ||
* Respiratory distress - secure airway and assist ventilation | * Respiratory distress - secure airway and assist ventilation | ||
* [[Methemoglobinemia]] - initiate oxygen therapy, give methylene blue if patient is symptomatic; Methylene blue dose 1 mg/kg IV over 5 to 30 minutes repeat dose may be given 1 hour after first if symptoms persist | * [[Methemoglobinemia]] - initiate oxygen therapy, give methylene blue if patient is symptomatic; Methylene blue dose 1 mg/kg IV over 5 to 30 minutes repeat dose may be given 1 hour after first if symptoms persist | ||
* Consider hemodialysis and acidification of urine if member has severe CNS depression | * Consider [[hemodialysis]] and acidification of urine if member has severe CNS depression | ||
* [[Hypoglycemia]] treat with D10 and thiamine | * [[Hypoglycemia]] treat with D10 and [[thiamine]] | ||
==Disposition== | ==Disposition== | ||
* Home in cases of mild skin exposure without burns | * Home in cases of mild skin exposure without burns | ||
* Observation for patients with | * Observation for patients with inhalation or ingestion exposure for at least 12 hours to ensure no serious symptoms develop | ||
* Admit patients with CNS symptoms or persistent pulmonary/gastrointestinal symptoms | * Admit patients with CNS symptoms or persistent pulmonary/gastrointestinal symptoms | ||
Revision as of 19:56, 1 October 2019
Background
- Clear, colorless liquid that has an ammonia-like odor
- Powerful reducing agent that is highly reactive
- Exposure to metal oxides makes it highly exothermic and combustible
- Used in rocket fuels, missile fuels, aircraft emergency power unit fuel (notably the F-16)
- Used in chemical manufacturing (intermediate for insecticides/herbicides/dyes, polymerization catalyst for making plastics, used to manufacture sodium azide [air bag propellant], used to make isoniazid and fluconazole
Toxic Dose
- OSHA limit 1 ppm in air for 8-hour workday
- NIOSH recommends 0.03 ppm in air for 2-hour period
- Odor threshold 3.7 ppm in air
Routes of Exposure
- Inhalation
- Skin contact / absorption (rapid within 30 seconds of contact)
- Ingestion
Mechanism of Action
- Hydrazine + ketone/aldehyde = hydrazones + B6 = hydrazones of pryidoxine
- "consumes" B6 in body
- functional B6 deficiency results
- Metabolism of hydrazine produces free radical intermediates
- Inhibits pyridoxine kinase as well as glutamic acid decarboxylase which results in decrease production of GABA neurotransmitter
Clinical Features
- Short term inhalation exposure may cause:
- Cough, oropharyngeal/pulmonary irritation
- Pulmonary edema
- CNS Depression, seizure, tremor
- Long term inhalation exposure:
- Above, plus may cause liver and kidney damage
- Ingestion
- Nausea/vomiting
- Uncontrollable shaking, seizure, nerve inflammation/polyneuritis, coma
- Contact exposure
- Dermatitis, chemical burns
- If absorbed systemically, can -> hemolytic anemia, methemoglobinemia
Differential Diagnosis
Evaluation
Management
Mild to Moderate Exposure
- Ensure patient has been decontaminated
- Irrigate eyes with normal saline or water if exposed
- Treat chemical burns if present
- Monitor pulmonary status
- Monitor for development of methemoglobinemia
Severe Exposure
- Seizures - pyridoxine 25 mg/kg IM or IV up to 5 grams plus benzodiazepine
- Respiratory distress - secure airway and assist ventilation
- Methemoglobinemia - initiate oxygen therapy, give methylene blue if patient is symptomatic; Methylene blue dose 1 mg/kg IV over 5 to 30 minutes repeat dose may be given 1 hour after first if symptoms persist
- Consider hemodialysis and acidification of urine if member has severe CNS depression
- Hypoglycemia treat with D10 and thiamine
Disposition
- Home in cases of mild skin exposure without burns
- Observation for patients with inhalation or ingestion exposure for at least 12 hours to ensure no serious symptoms develop
- Admit patients with CNS symptoms or persistent pulmonary/gastrointestinal symptoms