Hydrazine toxicity: Difference between revisions
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* NIOSH recommends 0.03 ppm in air for 2-hour period | * NIOSH recommends 0.03 ppm in air for 2-hour period | ||
* Odor threshold 3.7 ppm in air | * Odor threshold 3.7 ppm in air | ||
===Routes of Exposure=== | ===Routes of Exposure=== | ||
* Inhalation | * Inhalation | ||
* Skin contact / absorption (rapid within 30 seconds of contact) | * Skin contact / absorption (rapid within 30 seconds of contact) | ||
* Ingestion | * Ingestion | ||
===Mechanism of Action=== | ===Mechanism of Action=== | ||
* Hydrazine + ketone/aldehyde = hydrazones + B6 = hydrazones of pryidoxine | * Hydrazine + ketone/aldehyde = hydrazones + B6 = hydrazones of pryidoxine | ||
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* Ingestion may cause nausea, vomiting, uncontrolled shaking, inflammation of nerves, drowsiness, coma | * Ingestion may cause nausea, vomiting, uncontrolled shaking, inflammation of nerves, drowsiness, coma | ||
* Short term contact exposure may cause dermatitis and/or chemical burn, can also lead to hemolytic anemia once absorbed | * Short term contact exposure may cause dermatitis and/or chemical burn, can also lead to hemolytic anemia once absorbed | ||
===Signs and Symptoms=== | ===Signs and Symptoms=== | ||
* Dizziness, nausea, itching, skin burning, tearing, coughing, excitement, tremors, polyneuritis, impaired cognition, lethargy, convulsions | * Dizziness, nausea, itching, skin burning, tearing, coughing, excitement, tremors, polyneuritis, impaired cognition, lethargy, convulsions | ||
===Evaluation | |||
==Differential Diagnosis== | |||
==Evaluation== | |||
* Monitor vital signs and mental status | * Monitor vital signs and mental status | ||
* Examination with emphasis on skin, lungs, central nervous system | * Examination with emphasis on skin, lungs, central nervous system | ||
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* Ancillary testing - chest x-ray and pulmonary function testing if inhalation exposure or patient has pulmonary symptoms | * Ancillary testing - chest x-ray and pulmonary function testing if inhalation exposure or patient has pulmonary symptoms | ||
==Management== | |||
* Mild to Moderate Exposure | * Mild to Moderate Exposure | ||
** Ensure patient has been decontaminated | ** Ensure patient has been decontaminated | ||
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==See Also== | ==See Also== | ||
*[[Pyridoxine]] | |||
*[[Methylene blue]] | |||
==References== | ==References== | ||
Revision as of 07:21, 16 February 2018
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 pryidoxine kinase as well as glutamic acid decarboxylase which results in decrease production of GABA neurotransmitter
Clinical Features
Health Effects
- Short term inhalation exposure may cause coughing, irritation of throat/lungs, development of pulmonary edema, central nervous system depression, convulsions, tremors, or seizures
- Long term inhalation exposure may cause liver and kidney damage
- Ingestion may cause nausea, vomiting, uncontrolled shaking, inflammation of nerves, drowsiness, coma
- Short term contact exposure may cause dermatitis and/or chemical burn, can also lead to hemolytic anemia once absorbed
Signs and Symptoms
- Dizziness, nausea, itching, skin burning, tearing, coughing, excitement, tremors, polyneuritis, impaired cognition, lethargy, convulsions
Differential Diagnosis
Evaluation
- Monitor vital signs and mental status
- Examination with emphasis on skin, lungs, central nervous system
- Labs - serum electrolytes, renal function, urine analysis, complete blood count, liver function test, pH, lactate level, monitor methemoglobin levels
- Ancillary testing - chest x-ray and pulmonary function testing if inhalation exposure or patient has pulmonary symptoms
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 methhemoglobinemia
- 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 inhalational or ingestion exposure for at least 12 hours to ensure no serious symptoms develop
- Admit patients with CNS symptoms or persistent pulmonary/gastrointestinal symptoms