Hydrazine toxicity: Difference between revisions
 
(4 intermediate revisions by 3 users not shown)
Line 5: Line 5:
* Used in rocket fuels, missile fuels, aircraft emergency power unit fuel (notably the F-16)
* 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
* 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
*Hydrazine is used as a propellant in the International Space Station


===Toxic Dose===
===Toxic Dose===
Line 21: Line 22:
** functional B6 deficiency results
** functional B6 deficiency results
* Metabolism of hydrazine produces free radical intermediates
* Metabolism of hydrazine produces free radical intermediates
* Inhibits pryidoxine kinase as well as glutamic acid decarboxylase which results in decrease production of GABA neurotransmitter
* Inhibits pyridoxine kinase as well as glutamic acid decarboxylase which results in decrease production of GABA neurotransmitter
 
[[Category:Toxicology]]
[[Category:Space Medicine]]


==Clinical Features==
==Clinical Features==
===Health Effects===
*Short term inhalation exposure may cause:
* Short term inhalation exposure may cause coughing, irritation of throat/lungs, development of pulmonary edema, central nervous system depression, convulsions, tremors, or seizures
**[[Cough]], oropharyngeal/pulmonary irritation
* Long term inhalation exposure may cause liver and kidney damage
**[[Pulmonary edema]]
* Ingestion may cause nausea, vomiting, uncontrolled shaking, inflammation of nerves, drowsiness, coma
**[[CNS Depression]], [[seizure]], [[tremor]]
* Short term contact exposure may cause dermatitis and/or chemical burn, can also lead to hemolytic anemia once absorbed
*Long term inhalation exposure:
 
**Above, plus may cause [[hepatic failure|liver]] and [[renal failure|kidney damage]]
===Signs and Symptoms===
*Ingestion
*  Dizziness, nausea, itching, skin burning, tearing, coughing, excitement, tremors, polyneuritis, impaired cognition, lethargy, convulsions
**[[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==
{{Space medicine}}
{{Inhalation exposure}}


==Evaluation==
==Evaluation==
* Monitor vital signs and mental status
*BMP
* Examination with emphasis on skin, lungs, central nervous system
*[[LFTs]]
* Labs - serum electrolytes, renal function, urine analysis, complete blood count, liver function test, pH, lactate level, monitor methemoglobin levels
*CBC
* Ancillary testing - chest x-ray and pulmonary function testing if inhalation exposure or patient has pulmonary symptoms
*[[UA]]
*[[VBG]], MetHb
*[[Lactate]]
*[[CXR]] if inhalational exposure or pulmonary symptoms


==Management==
==Management==
Line 53: Line 66:
* 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 inhalational or ingestion exposure for at least 12 hours to ensure no serious symptoms develop
* 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


Latest revision as of 20:06, 17 July 2024

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
  • Hydrazine is used as a propellant in the International Space Station

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

Differential Diagnosis

Space medicine

Inhalation injury

Unintentional
Terrorism

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

See Also

References

Retrieved from "https://www.wikem.org/w/index.php?title=Hydrazine_toxicity&oldid=374112"