Hydrazine toxicity: Difference between revisions

(Created page with "==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...")
 
 
(11 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


===Toxicology===
===Toxic Dose===
===Toxic Dose===
* OSHA limit 1 ppm in air for 8-hour workday
* OSHA limit 1 ppm in air for 8-hour workday
* 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
Line 20: 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:
===Signs and Symptoms===
**Above, plus may cause [[hepatic failure|liver]] and [[renal failure|kidney damage]]
* Dizziness, nausea, itching, skin burning, tearing, coughing, excitement, tremors, polyneuritis, impaired cognition, lethargy, convulsions
*Ingestion
===Evaluation===
**[[Nausea/vomiting]]
* Monitor vital signs and mental status
**Uncontrollable shaking, [[seizure]], nerve inflammation/polyneuritis, [[coma]]
* Examination with emphasis on skin, lungs, central nervous system
*Contact exposure
* Labs - serum electrolytes, renal function, urine analysis, complete blood count, liver function test, pH, lactate level, monitor methemoglobin levels
**[[rash|Dermatitis]], [[chemical burns]]
* Ancillary testing - chest x-ray and pulmonary function testing if inhalation exposure or patient has pulmonary symptoms
**If absorbed systemically, can -> [[hemolytic anemia]], [[methemoglobinemia]]
 
==Differential Diagnosis==
{{Space medicine}}
{{Inhalation exposure}}
 
==Evaluation==
*BMP
*[[LFTs]]
*CBC
*[[UA]]
*[[VBG]], MetHb
*[[Lactate]]
*[[CXR]] if inhalational exposure or 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 [[methemoglobinemia]]


===Management===
===Severe Exposure===
* Mild to Moderate Exposure
* [[Seizures]] - [[pyridoxine]] 25 mg/kg IM or IV up to 5 grams plus [[benzodiazepine]]
** Ensure patient has been decontaminated
* Respiratory distress - secure airway and assist ventilation
** Irrigate eyes with normal saline or water if exposed
* [[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
** Treat chemical burns if present
* Consider [[hemodialysis]] and acidification of urine if member has severe CNS depression
** Monitor pulmonary status
* [[Hypoglycemia]] treat with D10 and [[thiamine]]
** 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==
==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


==See Also==
==See Also==
:[[Pyridoxine]]
*[[Pyridoxine]]
:[[Methylene blue]]
*[[Methylene blue]]
 
 


==References==
==References==

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"