eMedicine Specialties > Emergency Medicine > Warfare - Chemical, Biological, Radiological, Nuclear and Explosives

CBRNE - Cyanides, Hydrogen: Differential Diagnoses & Workup

Author: Erik D Schraga, MD, Consulting Staff, Department of Emergency Medicine, Mills-Peninsula Emergency Medical Associates; Consulting Staff, Permanente Medical Group, Kaiser Permanente, Santa Clara Medical Center
Coauthor(s): Andre Pennardt, MD, FACEP, FAAEM, Adjunct Assistant Professor of Military and Emergency Medicine, Uniformed Services University of the Health Sciences; Consulting Staff, Department of Emergency Medicine, Aviation Medicine and Dive Medicine, Womack Army Medical Center
Contributor Information and Disclosures

Updated: Mar 11, 2008

Differential Diagnoses

CBRNE - Cyanides, Cyanogen Chloride
Toxicity, Ethylene Glycol
CBRNE - Nerve Agents, Binary: GB2, VX2
Toxicity, Hydrogen Sulfide
CBRNE - Nerve Agents, G-series: Tabun, Sarin, Soman
Toxicity, Isoniazid
CBRNE - Nerve Agents, V-series: Ve, Vg, Vm, Vx
Toxicity, Organophosphate and Carbamate
Shock, Septic
Toxicity, Carbon Monoxide

Other Problems to Be Considered

Consider the diagnosis of cyanide poisoning in patients with rapid collapse or seizures accompanied by metabolic acidosis and decreased oxygen consumption. Other agents that may have similar features in toxicity include the following:

Methemoglobin-inducing agents
Carbon monoxide
Inert gases (simple asphyxiants)
Hydrogen sulfide
Azides
Arsine
Phosphine
Monomethylhydrazine
Isoniazid
Water hemlock
Strychnine
Organophosphates
Metformin

Workup

Laboratory Studies

  • Arterial and venous blood gases: Cyanide toxicity is characterized by a normal arterial PO2 and an abnormally high venous PO2 (decreased arteriovenous oxygen difference [A-VO2]).
  • Serum chemistries and lactate level: Cyanide poisoning is classically associated with high anion gap metabolic acidosis and elevated lactate level.
  • Cyanide levels
    • Cyanide levels are generally not available in time to guide acute treatment but may be confirmatory. The preferred test is an RBC cyanide level.
    • With this method, mild toxicity is observed at concentrations of 0.5-1.0 mcg/mL. Concentrations of 2.5 mcg/mL and higher are associated with coma, seizures, and death.
  • Carboxyhemoglobin level: Obtain carboxyhemoglobin level of patient to exclude carbon monoxide poisoning, especially in smoke inhalation victims.
  • Methemoglobin level: Obtain a methemoglobin level, especially in cyanotic patients. Also, following the treatment of cyanide poisoning with sodium nitrite, methemoglobin levels are useful (see Treatment).

Other Tests

  • ECG: Shortening of the ST segment with eventual fusion of the T wave into the QRS complex has been observed.

Procedures

  • Endotracheal intubation is indicated for treatment of apneic cyanide casualties.

More on CBRNE - Cyanides, Hydrogen

Overview: CBRNE - Cyanides, Hydrogen
Differential Diagnoses & Workup: CBRNE - Cyanides, Hydrogen
Treatment & Medication: CBRNE - Cyanides, Hydrogen
Follow-up: CBRNE - Cyanides, Hydrogen
Multimedia: CBRNE - Cyanides, Hydrogen
References
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References

  1. Armstrong J. Chemical warfare. RN. Apr 2002;65(4):32-9. [Medline].

  2. Baskin SI, Brewer TG. Cyanide poisoning. In: Medical Aspects of Chemical and Biological Warfare. 1997:271-286.

  3. Baud FJ, Borron SW, Megarbane B. Value of lactic acidosis in the assessment of the severity of acute cyanide poisoning. Crit Care Med. Sep 2002;30(9):2044-50. [Medline].

  4. Borron SW, Baud FJ, Mégarbane B, Bismuth C. Hydroxocobalamin for severe acute cyanide poisoning by ingestion or inhalation. Am J Emerg Med. Jun 2007;25(5):551-8. [Medline].

  5. Brennan RJ, Waeckerle JF, Sharp TW. Chemical warfare agents: emergency medical and emergency public health issues. Ann Emerg Med. Aug 1999;34(2):191-204. [Medline].

  6. Burda AM, Sigg T. Pharmacy preparedness for incidents involving weapons of mass destruction. Am J Health Syst Pharm. Dec 1 2001;58(23):2274-84. [Medline].

  7. Department of the Army. Blood agents (Cyanogens). In: Field Manual 8-285: Treatment of Chemical Agent Casualties and Conventional Military Chemical Injuries. 1995:VI-1-2.

  8. Greenfield RA, Brown BR, Hutchins JB. Microbiological, biological, and chemical weapons of warfare and terrorism. Am J Med Sci. Jun 2002;323(6):326-40. [Medline].

  9. Kirk MA, Gerace R, Kulig KW. Cyanide and methemoglobin kinetics in smoke inhalation victims treated with the cyanide antidote kit. Ann Emerg Med. Sep 1993;22(9):1413-8. [Medline].

  10. Lynch EL, Thomas TL. Pediatric considerations in chemical exposures: are we prepared?. Pediatr Emerg Care. Mar 2004;20(3):198-208. [Medline].

  11. Martin CO, Adams HP. Neurological aspects of biological and chemical terrorism: a review for neurologists. Arch Neurol. Jan 2003;60(1):21-5. [Medline].

  12. Morocco AP. Cyanides. Crit Care Clin. Oct 2005;21(4):691-705, vi. [Medline].

  13. Musshoff F, Schmidt P, Daldrup T. Cyanide fatalities: case studies of four suicides and one homicide. Am J Forensic Med Pathol. Dec 2002;23(4):315-20. [Medline].

  14. Rosenbloom M, Leikin JB, Vogel SN. Biological and chemical agents: a brief synopsis. Am J Ther. Jan-Feb 2002;9(1):5-14. [Medline].

  15. Sauer SW, Keim ME. Hydroxocobalamin: improved public health readiness for cyanide disasters. Ann Emerg Med. Jun 2001;37(6):635-41. [Medline].

  16. Sidell FR, Patrick WC, Dashiell TR. Cyanide. In: Jane's Chem-Bio Handbook. 1998:79-88.

  17. USACHPPM. Cyanide. In: USACHPPM Tech Guide 244: The Medical NBC Battlebook. 1999:V-36-37.

  18. USAMRICD. Cyanide. In: Field Management of Chemical Casualties Handbook. 1996:37-40.

  19. USAMRICD. Cyanide. In: Medical Management of Chemical Casualties Handbook. 1999:38-58.

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Further Reading

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Keywords

cyanides, AC, hydrocyanic acid, HCN, cyanide, chemical warfare agent, chemical weapon, cyanide exposure, hydrogen cyanide exposure, cyanogen chloride, cyanide poisoning, hydrogen cyanide poisoning, hydrogen cyanide exposure, terrorism

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Contributor Information and Disclosures

Author

Erik D Schraga, MD, Consulting Staff, Department of Emergency Medicine, Mills-Peninsula Emergency Medical Associates; Consulting Staff, Permanente Medical Group, Kaiser Permanente, Santa Clara Medical Center
Disclosure: Nothing to disclose.

Coauthor(s)

Andre Pennardt, MD, FACEP, FAAEM, Adjunct Assistant Professor of Military and Emergency Medicine, Uniformed Services University of the Health Sciences; Consulting Staff, Department of Emergency Medicine, Aviation Medicine and Dive Medicine, Womack Army Medical Center
Andre Pennardt, MD, FACEP, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, Association of Military Surgeons of the US, International Society for Mountain Medicine, National Association of EMS Physicians, Special Operations Medical Association, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Medical Editor

Suzanne White, MD, Medical Director, Regional Poison Control Center at Children's Hospital, Program Director of Medical Toxicology, Associate Professor, Departments of Emergency Medicine and Pediatrics, Wayne State University School of Medicine
Suzanne White, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Clinical Toxicology, American College of Epidemiology, American College of Medical Toxicology, American Medical Association, and Michigan State Medical Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Rick Kulkarni, MD, Medical Director, Assistant Professor of Surgery, Section of Emergency Medicine, Yale-New Haven Hospital
Rick Kulkarni, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: WebMD Salary Employment

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Robert G Darling, MD, FACEP, Clinical Assistant Professor of Military and Emergency Medicine, Uniformed Services University of the Health Sciences, F Edward Hebert School of Medicine; Director, Center for Disaster and Humanitarian Assistance Medicine
Robert G Darling, MD, FACEP is a member of the following medical societies: American College of Emergency Physicians, American Medical Association, and Association of Military Surgeons of the US
Disclosure: Nothing to disclose.

 
 
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