Medical Aspects of Chemical Warfare (2008) - The Black Vault

Medical Management of Chemical Toxicity in PediatricsExhibit 21-5Mnemonic for Recognition ofCyanide ToxicityFAT RED CATS• F: flushing of skin• A: almonds (bitter almond smell)• T: tachycardia• R: red (red/pink skin, bright red retinal vessels)• E: excitation of nervous system• D: dizziness, death, recent depression history• C: confusion, coma, convulsions• A: acidosis (metabolic or lactic), anion gap• T: tachypnea• S: soot in noseamyl nitrite, sodium nitrite, and sodium thiosulfate(Table 21-8). 96–98 Antidotes should be provided onlyfor significantly symptomatic patients, such as thosewith impaired consciousness, seizures, acidosis, hypotension,hyperkalemia, or unstable vital signs. 100Even when patients are rendered comatose by inhalinghydrogen cyanide gas, antidotes may not be necessaryif the exposure is rapidly terminated, the patient hasregained consciousness on arrival at the hospital, andthere is no acidosis or vital sign abnormality. 101Supportive Therapy. Regardless of the antidote,treatment always consists of supportive therapy, 96which alone may reverse the effects of cyanide even inthe face of apnea. 96,97,101 Supportive therapy includes decontamination,oxygen, hydration, and administrationof anticonvulsants. 96–98,101 Decontamination measuresshould take place prior to patient transport to a medicalcenter. First responders and healthcare professionalsshould take precautions not to intoxicate themselvesthrough direct mouth-to-mouth resuscitative efforts. 98They must also wear personal protective equipmentwhen transporting the victims to areas with adequateventilation. 96 Clothes are an obvious source of recontaminationand must be removed from the victim. Thevictim’s skin should be flushed with copious volumesof water, 96,97 the temperature of which becomes a considerationfor children who may not tolerate extremes ofcold or hot. Timely supportive care is important becauseantidote kits may not be available.Antidotal Therapy. The US standard cyanide antidotekit uses a small inhaled dose of amyl nitrite followedby IV sodium nitrite and sodium thiosulfate. 96,102This antidote converts a portion of the hemoglobinTable 21-8Multistage antidote kit Treatment for Managing unconscious,Cyanide-Exposed Patients*Amyl Nitrite Ampules Sodium Nitrite (for Hb = 12) Sodium Thiosulfate (for Hb = 12)For children ≤ 30 kg:• Crush 1 amp in gauze close tothe mouth and nose of breathingvictim• Inhale fore 15 secs, rest for 15 secs• Replace pearls every 30 secs untilsodium nitrite can be administeredFor adults:• See aboveFor children ≤ 30 kg:• 0.19–0.39 mL/kg not to exceed10 mL of 3% solution to slow IVover less than 5 mins or slower ifhypotension develops• For every 1 g/dL increase ordecrease change in Hb, changedose by approximately 0.03 mL/kg accordingly• May repeat dose at half the originaldose in 30 min if neededFor adults:• 10 mL of 3% solution slow IVover no less than 5 min or slowerif hypotension developsFor children ≤ 30 kg:• 0.95–1.95 mL/kg not to exceed 50mL of 25% solution IV over 10–20min• For every increase or decreasechange in Hb of 1 g/dL, changesodium thiosulfate by 0.15 mL/kg accordingly• May repeat dose at half originaldose in 30 min if neededFor adults:• 50 mL of 25% solution IV over10–20 min*Other treatments include evacuation, decontamination, administration of 100% oxygen, and correction of acidosis, hypovolemia, andseizures.Hb: hemoglobinIV: intravenousData sources: (1) Cyanide antidote [package insert]. Buffalo Grove, Ill: Taylor Pharmaceuticals; 1998. (2) Berlin CM. The treatment ofcyanide poisoning in children. Pediatrics. 1970;46:793–796. (3) Hall AH, Rumack BH. Clinical toxicology of cyanide. Ann Emerg Med.1986;15:1067–1074.675