Hypotension and coma in a 5-year-old victim of smoke inhalation
You are alerted by paramedics who are en route to the emergency department. They will arrive within 10 minutes with two apparent smoke-inhalation victims: a young woman, approximate age 35, and her son, approximate age 5. Upon arrival at the scene, firefighters found both victims unconscious near the doorway; the entire house was smoke-filled. The fire, which was confined to the child’s bedroom and two adjacent rooms, was started by a toy that the child poked into an electric space heater. It is probable that the woman was in another part of the house when the fire began and attempted to rescue the child but was overcome by the thick black smoke. Both victims are unconscious. The paramedics report no evidence of trauma or burns in either victim. The mother has nonpurposeful movements, but the child is flaccid and unresponsive to painful stimuli. Soot is present in the child’s nose and throat.
En route to the hospital, IVs were started. The woman’s vital signs include BP 70/50 mm Hg, pulse 120/min, respiration rate 30/min. She is being administered 100% oxygen via face mask. The child’s vital signs include BP 50/20 mm Hg, pulse 50/min, respiration rate 0/min. He is intubated and mechanically ventilated, and is being administered supplemental oxygen.
Upon arrival at the hospital, the woman is improved but is lethargic and disoriented; the child is still unresponsive even to deep pain. Both victims have adequate pO2 levels. The mother’s initial carboxyhemoglobin level is 25%; the child’s carboxyhemoglobin level is 40%. The child remains bradycardic and hypotensive.
The following day, having heard that cyanide may have played a role in the condition of these smoke-inhalation victims, a neighboring couple, who have recently learned that for 2 years they had been drinking well water containing 212 parts per billion (ppb) cyanide, are concerned that they may experience adverse health effects. They ask to be evaluated.
(a) What are the possible causes of coma in the fire victims?
(b) What laboratory tests would help to confirm the diagnosis?
(c) What treatment should be initiated immediately?
(d) What are the possible long-term sequelae for the fire victims and the neighbors who drank cyanide-containing well water?
Answers can be found in Challenge answers (6) through (13) on pages 18–19.