How is carbon monoxide poisoning confirmed in smoke inhalation victims?

How is carbon monoxide poisoning confirmed in smoke inhalation victims?

• A. Chest X-ray
• B. White blood cell count
• C. Carboxyhemoglobin level on ABG or VBG
• D. Serum lactate

Answer: (C)

Measuring carboxyhemoglobin in the blood is how you confirm carbon monoxide poisoning from smoke inhalation. CO binds tightly to hemoglobin, forming carboxyhemoglobin, which reduces the blood’s oxygen-carrying capacity and shifts the oxygen dissociation curve, impairing tissue oxygen delivery. The definitive test is to obtain an arterial or venous blood sample and assess carboxyhemoglobin level with co-oximetry as part of an ABG or VBG analysis. This directly detects CO-bound hemoglobin and gives a quantitative value that supports the diagnosis and indicates severity. Imaging like chest X-ray cannot confirm CO poisoning; it may reveal complications of smoke inhalation later but not the cause itself. White blood cell count is nonspecific, and serum lactate can be elevated in many conditions causing tissue hypoxia, so neither is diagnostic for CO exposure. Pulse oximetry can be misleading in CO poisoning because it cannot distinguish oxyhemoglobin from carboxyhemoglobin, so it’s not reliable for confirming exposure.

Measuring carboxyhemoglobin in the blood is how you confirm carbon monoxide poisoning from smoke inhalation. CO binds tightly to hemoglobin, forming carboxyhemoglobin, which reduces the blood’s oxygen-carrying capacity and shifts the oxygen dissociation curve, impairing tissue oxygen delivery. The definitive test is to obtain an arterial or venous blood sample and assess carboxyhemoglobin level with co-oximetry as part of an ABG or VBG analysis. This directly detects CO-bound hemoglobin and gives a quantitative value that supports the diagnosis and indicates severity.

Imaging like chest X-ray cannot confirm CO poisoning; it may reveal complications of smoke inhalation later but not the cause itself. White blood cell count is nonspecific, and serum lactate can be elevated in many conditions causing tissue hypoxia, so neither is diagnostic for CO exposure. Pulse oximetry can be misleading in CO poisoning because it cannot distinguish oxyhemoglobin from carboxyhemoglobin, so it’s not reliable for confirming exposure.