Asphyxiation by Cake: An Unusual Case of Dyspnea

Differential diagnosis
When CO₂ toxicity is suspected, other conditions should be considered, as there may be more than one process involved. For example, other causes of coma or dyspnea should be investigated, including trauma, hypoglycemia, CO, methemoglobinemia, or other metabolic processes. In addition, a patient may have a pre-existing condition, such as a trauma or an altered mental status due to drugs or alcohol, all of which can increase his or her susceptibility to the effects of CO₂.

Evaluation and treatment
Useful laboratory testing includes arterial blood gas, venous co-oximetry for carboxyhemoglobin, chemistry panels, ethanol testing, and radiographs or CT, as indicated.

Initial management of suspected CO₂ toxicity entails first removing the patient from the source of the gas. Rescuers must exercise caution so as to prevent a mass-casualty incident. Once out of the dangerous environment, as long as the patient is conscious and spontaneously breathing, supportive measures are generally all that are necessary. Oxygen should be applied, after which the spontaneously breathing patient without underlying lung disease should rapidly return to normal.

If there is marked decrease in mental status or poor respiratory drive despite O₂ administration, intubation with mechanical ventilation may be required. A higher-than-normal RR will help remove excessive CO₂ in this instance.

If a respiratory acidosis is present, IV sodium bicarbonate should be avoided, as this may increase the level of serum CO₂. IV fluids and other supportive measures, including treatment for any concurrent conditions, may be indicated.

REFERENCES
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