Table 2 Summarized the evidence found in cases of N2O intoxication

Crime scene investigation

Presence of N2O cylinder on site connected to a tube, or whipped canister, or plastic bag. Anamnesis of recent anesthesia.

Autoptic examination

Cyanosis, conjunctival petechiae, visceral congestion, and pulmonary edema. Exclusion of traumatic lesions.

Histological examination

Cerebral edema, widespread stasis, contraction bands in the myocardium. Exclusion of hemorrhage or other traumatic evidence.

Immunohistochemical examination

Positivity of ischemia-reperfusion markers indicative of hypoxia.

Toxicological examination

Finding of N2O in blood and urine. Exclusion of other causes of intoxication (alcohol, drugs, etc)