Delayed transient loss of consciousness in acute carbon monoxide intoxication

In acute carbon monoxide intoxication the presence of altered consciousness, ranging from transient loss of consciousness to coma, represents a poor prognostic factor and modifies the approach to therapy. Transient loss of consciousness is, as a rule, contemporaneous to the exposure, generally occurring at the scene of the intoxication. We report an unusual case of delayed transient loss of consciousness, occurring in the absence of any other evident aetiology, in one member of an orchestra composed of 110 members after a mass carbon monoxide poisoning.