Mild exposure will cause headache, dizziness, drowsiness, mucosal irritation, and GI upset. Progression to coma can occur for several hours. Severe exposure leads to impaired consciousness and coma, arrhythmias, hypotension, cardiovascular collapse, respiratory irritation, and death [120] . The death can occur within minutes of inhalation [1] . Because hydrogen cyanide is excreted by the lungs, a patient's breath may have the characteristic of a bitter almond odor. The pupillary light reflex may be delayed [120] . Focal neurological signs are usually not prominent.