Definition VERY difficult to diagnose, the key is to remain suspicious and vigilant. Can lead to hemodynamic collapse. Intraoperatively, a sudden drop in ETCO2 is suggestive of increased deadspace which has many potential causes, including pulmonary embolism. Symptoms (in awake patients) include dyspnea, tachypnea, chest pain, palpitations. Signs include hemoptysis, rales, wheezing, split heart sounds. […]