Non-invasive ventilation and standard mechanical ventilation can have very deleterious hemodynamic effects on patients with cardiac tamponade because of the drop in preload that results from positive pressure ventilation. The threshold for intubation in these patients should probably be raised. If you are ever caring for a patient with cardiac tamponade that definitely needs to be intubated and ventilated, be prepared for a significant drop in blood pressure and the potential need for pericardiocentesis. Once the patient is intubated, do everything possible to avoid high ventilatory pressures. [Ho AM, Graham CA, Ng CSH, et al. Timing of tracheal intubation in traumatic cardiac tamponade: a word of caution. Resuscitation 2009;80:272-274.]
