Necessarily leads to decreased stroke volume and cardiac output, causing a sympathetic response. Critical to understand is that positive pressure ventilation, combined with tamponade, can further reduce preload and actually cause catastrophic hypotension and even cardiac death. Thus, NEVER initiate positive pressure ventilation until the pericardial space has been drained – if general anesthesia is needed, spontaneous ventilation is mandatory, thus ketamine (or sevoflurane) is the drug of choice. Induction should not take place until the surgical team is ready to make incision.
Video: Cardiac Tamponade