Pseudo tamponade soon after cardiac surgery: a report of three cases

To describe a syndrome suggestive of tamponade but secondary to increased intra-thoracic pressure due to undetected dyssynchronous expiratory efforts in mechanically ventilated patients soon after cardiac surgery.

A retrospective chart review of three patients immediately after cardiac surgery.

All patients developed the tetrad of decreased blood pressure, increased central venous pressure, decreased cardiac index and decreased urine output soon after cardiac surgery without other obvious reasons. In all patients, tamponade was suspected. In all cases, physical examination found no marked evidence of patient-ventilator dyssynchrony but evidence of abdominal muscle tensing and intermittent expiratory efforts not in synchrony with the ventilator cycle. In all patients, sedation and muscle relaxation led to a decrease in central venous pressure, improved blood pressure and improved cardiac index and urine output with full resolution of the syndrome. All patients were successfully extubated within 24 hours of surgery.

In some postoperative cardiac surgery patients expiratory efforts which are not in synchrony with mechanical ventilation and not immediately obvious to clinicians or intensive care unit nurses can simulate tamponade. Greater awareness of this syndrome may decrease the chance of diagnostic error.