HEMODYNAMIC CONSEQUENCES OF WARM CARDIAC IRRIGATION DURING CARDIAC-SURGERY

Following cardiopulmonary bypass (CPB) and prior to closing the chest, some surgeons irrigate the heart and pericardium with warm saline. Th is prospective study using each patient as his own control, evaluated the haemodynamic effects of warm (44 +/- 5 degrees C) irrigation on th e heart and pericardium following CPB. Following discontinuation of CP B, a Mon-a-therm model 6500 thermocouple monitor measured the myocardi al septum and the irrigating fluid temperatures. Immediately before, d uring and two minutes after irrigation of the heart and pericardium, w e measured heart rate (HR), systemic blood pressure (BP), pulmonary ar tery pressure (PAP), central venous pressure (CVP), thermodilution car diac output, and calculated systemic vascular resistance (SVR). During warm irrigation, HR increased from 93 +/- 15 to 101 +/- 13 min(-1) an d systolic BP increased from 111 +/- 17 to 131 +/- 27 mmHg. After irri gation, HR decreased to 96 +/- 12 min(-1) with no change in systolic B P. The calculated SVR after irrigation increased to 1117 +/- 413 dynes .sec.cm(-5) from the pre-irrigation value of 821 +/- 243 dynes.sec.cm( -5), while cardiac index decreased to 2.4 L.min(-1).m(-2) from its pre irrigation value of 2.99 L.min(-1).m(-2). Warm irrigation of the peric ardial pouch causes tachycardic and hypertensive responses in patients undergoing cardiac surgery.