Optimal fluid amount for haemodynamic benefit in cardiac tamponade

The present study was undertaken to assess the effect of volume expansion on cardiac haemodynamics in patients with cardiac tamponade and to ascertain an optimum amount of fluid that can produce the maximum benefit in tamponade patients.

In patients of tamponade, interim measures may occasionally be needed when facilities for pericardial fluid drainage are not immediately available. Intravascular volume expansion is the most commonly advocated measure but with limited scientific data.

Patients ≥16 years of age with large circumferential pericardial effusion and showing echocardiographic evidence of cardiac tamponade were included. Haemodynamically unstable patients, those with structural heart diseases, pregnant females, and those undergoing haemodialysis were excluded. The various haemodynamic parameters were measured using Edwards Life Sciences Vigilance II monitor, Swan Ganz CCO catheter, intrapericardial access, and arterial access at baseline and after each 250 ml fluid over 5 min (total 1000 ml in 20 min). The entire fluid was drained at the end of the procedure.

A total of 28 patients constituted the study group, all of whom exhibited an improvement in haemodynamic parameters (systolic blood pressure, cardiac output) and a rise of the intracardiac pressures with volume expansion. Significant (p<0.05 ) increase in systolic and diastolic blood pressure, cardiac output, and cardiac index occurred up to 250–500 ml bracket; above which the significance was lost. A higher resting heart rate, a lower SBP at presentation, a higher initial intrapericardial pressure, and a lower cardiac index were the statistically significant predictors of a >15% increase in cardiac index.

Rapid infusion of as little as 250 ml intravenous normal saline may improve the cardiac haemodynamics in a significant proportion of tamponade patients.