TAMPONADE IN PATIENTS UNDERGOING CARDIAC-SURGERY - A CLINICAL-ECHOCARDIOGRAPHIC DIAGNOSIS

The purpose of this study was to evaluate the sensitivity of current e chocardiographic criteria in detecting cardiac tamponade in the patien t who has undergone cardiovascular surgery. Because the current echoca rdiographic criteria for tamponade were initially developed and studie d predominantly in patients with medical problems, relatively less inf ormation is available in patients who have undergone cardiac surgery. Of 848 consecutive patients who underwent cardiovascular surgery, pati ents were selected for the study if they had clinical or hemodynamic d eterioration and had undergone an echocardiogram just before a success ful pericardiocentesis or a surgical evacuation of pericardial blood o r clot. The echocardiograms were evaluated for evidence of chamber col lapse, cardiac motion, Doppler flow variations, and the location and w idth of pericardial separation. Fourteen patients were identified who met the inclusion criteria (clinical or hemodynamic deterioration, rec ent echocardiogram, and successful intervention) for cardiac tamponade . The clinical and hemodynamic findings were hypotension (13 patients) , low cardiac output (7), low urine output (3), cardiopulmonary arrest (1), elevated central venous pressure (1), and shortness of breath (1 ). In these patients current echocardiographic criteria were seen infr equently: chamber collapse in the right atrium (6 of 14 patients) and right ventricle (4 of 14); Doppler flow variation (2 of 5); and swingi ng heart (0 of 15), whereas increased pericardial separation (greater than or equal to 10 mm) was seen in all (14 of 14) the patients. Altho ugh the sensitivity of current echocardiographic criteria for tamponad e was not high (0% to 43%), the sensitivity of a combined index (unexp lained clinical or hemodynamic deterioration and pericardial echo sepa ration width greater than or equal to 10 mm) was high (100%) in this g roup of patients who had undergone surgery. In this study standard ech ocardiographic criteria were found to be relatively unreliable in dete cting cardiac tamponade in patients who had undergone cardiac surgery. However, the presence of greater than or equal to 10 mm of pericardia l separation (fluid/clot) and unexplained clinical or hemodynamic dete rioration appeared to be sensitive in detecting tamponade.