Prediction of postoperative cardiac surgical morbidity and organ failure within 4 hours of intensive care unit admission using esophageal Doppler ultrasonography

Objective: To compare esophageal Doppler ultrasonography with standard hemo dynamic variables used in postoperative care for the prediction of postoper ative complications after cardiac surgery. Design:Prospective, observational pilot study. Setting: University hospital, multidisciplinary intensive care unit. Patients: Postoperative cardiac surgical patients. Interventions Standard postoperative management as guided by routinely meas ured hemodynamic variables. Measurements: An esophageal Doppler ultrasound probe was inserted for measu rement of stroke volume (SV), cardiac output (88), and other flow-related v ariables. Both these and routine hemodynamic variables (mean arterial press ure, central venous pressure, heart rate, arterial base deficit, urine outp ut, core-toe temperature difference) were recorded at half-hourly intervals for the first 4 postoperative hrs. The incidence of systemic inflammatory response syndrome at 24 hrs, Acute Physiology and Chronic Health Evaluation II, and multiple organ failure scores, postoperative complications, and le ngth of ICU and hospital stays were recorded. Main Results:Twenty consecutively admitted patients were studied: eight aft er emergency bypass grafting and 12 after elective bypass grafts and/or val ve replacement Of the nine patients who developed postoperative complicatio ns, two died. At admission, significant differences were seen between patie nts with a complicated and those with an uncomplicated surgical procedure f or SV, heart rate, and standard base excess, but not for cardiac output By using receiver operator characteristic curves, SV was the best marker for p redicting postoperative complications during the initial postoperative peri od. Conclusions:A low SV and a high heart rate, both at ICU admission and durin g the subsequent 4 hrs, were the best prognostic factors for development of complications after cardiac: surgery. Cardiac output values were not usefu l. This pilot study suggests that the minimally invasive technique of esoph ageal Doppler ultrasonography may be a useful tool to assist early prognost ication.