NONINVASIVE HEMODYNAMIC MONITORING OF CRITICAL PATIENTS IN THE EMERGENCY DEPARTMENT

Objective: To evaluate the feasibility of multicomponent noninvasive h emodynamic monitoring in critical emergency patients and to compare th is technique with simultaneous invasive monitoring by the pulmonary ar tery thermodilution catheter. Methods: A prospective observational stu dy was done comparing invasive monitoring and noninvasive monitoring i n 60 critically ill or injured patients who required hemodynamic monit oring shortly after entering the ED of a university-affiliate county h ospital. Cardiac output (CO) values measured by the standard thermodil ution pulmonary artery catheter technique were compared with simultane ously obtained measurements using a noninvasive bioimpedance method. C oncurrent measurements were made of pulse oximetry to screen pulmonary function and transcutaneous oximetry to assess tissue perfusion. Resu lts: The impedance CO values closely approximated those for the thermo dilution method; r 0.81, p < 0.001, Significant circulatory abnormalit ies, including hypotension, reduced cardiac index, arterial hemoglobin desaturation, tissue hypoxia, reduced O-2 delivery, and consumption, were found in 54 of the 60 (90%) patients, The cardiac index decreased in 44% of the patients, the transcutaneous O-2 decreased in 39%, and the O-2 saturation by pulse oximetry fell in 22% during the observatio n period in the ED (commonly lasting 2-8 hours). Conclusions: Noninvas ive monitoring can provide hemodynamic and perfusion information previ ously available only by invasive thermodilution catheters, Such noninv asive monitoring can display continuous on-line real-time data, allowi ng immediate recognition of circulatory abnormalities and providing a means to titrate therapy to appropriate therapeutic goals.