Afterload-related cardiac performance: a hemodynamic parameter with prognostic relevance in patients with sepsis in the Emergency Department

Abstract

Introduction: Afterload-related cardiac performance (ACP) was developed to describe cardiac function in patients with sepsis, when cardiac output (CO) is increased due to a decline in systemic vascular resistance (SVR). We now studied the prognostic relevance of ACP in comparison with the cardiac index (CI) and cardiac power index (CPI) in patients at a very early stage of community-acquired sepsis (CAS) in the Emergency Department. (Figure Presented) Methods: In patients >=18 years admitted to our Emergency Department with CAS (infection and >=2 SIRS criteria), CI, CPI, and ACP were measured either non-invasively (TaskForce-Monitor; CNSystems, Austria) or invasively. ACP was calculated as ACP = 100 x CO / (560.68 x SVR-0.64). Cardiac function was graded into normal (>80%), slightly (61 to 80%), moderately (41 to 60%) or severely impaired ( <0.01), whereas no differences were observed for CI or CPI, respectively. In severe sepsis or septic shock, impairment of ACP was observed more often than in sepsis (Figure 1A). Nonsurvivors showed a significantly depressed ACP already on admission and after 72 hours (Figure 1B), whereas CPI differed only after 72 hours between survivors and nonsurvivors (0.52 +/- 0.18 vs. 0.32 +/- 0.17, P <0.05) and CI showed no differences in this regard. ACP correlated better with APACHE II score (r = -0.371, P <0.001) than CPI (r = -0.330, P <0.001) or CI (r = -0.220, P <0.001). Only ACP correlated with serum levels of procalcitonin (r = 0.224, P <0.01) and IL-6 (r = -0.173, P <0.05). Conclusions: Taken together, only the parameter ACP but not CI nor CPI is able to detect an early impairment of cardiac function in patients with CAS and provides prognostic information on admission.