Early sepsis detection in critical care patients using multiscale blood pressure and heart rate dynamics

Abstract

Sepsis remains a leading cause of morbidity and mortality among intensive care unit (ICU) patients. For each hour treatment initiation is delayed after diagnosis, sepsis-related mortality increases by approximately 8%. Therefore, maximizing effective care requires early recognition and initiation of treatment protocols. Antecedent signs and symptoms of sepsis can be subtle and unrecognizable (e.g., loss of autonomic regulation of vital signs), causing treatment delays and harm to the patient. In this work we investigated the utility of high-resolution blood pressure (BP) and heart rate (HR) times series dynamics for the early prediction of sepsis in patients from an urban, academic hospital, meeting the third international consensus definition of sepsis (sepsis-III) during their ICU admission. Using a multivariate modeling approach we found that HR and BP dynamics at multiple time-scales are independent predictors of sepsis, even after adjusting for commonly measured clinical values and patient demographics and comorbidities. Earlier recognition and diagnosis of sepsis has the potential to decrease sepsis-related morbidity and mortality through earlier initiation of treatment protocols.

Keywords: Critical care; Dynamics; ECG; Infection; Machine learning; Sepsis.

Figure 1

(Left panel) Plot of MAP time series for a septic and a control subject, and their corresponding multiscale entropy at Scale 4. (Right panel) Plot of HR time series for a septic and a control subject, and their corresponding multiscale entropy at Scale 4. The HR and MAP time series have been normalized by their standard deviations for illustration purposes

Figure 2

Area under the receiver-operating characteristic (ROC) curve of Model 3 (Combining Entropy, EMR, and socio-demographic-patient history features). The AUROC on test set and training set was 0.78 and 0.80 respectively. The model 3 achieved a specificity of 0.55 at 0.85 sensitivity level (for the test set).