Arterial blood pressure correlates with 90-day mortality in sepsis patients: A retrospective multicenter derivation and validation study using high-frequency continuous data

Objective To identify the outcome of patients with sepsis using high-frequency blood pressure data. Materials and methods This retrospective observational study was conducted at a university hospital ICU (derivation study) and at two urban hospitals (validation study) with data from adult sepsis patients who visited the centers during the same period. The area under the curve (AUC) of blood pressure falling below threshold was calculated. The predictive 90-day mortality (primary endpoint) area under threshold (AUT) and critical blood pressure were calculated as the maximum area under the curve of the receiver operating characteristic curve (AUCROC) and the threshold minus average AUT (derivation study), respectively. For the validation study, the derived 90-day mortality AUCROC (using critical blood pressure) was compared with Sequential Organ Failure Assessment (SOFA), Simplified Acute Physiology Score (SAPS) II, Acute Physiology and Chronic Health Evaluation (APACHE) II, and APACHE III. Results Derivation cohort (N = 137): The drop area from the mean blood pressure of 70 mmHg at 24-48 hours most accurately predicted 90-day mortality [critical blood pressure, 67.8 mmHg; AUCROC, 0.763; 95% confidence interval (CI), 0.653-0.890]. Validation cohort (N = 141): The 90-day mortality AUCROC (0.776) compared with the AUCROC for SOFA (0.711), SAPSII (0.771), APACHE II (0.745), and APACHE III (0.710) was not significantly different from the critical blood pressure 67.8 mmHg (P = 0.420). Conclusion High-frequency arterial blood pressure data of the period and extent of blood pressure depression can be useful in predicting the clinical outcomes of patients with sepsis.