Associations between mean arterial pressure and 28-day mortality according to the presence of hypertension or previous blood pressure level in critically ill sepsis patients

Abstract

Background: We aimed to investigate the association between average mean arterial pressure (a-MAP) and mortality in critically ill sepsis patients according to the presence of hypertension and previously measured blood pressure (BP). Methods: From August 2008 to September 2014, patients with severe sepsis or septic shock presenting to the ED were categorized into four groups according to a-MAP during the initial 24 hours (group 0, a-MAP <65 mmHg; group 1, 65 mmHg ≤ a-MAP <75 mmHg; group 2, 75 mmHg ≤ a-MAP <85 mmHg; group 3, a-MAP ≥85 mmHg). A low previous BP was defined as previous a-MAP ≤85 mmHg, and a high previous BP is defined as a-MAP >85 mmHg. The primary outcome was 28-day mortality. Results: A total of 1,395 patients were included. The 28-day mortality rates were 15.1% in patients overall, 39.7% in group 0, 18.3% in group 1, 10.1% in group 2, and 13.4% in group 3. In the regression analyses, mortality in group 2 was significantly lower compared with group 1 [odds ratio (OR), 0.33] or group 3 (OR, 0.31) in patients with hypertension. In the low previous BP group, there was greater mortality in group 3 compared to group 1 (OR, 2.42) and group 2 (OR, 3.88). In the high previous BP group, mortality was lower in group 2 compared with group 1 (OR, 0.32). Conclusions: In critically ill sepsis patients, there were different trends in mortality according to a-MAP depending on the presence of hypertension or previous BP.