Mean arterial pressure/norepinephrine equivalent dose index as an early measure for mortality risk in patients with shock on vasopressors

Abstract

Abstract Purpose We aimed to investigate the association between the early mean arterial pressure (MAP)/norepinephrine equivalent dose (NEQ) index and mortality risk in patients with shock on vasopressors, and further identify the breakpoint value of the MAP/NEQ index for high mortality risk. Methods Based on the MIMIC-IV database, we conducted a retrospective cohort study involving 19,539 eligible ICU records assigned to 3 groups (1st tertile, 2nd tertile, and 3rd tertile) by different MAP/NEQ indexes within 24 h of ICU admission. The study outcomes were 7-day, 14-day, 21-day, and 28-day mortality. A Cox model was used to examine the risk of mortality following different MAP/NEQ indexes. The receiving operating characteristic curve (ROC) was used to evaluate the predictive ability of the MAP/NEQ index. The restricted cubic spline was applied to fit the flexible correlation between the MAP/NEQ index and risk of mortality, and segmented regression was further used to identify the breakpoint value of the MAP/NEQ index for high mortality risk. Results Multivariate Cox analysis showed that a high MAP/NEQ index was independently associated with decreased mortality risks. The areas under the ROC curve of the MAP/NEQ index for different mortality outcomes were nearly 0.7. The MAP/NEQ index showed an L-shaped association with mortality outcomes or mortality risks. Exploration of the breakpoint value of the MAP/NEQ index suggested that a MAP/NEQ index less than 183 might be associated with a significantly increased mortality risk. Conclusions An early low MAP/NEQ index was indicative of poor prognosis in patients with shock on vasopressors.