Hospital stay and mortality in high-risk patients after noncardiac surgery has been associated with a triple low anesthesia. However, the association between anesthesia-related factors and perioperative outcome after cardiac surgery remains unclear.We tested the effect of a novel triple low state: low mean arterial pressure (MAP) <65 mmHg and low bispectral index (BIS) <45 during a low target effect-site concentration (Ce) <1.5 μg ml-1 of propofol anesthesia on postoperative duration of hospitalization and 30-day mortality in cardiac valvular patients. In this prospective observational study, univariable and multivariable logistic regression analyses were used to determine whether perioperative factors, in particular, cumulative duration of triple low state were independently associated with duration of hospitalization and 30-day mortality among patients who underwent elective valvular replacement. 489 patients were included in the final analysis. After adjusting for related covariates, cumulative duration of the triple-low state was not associated with prolonged hospitalization (multivariable odds ratio: 1.007; 95 % confidence interval 0.997-1.017; P = 0.564), but was a significant predictor of 30-day mortality (multivariable odds ratio: 1.016; 95 % confidence interval 1.002-1.031; P = 0.030). Compared to a triple-low duration of <15 min, a duration >60 min increased the 30-day mortality rate by 8 times. After adjusting for patient- and procedure-related characteristics, the cumulative duration of a triple-low state (intraoperative low MAP, low BIS, and low Ce) was associated with poorer 30-day mortality, but not with prolonged duration of hospital stay.The mortality risk was even greater when a cumulative time >60 min.
Keywords: Bispectral index; Mean arterial pressure; Mortality; Target effect-site concentration.