Associations Between Mean Arterial Pressure and Poor ICU Outcomes in Critically Ill Patients With Cirrhosis: Is 65 The Sweet Spot?

ABSTRACT

OBJECTIVES: Mean arterial pressure is critically important in patients with cirrhosis in the ICU, however, there is limited data to guide therapies and targets. DESIGN: Retrospective observational study. SETTING: Tertiary care ICU. PATIENTS Two hundred and seventy-three critically ill patients with cirrhosis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We performed a comprehensive time-weighted mean arterial pressure analysis (time-weighted-average-mean arterial pressure and cumulative-time-below various mean arterial pressure-thresholds) during the first 24-hours after ICU admission (median 25 mean arterial pressure measurements per-patient). Time-weighted-average-mean arterial pressure captures both the severity and duration of hypotension below a mean arterial pressure threshold and cumulative-time-below is the total time spent below a mean arterial pressure threshold. Individual univariable and multivariable logistic regression models were assessed for each time-weighted-average-mean arterial pressure and cumulative-time-below mean arterial pressure threshold (55, 60, 65, 70, and 75 mm Hg) for ICU-mortality. Time-weighted-average-mean arterial pressure for 1 mm Hg decrease in mean arterial pressure below 75, 70, 65, 60, and 55 mm Hg, the odds for ICU-mortality were 14%, 18%, 26%, 41%, and 74%, respectively (p < 0.01, all thresholds). The association between time-weighted-average-mean arterial pressure and ICU-mortality for each threshold remained significant after adjusting for model for end-stage liver disease-sodium score, mechanical ventilation, vasopressor use, renal replacement therapy, grade 3/4 hepatic encephalopathy, WBC count, and albumin. Cumulative-time-below odds for ICU-mortality were 4%, 6%, 10%, 12%, and 12% for each-hour spent below 75, 70, 65, 60, and 55 mm Hg, respectively. In the adjusted models, significant associations only remained for mean arterial pressure less than 65 mm Hg (odds ratio, 1.07; 95% CI, 1.00-1.14; p = 0.05) and < 60 mm Hg (odds ratio, 1.10; 95% CI, 1.01-1.18; p = 0.04). CONCLUSIONS: These data suggest that maintaining a mean arterial pressure of greater than 65 mm Hg may be a reasonable target in patients with cirrhosis admitted to the ICU. However, further prospective randomized trials are needed to determine the optimal mean arterial pressure-targets in this patient population.