Clinical, biochemical and haemodynamic variables as independent predictors of 90-day mortality : The Simple Intensive Care Studies-I

INTRODUCTION. Clinical, biochemical and haemodynamic variables are used to diagnose circulatory shock and guide treatment in the critically ill. Literature is inconsistent which clinical signs have the best prognostic value on top of well-validated prognostic scores such as the simplified acute physiology score (SAPS II). OBJECTIVES. The objective of the Simple Intensive Care Studies-I (SICS-I: NCT02912624) was to evaluate the association of clinical, biochemical and haemodynamic variables with 90-day mortality in a large, consecutive, cohort of critically ill patients [1]. METHODS. This prospective cohort study included all consecutive adults who were acutely admitted with an intensive care unit (ICU) stay expected to last beyond 24 hours. We conducted a protocolised clinical examination and critical care ultrasonography (CCUS) within 24 hours of ICU admission. Our primary outcome was 90-day mortality. Our secondary outcomes were 7-and 30-day mortality, and 90-day mortality by type of circulatory shock and clinical subgroups. We used multivariable Cox regression analyses to identify independent predictors of mortality. RESULTS. From 27 March 2015 until 22 July 2017, 1104 patients were included. A total of 298 patients (28%) died at 90-day follow-up. Patients who died were older, more often ventilated, unconscious and dependent on noradrenalin, had lower blood pressures and urine output, and more often had an impaired microcirculation (tables 1-3). Multivariable Cox regression adjusted for age and SAPS-II score showed that respiratory rate (HR 1.02; 95% CI 1.00-1.04), unrespon-siveness (HR 1.53; 95% CI 1.08-2.16) and serum lactate (HR 1.08; 95% CI 1.03-1.13) were independently associated with 90-day mortality. In patients with septic shock independent predictors were mottling rate (HR 1.27; 95% CI 1.02-1.58) and serum lactate (HR 1.11; 95% CI 1.02-1.22), whereas diuresis <0.5 ml/kg/h (HR 2.27; 95% CI 1.00-5.15) and a mean arterial pressure <70 mmHg despite vasopressor treatment (HR 5.08; 95% CI 2.00-12.9) were independent predictors in patients with heart failure. CONCLUSIONS. Simple clinical variables as respiratory rate, consciousness, and serum lactate are independently associated with 90-day mortality in a large, unselected cohort of critically ill patients. The predictive value of clinical signs changed in clinical subgroups. Skin mottling and lactate showed the strongest associations in patients with septic shock and impaired diuresis and low mean arterial pressures were independently associated with 90-day mortality in patients with heart failure. [Table Presented].