Association between resuscitation in the critical care resuscitation unit and in-hospital mortality

Patients who present in shock have high expected mortality and early resuscitation is crucial to improve their outcomes. The Critical Care Resuscitation Unit (CCRU) is a specialized unit at the University of Maryland Medical Center (UMMC) that prioritizes early resuscitation of critically ill patients. We hypothesized that lactate clearance and reduction of Sequential Organ Failure Assessment (SOFA) score during CCRU stay would be associated with lower in-hospital mortality.

We performed a retrospective analysis of adult patients who were admitted to the CCRU between 01/01/2018-12/31/2018 and had a diagnosis of severe shock, determined by serum lactate ≥4 mmol/L. We excluded patients who died during CCRU stay. We used multivariable logistic regression to evaluate the association between lactate clearance and reduction in SOFA scores during CCRU stay and in-hospital mortality.

Out of 1740 patients admitted to the CCRU in 2018, 172 (10%) had serum lactate ≥4 mmol/L. Twenty-two (13%) patients died during their CCRU stay. Our primary analysis included 129 patients with lactate clearance data and 136 patients with SOFA data. Average patients' age was 54 years, and median length of stay in the CCRU was 6 h 55 min. The average lactate and SOFA score on admission were 7.4 (3.8) mmol/L and 8.3 (4.7), respectively. Average lactate clearance was 1.9 (3.1) and average SOFA score reduction was 0.2 (2.9). In multivariable logistic regressions evaluating SOFA score and lactate separately, SOFA score reduction during CCRU stay was associated with lower in-hospital mortality (OR 0.83, 95% CI: 0.70-0.97) but lactate clearance was not (OR 0.90, 95% CI 0.78-1.03). In forward stepwise multivariable analysis containing both SOFA score and lactate values, SOFA score clearance during CCRU stay was still associated with decreased in-hospital mortality (OR 0.84, 95% CI 0.72-0.98).

Care in the CCRU is more effective at reducing lactate than SOFA scores in patients with severe shock. However, SOFA score reduction in the resuscitation phase during the CCRU stay was associated with decreased odds of in-hospital mortality in this group of patients. Further studies are necessary to confirm our observations.