Performance of illness severity scores to guide disposition of emergency department patients with severe sepsis or septic shock.

Objective: To determine the number of emergency department (ED) patients with severe sepsis who are admitted to the ICU and to assess whether the predisposition, infection, response and organ failure (PIRO) score can be used as a clinical decision-making tool for guiding the disposition of ED sepsis patients to wards or the ICU.
Methods: This is a prospective study including ED patients with severe sepsis and septic shock. The PIRO score and in-hospital mortality were assessed in patients admitted to wards and ICUs. The sensitivity and specificity of the PIRO score and clinical judgement of the ED physician for guiding adequate disposition to wards or the ICU were assessed.
Results: A total of 47 of 153 patients were admitted to the ICU. Thirty-nine of 106 ward admissions had a 'do not resuscitate' status (not included in analysis). Mortality was 1.5 and 21% in patients initially admitted to a ward and the ICU, respectively. Unanticipated transfer from the ward to the ICU occurred in eight of 67 patients, resulting in higher mortality (38%, P=0.002, false negatives). Nine surviving patients admitted to the ICU for mere observation for less than 1 day were defined as false positives. Sensitivity of clinical judgement and of PIRO score (cut-off 9.5) alone or combined with clinical judgement were 0.92, 0.75 and 0.98, respectively (P<0.001). For specificity, these were 0.71, 0.56 and 0.40, respectively (P<0.001).
Conclusion: Two-thirds of ED patients with severe sepsis were admitted to the ward, of whom ∼13% clinically deteriorated, resulting in ICU admission and higher mortality. The PIRO score adds little value over clinical judgement in guiding adequate disposition to wards or the ICU.