Early Identification of Those Acute Medical Admissions That Will Require Critical Care

Background Removal of the Intensive Care Unit (ICU) at the Vale of Leven Hospital mandated the identification and transfer out of those acute medical admissions with a high risk of requiring ICU. Aims To develop triaging tools that identified such patients and compare them with other scoring systems. Methods A retrospective analysis of physiological and arterial gas measurements from 1976 acute medical admissions produced PREEMPT-1. A simpler one for ambulance use (PREAMBLE-1) was produced by the addition of peripheral oxygen saturation to a modification of MEWS (Modified Early Warning Score). Prospective application of these tools produced a larger database of 4447 acute admissions from which logistic regression models produced PREEMPT-2 and PREAMBLE-2 which were then compared to the original systems and seven other early warning scoring systems. Results In patients with arterial gases the area under the Receiver Operator Characteristic curve (ROC AUC) was significantly higher in PREEMPT-2 (89·1%) and PREAMBLE-2 (84.4%) than all other scoring systems. Similarly, in all patients, it was higher in PREAMBLE-2 (92·4%) than PREAMBLE-1 (88·1%) and the other scoring systems. Conclusions Risk of requiring ICU can be more accurately predicted using PREEMPT-2 and PREAMBLE-2, as described here, than by other early warning scoring systems developed over recent years. Introduction In October 2003, acute surgical and Emergency Department (ED) services at the Vale of Leven Hospital were transferred to the Royal Alexandra Hospital (RAH) in Paisley. “Stand-alone” acute medical services continued with on-site anaesthetic cover, and the ED was replaced by a Medical Assessment Unit (MAU). The planned removal of the remaining Intensive Care Unit (ICU) bed stimulated the desire to develop tools to help identify patients at greatest risk of requiring ICU care, to allow transfer elsewhere as early as possible. A review of the literature in late 2004 showed only two of the earliest versions of the scoring systems assessed below, and none that had risk of requiring ICU as the primary target. The retrospective audit described below was therefore undertaken to develop suitable triaging tools which are described here. The PREcritical Emergency Medical Patient Triage (PREEMPT) tool was designed to be used in the hospital based on routine physiological and arterial blood gas measurements readily available in the emergency department. The PRE-Admission Medical Blue-Light Emergency (PREAMBLE) tool was designed for ambulance use, only using routinely collected physiological measurements, to allow a rapid risk assessment and decision regarding by-pass to another hospital. As