Prevention of inhospital cardiac arrest: a project based on a clinical severity score assessment

The Arresto CardioRespiratorio Ospedaliero (ACRO) (Inhospital Cardiac Arrest Prevention) group is a multiprofessional team constituted of intensivists, cardiologists, emergency physicians and critical care nurses involved in treatment and prevention of inhospital cardiac arrest (IHCA) of the Health System of Florence (six hospitals; 1600 beds; 850,000 inhabitants). In the past the ACRO group focused its efforts on early defibrillation: most of the personnel has been trained in basic life support and advanced cardiac life support and defibrillators have been placed at each floor of the hospitals. But about 2/3 of IHCA cases are sustained by asystole (A) and pulseless electrical activity (PEA), conditions with a low percentage of positive cardiopulmonary resuscitation. Most of these IHCA do not occur unexpectedly: 80% of patients have documented clinical deterioration (increase of respiratory rate, lowered blood pressure, altered level of consciousness) in the 6–12 hours preceeding IHCA. On the basis of these data, the ACRO group has recently planned a project to prevent IHCA by early detection and treatment of clinical deterioration. The project is based on a periodic assessment of all the in-ward patients at risk by the Modified Early Warning Score (MEWS), a simple clinical score based on six parameters (systolic blood pressure, heart rate, respiratory rate, level of consciousness, diuresis, temperature). Ward patients at risk are those admitted with an acute abdomen, pancreatitis, trauma, patients with coexisting medical conditions, those undergoing major surgery, patients following ICU discharge and patients causing a concern to nursing and medical staff. High values of MEWS (>3) or a sudden increase of the score will trigger a closer patient assessment, the need to recheck MEWS on the next observation and/or the alert of the internal emergency medical team; the patient will be admitted to the ICU or high-dependency unit, if necessary. To evaluate the feasibility of the project, in particular to assess the impact on nursing workload and to quantify the number of patients with deteriorating clincal conditions, we performed a survey in the two main hospitals of our area. On two different working days (18 June 2002 and 3 February 2003) we assessed the MEWS in all the in-ward patients. During the survey were evaluated 850 patients, 413 the first day and 437 the second day, with a mean time of examination of 5 min 40 s. Two hundred and forty patients (28,3%) had a MEWS of 0, 308 (36.3%) had MEWS of 1, 158 (18.6%) had MEWS of 2, 72 (8.5%) had MEWS of 3, 34 (4%) had MEWS of 4, 18 (2.1%) had MEWS of 5 and 19 (2.2%) had MEWS > 5.

Present results indicate that MEWS assessement is simple and does not interfere excessively on nursing workload, so it could be routinely used on a large number of patients. The high percentage of patients with signs of possible clinical deterioration (values of MEWS > 3; about 17%) seems to justify our project; further confirmation will be provided by the results of the follow-up of these patients, which is ongoing.