Identifying the sick: can biochemical measurements be used to aid decision making on presentation to the accident and emergency department

Background. Early and accurate identification of patients whomay benefit from aggressive optimal medical intervention isessential if improved outcomes in terms of survival are to beachieved. We studied the usefulness of routine clinical measurementsand/or markers of metabolic abnormality in the early identificationof those patients at greatest risk of deterioration on presentationto the accident and emergency department. Methods. We conducted a prospective observational study in theaccident and emergency department of a 602-bed district generalhospital. Routine clinical measurements (heart rate, systolicblood pressure, temperature, oxygen saturation in room air,level of consciousness and ventilatory frequency) and venousblood analysis for metabolic markers (pH, bicarbonate, standardbase excess, lactate, anion gap, strong ion difference, andstrong ion gap) and biochemical markers (Na⁺, K⁺, Ca⁺, Cl⁺,