RESPIRATORY RATE PREDICTS CARDIOPULMONARY ARREST FOR INTERNAL-MEDICINE INPATIENTS

Objective: To assess whether vital sign measurements could identify in ternal medicine patients at risk for cardiopulmonary arrest. Design: R etrospective case-control study comparing 72 hours of pre-arrest vital sign measurements with 72 hours of vital sign measurements for patien ts from the same units who did not experience cardiopulmonary arrest. Setting: Twelve non-intensive care internal medicine units at a large midwestern academic medical center. Patients: Cases included all 59 in patients who had experienced cardiopulmonary arrest between May 1989 a nd December 1990; patients who were designated do-not-resuscitate (DNR ) or had less than 72 hours of vital sign recordings were excluded. Co ntrols included 91 inpatients without cardiopulmonary arrest who were matched for units and who had 72 hours of vital sign recordings. Resul ts: The occurrence of one or more respiratory rates > 27 breaths per m inute over a 72-hour period had a sensitivity of 0.54 and a specificit y of 0.83 (odds ratio = 5.56, 95% CL = 2.67-11.49) in predicting cardi opulmonary arrest. Other respiratory rate thresholds were also predict ive of arrest. The ability of respiratory rate to predict arrest was s tronger in units with high incidences of arrest relative to units with low incidences, for example, in units for the management of gastroint estinal disease (sensitivity = 1.00, specificity = 0.86) and renal dis ease (sensitivity = 0.69, specificity = 0.87). Respiratory rate remain ed a significant predictor (p < 0.001) after controlling for patient a ge and gender. Pulse rate and blood pressure were not predictive of ca rdiopulmonary arrest. Conclusions: Using elevated respiratory rates as a signal for focused diagnostic studies and therapeutic interventions in internal medicine patients may be useful in reducing the incidence of subsequent cardiopulmonary arrest, and lowering associated morbidi ty and mortality.