Predicting the need for medical intensive care monitoring in drug-overdosed patients

Drug overdose (OD) is one of the most common single diagnoses admitted to m edical intensive care units (MICUs). The diagnosis results in relatively li ttle morbidity or mortality, suggesting a need to improve the methods utili zed in deciding on MICU admission. Our objective in this study was to devel op a quantitative system whereby the emergency room (ER) physician, with re asonable safety and ease, would be able to discriminate between the need fo r an ICU and a nonmonitored bed. We reviewed the charts of 216 consecutive MICU admissions for intentional OD involving 199 patients between the years 1995 and 1998. Clinical histories, vital signs, laboratory data inclusive of toxicologic analysis, and both APACHE II and Glasgow coma scores (GCS) w ere assessed from the ER and on transfer to the MICU 4-6 hours later. These scores, as well as individual components of the APACHE II score, were eval uated for significance. Of 216 admissions reviewed, 75 (35%) had MICU-requi ring morbidity: intubation 61%, pneumonia 20%, arrhythmia or EKG changes 20 %, and hypotension 3%. Mortality was 2.7%. The remaining admissions were fo r ICU monitoring due to lethargy, irritability, laboratory abnormalities, o r simply based on the diagnosis of drug overdose. Urine examinations for dr ugs were positive in only 53%, with the most common agent identified being benzodiazepines (39%). Age, Apache II score, and GCS were significantly dif ferent between those patients who developed MICU-requiring morbidity and th ose who did not, as well as when comparing the morbidity with the mortality group. Receiver operator control (ROC) curves reveal that both the APACHE and GCS are excellent and equal predictors of morbidity, with a GCS of less than or equal to 12 having 88% sensitivity and 92% specificity in predicti ng MICU-requiring morbidity. We conclude that ER evaluation of GCS can be u sed to accurately assess and predict the need for MICU monitoring in drug o verdose. OD patients with a persistent GCS of greater than 12 or who do not demonstrate any hemodynamic, infectious, or electrocardiographic complicat ions in the ER do not require MICU admission.