It might be time to start treating patients with pulmonary embolism as outpatients.
Over 6 years ago two papers were published by the same authors that presented similar prediction rules to identify patients with pulmonary embolism who are at low risk and can be treated as outpatients. The original paper known as Pulmonary Embolism Severity Index (PESI) will be discussed in the next paragraph as it has been simplified. This paragraph will present a very similar prediction rule. It was derived from a retrospective chart review and consists of 10 demographic, historic, and clinical findings. The rule consists of: age >70, history of cancer, heart failure, chronic lung disease, chronic renal disease, cerebrovascular disease, pulse rate >110 bpm, systolic blood pressure <100mm Hg, altered mental status and arterial oxygen saturation <90%. Patients with none of these factors were defined as low risk. The 30-day mortality rate for low risk patients was 0.6% in the derivation sample (10,354 patients), 1.5% in the internal validation sample (5177 patients) and 0% in the external validation sample (221 patients). In addition, the rate of adverse medical outcome was <1% in all study samples.
Pretty darn good. Can it get any better.
The original PESI score was based on 11 variables, each assigned a numerical score. The score was tallied and patients were placed into five severity classes. Inpatient death and nonfatal complications were ⩽ 1.1% in class I (score <65) and ⩽ 1.9% in class II (score 66-85).
The simplified PESI was pared down to 6 variables: age > 80, history of cancer, chronic cardiopulmonary disease, heart rate >110 bpm, systolic blood pressure <100mm Hg and oxyhemoglobin saturation <90%. If none of these variables were present the patient was classified as low risk. This simplification proved to have a similar prognostic accuracy as the original. The 30-day mortality was 1% in the derivation sample (995 patients) and validation cohort (7106 patients).
