Use of pulse oximetry to predict in-hospital complications in normotensive patients with pulmonary embolism.
OBJECTIVE
A simple method is needed to risk stratify normotensive patients with pulmonary embolism. We studied whether bedside clinical data can predict in-hospital complications from pulmonary embolism.


METHODS
We performed a multicenter derivation phase, followed by validation in a single center. All patients were normotensive; the diagnosis of pulmonary embolism was established by objective imaging. Classification and regression analysis was performed to derive a decision tree from 27 parameters recorded from 207 patients. The validation study was conducted on a separate group of 96 patients to determine the derived criterion's diagnostic accuracy for in-hospital complications (cardiogenic shock, respiratory failure, or death).


RESULTS
Mortality in the derivation phase was 4% (n = 8) at 24 hours and 10% (n = 21) at 30 days. A room-air pulse oximetry reading <95% was the most important predictor of death; mortality was 2% (95% confidence interval [CI]: 0% to 6%) in patients with pulse oximetry >or=95% versus 20% (95% CI: 12% to 29%) with pulse oximetry <95%. In the validation phase, the room-air pulse oximetry was <95% at the time of diagnosis in 9 of 10 patients who developed an in-hospital complication (sensitivity, 90%) and >or=95% in 55 of 86 patients without complications (specificity, 64%).


CONCLUSIONS
Mortality from pulmonary embolism in normotensive patients is high. A room-air pulse oximetry reading >or=95% at diagnosis is associated with a significantly lower probability of in-hospital complications from pulmonary embolism.
Kline
Jeffrey A
JA
Department of Emergency Medicine, Carolinas Medical Center, Charlotte, North Carolina 28323-2861, USA. JKline@carolina.rr.com
Hernandez-Nino
Jackeline
J
Newgard
Craig D
CD
Cowles
Dana N
DN
Jackson
Raymond E
RE
Courtney
D Mark
DM
D001794:Blood Pressure / Q000502:physiology; D006760:Hospitalization; D006801:Humans; D010092:Oximetry / Q000592:standards*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D015203:Reproducibility of Results; D012131:Respiratory Insufficiency / Q000209:etiology / Q000517:prevention & control*; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D012770:Shock, Cardiogenic / Q000209:etiology / Q000517:prevention & control*; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology