SpO2 /FIO2 on Presentation as a Predictor for Early Hemodynamic Deterioration in Intermediate Risk Acute Pulmonary Embolism.

BACKGROUND

Patients with intermediate-risk acute pulmonary embolism are at risk of hemodynamic deterioration, and identification of risk factors for decompensation could guide the administration of thrombolytics. We aimed to assess whether SpO2 /FIO2 on presentation is associated with early hemodynamic deterioration in this population.

METHODS

A retrospective chart review of subjects admitted between 2006 and 2018 with intermediate-risk pulmonary embolism (hemodynamically stable with right ventricle to left ventricle ratio > 0.9 or tricuspid annular plane systolic excursion < 18 mm). Early hemodynamic deterioration was defined as requirements for vasopressors or rescue thrombolytics within 48 h. Results are presented as median (interquartile range).

RESULTS

A total of 178 subjects were included. Early hemodynamic deterioration occurred in 13% of the subjects and was associated with a median (interquartile range) lower SpO2 /FIO2 on presentation in univariate analysis (243 [123-275] versus 438 [335-457], P < .001) and in a multivariate analysis, including heart rate and right ventricle to left ventricle ratio as covariates (odds ratio 0.992, 95% CI 0.987-0.996; P < .001). The initial SpO2 /FIO2 predicted hemodynamic deterioration with an area under the receiver operating characteristic curve of 0.81 and a threshold of 260 was associated with a sensitivity of 74% and specificity of 88%. Sensitivity analyses restricted to subjects with hypoxemia on presentation and subjects with an elevated troponin level led to similar results.

CONCLUSIONS

In intermediate-risk pulmonary embolism, SpO2 /FIO2 on presentation can help predict the risk of early hemodynamic deterioration.