Arterial Blood Gas Analysis as a PrognosicIndicator in Acute Pulmonary Embolism

Abstract

Background: Acute pulmonary embolism (PE) is a potentially life-threatening condition that requires accurate risk stratification. In patients with PE the prognostic value of arterial blood gas (ABG) abnormalities remains controversial. Aim: To assess the prognostic value of ABG parameters and their association with established prognostic indicators such as the Pulmonary Embolism Severity Index (PESI), pro-B-natriuretic peptide (pro-BNP) levels, blood pressure status, and thrombus localization on contrast-enhanced computed tomography pulmonary angiography (CTPA). Methods: This retrospective study included 83 hospitalized patients with acute pulmonary embolism (PE) confirmed by CTPA during 2023. Demographic characteristics, ABG parameters, laboratory findings, PESI score, hemodynamic status and thrombus localization were collected from records at admission. Patients were divided into survivor and non-survivor groups based on in-hospital outcomes. Logistic regression and correlation analyses were performed using SPSS version 26.0. Statistical significance was defined as p < 0.05. Results: The mean age of the patients was 69.3 ± 11.2 years, and 56.6% of patients were female. Hypocapnia (69.9%) and alkalemia (42.2%) were common findings. Most ABG parameters did not differ significantly between survivor and non-survivor. Although all patients presenting with acidemia (pH < 7.35) died during hospitalization, his finding was not statistically significant due to the small number of cases. Lower (more negative) base excess values were an independent predictor of mortality (OR=0.82, p=0.014). The PESI score was significantly higher in non-survivors than in survivors (p < 0.001) and emerged as the strongest predictor of in-hospital mortality. Conclusions: Most ABG parameters were not independent predictors of in-hospital mortality. However, acidemia and negative base excess may help identify patients at increased risk and provide complementary prognostic information. The PESI score remained the strongest predictor of mortality. More large studies are needed to better understand the role of ABG in predicting outcomes in acute PE.

Received: 13 March 2026  │  Accepted: 10 June 2026  │  Published: 23 July 2026