Changes in arterial blood gas analysis results according to body mass index in patients with acute dyspnea admitted through emergency department, and usefulness for predicting prognosis

Lee, Keun Taek; Sung, Won Young; Lee, Jang Young; Lee, Won Suk; Seo, Sang Won

J Korean Soc Emerg Med > Volume 30(6); 2019 > Article

Original Article

Journal of The Korean Society of Emergency Medicine 2019;30(6): 545-554.

응급실을 통해 입원한 급성 호흡 곤란 환자의 체질량지수에 따른 동맥혈 가스 분석 결과의 변화와 예후 예측 유용성

이근택

을지대학교 의과대학 응급의학교실

Changes in arterial blood gas analysis results according to body mass index in patients with acute dyspnea admitted through emergency department, and usefulness for predicting prognosis

Department of Emergency Medicine, Eulji University College of Medicine, Daejeon, Korea

Correspondence

Won Young Sung ,Tel: 042-611-3256, Fax: 042-611-3880, Email: sage77@eulji.ac.kr,

Received: June 10, 2019; Revised: October 28, 2019 Accepted: October 30, 2019. Published online: December 31, 2019.

ABSTRACT

Objective:
This study examined the change tendency in the arterial blood gas analysis (ABGA) results according to the body mass index (BMI) of patients admitted through the emergency department (ED) with dyspnea, as well as the risk factors for intensive care unit (ICU) admission and in-hospital mortality in obese patients.
Method:
A retrospective study was conducted on 768 patients, who were admitted to the ED for dyspnea during 2017 and underwent ABGA. The patients were divided into four groups according to their BMI. Multivariate logistic regression analysis was used to determine the risk factors of ICU admission and in-hospital mortality in obese patients using the ABGA results.
Results:
A higher BMI was associated with a lower pH (P<0.001) and higher arterial carbon dioxide pressure (PaCO₂, P=0.001), hematocrit (P=0.009), and lactate concentration (P=0.012). In the obese group, low pH (odds ratio [OR], 5.780; P<0.001 and OR, 16.393; P=0.013), high PaCO₂ (OR, 1.123; P=0.005), high lactate concentration (OR, 1.886; P=0.015), and base excess reduction (OR, 1.267; P=0.001) were the risk factors for ICU admission, whereas pH<7.33 (OR, 14.493; P=0.014) and high lactate concentration (OR, 1.462; P=0.008) were the risk factors for in-hospital mortality. The pH (area under the curve [AUC], 0.817; AUC, 0.890) and lactate concentration (AUC, 0.762; AUC, 0.728) were useful for predicting the ICU admission and in-hospital mortality.
Conclusion:
A higher BMI in the subjects was associated with a lower pH and higher lactate concentration. In addition, pH and lactate concentration were significant risk factors for ICU admission and in-hospital mortality.

Key words: Dyspnea; Blood gas analysis; Body mass index; Emergency department