Clinical signs as diagnostic test to assess hypoxemia in children with acute asthma exacerbation

Abstract

Asthma attack can cause hypoxemia. One of the methods to detect hypoxemia is by using pulse
oximetry. However, this tool is not always available in some health care centres. Therefore, a
more rapid and simple diagnostic tool is needed as an alternative method to detect hypoxemia.
This study aimed to assess signs and symptoms as diagnostic tools for hypoxemia in children
with asthma. This was an analytical observational with cross-sectional design performed in
Department of Pediatrics, Dr. Sardjito General Hospital/Faculty of Medicine, Universitas Gadjah
Mada, Yogyakarta. The study was started in Februari 2010 until the sample size was sufficient.
Seventy seven children with asthma between 0 – 18 years old who were presented to Emergency
Department and Respiratory Outpatient Clinic were involvoled in this study. All subjects were
examined for clinical signs and oxygen saturation as the gold standard. The prevalence of
hypoxemia in children with asthma in this study was 18.2%. The best single clinical predictor of
hypoxemia was tachycardia that yielded a sensitivity of 86% (95%CI: 67 – 100%) and specificity
of 59% (95%CI: 49 – 71%), and nasal flaring yielded a sensitivity of 79% and specificity of
79%. The combination of 2 clinical signs namely chest wall retraction-nasal flaring increased a
sensitivity of 79% and specificity of 71%, chest wall retraction-tachycardia increased a sensitivity
of 86% and a specificity of 76%, chest wall retraction-tachypnoe increased a sensitivity of 86%
and a specificity of 51%, tachycardia-tachypnoea increased a sensitivity of 79% and a specificity
of 76%. The combination 3 clinical sign namely chest wall retraction-tachycardia-tachypnoea
yielded a sensitivity of 79% and specificity of 79%. In conclusion, chest wall retraction and
tachycardia have higher diagnostic score than other clinical signs to assess hypoxemia in children
with asthma on acute exacerbation.

Keywords: asthma - hypoxemia - clinical signs - children - assessment