Associations between indicators of new semi-quantitative express-test for procalcitonin and indicators of saturation in patients with community-acquired pneumonia
Authors: Tsygankova Oksana V. , Bairamova S. S. , Nikolaev K. Yu. 
Published: June 2023

Objective. To evaluate the associations between the indicators of a new semi-quantitative express-test for procalcitonin and saturation levels in hospitalized patients with community-acquired pneumonia.
Due to a high rate of growth of the incidence of severe community-acquired pneumonia, which leads to disability of the working population and claims thousands of lives, there is a need for early verification of the severity degree and a timely initiation of treatment. Traditional clinical, radiologic, laboratory and bacteriological criteria for inflammatory reactions (fever, increased pulmonary infiltration and leukocytosis, detection of potential pathogens in sputum or hemocultures) are not specific for pneumonia. Similar clinical and radiologic manifestations can also be noted in other pathological conditions, for example, in atelectasis of the lung, lung infarction, congestive heart failure, as well as acute respiratory distress syndrome. In this regard, the study of new diagnostic markers of community-acquired pneumonia is an actual direction in modern therapeutic diagnostics. Being a fast and highly sensitive method, the express test for procalcitonin can be a valuable predictive marker for the severe course of community-acquired pneumonia. Of interest is the relationship of procalcitonin with an indicator reflecting the presence of respiratory failure the level of saturation.
Materials and methods. A single-stage comparative study involved 123 patients admitted to the hospital with a confirmed diagnosis of community-acquired pneumonia. On the first day after admission to the hospital, all patients underwent a general clinical examination, an overview X-ray of the chest organs, and determination of the plasma procalcitonin level using a semi-quantitative express-test as well as the saturation level. According to the results of the examination, the patients were divided into two groups: patients with saturation 94 % (n=43), and patients with saturation 94 % (n=80). The group of patients with saturation values 94 % consisted of 23 (53.5 %) women and 20 (46.5 %) men. The group of patients with saturation values 94 % consisted of 42 (52.5 %) women and 38 (47.5 %) men. The mean age of the patients was 56.719.1 and 45.620.7 (MSD) years, respectively, p=0.005. Statistical processing of the obtained data was carried out using the SPSS 13.0 software package.
Results. Patients with low saturation values ( 94 %) had higher heart rate (p=0.001) and respiratory rate (p=0.001), and the levels of erythrocytes (p=0.001), hemoglobin (p=0.003) and albumin (p=0.001) were significantly lower than in patients with higher saturation levels 94 %. For patients with signs of respiratory failure and saturation indices 94 %, a more pronounced increase in the level of express-test for procalcitonin was characteristic (p=0.001). According to regression analysis, the express-test for procalcitonin 2 ng/ml by 13.8 % (CI 1.5131.3), age by 3 %, and heart rate by 11 % increase the risk of low saturation in patients with community-acquired pneumonia.
Conclusion. Low values of blood oxygen saturation 94 % in hospitalized patients with community-acquired pneumonia are directly associated with high values of the new semi-quantitative express-test for procalcitonin (more than 2 ng/ml), that can be used for individual risk stratification.