Frühdiagnose akuter systemischer Infektionen und Prädiktion der bronchopulmonalen Dysplasie bei Frühgeborenen mittels einer elektronischen Nase (Cyranose)

Every year approximately 60,000 children are born prematurely in Germany, 1.3 % of whom are considered very small preterm infants with a birth weight of < 1500 g (IQTIG, 2021). The most common causes of mortality in this patient population include acute systemic infections as well as chronic respiratory diseases such as bronchopulmonary dysplasia (BPD), which has an incidence of 10-25 % of all very small preterm infants across Europe (Gortner et al., 2011). This is due to a disturbed lung development caused by the premature birth in combination with pre- and postnatally acting noxae, which cause an inflammatory reaction. Especially due to the high vulnerability of preterm infants, the earliest possible diagnosis of acute systemic infection as well as prediction of BPD is crucial for the clinical course of the diseases and the prognosis of the preterm infant. The establishment of a suitable method for targeted early diagnosis and prediction of diseases in preterm infants is a major challenge for medical research. Preliminary studies have shown that the electronic nose (cyranose), an electronic equivalent to the biological sense of smell, may be applicable as a new and non-invasive diagnostic tool in neonatology. The cyranose is able to detect volatile organic compounds (VOCs) over a sample and aggregating them into a "smellprint", a kind of fingerprint of the sample. These smellprints can then be statistically compared with each other. The overall aim of this study was to investigate whether the cyranose can be used to differentiate between samples from preterm infants with and without developing BPD and preterm infants with and without acute systemic infection. Because noninvasively obtained samples are of particular interest for potential clinical use, urine, stool, saliva, and tracheal aspirate samples were examined. For this purpose, 21 premature infants of the University Hospital Marburg were observed over a period of six weeks postnatally or until the time of their discharge from inpatient treatment. When possible, urine, stool, and saliva were obtained weekly, as well as tracheal aspirate during initial intubation, shortly before extubation, or when clinically indicated for aspiration. These samples were then analyzed by the cyranose and statistically compared by linear discriminant analysis. Here, tracheal aspirate, urine, and stool samples could be used to differentiate between smellprints from children with and without an acute systemic infection and with and without developing BPD. The pilot study conducted as part of this dissertation was able to confirm the feasibility and provide important results, which now need to be verified by means of larger studies. In summary, the evidence found in this work encourages further research to investigate the potential of the cyranose to detect acute systemic infections and predict BPD in preterm infants using urine, stool, and tracheal aspirate samples.