2nd order laboratory parameters – depending on the results of the medical history, physical examination, etc. – for differential diagnostic clarification
- CRP (C-reactive protein); more appropriate is the determination of procalcitonin, which allows some differentiation of bacterial and viral infections. Note: The CRP rise is approximately 6-12 hours after the onset of an acute inflammatory reaction. The maximum can be expected after 48-72 hours, i.e., in acute infection, clinical deterioration precedes the CRP rise.After the onset of bacterial, fungal and parasitic infection, procalcitonin rises within a few hours (2-3 h) and reaches its maximum after 24 hours. Its biological half-life is 25-30 hours. A lack of decrease is evidence of persistence of infection!
- Leukocytes (white blood cells).
- Bacteriology (cultural)
- Sputum, tracheal secretions, bronchial secretions for pathogens and resistance [not usually required for acute bronchitis!]Note: Send only macroscopically purulent sputum specimens or other deep respiratory materials. Sputum should be obtained by vigorous coughing – preferably in the morning.
Antigen detection
- Influenza, respiratory syncytial virus (RSV), mycoplasma, Legionella if applicable.
Serology
- Detection of antibodies against chlamydia, adenovirus, coxsackie virus, ECHO virus, influenza A/B virus, parainfluenza virus, respiratory syncytial virus (RSV).
- Blood gas analysis (BGA) – to study lung function in severe courses.