2nd order laboratory parameters – depending on the results of the medical history, physical examination, etc. – for differential diagnostic clarification
- Small blood count
- Inflammatory parameters – CRP (C-reactive protein).
- Potassium, magnesium, calcium
- TSH – to exclude thyroid dysfunction.
- Renal parameters – urea, creatinine, cystatin C or creatinine clearance if necessary.
- Highly sensitive cardiac troponin T (hs-cTnT) or troponin I (hs-cTnI) – if myocardial infarction (heart attack) is suspected.
- D-dimers (end product of proteolysis of fibrin) – for suspected pulmonary embolism: negative predictive value 99.3%, thus suitable for screening! (See also under “Pulmonary Embolism/Physical Examination” Wells score to determine the clinical probability of pulmonary embolism)If positive: CTPA (computed tomography of the pulmonary arteries), V/P scintigraphy (ventilation/perfusion scintigraphy).
- Blood gas analysis (ABG); determination of:
- Virological examination – if viral infection is suspected.
- Bacteriological examination – if bacterial infection is suspected.
- Specific antibodies (see, for example, in collagenoses, ankylosing spondylitis, rheumatoid arthritis) – if autoimmune diseases are suspected.
- Blood gas analysis (ABG); determination of:
- Venous: pH, (lactate).