Shortness of Breath (Dyspnea): Test and Diagnosis

Laboratory parameters of the 1st order – obligatory laboratory tests.

  • Small blood count
  • Inflammatory parameters – CRP (C-reactive protein) or PCT (procalcitonin).
  • Urine status (rapid test for: pH, leukocytes, nitrite, protein, glucose, ketone, urobilinogen, bilirubin, blood), sediment, if necessary urine culture (pathogen detection and resistogram, that is, testing suitable antibiotics for sensitivity / resistance).
  • Electrolytes – calcium, potassium, magnesium, sodium.
  • Blood gas analysis (ABG) – in acute dyspnea, respiratory insufficiency; determination of:
    • Venous: pH, pCO2, BE, (lactate) [lactate ↑ = oxygen deficiency due to inhibition of aerobic glycolysis].
    • Arterial: pO2, pCO2
  • NT-proBNP (N-terminal pro brain natriuretic peptide); Indications:

    Assessment: correlation between NT-pro-BNP and stage of heart failure (heart failure; grade by NYHA, median/95th percentile).

    • NYHA I: 342/3,410 ng/l
    • NYHA II: 951 / 6,567 ng/l
    • NYHA III: 1,571 / 10,449 ng/l
    • NYHA IV: 1,707 / 12,188 ng/l

    Reference:

    • BNP values < 100 ng/l and NT-proBNP values < 300 ng/l allow to exclude acute heart failure (heart failure) with high probability in patients with acute dyspnea (European Society of Cardiology).
    • If BNP values > 500 ng/l, heart failure is probably present.

    Note: Elevated values are reported for women on hormone replacement therapy and renal insufficiency/dialysis.

Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.