1st order laboratory parameters – obligatory laboratory tests.
- Blood gas analysis (ABG); arterial if centralization is present; otherwise, blood sampling from earlobe Results:
- Central cyanosis: decreased arterial partial pressure of oxygen (PaO2; depending on age, 78-95 mmHg) [= arterial hypoxia].
- Peripheral cyanosis: normal arterial partial pressure of oxygen (PaO2).
- Hemiglobin cyanosis* : central cyanosis with normal arterial partial pressure of oxygen (PaO2); arterial oxygen saturation (SaO2) measured by pulse oximeter is low.
- Small blood count (Hb, hematocrit; Ery).
Laboratory parameters 2nd order – depending on the results of the history, physical examination and the obligatory laboratory parameters – for differential diagnostic clarification.
- D-dimers – for suspected thrombosis or pulmonary embolism.
- * CO-hemoglobin (synonyms: CO-Hb, carboxyhemoglobin, carbon monoxide hemoglobin) (in heparin or EDTA blood) – if CO intoxication is suspected.
- * Methemoglobin (Met-Hb; in heparin or EDTA blood) – if methemoglobinemia is suspected.
- Sulfhemoglobin determination by spectroscopy – if sulfhemoglobinemia is suspected.
- Small blood count
- Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
- Fasting glucose (fasting blood glucose).
- Thyroid parameters – TSH
- Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (gamma-GT, GGT).
- Renal parameters – urea, creatinine.
- Coagulation parameters – PTT, Quick
- Blood cultures, smears from drains, etc.
