The symptom cyanosis is described by:
- Central cyanosis* – bluish discoloration of skin and central mucous membranes (e.g., tongue).
- Peripheral cyanosis* – blue discoloration of the lips and the acras (finger/toe extremities, nose, ears); in contrast, the central mucous membranes are rosy!
- Generalized (e.g., in heart failure/heart failure).
- Localized (e.g., in phlebothrombosis/thrombotic occlusion of deep veins).
- Hemiglobin cyanosis
- Carboxyhemoglobinemia – cherry red cyanosis (rare) due to appearance of carboxyhemoglobin.
- Methemoglobinemia – cyanosis; the blood becomes a slate gray color due to the appearance of methemoglobin (Met-Hb).
- Sulfhemoglobinemia – greenish-black discolored blood due to the appearance of sulfhemoglobin.
* Lewis test – even when the earlobe is massaged, it remains cyanotic in central cyanosis; in peripheral cyanosis, the earlobe becomes pink.
Warning signs (red flags)
The following additional symptoms and complaints may occur in patients whose disease is acutely threatening:
- Dyspnea (shortness of breath) – acute tachypnea (increased respiratory rate) associated with speech dyspnea is a high-risk situation! → think of: Pulmonary embolism (LE; occlusion of one or more pulmonary arteries by a blood clot); differential diagnoses (including pneumothorax, pneumonia, bronchospasm).
- Thoracic pain (chest pain)
- Clouding or loss of consciousness
The following symptoms and complaints may indicate hemiglobin cyanosis:
- Central cyanosis (with unremarkable pulmonary and cardiac findings).
- Exertional dyspnea (dyspnea on exertion).
- Cephalgia (headache)
- Vertigo (dizziness, vertigo)
- Tachycardia (heartbeat too fast: > 100 beats per minute).
- Restlessness
- Somnolence (abnormal sleepiness)
Other indications
- Patients with anemia (anemia; low hemoglobin) are cyanotic only in the presence of marked hypoxia (oxygen deficiency). With anemia me hemoglobin values around 5 g/dl cyanosis can no longer occur!
- Patients with polyglobulia (high hemoglobin) can be cyanostic despite a normal gas exchange of the lungs. This is due to the fact that the existing (increased) hemoglobin is not fully oxygenated. This leads to the threshold of 5 mg/dl non-oxygenated hemoglobin is exceeded.
