Exam

Cyanosis

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Cyanosis, Peripheral Cyanosis, Central Cyanosis

  • See Also
  1. Neonatal Cyanosis
  2. Hyperpigmentation
  3. Medication Causes of Hyperpigmentation
  4. Oxygen Saturation
  5. Hypoxia
  • Pathophysiology
  1. Blood components responsible for Cyanosis
    1. Deoxygenated Hemoglobin > 5 g/dl or
    2. Methemoglobin >1.5 g/dl or
    3. Sulfhemoglobin >0.5 g/dl
  • Precautions
  1. Cyanosis appears when at least 5 g/dl of Hemoglobin is deoxygenated (desaturated)
    1. Anemic patients (e.g. Hemoblobin <10 g/dl)
      1. May not appear cyanotic despite Hypoxia
    2. Polycythemic patients (e.g. Hemoblobin >17-20 g/dl) such as those with COPD or Pulmonary Hypertension
      1. May appear cyanotic in mild Hypoxia
  • Signs
  1. Blue coloration to skin and mucous membranes
  • Causes
  • Central Cyanosis (Cyanosis of the trunk and head)
  1. Airway obstruction (e.g. Airway Foreign Body)
  2. Asthma
  3. Interstitial Lung Disease
  4. COPD
  5. Atelectasis
  6. Pulmonary Embolism
  7. Hypoventilation (e.g. Altered Level of Consciousness)
  8. Pulmonary Edema
  9. Pneumonia
  10. Pulmonic stenosis
  11. Congestive Heart Failure
  12. Non-Hemoglobin related causes
  13. Methemoglobinemia
  14. Polycythemia Vera
  15. Myocardial Infarction
  • Causes
  • Peripheral Cyanosis (local Cyanosis or extremity Cyanosis)
  1. Early in course of Central Cyanosis causes (that will progress to Central Cyanosis without intervention)
  2. Hypovolemia
  3. Cold extremities
  4. Raynaud Syndrome
  5. Peripheral Arterial Disease
  6. Deep Vein Thrombosis
  7. Venous Stasis
  • Differential Diagnosis
  1. See Skin Discoloration
  • References
  1. Degowin (1987) Diagnostic Examination, p. 335-6