Cyanosis, purple Skin, or Hypoxia

CYANOSIS , PURPLE SKIN, HYPOXIA.

Cyanosis is a bluish or purplish tinge to the skin and mucous membranes. See the images

Before the era of rapid blood gas analysis, clinicians often assessed hypoxemia on clinical grounds alone, primarily by looking for cyanosis in the perioral area and fingers. Clinical assessment of hypoxemia is now known to be notoriously unreliable.

A host of factors, from natural skin pigment to room lighting, can affect detection of cyanosis. As with many other physical examination findings, significant interobserver variation occurs in detecting cyanosis. Physicians may diagnose cyanosis as an indicator of hypoxemia when the patient has normal oxygen saturation; alternatively, physicians may miss cyanosis when it should be present (the patient has very low oxygen saturation with normal haemoglobin).