發紺

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發紺
Cynosis.JPG

手部發紺
ICD-10 R23.0
ICD-9 782.5
eMedicine med/3002


發紺Cyanosis,「紺」音同「幹」),或稱紫紺蒼藍症,是因在接近皮膚表面的血管出現脫後的血紅蛋白,令皮膚或黏膜青色的徵狀。根據Lundsgaard和Van Slyke的著作[1],當去氧血紅素的濃度達到5.0 g/dL以上時,就會開始發紺[2],但常常被忽略的是,這個數字是從動脈及周圍靜脈的血氧濃度估計來的。[3] Since estimation of hypoxia is usually now based either on arterial blood gas measurement, or pulse oximetry, this is probably an overestimate, with evidence that levels of 2.0 g/dL of deoxyhemoglobin may reliably produce cyanosis.[4] Since, however, the presence of cyanosis is dependent upon there being an absolute quantity of deoxyhemoglobin, the bluish color is more readily apparent in those with high hemoglobin counts than it is with those with anemia. Also the bluer color is more difficult to detect on deeply pigmented skin. When signs of cyanosis first appear, such as on the lips or fingers, intervention should be made within 3–5 minutes because a severe hypoxia or severe circulatory failure may have induced the cyanosis.

種類[编辑]

發紺可以是在手指,包括指甲,及其他四肢部位(稱為「末梢性發紺」),或是在嘴唇及面部(稱為「中心性發紺」)。

中心性發紺[编辑]

中心性發紺,或稱中央性發紺是因空氣循環或通風的問題,導致在肺部缺少氧合血液,或是因在皮膚表面血管內血液循環的減慢,令較多氧氣被抽離。激烈的發紺可以引起窒息哽塞,是最明顯呼吸被阻礙的徵狀。發紺的基本原理是脫氧的血紅蛋白呈現青色,而血管收縮更令情況明顯。因此,缺氧導致嘴唇及其他黏膜呈現青色。

其他亦會引起發紺徵狀的疾病:

末梢性發紺[编辑]

末梢性發紺是在四肢或末端的發紺,成因是微血管血液循環不良,例如在天氣冷時手會出現發紺。另外,情緒緊張、驚嚇、休克等狀況下,亦可以導致末梢性發紺,皮膚會冰冷發黑。但是,這種徵狀並非長久,有時只要在正常體溫下就能回復。

但是,現時有一種稱為「手足發紺」(或「手足紫紺症」)的病症,它有著末梢性發紺的徵狀,但若不適當處理這種病症是會致命的。

內部連結[编辑]

外部連結[编辑]

參考文獻[编辑]

  1. ^ Lundsgaard C, Van Slyke DD. Cyanosis. Medicine. 2(1):1-76, February 1923.
  2. ^ Mini Oxford Handbook of Clinical Medicine 7th. : 56. 
  3. ^ Cyanosis. Lundsgaard C, Van SD, Abbott ME. Cyanosis. Can Med Assoc J 1923 Aug;13(8):601-4.
  4. ^ Goss GA, Hayes JA, Burdon JG. Deoxyhaemoglobin concentrations in the detection of central cyanosis. Thorax 1988 Mar;43(3):212-3.