Starling Equation

Starling equation은 hydrostatic pressure와 oncotic forces을 이용하여 capillary에서 fluid의 이동(filtration & absorption)을 설명하는 식이다.

식

• fluid movement = k[(capillary hydrostatic pressure + interstitial oncotic force) - (capillary oncotic pressure + interstitial hydrostatic pressure) ]
  • k=filtration coefficient(permeability 반영)

임상적 연관성

• lymphatics: interstitial fluid volume에 기여
• peripheral edema 기전
  • capillary hydrostatic pressure 증가: Vasodilation, Venous obstruction, heart failure, sodium retention
  • interstitial oncotic pressure 증가: Hypothyroidism(non-pitting edema, myxedema)
  • vascular oncotic pressure 감소: Liver failure, Nephrotic syndrome
  • capillary permeability(k) 상승: 염증 반응, TNF-alpha, bradykinin, histamine, cytokines
  • Lymphatic obstruction/removal(lymphedema): elephantiasis, Bacterial lymphangitis(streptococci), trauma, surgery, tumor
• Pulmonary edema
  • Cardiogenic: left atrial pressure & venous pressure 증가 -> capillary pressure 증가
  • non-cardiogenic: permeability 증가, ARDS, sepsis

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