EDEMA(水肿)

EDEMA,Wang xinjun（王新军）Department of endocrinology Hainan medical collegeMP:The distribution of water between blood and interstitial tissues is maintained by a net equilibrium between hydrostatic and oncotic pressures.,Pathophysiology,Blood Interstitial tissuesHydrostatic pressure Hydrostatic pressure（流体静水压） (tissue tension)Colloid oncotic pressure Colloid oncotic pressure（胶体渗透压）,interstitial tissues,Inter：Latin prefix=among or between在之中Interstitial tissue（组织间隙） means tissue between the cells of a structure,Hydrostatic pressure静水压,Hydro-staticHydro ： waterStatic：not active or moving 静止的,oncotic pressure,oncotic pressure 胶体渗透压,Normally, fluid flows into the extravascular interstitial space in response to hydrostatic pressure in the precapillary arterioles and capillaries（intravascularinterstitial）, which is only partially offset by the opposing oncotic pressure （intravascularinterstitial）.,physiology,Blood Interstitial tissuesHydrostatic pressure Hydrostatic pressure（流体静水压） (tissue tension)Colloid oncotic pressure Colloid oncotic pressure（胶体渗透压）,Precapillary（前毛细管的）,Pre：Latin prefix=before prediabetes：糖尿病前期 prehypertension：高血压前期Capillary：毛细血管 precapillary：前毛细血管的 postcapillary：后毛细血管的,Intravascular（血管内的 ）,intra：a prefix meaning “within,” used in the formation of compound words. intracellular：细胞内的 intravenous：静脉内Vascular：血管的 vasculitis：血管炎 extravascular：血管外的,physiology,In the postcapillary venules, the lowered intravascular hydrostatic pressure is more than compensated by the intravascular oncotic pressure, resulting in return of interstitial water to the intravascular space.,Interstitial fluid, proteins, and cells are also removed from the interstitial space and, ultimately, returned to the blood through the lymphatics（淋巴系统）. Alteration of any of these forces upsets the equilibrium.,physiology,Lymphatics,lymph：淋巴 lymphatics：淋巴系统 lymphedema：淋巴水肿,An increase in the systemic venous pressure in congestive heart failure produces generalized edema（全身性水肿）;Occlusion of a vein may result in localized edema（局部性水肿）.Obstruction of lymphatic channels produces lymphedema.,pathophysiology,etiology,Reduction in the plasma albumin results in lowering the oncotic pressure of the plasma, permitting edema to form;albumin：the plasma protein with the highest contribution to oncotic pressureThis type of edema may first appear in areas of decreased tissue pressure such as the periorbital（眶周的 ）tissues.,etiology,Tissue inflammation by bacterial, chemical, thermal, or mechanical means increases capillary permeability（通透性） to make localized edema.,DEFINITION,Excessive accumulation of interstitial fluid, either localized（局部性） or generalized（全身性）, is termed edema.When the amount of generalized edema is great, the condition is termed anasarca （全身性水肿） or dropsy（浮肿）.,Pitting and non-pitting edema,Pitting edema：凹陷性水肿non-pitting edema：非凹陷性水肿,Edema,Pitting edema,Non-pitting edema,Pitting edema,In the adult, about 4.5 kg of fluid accumulates before it is detectable as pitting edema.,Pitting edema,To demonstrate the presence of edema, gently press your thumb into the skin against a bony surface, such as the anterior tibia（胫骨前）, fibula （腓骨）, dorsum （背部） of the foot, or sacrum（骶骨）.When the thumb is withdrawn, an indentation persists for a short time.,Edema,Pitting edema,Non-pitting edema,dependent edema,Because dependent edema（坠积性水肿） responds to gravity, it first appears in the feet and ankles of walking patient， or over the posterior calves or sacrum of the supine（仰卧的） patient.Seldom does dependent edema rise higher than the heart.,Anterior = Ant - erior = 前面的Posterior = Post - erior = 后面的Superior = sup - erior = 上面的Inferior = inf erior = 下面的anterior tibiaposterior calvessuperior vena cavaInferior vena cava,Anterior Posterior Superior Inferior,Brawny edema,Chronic edema of the legs leads to fibrosis of the subcutaneous tissues and skin, so they no longer pit on pressure：this is sometimes called brawny edema.,Brawny edema,etiology,Symmetric affecting both legs suggests that the problem is in the pelvis（骨盆） or more proximally.,etiology,Edema limited to the arms and head suggests superior vena cava obstruction（上腔静脉阻塞）.,etiology,Edema limited to one extremity suggests a local problem with vascular channels or local inflammation.,The distribution of edema,Symmetric affecting both legs suggests that the problem is in the pelvis or more proximally.Edema limited to the arms and head suggests superior vena cava obstruction.Edema limited to one extremity suggests a local problem with vascular channels or local inflammation.,Local edema,To evaluate local edema, the examiner must consider the local anatomy of the arteries, veins, lymphatics and soft tissues, the presence of any local inflammatory or structural disease and then form hypotheses as to the likely mechanism and anatomic site of the local problem.,etiology,Because exclusive dependence upon clinical information may miss cardiovascular causes of bilateral leg edema, consider measurement of B-type natruretic peptide（B型利钠肽） and/or echocardiographic（超声心动图） evaluation.,Clinical Causes of Edema,Generalized edema,Localized edema,Localized edema,Inflammation infectionAngioedemaVenous thrombosisVenous or lymphatic compression malignanciesChemical or physical injuries,Bilateral edema above the diaphragm,Superior vena cava obstruction,Bilateral edema below the diaphragm,Congestive cardiac failurePortal vein hypertension or obstructionInferior vena cava obstructionDrugs: calcium channel blockers angiotensin-converting enzyme inhibitors,Portal vein hypertension or obstruction,Cirrhosis肝硬化Portal vein thrombosis门静脉血栓形成Schistosomiasis血吸虫病,Inferior vena cava obstruction,ThrombosisExtrinsic compressionPregnancy,Inferior vena cava obstruction,Bilateral edema below the diaphragm,Congestive cardiac failurePortal vein hypertension or obstructionInferior vena cava obstructionDrugs: calcium channel blockers angiotensin-converting enzyme inhibitors,Generalized edema,HypoalbuminemiaRenal retention of salt and waterIncreased capillary permeability,hypoalbuminemia,hypo Latin prefix=below or under for example, hypoglycemia means 低血糖症emia Latin suffix=a condition of the blood For example, anemia means 贫血。,Hypoalbuminemia,Nephrotic