1、EdemaZhou YunThe Affiliated Hospital of Medical College of Ningbo UniversityEmergency DepartmentObjective Definition Classification Etiology and pathogenesis Differential diagnosisDefinition The excessive accumulation of intestitial fluid A pathologic process caused by diseases Not accompanied with
2、cellular edemaClassification According to the range that edema fluid spreads to:Generalized edema Localized edema According to the cause of edema:Renal edema Hepatic edema Cardiac edema Malnutritional edema lymphedemaClassification Generalized edema:Puffiness of the face Indentation of the skin“pitt
3、ing edema”Ascites&Hydrothorax Localized edemeEdemaPitting edemaAscitesEtiology and pathogenesis Imbalance of fluid exchange between plasma and interstitial compartment Imbalance of fluid exchange between extra-and intra-bodyImbalance of fluid exchange between plasma and interstitial compartmentCapil
4、lariesFigure 7-7Total Pressure Differences Inside and Outside Capillarypermeabilityobstruction1.Increased capillary blood pressure Causes:Elevated plasma volume Increased venous pressure General venous pressure,i.e.congestive heart failureLocal venous pressure,i.e.venous thrombosisArteriolar dilatio
5、n i.e.acute imflammationCapillary blood pressureForce driving fluid into interstitiumFormation of interstitial fluidEdemaWhen greater than lymphatic compensatory return2.Decreased plasma colloid osmotic pressureCauses:Plasma albumin content decrease Decrease of protein production i.e.hepatic cirrhos
6、is,malnutrition Excessive loss of protein i.e.nephrosis Elevated catabolism of protein i.e.chronic debilitating diseases,such as malignant tumor Plasma colloid osmotic pressureForce drawing water back into capillary from interstitiumFormation of interstitial fluidEdemaWhen greater than lymphatic com
7、pensatory return3.Obstruction of lymphticCauses:Blockage by cancerBlockage by infection,especially with filarial4.Increased capillary permeabilityCapillary permeabilityFiltration of more protein from capillary to interstitiumformation of interstitial fluidEdemaWhen greater than lymphatic compensator
8、y returnPlasma colloid osmotic pressureCauses:InflammationInfectionBurnAllergic responseTraumaAnoxiaAcidosisImbalance of fluid exchange between extra-and intra-body-Renal retention of sodium and waterIn normal condition,99-99.5%of total volume of sodium and water filtrated via glomeruli are reabsorb
9、ed by tubules.60-70%of filtrates are actively reabsorbed by proximal convoluted tubule.The reabsorptions of sodium and water at distal tubule and collection duct are regulated by hormone.Glomerular(filtration)and tubular(reabsorption)balance(G-T balance)Retention of sodium and waterGFR(glomerular fi
10、ltration rate)decreases,while tubular reabsorption does not decrease accordingly;Tubular reabsorption increases,while GRF does not increased.GFRReabsorption of proximal tubuleReabsorption of distal tubule and collection tubuleG-T imbalanceFactors determining the GFR:Filtration area and membrane perm
11、eability Filtration pressure Effective circulating blood volume or renal blood volume1.Decreased glomerular filtration rate(GFR)1.GFRCauses Extensive glomerular damage Acute or chronic glomerulonephritis Decrease of effective circulating blood volume Congestive heart failure,nephrotic syndromeRenal
12、blood volumeRenin-angiotensin systemSympathetic-adrenal medullary system GFR-Increased reabsorption in proximal tubuleIncreased filtration fraction(FF)2.glomerular filtration rate(GFR)renal plasma flow(RPF)=FFGFR:amount of plasma filtered at glomerulus into Bowmans capsuleFF is the fraction of renal
13、 plasma flow that is filtered at the glomerulusIn normal condition:FF:20%The protein concentration in the plasma entering the peritubular capillaries increasesThe peritubular capillary oncotic pressure increasesEnhancing fluid reabsorption from the renal interstitial space to the capillaryDecreases
14、renal interstitial pressurefavoring reabsorption across the tubular epithelium and minimizing back flux from the renal interstitial space to the tubule lumen.Reabsorption in proximal tubuleIncreased FF Increased FF make elevated reabsorption of proximal tubuleCauses of FF increasingCongestive heart
15、failure Nephrotic syndromeDecreased effective circulatory blood volumeSympathetic-adrenal medullary system excitingEfferent arteriole constricts stronger than afferent oneEfferent arteriole resistanceGFR is increased relative to renal plasma flowFFCongestive heart failureNephrotic syndromeEffective
16、circulatory blood volumeADH secretionRenal blood flowRenal perfusion pressureGFRsodium at macula densaSecretion of renin by Juxtaglomerular cell Sympathetic nerve excitationRenin-angiotensin-aldosterone system activation Retention of sodium and waterStimulation of volume-receptor in left atrium and
17、thoracic vessel-Increased reabsorption in distal tubule and collecting ductIncreased ADH(antidiuretic hormone)and ADS(aldosterone)secretion3.Question Why does congestive heart failure cause edema?General venous pressure Plasma colloid osmotic pressur because of dilution of blood Dysfunction of lymph
18、atic return because of increased venous pressure GFR FF ADH and ADSDifferential diagnosis Heart failure Renal diseases Cirrhosis Nutritional origin Idiopathic OthersDifferential diagnosisHeart Failure Occurs at lower part of the body(lower extremities)Symmetric location The presence of heart disease
19、s Cardiac enlargement Gallop rhythm Dyspnea Basilar rales Venous distention HepatomegalyDifferential diagnosisRenal diseases Hypoalbuminemia&Retention of sodium and water Associated:HematuriaProteinuriaHypertention Impaired renal functional test Characteristic of edema Puffiness of the face Differen
20、tial diagnosisCardiac/Renal disease Renal CardiacLocation onset from the face,onset from the lower periobital areas part of the bodyProgression progress quickly progress slowlyIdentity soft and mobile relatively solid,less mobileOther signs proteinuria signs of heart failure:hypertension cardiac enl
21、argement impaired renal venous distention functional test hepatomegaly Differential diagnosisLiver diseases(cirrhosis)Clinical evidence of hepatic disease Jaundice Spider angiomas Ascites Ascites refractory to the treatmentcirrhosisDifferential diagnosisIdiopathic edema Exclusive in women Periodic episodes Accompanied by abdominal distentionDifferential diagnosisOther Causes of Edema Hypothyroidism Pregnancy Estrogens AngioneuroticApproach to the patient GeneralizedLocalizedorHeartLiver KidneyVenous obstructionLymphatic obstruction
