诊断学 呕血与便血 英文版 ppt课件

Diagnosis ofGastrointestinal BleedingHematemesis and Hematochezia呕血与便血The approach to gastro-intestinal (GI) bleeding is tailored to the manner of appearance.Is bleeding acute or chronic?Intensive careWhere is the source of bleeding?Empiric therapyDiagnosisTreatment ( 经验治疗 )What is the causes of bleeding?Recognition of hemorrhage Intensive careWhere is the source of bleeding?Empiric therapyDiagnosisTreatment ( 经验治疗 )What is the causes of bleeding?Is bleeding acute or chronic?Recognition of hemorrhageClinical Manifestations1 Manner of bleeding presentation2 Hypovolemia (低血容量 ) or shock3 Anemia (贫血 ) Recognition of hemorrhagePatients manifest blood loss1) Hematemesis 呕 血 Bloody vomitus, either fresh and bright red or older and “coffee -ground” (hematin 酸化正铁血红素 ) in character Hemoptysis? Nosebleeding?Manner of bleeding presentationfrom the GI tract in five ways:2) Melena 黑 便Shiny, black, sticky, foul-smelling stool degradation of blood exogenous stool darkenersiron bismuth (铋剂 ) Manner of bleeding presentationManner of bleeding presentation3) Hematochezia 便 血bright red or maroon blood from the rectumpure bloodblood intermixed with formed stool bloody diarrheaManner of bleeding presentation4) Occult 隐 血detected only by testing the stool with a monoclonal antibody for human hemoglobin Estimate amount of bleeding from upper GI tract510 ml/d OB +5070 ml/d Melena 250300 ml in short time Hematemesis Manner of bleeding presentation5) without any objective sign of bleeding with symptoms of blood lossdizziness, dyspnea, angina cordis (心绞痛 ), or even shock digital examination (指检 ) ofthe rectumHypovolemia or shockSpeed and volume of blood lossWeakness, giddiness (眩晕 ), oliguria, (少尿 ) cold extremity, sweatingVital signs: tachycardia, (心动过速 ) hypotention (低血压 )Anemiapaledizzinesspalpitationeasy fatigabilitydyspnea angina cordisIs bleeding acute or chronic?1) Bleeding speedHematemesis of fresh blood generally indicates a more severe bleeding episode than melena, which occurs when bleeding is slow enough to allow time for degradation of blood Is bleeding acute or chronic?2) Hematocrit bleeding slowly hypochromic (血红蛋白过少 )microcytic (小细胞 ) red blood cells mean corpuscular volume (MCV， 平均血球压积 ) of the cells may be low Is bleeding acute or chronic?If blood loss is acute, the hematocrit dose not change during the first few hours after hemorrhage About 24 to 72 hours later, plasma volume is larger than normal and the hematocrit is at its lowest point 7 6 5 4 3 2 1Volume(Liters) 45%45%27%A B CIs bleeding acute or chronic?Hematocrit changesA Before bleeding B Immediately after bleeding C 2472 hours after bleedingIs bleeding acute or chronic?3) Blood pressure and heart ratedepend on u amount of blood lossu suddenness of blood loss u extent of cardiac and vascularcompensation postural hypotension - early physical findingtachycardia - greater loss, compensate recumbent (卧位 ) hypotension - final results Is bleeding acute or chronic?Is bleeding acute or chronic?Postural hypotension A postural drop in blood pressure of 10 to 15 mm HgIs bleeding acute or chronic?4) Bowel sound Active bowel sound usually be presented in acute bleeding from GI tractEmergent and intensive care Initiallyvital signs supine and upright blood pressure pulseIf blood loss is significant, intravenous fluids must be startedSaline or other balanced electrolyte solutions are most rapidly available Blood is sent to the lab. complete blood countclotting studiesroutine chemistry studies. Blood for typing and cross- matching is sent to the blood bank.Where is the source of bleeding?LocalizationUpper GI bleeding: bleeding from a source proximal to the ligament of Treitz.Lower GI bleeding: bleeding from a site distal to the ligament of Treitz.LocalizationTreitz: The ligament of Treitz is an anatomic landmark for the duodenal-jejunal junction.LocalizationDifferentiating features of upper GI and lower GI bleedingUpper GI Lower