به نام ایزد دانا

1. به نام ایزد دانا

2. GastrointestinalBleeding

3. Epidemiology • Gastrointestinal (GI) bleeding is a relatively common problem encountered in emergency medicine that requires early consultation and often admission • The overall mortality of GI bleeding is approximately 10% • Diagnostic modalities have improved much more than therapeutic techniques

4. GI bleeding is often easy to identify when there is clear evidence of vomiting blood or passing blood in the stool, but it may present subtly with signs and symptoms of hypovolemia, such as dizziness, weakness, or syncope

5. The approach to GI bleeding depends on whether the hemorrhage is located in the proximal or distal segments of the GI tract (i.e., upper or lower GI bleeding) • These segments are defined by the ligament of Treitz in the fourth section of the duodenum

6. In the United States, upper GI bleeding (UGIB) affects 50 to 150 people per 100,000 population each year and results in 250,000 admissions at an estimated annual cost of almost $1 billion • Lower GI bleeding (LGIB) affects a smaller portion of patients and results in proportionally fewer hospital admissions than UGIB

7. GI bleeding can occur in individuals of any age, but most commonly affects people in their 40s through 70s (mean age 59 years) • Most deaths caused by GI bleeding occur in patients older than age 60 years • UGIB is more common in men than women (2:1), whereas LGIB is more common in women

8. Significant UGIB requiring admission is more common in adults, whereas LGIB requiring admission is more common in children

9. Differential Considerations

10. Peptic ulcer disease, gastric erosions, and varices account for approximately three fourths of adult patients with UGIB • Diverticulosis and angiodysplasia account for approximately 80% of adults with LGIB

11. Esophagitis, gastritis, and peptic ulcer disease are the most common causes of UGIB in children, and infectious colitis and inflammatory bowel disease are the most common causes of LGIB in children • In children younger than age 2 years, massive LGIB is most often a result of Meckel's diverticulum or intussusception

12. At all ages, anorectal abnormalities are the most common cause of minor LGIB • Despite improved diagnostic techniques, no source of bleeding is identified in approximately 10% of patients with GI bleeding

13. Patients who have abdominal aortic grafts who present to the emergency department with GI bleeding should receive prompt surgical consultation in the emergency department for the possibility of aortoenteric fistula

16. Rapid Assessment and Stabilization

17. Most patients with GI bleeding are easy to diagnose because they present to the emergency department complaining of vomiting blood or passing black or bloody stool • The diagnosis is confirmed quickly by examination of the stool for the presence of blood

18. Patients with suspected GI bleeding who are hemodynamically unstable should undergo rapid evaluation and resuscitation • They should be undressed quickly, placed on cardiac and oxygen saturation monitors, and given supplemental oxygen as needed

19. At least two large-bore peripheral intravenous lines should be placed (minimum 18-gauge); blood should be drawn for hemoglobin or hematocrit, plateletcount, prothrombin time (PT), and type and screen or type and crossmatch; and crystalloid resuscitation should be initiated

20. Intravenous crystalloid fluid should be given as a 2-L bolus in adults or 20 mL/kg in children until the patient's vital signs have stabilized or the patient has received 40 mL/kg of crystalloid • Patients who remain unstable after 40 mL/kg of crystalloid should be given type O, type-specific, or crossmatched blood depending on availability

21. Persistently unstable patients should receive immediate consultation • patients with UGIB with a gastroenterologist and surgeon • patients with LGIB with a surgeon

22. Pivotal Findings • Keys to diagnosing GI bleeding : • History • physical examination • testing stool for blood • measuring hemoglobin or hematocrit

23. History

24. Patients usually complain of vomiting red blood or coffee ground–like material or passing black or bloody stool • Hematemesis(vomiting blood) occurs with bleeding of the esophagus, stomach, or proximal small bowel. Approximately 50% of patients with UGIB present with this complaint

25. Hematemesis may be bright red or darker (i.e., coffee ground–like) as a result of conversion of hemoglobin to hematin or other pigments by hydrochloric acid in the stomach • The color of vomited or aspirated blood from the stomach cannot be used to determine if the bleeding is arterial or venous in nature

26. Melena, or black tarry stool, occurs from approximately 150 to 200 mL of blood in the GI tract for a prolonged period. Melena is present in approximately 70% of patients with UGIB and a third of patients with LGIB • Black stool that is not tarlike may result from 60 mL of blood from the upper GI tract

27. Blood from the duodenum or jejunum must remain in the GI tract for approximately 8 hours before turning black • Occasionally, black stool may follow bleeding into the lower portion of the small bowel and ascending colon • Stool may remain black and tarry for several days, even though bleeding has stopped

28. Black stool also may be seen after ingestion of bismuth (e.g., Pepto-Bismol), which can confuse the situation because it is often taken for UGI distress. In contrast to melena, stool rendered black by bismuth is not positive on Hemoccult testing

29. Hematochezia, or bloody stool (bright red or maroon), most often signifies LGIB, but may be due to brisk UGIB with rapid transit time through the bowel • Because UGIB is much more common than LGIB, a more proximal source of significant bleeding must be excluded before assuming the bleeding is from the lower GI tract

30. Approximately two thirds of patients with LGIB present with red blood per rectum • Small amounts of red blood (e.g., 5 mL) from rectal bleeding, such as bleeding due to hemorrhoids, may cause the water in the toilet bowl to appear bright red. Bright red stools also can be seen after ingestion of a large quantity of beets, but Hemoccult testing would be negative

31. When taking the history, specific questions should address the duration and quantity of bleeding, associated symptoms, previous history of bleeding, current medications, alcohol, nonsteroidal anti-inflammatory drug and long-term aspirin ingestion, allergies, associated medical illnesses, previous surgery, treatment by prehospital personnel, and the response to that treatment

32. Patients with GI bleeding may complain of symptoms of hypovolemia, such as dizziness, weakness, or loss of consciousness, most often after standing up

33. Other nonspecific complaints include dyspnea, confusion, and abdominal pain • Rarely an elderly patient may present with ischemic chest pain from significant anemia • One in five patients with GI bleeding may have only nonspecific complaints

34. History is of limited help in predicting the site or quantity of bleeding • Patients with a previously documented GI lesion bleed from the same site in only 60% of cases

35. Gross estimates of blood loss based on the volume and color of the vomitus or stool (e.g., brown or black, pink or red) or the number of episodes of hemorrhage are notoriously inaccurate

36. Physical Examination

37. Vital Signs • Vital signs and postural changes in heart rate have been used to assess the amount of blood loss in patients with GI bleeding but are notoriously insensitive and nonspecific, with the exception of significant, sustained heart rate increase

38. All patients with a history suggesting GI bleeding who are hypotensive, are tachycardic, or have sustained postural changes of greater than 20 beats/min in heart rate should be assumed to have significant hemorrhage

39. Normal vital signs do not exclude significant hemorrhage • Postural changes in heart rate and blood pressure may occur in individuals who are not bleeding (e.g., elderly people, many normal individuals, individuals with hypovolemia from other causes)

40. General Examination • The physical examination is valuable in making the diagnosis and assessing the severity of blood loss and a patient's response to that loss

41. Careful attention is given to the patient's general appearance, vital signs, mental status (including restlessness), skin signs (e.g., color, warmth, and moisture to assess for shock and lesions such as telangiectasia, bruises, or petechiae to assess for vascular diseases or hypocoagulable states), pulmonary and cardiac findings, abdominal examination, and rectal and stool examination

42. Frequent reassessment is important because a patient's status may change quickly

43. Rectal Examination • Rectal and stool examination are often key to making or confirming the diagnosis of GI bleeding • The finding of red, black, or melenic stool early in the assessment is helpful in prompting early recognition and management of patients with GI bleeding

44. The absence of black or bloody stool does not exclude the diagnosis of GI bleeding • Regardless of the apparent character and color of the stool, occult blood testing is indicated

45. Ancillary Testing

46. Tests for Occult Blood • The presence of hemoglobin in occult amounts in stool is confirmed by tests such as guaiac (e.g., Hemoccult) Stool tests for occult blood may have positive results 14 days after a single, major episode of UGIB

47. False-positive results have been associated with ingestion of red fruits and meats, methylene blue, chlorophyll, iodide, cupric sulfate, and bromide preparations • False-negative results are uncommon but can be caused by bile or ingestion of magnesium-containing antacids or ascorbic acid. may show that it is maternal in origin

48. Tests to evaluate gastric contents for occult blood (e.g., Gastroccult) can be unreliable and should not be used for this purpose • In newborns, maternal blood that is swallowed may cause bloody stools; ; the Apt test may show that it is maternal in origin

49. Clinical Laboratory Tests • Blood should be drawn for evaluation of baseline hematocrit or hemoglobin, coagulation studies (PT and platelet count), and type and crossmatch (or type and screen if the patient is stable) • Hematocrit and hemoglobin are clinically useful tests that may be obtained at the patient's bedside, but they have significant limitations

50. The initial hematocrit may be misleading in patients with preexisting anemia or polycythemia • Changes in the hematocrit may lag significantly behind actual blood loss • Infusion of normal saline speeds equilibration of the hematocrit; how-ever, rapid infusion of crystalloid in nonbleeding patients also may cause a decrease in hematocrit by hemodilution