APPROACH TO GASTROINTESTINAL BLEEDING
Welcome to our talk on the emergency medicine approach to gastrointestinal bleeding. This lecture will tell you why it's an important problem and it will define the term gastrointestinal bleeding for you. And then we will take you from the perspective that the patient is being met out in the field by pre-hospital providers and then as the patient arrives to you in your emergency department or in your clinic. We will initially discuss the resuscitation and stabilization of these patients. After looking at the primary management of these patients we will discuss the consultants you will need and their secondary management. Finally, we will look at the likely causes of gastrointestinal bleeding.
Gastrointestinal bleeding is a very common problem in emergency medicine.
Between 50 to 150 people per 100,000 in a population present with this problem
per year. It also attributes to 250,000 annual admissions. In addition, approximately
one billion dollars are spent a year in health care costs alone for problems
related to gastrointestinal bleeding and another major issue related to gastrointestinal
bleeding, which definitely makes it pertinent to emergency medicine, is the
mortality is approximately 5 - 10% and has decreased in the past 15 years.
Pre-hospital treatment and evaluation is going to start with a brief initial survey to include airway, breathing, circulation, and mechanism of injury. Gastrointestinal bleeding is no different from any other emergency and requires the ABC's initially. You will want to intubate unresponsive patients and those unable to protect the airway and give 100% oxygen. Patients that cannot be intubated in the field due to excessive bleeding, vomiting, or anatomy can be managed safely and effectively by the Combitube. Pre-hospital treatment and evaluation is based on a patient's hemodynamic status. If there are any signs of any shock or unstable gastrointestinal bleeding, the priority is rapid transport.
The pre-hospital evaluator is going to be looking for signs of hemorrhagic shock and by that we mean looking for altered mental status, cool or clammy skin, increased capillary fill-time, tachycardia, hypotension.
We're going to be intubating unresponsive patients and those unable to protect their airway. Additionally, when we are transporting these patients, these patients should be transported in Trendelenburg's position: 45 degrees with their head down and on their left side, which is known as the Sim's position. For those patients who are unstable, no extra time should be taken at the scene establishing intravenous access. Large bore, intravenous line, should be placed enroute.
While at the scene, if there are objective findings of bleeding, document the quantity of blood. If time permits, utilize friends, family, or neighbors for a brief history. Also transport any medical records or medications if available. And all patients with active gastrointestinal bleeding, or those patients who are older than 40 years old, are potentially unstable and if possible should be transported on cardiac monitor and again with at least one large bore, 14 or 16 gauge peripheral intravenous catheter line in place if time permits.
Well now the patient is arriving in the emergency department. What would be the treatment and evaluation? Regardless of the patient's presentation, whether it be with hematemesis, hematochezia, or melena; associated with hypotension, tachypnea, tachycardia, dizziness, syncope, angina or altered mental status; the patient requires immediate resuscitation and stabilization. It is best to monitor the oxygenation with pulse oximetry, if available. Unstable patients require two large bore intravenous lines, cardiac monitoring, and frequent vital sign checks.
We will want to resuscitate using lactated ringers or normal saline, given in boluses from 250 milliliters to 1000 milliliters in order to maintain systolic blood pressure above 90 millimeters of mercury. We want to record vital signs after each bolus, auscultate the lungs for signs for fluid overload, and if the response is inadequate after 2 to 3 liters of crystalloid, consider blood transfusion. Additionally, those patients who do require more than 2 to 3 liters of crystalloid, we will want to place a Foley catheter and maintain urine output at 30 to 50 milliliters per minute.
Estimation of the rate and the amount of the acute gastrointestinal bleeding will guide resuscitation. A loss of 30 to 40% blood volume, approximately 1500 to 2000 milliliters, will usually present with frank shock, with tachycardia, tachypnea, hypotension, narrow pulse pressure, and altered mental status. A loss of 20 to 30% approximately 1000 to 1500 ml. of blood volume usually results in orthostatic changes. A loss of less than 15% of the circulating volume results in few symptoms, unless there is underlying cardiovascular or pulmonary disease.
The decision to administer blood should be based on the clinical findings of volume depletion or continued bleeding, more than on initial hematocrit levels.
A nasogastric tube should be placed in all patients with significant gastrointestinal bleeding regardless of the presumed source. For instance, bright red blood per rectum often unexpectedly originates from a massive upper GI bleed.
A negative gastric aspirate does not conclusively an upper gastrointestinal source and may result from intermittent bleeding or pyloric spasm or edema which prevents reflux of duodenal blood. In addition, the standard guaiac paper may yield falsely negative results in the presence of low gastric pH. If bright red blood or clots are found on nasogastric intubation, gastric lavage should be performed. To be effective it is best to use a large bore tube, usually oral. Room temperature saline is the preferred irrigant, as iced solutions have no proven benefit and have theoretical disadvantages.
As mentioned previously, if the patients require more than 2 to 3 liters of crystalloid fluid resuscitation, blood transfusions may be required. Uncrossed-matched O- negative red blood cells are usually available in the emergency department within zero to five minutes. Uncrossed-matched type specific packed red blood cells can be available in the emergency department within 15 minutes. This would create an approximate rise in hemoglobin and hematocrit to 1 to 1.5 grams per deciliter or 3 points per unit transfused, respectively. One would also get the same response from cross-matched packed red blood cells. The approximate time for their arrival in the E.D. is 45 minutes to an hour. Fresh frozen plasma is appropriate only in acutely bleeding patients, with a correctable coagulopathy, for example liver failure or warfarin therapy. The routine use of FFP after every 4 or 5 units of blood or packed cells in massively transfused patients is not justified. As for patients with ongoing gastrointestinal hemorrhage and fewer than 50,000 platelets per ml. These patients should receive platelet transfusions.
Now that we've talked about primary management and the immediate evaluation of the patient that's arriving in the emergency department, let's take time to take some a look at the necessary history taking and physical exam. With the history there are certain clinical manifestations that give clues as to the location of the GI bleed.
Gastrointestinal bleeding most commonly presents with hematemesis, coffee-ground emesis, melena, or hematochezia. Hematemesis and coffee-ground emesis usually suggest upper GI bleeding. Melena suggests a source at or proximal to the right colon. Hematochezia suggests a more distal colorectal lesion. Note that there are always exceptions to these rules.
Further from the history, more clues can be obtained as to the etiology of the GI bleed. For instance, weight loss or changes in bowel habits are classic symptoms of malignancy or IBD. Vomiting or retching is suggestive of a Mallory-Weiss tear. History of medications or drug ingestions should be sought, as salicylates, NSAID's, corticosteroids, or anticoagulants are associated with GI bleeding. In addition, if a patient is on beta blockers or nitrates, this would account for bradycardia in the face of hypovolemia. A history of pain can point to a source; for example, pain that is relieved by the onset of bleeding suggests peptic ulcer disease. Past history should focus on prior surgeries as well as a history of alcoholism or alcohol abuse. In addition, ingestion of iron or bismuth salicylate can mimic melena.
The physical examination of these patients in the E.D. one would want to focus on the following areas: The vital signs which may reveal an obvious hypotension or tachycardia; orthostatic changes may reveal an occult volume loss; however, remember some patients can tolerate substantial volume losses with minimal or no changes in vital signs and paradoxical bradycardia can occur in the face of severe volume loss. As mentioned previously, it could be secondary to medications or due to the location of bleeding which may stimulate vagal tone. The skin findings would show any signs of shock, underlying liver disease, or coagulopathy. Furthermore, a careful ear, nose, and throat examination may reveal an occult bleeding source that is not GI. An abdominal examination is mandatory. A rectal examination is mandatory for the detection of the color of the stool, presence of blood, masses, or rectal fissures or hemorrhoids.
What are the initial diagnostic studies that are important in the ED? Looking at laboratory analysis, the most important test is to type and crossmatch for 4 to 6 units of packed red blood cells. In addition, one would want to look at the CBC with platelets, coagulation studies, electrolytes, calcium, BUN, creatinine, glucose, and liver function tests. A rise in the BUN suggests an upper tract source of bleeding.
Furthermore, we want to obtain the EKG in patients over 40 years old, chest pain, or history of cardiovascular disease. In our use of radiography, we will want to obtain a chest x-ray in those who are over 40 years old, or have chest pain, shortness of breath, or have a history of pulmonary disease. We would also like to obtain abdominal films possibly utilizing flat, upright, or decubitus views to rule out perforation, ileus, or obstruction.
For secondary management, we are going to want to consult either gastroenterology
or general surgery. More than likely, endoscopy will be performed, as it
is the most accurate technique for identification of upper tract sites as well
as from the standpoint of control, sclerotherapy of esophageal varices can
control acute hemorrhage in 90% of those patients. In utilizing drug therapy,
histamine H2 antagonists, for instance cimetidine and ranitidine, should
given to all patients with acute GI bleeds although there use has never been
shown to increase survival. Vasopression is controversial and has severe
Now that we've stabilized our patient, we have time to consider the causes of gastrointestinal bleeding. For upper GI bleeding, peptic ulcer disease or duodenal or gastric ulcers, are the most common cause in children and adults. It occurs in approximately 45% of the patients. And it accounts for 56% of mortality from upper GI bleeding. Gastritis accounts for approximately 2% of mortality from upper tract sources. Gastric varices is a manifestation of portal hypertension. History and physical exam should focus on liver disease in portal hypertension.
This occurs in mostly adults and accounts for 33% of mortality from upper GI bleeding. Mallory-Weiss tears also occur and this is predominantly in adults. Retching and vomiting are events that increase intraabdominal pressure and a history of retching and vomiting though is only obtained in approximately 50% of the patients, and is commonly associated with alcoholism (75%), and hiatal hernias.
Esophagitis, while it is a common disease, it is an uncommon cause of bleeding. However, it is the most common cause of bleeding in pregnancy.
For lower gastrointestinal bleeding, this is most commonly found in elderly patients, and the most common causes are due to diverticulosis or angiodysplasia. When it does occur in young adults, it's most often due to ulcerative colitis and in children it is often due to Meckel's Diverticulum or Intussusception. In all ages, rectal abnormalities account for minor gastrointestinal bleeding. For specific causes of lower GI bleeding, diverticulosis occurs in approximately 49% of the patients over the age of 60 years old. Significant hemorrhage develops in only 3 to 5%. The majority of bleeding occurs from diverticula that are the right side. Angiodysplasia is found in 25% of the patients above the age of 60 and this occurs more commonly in males than females. Carcinoma is an uncommon cause of is an uncommon cause of lower GI bleeding and it only accounts for 5%. With Meckel's diverticulum, it's the most common cause of lower GI bleeding in children and it occurs at about 2 to 3% in children.
Symptoms most commonly occur during the first 2 years of life and painless rectal bleeding is the most common presentation. With Intussusception, this is the most common cause of intestinal obstruction in children of age 2 months to 6 years and up to 80% of the children will pass stool containing blood and mucous. This is known as the currant-jelly stool.
Let's summarize the ED approach to the patient who will be arriving with GI bleeding. We've taken you from how they present at their home, where they are met by prehospital personnel and they receive their prehospital evaluation and treatment. We then discussed the primary management guidelines once they arrive in the ED or in an outlying clinic. The most important aspect of their management, regardless of the presentation, will have to begin with immediate resuscitation and stabilization. You'll want to use your ABC's, airway, breathing, and circulation. You'll want to evaluate them for their hemodynamic status. You will follow a primary management protocol, regardless of what you believe to be the source of the GI bleeding, because there are so many exceptions to the rules. And lastly we discussed ED approach to a focused history and physical exam. We also lightly touched on aspects of secondary management and the etiology of GI bleeding.