Intestinal bleeding something we see on a weekly almost ...



January 26, 2001 Scribes: Patti and Kellie

ICM 8:00

Dr. Hodges

Gastrointestinal Bleeding

Notes regarding Dr. Hodge’s exam questions: All questions will come from the handout, so it is not necessary to read Stein. Pay attention to the bolded material and all of the diagrams. He will not ask any hard numbers or statistics, but he may ask what is most common. Expect patient scenarios. He said if you know the material, the questions will be very straightforward.

Definitions:

➢ Hematemesis - vomiting of blood

• There are two types hematemesis: bright red blood emesis and blood that has been in the stomach for an hour or more called coffee-ground emesis.

• Coffee-ground emesis usually represents mild bleeding that has stopped.

• Bright red blood signifies active bleeding, usually from an artery or an esophageal varix.

➢ Melena is black tarry stool, signifying old digested blood. Melena is NOT dark stools, but charcoal briquette black stools. “Dark” is not a color, and many normal people have dark stools. Melena has a characteristic odor like rotten eggs.

➢ Hematochezia is bright red blood from the rectum.

Patient Assessment

➢ First determine the urgency of the situation.

➢ Look at the vital signs, and see if the patient is cold and clammy. If he has lost 40% of his blood volume, he will be in circulatory shock, which is an acute emergency. People with resting tachycardia have lost 15-20% of their volume.

➢ You can also perform the tilt test. First take the blood pressure and pulse in the lying position, then have the patient stand up. Wait 30-60 seconds and check the blood pressure and pulse again. If the diastolic pressure goes down by more than 10 mmHg, or if the pulse goes up by more than 10, then the patient has volume contraction and needs to be admitted for tests and blood and fluid replacement.

➢ You do these things even before you see the lab work.

➢ Blood Tests

• The hematocrit can be misleading (see Fig 1 in the handout). It is the percentage of the total blood volume taken up by RBCs. Immediately after bleeding 2 units of blood, the hematocrit may not change very much. You may think that the patient is stable based on this number, but if you look at him he is tachycardic and hypotensive. Within hours the body will work to replace the blood volume and IV fluids may be given, and then the hematocrit will drop. Bottom line--look at the patient, not the lab results.

Resuscitation and Blood Transfusion

➢ When a patient comes in tachycardic and volume-contracted, the first thing to do is stabilize him.

➢ Begin by putting two IV lines in--one for the blood transfusion and the other for medications and saline. You always want to keep the hematocrit above 30%, especially in older patients. Below this there is a risk of coronary ischemia. Younger people can tolerate a hematocrit of about 25%.

➢ Blood is given by concentrated or packed RBCs. Whole blood is only used in trauma situations. Patients with clotting abnormalities are given fresh frozen plasma. Alcoholics with cirrhotic livers often need platelets as well due to hypersplenism.

Determining the Location of Bleeding

➢ The location of the bleeding can usually be determined by a thorough history. If he patient is vomiting coffee-ground blood, then he has an upper GI bleed. Melena is usually associated with an upper GI bleed from the stomach or duodenum. Bleeding from the cecum or right side of the colon may occasionally come out looking black as well because it takes about one day for stool to traverse the colon.

➢ GI guys like to put a nasogastric tube (NGT) down all patients with GI bleeds to assess whether the bleeding is still active.

• If bright red blood comes out of the NG tube, it is an urgent situation, and the patient is "scoped" immediately.

• If only black material (old digested blood) comes out of tube, then the bleeding has stopped, and endoscopy does not have to be done right away.

• If no black or red blood comes out of the tube, then the patient probably has a lower GI bleed.

Upper GI Bleeding

➢ The number one cause of upper GI bleeding in the US is ulcer disease. Bleeding occurs if the ulcer erodes into the wall of a small branch of the gastroduodenal artery or the celiac artery. The bleeding can range from a slight ooze to a massive hemorrhage.

• The two main causes of ulcer disease are infection with Helicobacter pylori and NSAID use.

• He showed a picture of an ulcer with a little purple "pimple" in the center of it. This is called a visible vessel or a sentinel clot (see fig 2).

□ The term “visible vessel” is a misnomer because the pimple seen is not a vessel but a clot that has formed in the side of the vessel wall.

□ When a vessel is transected, it will try to contract itself to stop the bleeding; but when there is a hole in the wall, it is harder for this to happen. The clot is the vessel's attempt to stop the bleeding.

□ The sentinel clot is a very ominous finding because it is right over an artery. These patients have usually bled quite a bit and generally require blood transfusions. There is about a 50% chance that the clot will dislodge.

□ When this is seen during endoscopy, therapy is applied to the area because of the high risk of rebleeding. We inject epinephrine around the area to make it swell and to tamponade the vessels that feed into that region. Then we take a probe attached to a generator and apply heat in an attempt to sear the two walls of the vessel back together.

□ Question from the floor (not audible but presumably about the incidence of rebleeding from these clots)-Answer: 50% without therapy. It has been shown that with therapy these patients have less bleeding and less surgery.

• Next he showed a picture of an ulcer without any evidence of a visible vessel. There is a slight amount of bleeding around the edge of the ulcer. This one has a low chance of rebleeding. The patient can go to the hospital floor.

➢ Another cause of upper GI bleeding is gastritis. On endoscopy of a patient with gastritis, you see erythema of the stomach lining and red petechiae, which are subepithelial hemorrhages.

• Just like ulcer disease, the two main causes of gastritis are infection with Helicobacter pylori and the use of NSAIDs like Motrin, ibuprofen, and aspirin. We see a lot of NSAID-induced ulcers, especially in the elderly arthritic population; these ulcers can be very severe and even life threatening. These patients often present with severe anemia because they have been bleeding for a couple of weeks. They complain of melena but no pain because the NSAIDs are analgesics. We also see a lot of NSAID-induced gastritis. Even the newer prescription NSAIDs like Vioxx that claim to be less toxic have been involved in duodenal ulcers.

• Gastritis can also occur when a person is under a lot of stress. This is seen a lot in ICU, surgical, and burn patients. The stomach gets less blood flow because the body is sending blood to other vital organs like the heart, kidney, and brain. It is also common to see gastric ulcers called stress ulcers in people who are hospitalized for other serious conditions.

➢ Esophageal varices are another common cause of upper GI bleeding. These varices are associated with alcoholism and cirrhotic liver disease.

• He showed a picture of a cirrhotic liver - see lots of nodules caused by scar tissue. This scar tissue causes increased resistance to blood flow from the portal vein through the liver and into the hepatic vein. This leads to portal hypertension, portal-caval shunting, and esophageal varices.

□ The spleen is connected to the portal vein, so it is common to get splenomegaly as well. When the spleen enlarges it chews up platelets, so cirrhotic patients will present with thrombocytopenia.

• The esophageal varices are very likely to rupture and bleed massively. These patients will come in vomiting cups and cups of bright red blood. The estimated mortality of the first variceal bleed is 25-30%. Some of these deaths are related to the exsanguination; in other cases the bleeding is stopped in time, but the patients have such bad liver disease that they are prone to develop sepsis and pneumonia, they often aspirate blood, and their livers are so bad that they don't have the immune system to fight off infections very well. Therefore, it is a very serious problem when you have cirrhosis and esophageal varices.

• He showed pictures of the varices. Looking down into the esophagus you see big dilated worm-like structures. It was thought in the old days that the varices started bleeding when gastric acid refluxed into the esophagus and irritated the mucosal surface. Now we know that they bleed because of the pressure behind them. Veins are thin walled vessels with very little muscle, so it does not take much pressure to make them burst. When you see a little red spot on the esophageal wall during endoscopy, you know that one of the varices has popped sometime in the recent past. When you see active bleeding, it is usually running, not spurting.

• These patients always come in vomiting bright red blood. They never come in with coffee ground emesis or melena. Many have a previous history of bleeding from varices. They usually have a history of heavy alcohol use and/or a positive hepatitis C test.

• Fortunately, 80% of the time the bleeding stops on its own. If it does not, then there are several ways to stop active bleeding:

□ There is a little needle that can actually be put into the varix to inject a sclerosing solution, which stops the bleeding. This is the technique used when there is active bleeding. Later the patient will undergo the banding procedure described next.

□ There is a better technique called banding (see Fig 3) that is easier to do and leaves less ulceration at the sight involved, but it is hard to do when there is acute bleeding. A little cup with preloaded rubber bands is attached to the end of the endoscope. The varix is suctioned up into the cup, and a rubber band is released and surrounds the base of the varix. This will choke off the blood supply to the varix and necrose it. Several days later the varix will be about 1/10 of its original size and the rubber band and the dead tissue will fall off, leaving scar tissue. The scope has 6 rubber bands, so 6 varices can be banded in one session. One banding session is usually not enough to get rid of all the varices; on average, three sessions are necessary. Banding keeps people from rebleeding, cuts down on the number of hospitalizations, and cuts down on the number of blood transfusions. However, it does not increase the patient’s life span; this is determined by the severity of the liver disease.

□ If the bleeding cannot be stopped or if it continues to recur, the next step is the Sengstaken-Blakemore or Minnesota tube. At this point, the chances of survival are 50-50 or less. This is a device with two balloons: one for the esophagus and the other for the stomach. The tube is delivered to the stomach, and the stomach balloon is blown up and pulled backwards until it reaches the fundus/esophagogastric junction. Then the esophageal balloon is expanded and will apply pressure or tamponade on the varices. These patients are usually intubated and on the ventilator by this point to protect their airway because they have a high risk of aspiration. This is a temporary procedure only; the balloons remain inflated for no more than 8 hours at a time so that the tissue is not necrosed. If there is further evidence of bleeding (blood in the NGT), then the balloons can be reinflated for another 8 hours. The tube can remain in for about 24 hours total. In a couple of days when the patient is stable, a sclerosing or banding procedure is attempted.

□ Another way to stop bleeding is the TIPS procedure--Transjugular IntraPeritoneal Shunt. This is performed by interventional radiologists. They place a catheter through the inferior vena cava, the heart, and eventually into the hepatic vein. Then they use a needle and just start poking around through liver tissue and injecting dye until they know for sure that they are in a portal vein branch. Now that they have a connection between the portal and systemic venous systems, they put a wire through that connection and dilate the tract with a balloon. Then they put a metal stint between those two veins to create a permanent connection between the hepatic vein and the portal vein. Now the portal system is under less pressure and the varices collapse. A common complication is clogging of the stint. This is a foreign body, and in about two years half of them will be clogged up. The radiologist can go back in and try to unclog it or put a smaller stint inside the original one.

➢ Mallory Weiss tears are an uncommon cause of upper GI bleeding. This is a tear in the mucosa between the esophagus and the stomach caused by severe retching; it is a mechanical force tear. These are normally seen in alcoholics or people who have been binge drinking and have a sudden retching episode.

• Patients present with vomiting of bright red blood. First stabilize them, put an NGT in, and if they are still bleeding, “scope” them immediately. They will heal up in a few days and don't need long term therapy.

➢ A rare cause of upper GI bleeding is an aortoduodenal fistula. This is important to know because if you miss it and the patient dies you are in a lot of trouble. This occurs when the patient already has a Y-shaped Dacron graft in the aorta, which sits right behind the duodenum. As a foreign body, the graft causes inflammation and can actually erode into the duodenum. If this does happen, there is a connection between your duodenum and your aorta (not good)—this leads to massive bleeding and the patient can exsanguinate within minutes if the connection is very large. Always examine the abdomen for large scars that may indicate an abdominal aneurysm repair.

• This connection can be seen on a CT scan. If you see this, call surgery stat. If the bleeding stops on its own, you have a small window of opportunity to send them to surgery to repair this. The majority will bleed out before they even get to the hospital.

Lower Gastrointestinal Bleeding

➢ The main cause of acute lower GI bleeding in the form of hematochezia is diverticulitis of the colon. It is a disease of aging commonly seen in people over 60. About 40% of the US population over 60 have diverticular disease. It occurs because of natural weaknesses in the wall of the colon and is thought to be related to low fiber diets. On endoscopic exam, you can see lots of outpouchings lined up in a row on the antimesenteric border. If one of them happens to be near a blood vessel, erosion can occur, leading to bleeding. They show up on barium enemas as little sacculations. The diverticula are most common on the left side of the colon, but they can be seen throughout the GI tract. The ones that most commonly bleed are in the right/ascending colon.

• These outpouchings should actually be called pseudo-diverticula because they do not contain muscle layers.

• The clinical history is almost always the same: the patient, usually over 50, is going about his daily business when without pain he notices cups and cups of blood coming out of his rectum. It occurs suddenly and painlessly, and it normally stops on its own.

• Treatment involves cleaning out the colon. Always do an endoscopy to document that the bleeding is due to diverticulitis and not cancer.

➢ The second cause of lower GI bleeding is angiodysplasia, which are little vascular malformations in the wall of the colon. They are usually small and ooze blood, causing a chronic anemia. They are found more often on the right side of the colon than the left, but they may been seen anywhere.

➢ Another cause is cancer in the colon. Cancers may produce bleeding, and by the time this occurs the tumor has often penetrated through the wall of the bowel into the lymph nodes. This is why we do the Guaiac test for occult blood in the stool and flexible sigmoidoscopy, hoping to catch early colorectal cancer.

• He showed a slide of a fairly large cancer encompassing the entire circumference of the bowel - an apple core lesion

➢ Colitis is yet another cause of lower GI bleeding. There are several types of colitis: ischemic, infectious, and radiation-induced. They all present the same (diarrhea for days to weeks and usually weight loss) and look the same on endoscopic exam.

➢ Another cause of painless rectal bleeding is Meckel’s diverticulum, seen frequently in children. If the pouch contains gastric mucosa, it will secrete gastric acid and will produce ulcerations in the colon.

➢ Hemorrhoids also cause chronic GI bleeding. The bleeding is always associated with bowel movements. It is bright red and of a small volume.

Scribe note: At this point it was 9:00 and Dr. Hodge’s decided to stop. He said to read the rest of it and pay close attention to the bold print, especially in the section entitled Guaiac tests.

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