Large Intestine and Gastrointestinal Bleed

1. Large Intestine and Gastrointestinal Bleed Rene Penate NMT 1713 August 1, 2007

2. Objective Identify the anatomy and physiology of large intestine explain the situations and detection of gastrointestinal bleeding Explain how to perform a GI Bleed Scan including radiopharmaceutical, patient dose, method of localization, indications, contraindications, patient preparation, acquisition, procedure, normal, and abnormal results.

3. What is the large intestine, and GI bleed? Commonly known as the Colon, is the last part of the digestive system. Its function is to absorb the remaining water from indigestible food matter, stores these unusable food matter (wastes) and then eliminates the wastes from the body. Gastrointestinal bleeding refers to any bleeding that starts in the gastrointestinal tract, which extends from the mouth to the large bowel. The degree of bleeding can range from nearly undetectable to acute, massive, and life-threatening. Bleeding may come from any site along the gastrointestinal tract

4. Anatomy of the large intestine The large intestine consists of the following parts: Cecum - is a pouch connected to the ascending colon of the large intestine and the ileum ascending colon -is smaller in caliber than the cecum , with which it is continuous. transverse colon -the longest and most movable part of the colon, passes with a downward convexity from the right hypochondriac region across the abdomen, opposite the confines of the epigastric and umbilical zones, into the left hypochondriac region, where it curves sharply on itself beneath the lower end of the spleen, forming the splenic or left colic flexure.

5. Anatomy Continues descending colon-passes downward through the left hypochondriac and lumbar regions, along the lateral border of the left kidney. sigmoid colon-forms a loop which averages about 40 cm. in length, and normally lies within the pelvis, but on account of its freedom of movement it is liable to be displaced into the abdominal cavity. Rectum-is about 12 cm long, is the final portion of the large intestine ending in the anal canal anal canal-approximately 2.5 to 4 cm long, extending from the anorectal junction to the anus. It is directed downwards and backwards. It is surrounded by inner involuntary and outer voluntary sphincters which keep the lumen closed in the form of an anteroposterior slit. Anus-is the external opening of the rectum

6. Gastrointestinal Bleed Acute GI Bleed can be attributed to perforation of intestines with foreign object, or any rupture that could of triggered a GI bleed( mostly in accidents). Chronic GI Bleed comes from ulcers, aspiring, inflammation, cancers, diverticula, or angiodysplasia (is a condition of stretched and fragile blood vessels in the colon that results in occasional loss of blood from the gastrointestinal (GI) tract) due to aging and degeneration of blood vessels.

7. Colonoscopy and Tagged RBC

8. GI Bleed Scan Radiopharmaceutical: Tagged red blood cells by pyrophosphate or stonnous chloride to 99mTcO4 (pertechnate) by in vitro or in vivo, or kit e.g., Ultratag, for active (acute) bleeding 99mTc-SC ( sulfur colloid) is used. Localization: Compartmental, tagged to and circulating with blood. Adult Dose: 99mTcO4: 20-30mCi (740-1110MBq) 99mTc-SC: 10-20mCi (370-740MBq)

9. Indications/ Method of Administration Detection and localization of bleeding sites in patients with active or intermittent gastrointestinal bleeding. This could be caused by aspirin, ulcers, perforation, cancers, inflammation, diverticula, or angiodysplasia. Detection and localization of secondary blood loss as in blood pooling in peritoneal cavity or ruptured arterial or venous supplies. 99Tc-SC: detection and localization of actively bleeding sites, for patients with portal hypertension (caused by obstruction of blood flow through the liver), and hypertension to abdominal collateral vessels. Method of administration: IV injections, or drawing, tagging, and reinjection of tagged and blood cells.

10. Contraindications/Patient Preparations Contraindication: patients with contrast studies under way. Patient preparation: identify the patient. Verify doctor’s order. Explain procedure. Obtain patient history ( most important). Obtain a signed consent for blood work. Instruct patient to empty bowel and bladder before beginning procedure. If possible, have patient look for active signs of bleeding (e.g., while in the bathroom emptying bowels)

11. Acquisition/Procedure Acquisition: Flow: 2-5 sec/frame, 60-180 seconds Dynamic: 60 sec/frame for 60 minutes Statics: 500,000-2,000,000 counts Procedure: Patient must sign consent form to take and return blood. It must also be signed by technologist and witness. In vitro method: extract 2-2.5 ml of blood into heparinzed syringe from patient and tagged with Ultratag. In vivo method: inject cold PYP, then 20 minutes later, inject radiotracer under camera for flow. Modified in vivo method: inject cold PYP and wait 20 minutes. Extract 2-2.5 mL of blood into a heparinized shielded syringe containing 30mCI of 99mTcO4. Mix for 5-10 minutes.

12. Continue Place patient in supine position, camera anterior and if possible from bottom of heart to lower bowel in view. If patient is tall, upper and lower pictures may be taken. Inject under camera for initial flow protocol. Acquire flow if active bleeding is suggested. 99mTc-SC is best used to present the active bleeding site. Sulfur colloid is taken up and removed quickly by the reticuloendothelial system (RES), so careful positioning, injection and computer start are important. Acquire statics interiorly. Include immediately and 5, 10, 15, 30, 45, and 60 minutes with RAO’s and LAO’s indicated of positive Or acquire dynamic study for 60 minutes after flow study. Delayed images as necessary. Show study. Laterals and posteriors may be indicated with presentation of a positive scan. Four hour and 24-hour delays may also be indicated. If a patient has a bowel movement after tagging, some hardy souls bag the bedpan and image it for activity, which would be signs of active bleeding.

13. Normal Results Heart and great vessels prominent Bladder, bowel, and penile activity not inlikely

14. Abnormal Results Flow: focal area of increased activity. Blood polling in abdominal cavity may also be present Statics: focal area peristalses with time. Blood pool may persist in abdominal cavity and may or may not move. If little or no movement, it may be vascular activity or pool in abdominal cavity. Typical focal areas of active bleeding include ascending, transverse, descending, and sigmoid colon, right colonic(hepatic) flexure, left colonic(splenic) flexure, and small bowel.

15. Abnormal Results

16. Conclusion Large Intestine allows the body to get rid of waste. GI Bleed scan assist doctors in the diagnosing and proper treatment of possible deadly gastrointestinal bleeds. Proper care for patient is the responsibility of the NMT, to allow for a satisfactory exam.

17. Quiz What is the recommended adult dose for GI Bleed scan with 99mTcO4? 5-10mCi of 99mTcO4 20-30mCi of 99mTcO4 15-30mCi of 99mTcO4 None of the above

18. Answer: B) 20-30mCi of 99mTcO4

19. 2. The celcum is the ending of the large intestine? True False

20. Answer: B) False, the cecum is the beginning of the large intestine where it connects with the small intestine.

21. 3. The require time/times interval a static view/views of the GI bleeding scan is/are? 5, 10, 15, 30, 35, 6o minutes 5, 15, 30, 45, 60 minutes 2, 10, 20, 30, 45, 60 minutes None of the above

22. Answer: 5, 10, 15, 30, 45, 60 minutes

23. 4. All of the following are radiopharmaceuticals use for GI bleed scan except: Ultratag RBC 99mTc-SC 99mTc O4 All of the above are correct None of the above

24. Answer: D) All of the above are correct

25. 5. The proper passage of bowel waste through the large intestine is: Cecum, ascending colon, transverse colon, rectum, descending colon Cecum, transverse colon, descending colon, rectum Cecum, ascending colon, transverse colon, descending colon, rectum None of the above

26. Answer: C) Cecum, ascending colon, transverse colon, descending colon, rectum