PANEL DISCUSSION ON LOWER GI BLEEDING
Introduction : Dr. Philip Augustine
Moderator : Dr. Sunil K. Mathai
Dr. Vinod Kumar, Dr. Rajendra N. Sonawane
Dr. Mohan K. Abraham, Dr. Nirmal Prabhu
Lower gastrointestinal bleeding, defined as bleeding from below the ligament of Trietz, encompasses a wide clinical spectrum ranging from trivial hematochezia (bleeding per reetum) to massive haemorrhage with shock. As per the bleeding registry of the American college of gastroenterology, lower gastrointestinal bleeding accounted for 24% of all bleeding events. The incidences of lower GI bleeding is higher in men and increases with age, presumably due to higher incidence of diverticulosis and vascular disease in the group.
Diverticulosis, Angiodysplasia, Inflammatory bowel disease, Neoplasms, Drug, indiced ulcers, Coagulopathy.
Definition of Massive Lower GI Bleeding
Passage of Large Volume of red or maroon blood through the rectum
Haemodynamic instability and shock
Initial decrease in haematocrit level of 6g/dl or less
Transfusion of at least 2 units of Packed Red blood cells
Bleeding that continues for 3 days
Significant rebleeding in 1 week
SMALL BOWEL BLEEDING
Small bowel bleeding often is the cause of obscure lower GI bleeding though massive bleeding can also occur.
Causes of Small Bowel Bleeding
Vascular Ectasias n Dieuafoy’s lesions nDrug induced ulcerations
Ectopic VaricesDiverticula Small Bowel Neoplastic Lesions
Haemosuccus pancreaticus Haemobilia
Non-Steroidal anti inflammatory drug ulceration
They have been noted increasingly to cause damage to the small bowel to the duodenum via cyclo oxygenase dependent and independent mechanisms and are a source considerable morbidty. Bleeding manifests as malacna and is usually self limited, but occasionally requires intervention. Apart from NSAIDs potassium chloride, anti metabolites and chemotherapeutic agents may cause small bowel unlceration and bleeding.
Laboratory tests include complete blood count and hematocrit values. Hematocrit values are preferred, as during the immediate phase of bleeding hemoconcentration may give rise to false hemoglobin levels. A coagulation profile including Activated Partial Thromboplastin Time (APTI), Prothrom bin time (PT) manual Platelet Count and Bleeding Time is needed to rule out coagulopathies predisposing to the bleed.
ENDOSCOPY IN LOWER GASTROINTESTINAL BLEEDING
Colonoscopy has an important role in diagnosis. A rapid colonic lavage is done with poly ethylene glycol or sodium phosphate preparations. This clears the intraluminal blood clot and stool providing an adequate environment for visualization of the lower GI mucosa and lesions. The candidates for colonoscopic evaluations are patients who are bleeding slowly or who have already stopped bleeding, using push enteroscopy, sonde enteroscopy, intra, operative enteroscopy, or lap assisted enteroscopy (LAPE) are used when coloscopy is negative or the bleed is suspected to be from the small bowel.
Wireless capsule endoscopy is a recent innovation in the field of evaluation of small bowel. It is useful in the elderly as there is no stress to the patient. Use is limited to small bleeds or intermittent bleeds. A capsule that transmits the images to a recorder attached to waist belt is swallowed. The images recorded are analysed after the transit of the capsule.23
Double contrast barium enema examination can be justified only for elective evaluation of unexplained lower GI bleeding. Barium enema examination should not be used in the acute4 haemorrhage phase because it makes subsequent diagnostic evaluation including angiography and colonoscopy impossible.
Elective contrast radiography of the small bowel and/or enteroclysis is often a valuable investigation for long term unexplained lower GI bleeding.
The role of nuclear scintigraphic imaging in diagnosis and treatment of patient who present with lower GI bleeding remains controversial. It is sensitive diagnostic tool (86%) and can detect haemorrhage at rates as low as 0.1 ml/min. It is non invasive, safe and there is no risk of contrast reaction. It has a low cost but all the advantages are often negated by the fact that it has limited resolution and no therapeutic capability. Technetium sulphur colloid and Indium In are usually used. Surgical therapy is not generally recommended on the basis of Radinuclide studies alone.
Selective mesenteric angiography. Mesenteric angiography can detect bleeding at a rate more than 0.5 ml/min. Superior mesenteric artery, inferior mesenteric artery and celiac axis are separately cannulated and imaged. Emergency angiography as an initial study is indicated in a highly selected group who present with massive bleeding. During angiography provocative methods of anticoagulant administration or vasopressors can be used to induce bleeding and localized but this is a risky procedure requiring substantial backup.
MANAGEMENT OF LOWER GI BLEEDING
Regardless of the level of bleeding the first priority is for resuscitation. Patient with massive lower GI bleeding should receive 2 large bore IV catheters. A rapid assessment of vital signs and urine output should be made. Whole blood, fresh frozen plasma and packed cells are used after assessing the volume loss and coagulation status. A nasogastic tube aspiration helps to rule out an upper GI bleeding but if the bleeding is intermittent, it maybe false negative. A Foley’s catheter is placed to measure the urine output. Careful digital rectal examination and protoscopy is done to exclude anorectal source of bleeding.
Vasopressin. It is given at the rate of 0.2 to 0.4 units/min. during vasopressin infusion patients are monitored for myocardial ischaemia, arrhythmia, hypertension and volume overload. Nitroglycerine patch or infusion can be used to overcome cardiac complication.
Thermal coagulation using heater probes lasers and Argon plasma coagulation is used for angiodysplasia and bleeding arterioles. Adrenaline and sclerosants like sodium ltetradecyl sulphate and aethoxy sclerol is used for hemostasis from bleeding vessels. Hemoclips are used for post polypectomy bleeds.
Super selective embolization or mesenteric vessels
Embolisation involves super selective catheterization of the bleeding vessel to minimize necrosis and ischaemia, which is the major side effect of embolization. Embolization is now reserved for high-rsik patients whose bleeding is refractory to conservative measures. If terminal mucosal branches cannot be catheterized surgery is advised.
Surgical options include elective resection of known bleeding points like carcinoma or Meckel’s diverticulum, or emergency surgery for an active bleed, localized by endoscopy or angiography. Blind subtotal colectomy is performed for presumed colonic haemorrhage that cannot be localized 7% and Blind segmental resection should not be performed.
FAECAL OCCULT BLOOD TGESTING
This is recommended for persons above the age of 50 years as a screening test for carcinoma, or as a part of the work up of anaemia. Persons found to have a positive test should undego anoscopy, colonoscopy or upper gastrointestinal endoscopy to rule out mucosal lesions.