Lower Gastrointestinal Bleeding Treatment & Management

The management of LGIB has 3 components, as follows:

• Resuscitation and initial assessment
• Localization of the bleeding site
• Therapeutic intervention to stop bleeding at the site

With advances in diagnostic and therapeutic endoscopy and angiography, the ability to localize and subsequently treat lower gastrointestinal bleeding (LGIB) has resulted in improved patient outcomes and reduced healthcare costs. The need for surgery also has been significantly reduced.

The sequence of using these modalities depends on the patient's clinical status, the rate of bleeding, and local expertise in specific surgical and nonsurgical procedures. Using any one modality should not preclude the subsequent use of another modality if required. In case of surgery, preoperative localization of bleeding is essential, because segmental colectomies performed after bleeding is localized are associated with the lowest morbidity and mortality.

According to the 2008 SIGN guideline, early endoscopy should be used within 24 hours of initial presentation of acute LGIB, where possible.^[13]

Massive LGIB is a life-threatening condition; although this condition manifests as maroon stools or bright red blood from the rectum, patients with massive upper gastrointestinal bleeding (UGIB) may also present with similar findings. Regardless of the level of the bleeding, one of the most important elements of the management of patients with massive UGIB or LGIB is the initial resuscitation. These patients should receive 2 large-bore intravenous (IV) catheters and isotonic crystalloid infusions. Meanwhile, rapid assessment of vital signs, including heart rate, systolic blood pressure, pulse pressure, and urine output, should be performed. Orthostatic hypotension (ie, a blood pressure fall of >10 mm Hg) is usually indicative of blood loss of more than 1000 mL.

Initial resuscitation involves establishing large-bore IV access and administration of normal saline. Besides ordering routine laboratory studies (eg, complete blood cell (CBC) count, electrolyte levels, and coagulation studies), blood should be typed and cross-matched. The patient's blood loss and hemodynamic status should be ascertained, and in cases of severe bleeding, the patient may require invasive hemodynamic monitoring to direct therapy.

The 2008 SIGN guideline states that patients in shock should receive fluid volume replacement without delay. Colloid or crystalloid solutions may be used to achieve volume restoration before administering blood products. Red cell transfusion should be considered after loss of 30% of the circulating volume.^[13]

Signs of hemodynamic compromise include postural changes with dyspnea, tachypnea, and tachycardia. An orthostatic drop in systolic blood pressure of more than 10 mm Hg or an increase in heart rate of more than 10 beats per minute is indicative of at least 15% of blood volume loss. The 2009 AAFP recommendations state that severe postural dizziness with a postural pulse increase of at least 30 beats per minute is a sensitive and specific indicator of acute blood loss of more than 630 mL.^[16]

A hematocrit level of less than 18% or a decrease of about 6% is indicative of significant blood loss that requires blood transfusions; the goal is to achieve a target hematocrit level of approximately 20-25% in young patients and a target hematocrit level of around 30% in high-risk, older patients. A coagulopathy, such as an international normalized ratio (INR) of greater than 1.5, may require correction with fresh frozen plasma; thrombocytopenia can be corrected with platelet transfusions.

Transfer to ICU

Patients who require admission to the intensive care unit and early involvement of both a gastroenterologist and a surgeon include the following:

• Patients in shock
• Patients with continuous active bleeding
• Patients at high risk, such as patients with serious comorbidities, those needing multiple blood transfusions, or those with an acute abdomen

In about 10% of patients presenting with LGIB, the source of bleeding is from the upper gastrointestinal (GI) tract. Some patients with LGIB should have a nasogastric (NG) tube placed, and if the aspirate or lavage does not show any blood or coffee ground–appearing material but dose show bile, bleeding originating from the upper GI tract is unlikely. In case of high suspicion, obtain an esophagogastroduodenoscopy (EGD) evaluation (see Esophagogastroduodenoscopy).

In patients who are hemodynamically stable with mild to moderate bleeding or in patients who have had a massive bleed that has stabilized, colonoscopy should be performed initially. Once the bleeding site is localized, therapeutic options include coagulation and injection with vasoconstrictors or sclerosing agents.

In cases of diverticular bleeding, bipolar probe coagulation, epinephrine injection, and metallic clips may be used. If recurrent bleeding is present, the affected bowel segment can be resected. In cases of angiodysplasia, thermal therapy, such as electrocoagulation or argon plasma coagulation, is generally successful. Angiodysplastic lesions may be missed at colonoscopy if the lesions are small or covered with blood clots.

The 2008 SIGN guideline states that colonoscopic hemostasis is an effective way to control hemorrhage from active diverticular or post-polypectomy bleeding in patients with massive LGIB.^[13]

Colonoscopy is useful in radiation therapy–induced gastrointestinal (GI) bleeding and in the treatment of colonic polyp lesions. Endoscopic treatment of radiation-induced bleeding includes topical application of formalin, Nd:YAG laser therapy, and argon plasma coagulation. Neoplastic bleeding due to polyps requires polypectomy. Patients diagnosed with colonic tumors may require surgical resection.

In patients in whom the bleeding site cannot be determined based on colonoscopy and in patients with active, brisk LGIB, angiography with or without a preceding radionuclide scan should be performed to locate the bleeding site as well as to intervene therapeutically.

Initially, vasoconstrictive agents, such as vasopressin (Pitressin), can be used. An experimental study of treatment of LGIB by selective arterial infusion of vasoconstrictors, such as epinephrine with propranolol and vasopressin, was reported. Although epinephrine and propranolol drastically reduced mesenteric blood flow, they also caused a rebound increase in blood flow and recurrent bleeding.

Vasopressin is a pituitary hormone that causes severe vasoconstriction in the splanchnic bed. Vasoconstriction reduces the blood flow and facilitates hemostatic plug formation in the bleeding vessel. Vasopressin infusions are more effective in diverticular bleeding, which is arterial, as opposed to angiodysplastic bleeding, which is of the venocapillary type. The results are less than satisfactory in patients with severe atherosclerosis and coagulopathy.

Intra-arterial vasopressin infusions begin at a rate of 0.2 U/min, with repeat angiography performed after 20 minutes. The bleeding stops in about 91% of patients receiving intra-arterial vasopressin but recurs in up to 50% of patients when the infusion is stopped.^[37] If bleeding persists, the rate of the infusion is increased to 0.4-0.6 U/min. Once the bleeding is controlled, the infusion is continued in an intensive care setting for 12-48 hours and then tapered over the next 24 hours. In patients with rebleeding, surgery should be considered.

Complications

During vasopressin infusion, monitor patients for recurrent hemorrhage, myocardial ischemia, arrhythmias, hypertension, and volume overload with hyponatremia. Nitroglycerine paste or drip can be used to overcome cardiac complications. Selective mesenteric infusion induces bowel wall contraction and spasms, which should not be confused with bowel wall ischemia. Do not administer vasopressin into systemic circulation intravenously, because this causes coronary vasoconstriction, diminished cardiac output, and tachyphylaxis. Vasopressin infusions are contraindicated in patients with severe coronary artery disease and peripheral artery disease.

An alternative to vasopressin infusion is embolization with agents such as gelatin sponge, coil springs, polyvinyl alcohol, and oxidized cellulose. Embolization involves superselective catheterization of the bleeding vessel to minimize necrosis, the most feared complication of ischemic colitis. This therapeutic modality is useful in patients in whom vasopressin is unsuccessful or contraindicated.

Initial experience with embolization suggested that complications of intestinal infarction were as high as 20%. With the advent of superselective catheterization and embolization of the vasa recta, successful embolization has been performed without intestinal infarction.^{[40, 41]} Embolization is performed using a 3 French (F) microcatheter placed coaxially through the diagnostic 5F catheter. The therapeutic catheter is advanced as far as the vasa recta over a 0.018-inch guidewire so as to decrease the risk of infarction.

Once the bleeding vessel is identified, microcoils are used to occlude the bleeding vessel and to achieve hemostasis. Although microcoils are most commonly used, polyvinyl alcohol and Gelfoam are also used alone or in conjunction with microcoils.^{[3, 42, 43]} However, if terminal mural branches of the bleeding vessel cannot be catheterized, abort the procedure and immediately perform surgery.

Kuo et al concluded superselective microcoil embolization for the treatment of LGIB is safe and effective.^[44] They reported complete clinical success in 86% of patients with a rebleeding rate of 14%. Minor ischemic complication rates were noted as 4.5%, and major ischemic complication rates were reported as 0%. The investigators also reviewed the data from 122 cases of lower GI superselective microcoil embolization in the literature, with meta-analysis performed in 144 patients. The combined analysis revealed a minor ischemic complication rate of 9% and a major ischemic complication rate of 0%.^[44]

Complications

Rosenkrantz et al reported 3 cases of colonic infarction.^[45] One patient died following segmental colectomy, and the other patients revealed full-thickness bowel wall injury in the resected specimen. Intestinal ischemia and infarction have also been reported. To prevent this complication, perform embolization beyond the marginal artery as close as possible to the bleeding point in the terminal mural arteries. At least 139 cases have been collected from the medical literature since 1972.

One of the advantages of upper or lower endoscopic evaluation is that it provides access to therapy in patients with gastrointestinal (GI) bleeding. Endoscopic control of bleeding can be achieved using thermal modalities or sclerosing agents. Absolute alcohol, morrhuate sodium, and sodium tetradecyl sulfate can be used for sclerotherapy of upper and lower GI lesions.

Endoscopic epinephrine injection is used commonly because of its low cost, easy accessibility, and low risk of complications. In a recent study, 175 patients underwent endoscopic epinephrine injection. Univariate analysis of 31 patients with rebleeding indicated that factors predictive of a high rebleeding rate included older age (≥60 y), American Society of Anesthesiology category III, IV, and V; severe anemia of greater than 8 g/dL; shock; epinephrine injection dose greater than or equal to 12 mL; and severe bleeding signs (hematemesis or hematochezia).^[46] } An additional hemostatic method such as clips or thermoregulation is needed to prevent subsequent bleeding.^[46]

Endoscopic thermal modalities (eg, laser photocoagulation, electrocoagulation, heater probe) can also be used to arrest hemorrhage. Endoscopic control of hemorrhage is suitable for GI polyps and cancers, arteriovenous malformations, mucosal lesions, postpolypectomy hemorrhage, endometriosis, and colonic and rectal varices. Postpolypectomy hemorrhage can be managed by electrocoagulation of the polypectomy site bleeding with either snare or hot biopsy forceps or by epinephrine injection.

The medical literature has also been reviewed for endoscopic treatment of significant lower GI bleeding (total of 286 patients in 8 publications). Hemorrhage was successfully arrested in 70% of patients, with a rebleeding rate of 15%. Endoscopic therapy for LGIB is a minimally invasive and viable option in carefully selected patients.^[47]

Hunter et al evaluated 222 GI endoscopic laser procedures in 122 patients and reported hemorrhage was arrested in 84% of the patients with GI bleeding.^[48] No perforations were reported in this series, but 1 death occurred and was attributed to laser therapy in a patient with duodenal ulcer and gastroduodenal artery bleeding.

Forty patients with GI arteriovenous malformations (AVMs) underwent 72 photocoagulation sessions with mostly argon laser; 15 of the 40 patients had significant hemorrhage from colonic AVMs; of those 15, there were no deaths following ablation.

Although the treatment options for angiodysplasias are numerous, including segmental bowel resection and selective mesenteric embolization, endoscopic coagulation of angiodysplasias is becoming a treatment of choice using either heated probe or lasers, such as Nd:YAG and argon. Argon laser treatment is recommended for mucosal or superficial lesions, because the energy penetrates only 1 mm. Nd:YAG lasers are more useful for deeper lesions, because they penetrate 3-4 mm.

Emergency surgery is required in about 10-25% of patients with lower gastrointestinal bleeding (LGIB) in whom nonoperative management is unsuccessful or unavailable.^[12]

Surgical indications

The indications for surgery include the following^{[15, 8]} :

• Persistent hemodynamic instability with active bleeding
• Persistent, recurrent bleeding
• Transfusion of more than 4 units packed red bloods cells in a 24-hour period, with active or recurrent bleeding

In addition, factors such as comorbid disease and individual surgical practices play a role in deciding which patient requires surgery. No contraindications exist with regard to surgery in hemodynamically unstable patients with active bleeding. In fact, if the patient is hemodynamically unstable because of ongoing hemorrhage, perform an emergency operation before any diagnostic study.

Segmental bowel resection and subtotal colectomy

Segmental bowel resection following precise localization of the bleeding point is a well-accepted surgical practice in hemodynamically stable patients. Subtotal colectomy is the procedure of choice in patients who are actively bleeding from an unknown source. According to the 2008 SIGN guideline, subtotal colectomy is recommended for the management of colonic hemorrhage that is uncontrolled by other procedures.^[13]

Intraoperative esophagogastroduodenoscopy (EGD), surgeon-guided enteroscopy, and colonoscopy may be helpful in diagnosing undiagnosed massive GI bleeding. Depending on the availability of local resources and the patient's condition, it may sometimes be better to perform subtotal colectomy with distal ileal inspection than to try to achieve these other tests, particularly if the surgeon is not privileged or comfortable with endoscopy.

Patients who are hemodynamically stable should have preoperative localization of the bleeding; patients who are hemodynamically unstable with active bleeding may undergo emergency exploratory laparotomy with intraoperative endoscopy. In patients who are hemodynamically stable, once the bleeding site is preoperatively localized, intra-arterial vasopressin is used as a temporizing measure to reduce the bleeding before patients undergo segmental colectomy. Using this approach the operative morbidity rate is approximately 8.6%, the mortality rate is around 10%, and the rate of rebleed ranges from 0-14%.^[37]

In patients undergoing emergency laparotomy, every attempt should be made to localize the bleeding intraoperatively, because a segmental colectomy is preferred. If the bleeding site is not localized, a subtotal colectomy with ileoproctostomy is performed with an inherent morbidity rate of around 37% and a mortality rate of about 11-33%. In addition, postoperative diarrhea can be a significant problem in elderly patients who undergo subtotal colectomy and ileorectal anastomosis.

In a subset of patients, surgery is still required, but with the use of nonsurgical diagnosis and intervention, the morbidity rate has been substantially reduced from around 37% to 8.6% in patients undergoing segmental colectomy. With advances in endoscopy and angiography, the rate of preoperative bleeding localization has steadily improved, impacting surgical outcomes in a positive way.

Contraindicated: Blind segmental resection

Practitioners must understand that blind segmental resection should not be performed because of a prohibitively high rebleeding rate of up to 75%, a morbidity rate up to 83%, and a mortality rate up to 60%. Once the bleeding point is identified, a limited segmental resection should be performed.

Acute LGIB is a common clinical entity and is associated with significant morbidity and mortality (10-20%). These factors are dependent on the patient age (>60 y), the presence of multiorgan system disease, transfusion requirements (>4 units), need for operation, and recent stress (eg, surgery, trauma, sepsis).

As discussed earlier, 3 major aspects are involved in managing LGIB. The initial priority is to treat the shock. Second, localization of the source of bleeding is required to perform the third task—formulating an interventional plan.

Insert a nasogastric (NG) tube in all patients. A clear bile-stained aspirate generally excludes bleeding proximal to the Treitz ligamentum. After initial resuscitation, undertake a search for the cause of the bleeding to precisely locate the bleeding point.

Following accurate localization by angiogram, bleeding can be temporarily controlled with either angiographic embolization or vasopressin infusion to stabilize the patient in anticipation of semiurgent segmental bowel resection. Segmental bowel resection is performed in the next 24-48 hours following correction of the patient's physiologic parameters, which include hypotension, hypothermia, acute hemorrhagic anemia, and deficient coagulation factors.

Use selective mesenteric embolization in high-risk patients for whom the operative management is associated with prohibitive risk of morbidity and mortality. If mesenteric embolization is used, these patients must be carefully monitored for bowel ischemia and perforation. Any evidence of ongoing bowel ischemia and/or unexplained sepsis following mesenteric embolization requires exploratory laparotomy to resect the affected bowel segment. Perform subtotal colectomy with ileoproctostomy in patients with multiple episodes of nonlocalized LGIB or bilateral sources of colonic hemorrhage.

Surgical intervention is required in only a small percentage of patients with LGIB. The surgical option depends on whether the bleeding source has been accurately identified preoperatively; if so, it is then possible to perform segmental intestinal resection.

If the bleeding source is unknown, an upper gastrointestinal endoscopy should be performed before any surgical exploration. At celiotomy, identifying the bleeding point is often impossible, as blood refluxes into the proximal and distal bowel.

The abdominal cavity is explored through a midline vertical incision. The assistance of a gastroenterologist is required for intraoperative endoscopic evaluation. The colonoscope is introduced, and the surgeon assists its passage. On-table colonic lavage and colonoscopy may identify the colonic source of bleeding. Surgeon-guided intraoperative small bowel enteroscopy is also performed when no colonic source of bleeding is identified. Again, the colonoscope can be used for this procedure.

Unlike colonoscopy, enteroscopy is performed during the advancement of the scope. Colonoscopic manipulation of the small bowel may cause iatrogenic mucosal tears and hematomas, which may be mistakenly identified as a source of bleeding. Another intraoperative strategy is to clamp segments of the bowel with noncrushing intestinal clamps to identify the segment that fills with blood. If the bleeding point cannot be diagnosed through intraoperative pan-intestinal endoscopy and examination, and if evidence points to a colonic bleeding, perform a subtotal colectomy with end ileostomy.

Hypotension and shock are the eventual consequences of blood loss, but this depends on the rate of bleeding and the patient's response. Clinical development of shock may precipitate myocardial infarction, cerebrovascular accident, and renal or hepatic failure. Azotemia occurs in patients with gastrointestinal blood loss.

Patients who have had surgery of the lower gastrointestinal (GI) tract are prone to the development of complications. The most common early postoperative complications are intra-abdominal or anastomotic bleeding, ileus, mechanical small bowel obstruction (SBO), intra-abdominal sepsis, localized or generalized peritonitis, wound infection and/or dehiscence, Clostridium difficile colitis, pneumonia, urinary retention, urinary tract infection (UTI), deep venous thrombosis (DVT), and pulmonary embolus (PE).

Intra-abdominal sepsis following colorectal surgery is a life-threatening complication and requires aggressive resuscitation. Systemic conditions (eg, severe blood loss and shock, poor bowel preparation, irradiation, diabetes, malnutrition, hypoalbuminemia) may adversely affect anastomotic healing. Changes in anatomy and physiology of the large bowel, high bacterial content, improper operative technique, tension, and ischemia can cause anastomotic leak associated with abscess and intra-abdominal sepsis. This condition requires either laparotomy (if the sepsis is generalized) or percutaneous drainage (if the sepsis is localized).

Delayed complications usually occur more than 1 week after surgery, the most common of which are anastomotic stricture, incisional hernia, and incontinence.

Patients who are hemodynamically unstable with active bleeding should be admitted to the medical intensive care unit (MICU). Early consultation with both a gastroenterologist and a surgeon is recommended.

Postoperative office visits every 2 weeks are essential to ensure proper wound healing. Upon discharge, a general diet abundant in fruits and vegetables is recommended. Patients are instructed to drink 6-8 glasses of fluid per day. Psyllium seed preparations should also be started. The AAFP recommends 32 g of fiber supplementation per day.^[16]

Increased levels of physical activity may prevent the progression of diverticular disease, according to the AAFP 2009 recommendations. The AAFP also notes that aspirin and NSAID use is associated with increased risk of diverticular bleeding.^[16]

The need for a follow-up colonoscopy is determined by a recurrence of symptoms. Angiodysplasia is more likely to rebleed if untreated and may require follow-up intervention to localize and treat recurrent bleeding. Colonoscopic electrocoagulation is generally successful in such situations.