Metastases involving the gastrointestinal system

S e m i n a r s in Oncology Nursing, Vol 14, No 3 (August), 1998: pp 187-198

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OBJECTI'~S: To lrrovide a review of metastatses involving the gastrointestinal system, inchtding the specqfic problems of liver metastasis, bowel obstruction, ascites, bilia~ obstruction, and gastrointestinal

fistulas. DATA SOURCES: Research studies, review articles, and book chapters.

METASTASES INVOLVING THE

GAST RO INT E ST INAL SYSTEM

C ONCI.,USIONS: When metastasis involves the gastrointestinal tract, the emotional distress is coupled with debilitatitrg s~ymptoms and marked nutritional deficits. Treatment decisions must consider potential benefits and risks and affect on quality of life.

IMPLICATIONS FOR NqJRSING PRACTICE: An understanding of the disease process and alternative treatmerit interventions will assist nurses to effectively anticipate and manage symptoms that may develop and educate patients and families so they can participate in decisions regarding their treaonent.

From the Saint ViBeents Conlprchensive Cancer Center, New York. AT; atwl Ambtdatory. C~,re-Mextk.al Oneology, Menu~r'icd SloanKettering Cancer Center, New York, b 3: Joanne Frankel Kelvin, RN. MSN, AOCN: Directm- qt'Clinical Ser'tqces, Saint Vincents Comprehensive Cancer Center, New York, NY: Joan Scagliola, RN, MSN, AOCN: Manager, CtinicmlNus~e Spetqcdist, Ambtdattny Care-Medic~d Otwology. blemot~ SloanKettering (Jancer Center, New York, ,~,q'. Address reprint requests to Joanne Frankel Kelvin, RN, MSN, AOCN, 420 East 72nd St, Apt 11G, New York, NY 10021.

C~o*r~hz ©1998 b3, IEB. 8oamtk-'rs CompayD, 0749-2081/98/1403-000458. OfffO

JOANNE FRANKEL KELVIN AND JOAN S C A G L I O L A

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HE DEVELOPMENT of metastases involving the gastrointestinal (GI) system is the result of multiple complex pathologic events. Neovascularization within a proliferating primary tumor enables delivery of adequate oxygen and nutrients to support further proliferation. As the tumor grows, neoplastic cells invade adjacent tissues and compress surrounding structures. Clumps of cells eventually break away from the primary tumor mass and metastasize to distant sites. Some may be released from the outer edge of the tumor into the peritoneal cavity, implanting and proliferating on the surfaces of various organs. Some neoplastic cells may disseminate through the lymphatic system to regional or distant lymph nodes. Some neoplastic cells disseminate through the vascular system, arrest in the capillary beds of distant organs, invade interstitial tissues, and proliferate within these organs. Neovascularization supports further proliferation and growth of the secondary tumor, which subsequently may replace the organ parenchyma with malignant eells. 1,2 The development of metastatie disease is devastating for patients and families, and is associated with little chance of cure. When metastasis involves the GI system, the emotional distress is coupled with debilitating symptoms and marked nutritional deficits. Treatment decisions must consider potential benefits and risks as these patients are not necessarily in the end stages of disease and may in fact have a high performance status. Even if the treatment cannot prolong life, aggressive therapy may be warranted if treatment can maintain or improve quality of life and offer symptom relief with little risk of harm to the patient. Oneology nurses must be knowledgeable about the pathology, etiology, clinical presentation, diagnosis, and treatment of metastases

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involving the GI tract to effectively care for patients dealing with these significant problems. LIVER METASTASIS

Pathology and Etiology The liver parenchyma receives approximately 20% of its blood supply from the hepatic artery and 80% from the portal vein. Cancers from the gastrointestinal tract spread via the portal circulation. Cancers from other sites spread to the liver via the hepatic artery, by local invasion, or as a result of peritoneal seeding. As the tumor cells proliferate within the liver, they invade the parenchyma, potentially compromising liver function, and can compress the hepatic ducts, potentially obstructing the biliary system. Liver metastasis is most commonly seen with cancers of the colon and rectum. Other diseases that are likely to metastasize to the liver include cancers of the stomach, pancreas, breast, lung, ovary, endometrium, and uterus, as well as melanoma, lymphoma, multiple myeloma, and cancers of unknown primary. 3 In colorectal cancer, the liver is often the only site of metastatic disease; these patients have the best prognosis. With other cancers, widespread metastasis is commonly present at the time disease in the liver is diagnosed; these patients have a poor prognosis, with a limited survival time.

Clinical Presentation and Diagnosis In some patients, liver metastasis may first be detected by changes in routine follow-up laboratory and radiologic studies. Patients may present with general systemic symptoms and/or pain. Early symptoms include early satiety associated with abdominal fullness, change in the color of urine, and change in the color and consistency of stool. Because of the role of the liver in the metabolism of nutrients, production of bile, and synthesis of substances necessary for coagulation, there may be manifestations of altered liver function. Late symptoms include anorexia and weight loss, fatigue, fever, and sometimes jaundice. Hepatomegaly and ascites also may be seen. With progression of disease, lethargy, encephalopathy, and coma can develop. 4,5 Although liver function tests may be elevated, and patients with eolorectal cancer may have an increase in earcinoembryonie antigen, laboratory tests are not as sensitive as radiologie images in detecting the presence of metastatic spread to the liver.

Treatment The goals of treatment in patients with liver metastasis are to control the primary tumor, inerease survival, and palliate symptoms. Depending on the patient's clinical status, surgery, chemotherapy, and radiation therapy all play a role. Surgical reseetion of the hepatic lesion(s) is the only curative treatment, and may be an option if the liver is the only site of metastatic disease, primarily in eoloreetal cancer. Complete resection when there are one to three lesions is associated with an increase in the 5-year survival rate by at least 25%.6 The benefit of resetting when there are more than three lesions is controversial. Postoperative complications of hepatic resection include hemorrhage, biliary fistula, subphrenie abscess, infection, pneumonia, transient metabolie eomplieations, portal hypertension, and dotting defects. 7 Improvements in surgical techniques have reduced intraoperative blood loss and postoperative complications. Unfortunately, only a small number of patients with liver metastasis are candidates for resection. Cryosurgery is an alternative surgieal approach for patients who are not eligible for hepatic resection because of bilobar involvement, the presenee of multiple tumors, or proximity to major vessels. It involves the destruction of tissue through freezing. At the time of laparotomy, intraoperative ultrasound is used to loeate lesions. Cryoprobes are inserted into the tumor and the freezing process is initiated. The process is monitored with ultrasound to assure adequate tumor destruetion with minimal damage to the surrounding healthy tissue. The lesions are left in plaee, become necrotic, and are ultimately reabsorbed by the body. Technical complications from eryosurgery include hemorrhage from cracking of the liver as it thaws following treatment, hemorrhage from the cryoprobe tract, and bile duet injury or fistula. Additional complications include transient leukoeytosis, eoagulopathy, and elevations in liver enzymes; myoglobinuria-induced acute tubular neerosis seeondary to release of a myoglobin-like substance from destroyed tumor cells; subphrenic abscess; pleural effusion; hyperkalemia; hyperurieemia; and fever, s,9 Chemotherapy is widely used in patients with metastatic disease because most patients with liver metastasis are not surgieal candidates. Speeifie drug regimens and corresponding response rates vary widely based on the primary site of

METASTASES

disease, but the results generally have been disappointing, s° Regional chemotherapy via hepatic artery infusion is an alternative approach for some patients. Although the liver parenehyma reeeives most of its blood supply from the portal vein, metastatic lesions are supplied almost exclusively by the hepatic artery. Thus, chemotherapeutic agents administered through the hepatic artery will effectively perfuse the tumor cells without exposing the hepatic parenehyma to significant amounts of drug. In addition, when using drugs with a short half-life that are extracted by the liver on the first pass, systemic circulation of the drug is minimal. Thus, hepatic artery infusion enables the delivery of high concentrations of drug to the tumor eells, with minimal systemic exposure and toxicity.7,1°-12 Most studies have used 5-fluorouraeil and fluorodeoxyuridine, although mitomyein, eisplatin, and doxorubiein also have been evaluated. Hepatic artery infusion has been studied in patients with unreseetable liver disease without extrahepatie metastasis, as adjuvant therapy after resection of hepatic metastases, and in combination with systemic chemotherapy. General response rates to systemic treatments are 25% to 50% partial responses in either measurable disease or eareinoembryonie antigen levels. The overall life expeetaney has not shown improvement. With regard to hepatic artery infusion with fluorodeoxyuridine, responses are again in the 50% range by either tumor response or eareinoembryonie antigen levels. Survival has not shown improvement, nor has there been a decrease in metastasis to other organs with hepatic artery infusion. 6 New studies are planning to categorize patients by biological markers that identify enzymes. It is hoped that the enzymes will be able to identify tumors that will metastasize predominantly to the liver only and those that will metastasize more widespread to the other organs. Access to the hepatic artery is most commonly obtained surgically. Catheter placement should be completed as an operative procedure by a surgeon skilled in the teehnique to avoid catheter dislodgment. Dislodgment is a complication rarely seen if placement is done surgically, and the newer catheters are considered self-loeMng catheters with prongs that do not allow dislodgment to oeeur. Another safety precaution is to perform a nuclear dye study before administering ehemotherapy to cheek for proper plaeement. The tip of the

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catheter is ptaeed into the proper hepatic artery, distal to the gastroduodenal artery. Blood vessels that supply the stomach, pancreas, and bile duet are ligated to prevent perfusion of these organs with chemotherapy. A eholeeysteetomy is often performed to prevent chemical eholeeystitis.6 The distal end of the catheter is attached to a port, which can be accessed and eonneeted to an external pump, or to a totally implantable infusion pump. The implantable pump is placed in a surgically created subcutaneous poeket, usually in the lower abdomen. The main chamber or reservoir of the pump is reflled by pereutaneous puncture and assures sustained release of drug. Between cycles of chemotherapy, the pump is filled with a glycerol solution or a heparinized saline solution to maintain pateney. Flow rates can be adjusted as needed; for example, to accommodate changes in altitude if the patient will be flying. Some implantable pumps have a side port allowing for bolus injection of drug as well as continuous infusion. Complications of hepatic artery infusion are related to catheter placement, pump placement, or chemotherapy toxicity. Complications related to catheter placement include thrombosis, arterial spasm, bleeding, sepsis, and stroke. 1° Complications of pump placement include pump pocket hematomas, seromas, and infections. 6,1°q2 Toxieities of treatment include hepatic toxicity, biliary sclerosis, gastritis, and uleer disease. Liver function tests must be monitored regularly to detect early signs of toxicity requiring discontinuation of treatment. Administration of dexamethasone may prevent and/or reverse biliary selerosis. 6 Myelosuppression, nausea, vomiting, and diarrhea, significant toxieities of systemic chemotherapy, generally are not seen with hepatic artery infusion. Severe gastric symptoms may indicate dislocation of the catheter, resulting in perfusion of the stomaeh with chemotherapy through the gastrie artery. This can be diagnosed with radiologie flow studies. Hepatic artery embolization is a treatment option in highly vascular tumors, such as primary neuroendoerine tumors. Particles are injected through the hepatie artery to occlude the mierovaseulature, reducing the tumor's blood supply with minimal effect to the hepatic parenehyma. Chemoembolization is a modification of this treatment in which a eytotoxie agent is entrapped within the embolization particle. In addition to the isehemie

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effect of the embolization, this provides a prolonged local exposure of the tumor to the cytotoxic agent. 12,13 Because of the localized nature of the treatment, there is minimal systemic circulation and toxicity. Treatment can be repeated at defined intervals. The most common adverse effects of this treatment are nausea, vomiting, fever, pain, and changes in liver function tests. Other complications include injury to the bowel, pancreas, and lungs due to embolization of vessels that supply these organs, as well as eholecystitis and tumor lysis syndrome. 6 Radiation therapy administered to the whole liver has demonstrated limited effectiveness because of the need to keep cumulative doses at or below 35 Gy to avoid hepatic toxicity. Although low doses can be effective in the palliation of pain, the duration of response is short. 4 Efforts to increase the dose to the tumor without increasing the dose to the surrounding normal hepatic tissue include interstitial braehytherapy and threedimensional conformal radiation therapy. Interstitial brachytherapy involves the placement of radioactive sources inside the tumor, either permanently, using low dose-rate isotopes such as iodine 125, or at the time of surgery, using high dose-rate isotopes such as iridium 192. External beam treatment with three-dimensional conformal radiation therapy uses sophisticated computer imaging to direct the radiation beams more precisely to the target area. MALIGNANT BOWEL OBSTRUCTION Pathology and Etiology Obstruction of the bowel causes the cessation of the normal movement of intestinal contents through the GI tract. Although a number of benign problems can cause bowel obstruction in the patient with cancer (eg, abdominal or pelvic adhesions, inflammatory lesions, fecal impaetion), the most frequent causes of malignant bowel obstruction are • Extrinsic occlusion of the lumen: from spread of tumor to adjacent structures (eg, pancreatic or gastric tumor to duodenum., prostate tumor to rectum) or from mesenteric or omental masses • Intrinsic occlusion of the lumen: from a polypoid lesion or from annular tumor dissemination • Intestinal motility disorders (ie, pseudo-obstruction, signs and symptoms of bowel obstruction without a mechanical block): from infiltration of mesentery or bowel muscle and nerves, malignant involvement of

the celiac plexus, or paraneoplastic neuropathy in patients with lung cancer. 14-16 Obstruction of the bowel leads to a number of physiologic changes. There is decreased absorption and increased secretion with subsequent accumulation of fluids and electrolytes within the bowel lumen proximal to the site of obstruction. Increased gas from swallowed air also accumulates, and together these can lead to significant abdominal distention. This in turn impairs diaphragmatic movement, compromising respirations. Stasis within the bowel leads to overgrowth of bowel flora. If blood flow is impaired (ie, strangulated obstruction), ischemia may progress to infarction, necrosis, and perforation. Intestinal contents can pass into the peritoneum and the mesenteric circulation, leading to peritonitis and sepsis. 16,17 Three percent of all terminally ill patients will develop bowel obstruction, is Cancers most commonly leading to bowel obstruction are ovarian, coloreetal, gastric, and pancreatic cancers. Cancers of the cervix, uterus, bladder, and breast, as well as lymphoma, melanoma, soft tissue sarcoma, and Kaposi's sarcoma, are also associated with bowel obstruction, is,is,19 Clinical Presentation and Diagnosis The clinical presentation depends on the location of the obstruction and whether it is partial or complete. Onset may be acute, but is more commonly insidious, over weeks or months. Symptoms may be intermittent or may gradually worsen and become continuous. 14Abdominal pain is colicky in nature. Obstruction in the stomach or upper small bowel presents most acutely, with vomiting, severe dehydration, and minimal or absent abdominal distention. If the obstruction is at the gastric outlet, the loss of HC1 and KC1 may lead to metabolic alkalosis, hypokalemia, and hypoehloremia. If the obstruction is at the distal duodenum, the loss of biliary and pancreatic secretions may lead to metabolic acidosis. Obstruction in the lower small bowel presents less acutely, with moderate vomiting and dehydration, some abdominal distention, and lack of feces or flatus. Patients will commonly have severe electrolyte imbalances. Obstruction in the large bowel presents insidiously. Patients will have pronounced abdominal distention and lack of feces or flatus, although overflow diarrhea may occur. Vomiting is a late sign. In patients with earcinomatosis, there may be multiple sites of obstruction. If strangulation

METASTASES

with isehemia is present, fever, rebound tenderness, and leukocytosis may be seen. However, absence of these signs does not rule out strangnla-

tion.lS-17,19 Diagnosis is made based on presenting signs and symptoms and radiologic studies. Flat and upright films of the abdomen may reveal dilated loops of bowel, increased gas and fluid accumulation, and multiple air-fluid levels. Contrast studies, computed tomography, and endoscopy may be indicated.16,17 Treatment

Guidelines for medical versus surgical management are conflicting. Medical management is generally the initial approach taken in the patient with bowel obstruction. Bowel rest without oral intake may be attempted for 24 to 48 hours before initiating nasogastic suctioning to decompress the bowel and relieve abdominal distention. Longterm indwelling intestinal tubes are rarely used. Correction of fluid, electrolyte, and acid-base imbalances is guided by measurement of serum electrolytes, pH, and arterial blood gasses. Analgesics, antiemetics, and anticholinergics are prescribed to manage pain, nausea, and vomiting. The length of time recommended to maintain a trial of medical management is controversial and varies from 24 hours to 14 days. 16,2° If there is no significant clinical improvement, surgery is considered. Decisions regarding who should have surgery and what type of surgery is indicated are difficult for the clinician. Quality of life issues in patients with poor long-term survival must be considered. Potential complications following surgery are significant and include wound infection, dehiscence, fistula, further obstruction, abscess, sepsis, deep vein thrombosis, and pulmonary embolus. 15 In addition, nearly one third of patients with malignant bowel obstruction will develop a subsequent bowel obstruction from their disease following resolution of the first obstructive event. 21 On the other hand, the mortality rate with isehemic bowel is 30%. 16 Patients with perforation, peritonitis, and strangulation require surgery. 19 Prognostic factors that indicate a potential benefit from surgery include good performance status, good nutritional status, a single site of obstruction, and limited tumor spread, is Resection of the source of obstruction with reanastamosis is not often possible with metastatic disease. Surgery usually is limited to a bypass procedure. If the obstruction is in the colon, a proximal diverting colostomy or

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ileostomy is performed. In a small number of patients, endoscopic laser treatment or stent placement may be effective in relieving obstruction, is Because most patients with malignant bowel obstruction are not candidates for surgery, longterm medical management is the approach often used. Gastric drainage is obtained with a gastrostomy tube placed endoscopically or percutaneously through the abdominal wall. This is much more comfortable for patients than long-term nasogastric suctioning. The tube is clamped intermittently, and many patients can maintain adequate hydration with small low-residue fluid meals. Intravenous fluids may be indicated to prevent agitation and renal failure from dehydration. Administration of fluids through hypoderrnoclysis is also effective. The use of total parenteral nutrition is controversial. It may be appropriate in selected patients who are expected to survive for prolonged periods of time at home. is MALIGNANT ASCITES

Pathology and Etiology Malignant ascites is the abnormal accumulation of serous fluid in the peritoneal cavity. It occurs when the amount of peritoneal fluid produced exceeds the ability of the body to drain the cavity. This may result from increased production of fluid, as seen in extensive peritoneal tumor seeding with exudation from the tumor surfaces, or it may result from impaired peritoneal and lymphatic absorption of fluid and protein, as seen with tumor obstruction of the thoracic duct or other lymphatic channels. Ascites also may be seen with liver metastasis due to obstruction of the hepatic venous system as well as decreased albumin.22, 23 Malignant aseites occurs most frequently from cancer of the ovary and may be seen at the time of initial diagnosis. These patients have the best prognosis and generally receive aggressive curative therapy. In other cancers, ascites generally is a sign of advanced disease, with survival limited only to several months. These include cancers of the endometrium, cervix, colon, rectum, stomach, pancreas, breast, lung, testes, and prostate, as well as lymphoma, mesothelioma, and cancers of unknown primary.22, a3

Clinical Presentation and Diagnosis Symptoms develop once fluid accumulation in the abdomen exceeds 500 mL. Patients commonly complain that clothes do not fit due to increasing

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abdominal girth. Pressure on the GI tract results in symptoms of anorexia, indigestion, nausea, vomiting, and constipation. Increased abdominal pressure leads to elevation of the diaphragm and decreased intrathoraeic space, resulting in symptoms of dyspnea, orthopnea, and fatigue. Pressure on the abdominal organs causes generalized abdominal pain. Patients will have abdominal distention and bulging of the flanks. Skin will be tightly stretched and shiny in appearance, and the umbilicus may be everted. 22-24 Diagnosis is made with abdominal paraeentesis. Fluid is sent for gross inspection, cytology, chemistry, cell count, and microbiology. Malignant aeites is most commonly bloody or serosanguinous. Chylous ascites, a milky fluid, can be seen with obstruction of the lymphatics, as in abdominal lymphoma2 5 Treatment

In selected patients with a good prognosis, aggressive therapy is initiated. Surgical debulking of tumor (ie, cytoreduetion) is performed in preparation for intraperitoneal chemotherapy. This is a radical procedure, associated with significant risks, including hemodynamie instability from fluid shifts, pneumonia, infection, and prolonged ileus2 6 For most patients, aseites is a sign of advanced disease, associated with the failure of curative attempts to control the disease. The goal of treatment is palliation. Abdominal paraeentesis is used in patients in whom large amounts of fluid have accumulated, resulting in significant symptoms. Relief is immediate and dramatic. Unfortunately, because the underlying cause is not eliminated, fluid will reaccumulate, and relief is only for a short duration of time. Repeated paracentesis is often required. To facilitate repeated drainage of fluid while minimizing the risk of infection and injury to the intraperitoneal viscera from repeated paracentesis, permanent catheters are often implanted. Large volumes of fluid can be removed at one time, but removal of more than 2 L can result in depletion of protein, electrolyte imbalance, and hypotension. 27 Intracavitary therapy is another approach taken in the treatment of aseites. Temporary or implanted catheters may be used to instill antineoplastic agents into the peritoneal cavity. Radioactive isotopes have been administered, particularly colloidal suspensions of radioactive phosphorus. More commonly, chemotherapeutic agents are used. Because of the limited peritoneal absorption,

drugs can be administered intraperitoneally in high doses with few systemic effects. Chemotherapeutic agents used include 5-fluorouracil, mitomytin, cisplatin, doxorubiein, and mitoxantrone. The response is greater in patients with less disease, so intraperitoneal chemotherapy is frequently administered after debulking surgery. Biologic response modifiers, such as ~- and [~-interferon, also have been administered intraperitoneally. 25 Peritoneovenous shunting is used in some patients to relieve symptoms of aseites. Fluid is continously drained from the peritoneal cavity and channelled into the venous circulation. The shunt consists of a length of tubing; one end is placed in the peritoneal eavity; the other is tunnelled subcutaneously and inserted into the superior vena eava. A one-way valve in the tubing opens with each inhalation as the intraperitoneal pressure inereases and the intrathoracic pressure decreases, allowing the fluid to flow upward into the superior vena cava. 27 Complications include shunt malfunctions such as kinking or occlusion, pulmonary edema from rapid intravaseular infusion of large quantities of fluid, disseminated intravascular coagulation, infection, and pulmonary embolus. 22,23 BILIARY OBSTRUCTION

Pathology and Etiology Biliary obstruction from metastatic disease most commonly results from extrinsic compression of the biliary tree by tumor. Increased amounts of biliary substances build up in the blood and may accumulate in the tissues, resulting in jaundice. Obstruction can occur at any point along the biliary tree. Proximal obstruction (ie, hepatic and cystic ducts) results from direct extension of tumor from the liver or gall bladder. Distal obstruction (ie, common bile duct) may result from direct extension of tumor from the pancreas, ampulla, duodenum, stomach, or colon, or from lymphadenopathy secondary to lymphoma or breast can0er.18,27,28

Clinical Presentation and Diagnosis Onset of biliary obstruction may be acute or gradual. Patients may present with jaundice of skin, selera, and mucous membranes; dark urine; pale stools; pruritus; and pain. An abdominal mass may be palpable. Fever and chills may indicate the presence of aseending cholangitis. 27,2s Abdominal ultrasound is used to image the biliary tree; dilated duets may help to localize the

METASTASES

site of obstruction. Abdominal computed tomography may provide information regarding the extent of tumor. Endoscopic retrograde cholangiopancreatography, enabling direct visualization of the biliary tree, or pereutaneous transhepatie eholangiography also may be performed. Bilirubin and alkaline phosphatase levels may be elevated, ls,2s

Treatment Curative resection is not an option for most patients with biliary obstruction secondary to metastatic disease. The goal of treatment for these patients is symptom management by palliation of jaundice, pruritus, and pain and prevention of ascending eholangitis.18 There is debate in the literature about the optimal approach to decompress the biliary tract: surgical bypass versus nonsurgical stenting. Surgical bypass with choledoehojejunostomy or choleeystojejunostomy may be more appropriate in patients with a life expectancy of longer than 6 months. 2s Placement of stents to relieve obstruction is an alternative approach. Internal stents are preferred to external T-tubes and drainage bags that can leak, irritate the skin, and are difficult for the patient to manage. Stents can be placed pereutaneously or endoseopieally. Complications of pereutaneously placed stents include biliary leakage, sepsis, and hemorrhage; complications of endoscopieally placed stents include eholangitis and sepsis, is Regardless of the method of placement, stents may become clogged with time, resulting in a return of obstructive signs and symptoms. The newer self-expandable metal stents are easier to place and are associated with longer patency, less discomfort, and decreased complications compared with silastie stents. 18 Following relief of the obstruction, chemotherapy or radiation therapy may be used if the underlying cause of obstruction is amenable to treatment. In patients with ascending eholangitis, treatment with antibiotics is also initiatedS GASTROINTESTINAL FISTULAS

Pathology and Etiology Gastrointestinal fistulas are abnormal communications between the lumen of the GI tract and the skin or another organ (eg, bladder, vagina, another portion of the GI tract). They are classified by their sites of origin and termination (eg, enteroeutaneous, enterovesieal, colovaginal). Fistulas are also classified by the amount of drainage as either high output (>500 mL/d) or low output (<500 mL/d). 29

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Fistulas ean develop as a consequence of tumor adherence to any portion of the GI tract with subsequent necrosis and break in the integrity of the bowel wall. Leakage of intestinal eontents leads to the development of an abscess and/or tracts to the skin or other organs. 29

Clinical Presentation and Diagnosis There are a number of signs and symptoms that may be seen in the patient with a fistula. Local manifestations depend on where the fistula terminates. Cutaneous fistulas will present initially with progressive abdominal tenderness followed by drainage of intestinal contents through the skin. If the fistula ends in the vagina, there may be fecal drainage from the vagina. If the fistula ends in the bladder, the patient may present with recurrent episodes of cystitis and hematuria. Fistulas are often associated with infection, related to the abscess that may precede the fistula or from leakage of intestinal contents into the peritoneal cavity. The patient may present with fever, malaise, anorexia, abdominal pain, or sepsis. Fluid and electrolyte imbalances are seen in patients with high-output fistulas. Nutritional deficits develop if the fistula results in the bypass of intestinal contents away from most of the absorbing intestine. 3° Diagnostic tests are used to determine the origin and structure of the fistula and to detect the presence of an associated abscess. Cutaneous fistulas are diagnosed by a fistulogram, in which contrast material is injected down the fistula tract to visualize it. Fistulas that terminate in other locations are more difficult to diagnose. Cystoscopy is used to detect enterovesicle fistulas; upper and lower GI contrast studies are used to locate fistulas that run from one part of the GI tract to another. Ultrasound and CT also may be used in the diagnosis of fistulas. 29,3° Treatment Care of the patient with a fistula is complex and includes management of the fistula with treatment of associated infection, protection of the skin from drainage, correction of fluid and electrolyte imbalances, and maintenance of nutrition. Pereutaneous drainage of the fistula and associated abscess eavities is achieved with drainage catheters. Suction may be applied. Adequate drainage is essential for the formation of granulation tissue to fill up the spaces and close the fistula. 3° Fistula closure is enhanced if fistula output is minimized. Somatostatin has demonstrated effeetiveness in decreasing the volume of

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intestinal secretions and fistula output, possibly promoting spontaneous fistula closure. 29 Measures to protect the skin from damage by eaustic proteolytie enzymes and bile aeids, as well as from maceration from moist dressings, are essential. Ointments and skin sealants provide only limited proteetion. Solid skin barriers should be used whenever possible, but they may be difficult to apply if the fistula is near a surgical wound or in a deep skin fold. If the output is minimal (<100 mL/24 hr), absorbent dressings are adequate to contain the drainage. Chareoal impregnated dressings may be used to filter odor if that is a problem. Tape should be avoided if frequent dressing changes are required; Montgomery straps, rolled gauze, or stockinette may be used. With greater output; pouehing is the preferred method of containing the drainage. The poueh will eontain the odor as well. These aggressive measures to protect the skin and eontain the drainage are essential to optimize patient comfort. 31 Correction of fluid, electrolyte, and aeid-base imbalances is of partieular eoneern with highoutput fistulas, in whieh patients may lose as much as 3 L of fluid a day through their fistula. Direet measurement of the eleetrolyte eomposition of the fistula fluid may be necessary to assure effective replacement of losses .29 The optimal route for nutritional support in the patient with a fistula is not fully established. Calorie needs are high, and the use of total parenterm nutrition ean assure adequate intake of nutrients while putting the bowel at rest to deerease fistula output. However, in most patients, the benefits are probably outweighed by the intestinal atrophy that develops in the absence of enteral feedings as well as the numerous risks associated with total parental nutrition. Enteral feedings are generally maintained in most patients. 29 Spontaneous fistula elosure in the patient with underlying malignaney is diffieult to obtain. If there is no response to conservative therapy after 4 to 6 weeks, surgical reseetion of the involved bowel and fistula, with drainage of the associated abscess, may be considered. SYMPTOM MANAGEMENT Ymptoms of metastasis involving the GI traet include abdominal pain, abdominal distention, nausea and vomiting, pruritus, bleeding, and nutritional deficits (Table 1).

S

Abdominal pain should be thoroughly assessed with regard to loeation, quality, severity, temporal pattern (eg, onset, duration, continuous or intermittent), exaeerbating and relieving faetors, interferenee with activities of daily living, assoeiated psyehologieal distress, and effectiveness of previous and eurrent analgesic regimens. Pain from aseites is usually diffuse; however, pain from liver metastasis, a result of hepatie eapsular distention or bleeding within the liver, is generally loealized to the right upper quadrant, possibly radiating to the back. Whereas the pain assoeiated with liver metastasis and ascites is generally continuous, the pain seen with bowel obstruction and biliary obstruetion is generally intermittent and eolieky. Continuous pain is best treated with opioids. Constipation assoeiated with opioids ean be managed with the regular use of stool softeners, laxatives, and inereased fluids. Patients with intestinal eolie may have increasing pain with stimulant laxatives and gastrokinetie antiemeties (eg, eisapride, metoelopramide). Antispasmodics (eg, loperamide, hyoseine) may be more effective for relief of colicky pain than morphine. ~4,1s,ls Selecting the optimal medieations to treat pain is rarely easy. Use of the oral route of administration often is not possible. Dermal patches (eg, fentanyl) or continuous infusions through subeutaneous or intravenous routes may be most effeetive. Many of the medieations used to treat pain will eause dry mouth; however, this can be relieved by sueking on lee or taking small sips of water. Abdominal distention from bowel obstruetion or ascites will exacerbate the patient's pain. Bed rest, with elevation of the head of the bed, may be the most comfortable position for patients with severe abdominal distention. Maintaining elevation of the head will also reduce pressure on the diaphragm and promote optimal thoraeie expansion, redueing respiratory distress. In the patient with ascites, use of diuretics may help the body eliminate fluid and provide additional relief. ~2 Nausea and vomiting may be a significant problem in bowel obstruetion and also may be seen with aseites. Medications that increase gastric emptying and GI motility (eg, metoelopramide, cisapride) may be effective with partial obstruetion; however, they may increase symptoms in patients with complete bowel obstruction. Other medications that may be more effective in relieving nausea and vomiting related to obstruction inelude haloperidol, dexamethasone, oetreotride,

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TABLE 1. Nursing Implications Associated With Metastasis to the Gastrointestinal System Clinical Manifestation

Abdominal pain

Potential Etiology Liver metastasis Intrahepatic hemorrhage Ascites Constipation Bowel obstruction Dislodged hepatic arterial catheter

Chemical cholecystitis (associated with hepatic arterial perfusion) Flatus Abdominal distention

Ascites Bowel obstruction Constipation

Nausea and vom- Bowel obstruction iting Ascites Constipation

Pruritus

Nursing Assessments

Nursing Interventions

Pain assessment (ie, location, duration, characteristics, intensity, etc) Bowel function Analgesic use Fluid and electrolyte balance (ie, appropriate laboratory studies, skin turgor, etc) Abdominal girth Diet and eating patterns

Facilitate diagnostic workup Assure fluid and electrolyte balance Promote comfort Institute bowel program Institute pharmacologic interventions as needed (ie, antiemetios, analgesics, anticholinergics, or antispasmodics) Gastric drainage via gastrostomy tube as indicated

Monitor bowel sounds Assess for anorexia, indigestion, nausea, vomiting, and constipation Assess for dyspnea, orthopnea, fatigue Assess for abdominal pain Measure, monitor, and document abdominal girth

Facilitate diagnostic workup Prepare patient for intraperitoneal or intracavitary therapy as indicated Prepare for abdominal paracentesis as indicated Prepare for peritoneovenous shunt as indicated Insert and manage nasogastrio intubation for decompression or gastdc drainage as indicated Promote adequate nutdtional intake Manage gastrostomy tube dudng palliative care phase as needed Promote comfort associated with pain, nausea, and vomiting Institute bowel program as needed Administration and monitoring of prescribed medications such as diuretics Elevate head of bed to relieve diaphragmatic pressure

Monitor fluid and electrolytes Facilitate diagnostic workup Color and consistency of emesis Insure adequate hydration Bowel sounds Promote adequate nutrition Bowel patterns Administer medications that increase GI emptying and motility Administer antiemetics Promote optimal defecation Dry skin Location, onset, duration, and Patient and caregiver education to Elevated bilirubin intensity minimize or eliminate provocative Altered liver function Previous history of pruritus factors Drug sensitivities Previous and current history of Apply topical preparations of emollient Drug side effects cancer creams or lotions Cutaneous reactions to Concurrent health conditions Bathe with mild soap, soaps made for chemotherapy and biologic Presence of infection sensitive skin response modifiers Environmental factors (tempera- Use topical mild corticosteroids (unless Associated with some primary ture and humidity) pruritus is secondary to radiation) cancers Physical factors (tight, constric- Add colloidal oatmeal treatment early Dry desquamation associated tive clothing) to the bath with radiation therapy Evidence of scratching Maintain a humid environment Infection Skin turgot, texture, thickness, Use cotton flannel blankets as needed color, temperature, and presWash sheets, clothing in mild soaps ence of lesions Limit bathing to 30 rain daily or every Presence of rash or erythema other day

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TABLE 1. (Continued) Clinical Manifestation

Potential Etiology

Nursing Assessments

Nursing Interventions

Current prescribed and over-thecounter medications Nutritional and fluid status Current skin care practices Relevant laboratory values (ie, complete blood cell count, chemistry) Factors that relieve and aggravate itching Emotional status

Bleeding

Liver metastasis Decreased synthesis of clotting factors

Add oil at the end of a bath Recommend loose-fitting cotton clothing Recommend and allow adequate rest periods Administer antihistamines as prescribed, with increased doses at bedtime Teach and use nonpharmacologic approaches, such as distraction, relaxation, imagery, or cutaneous stimulation Assess skin for petechiac, Avoid trauma ecchymosis and purpura Avoid invasive procedures Assess GI tract for hematemesis, Apply pressure to site after blood rectal bleeding, guiac positive drawing or injections Avoid use of aspirin products, nonstestools Assess genitourinary tract for roidal anti-inflammatory drugs and hematuria, vaginal bleeding corticosteroids Assess respiratory system for Inject vitamin K as prescribed hemoptysis Infuse fresh-frozen plasma or red Assess central nervous system blood cells as prescribed for mental status changes

Nutritional deficits Liver metastasis Assess for signs and symptoms of anorexia/cachexia GI metastasis Psychosocial abnormalities Assess for signs and symptoms of dysphagia Metabolic abnormalities Effects of tumor (ie, release of Assess for signs and symptoms cytokines from tumor) of xerostom ia Nutritional status and intake Laboratory studies (albumin, transferrin, prealbumin, urinary creatinine, nitrogen balance, total lymphocyte count, anergy panel

Instruct and assist patient to keep an accurate calorie diary Nutritional support (oral or enteral) Evaluate potential use of appetite stimulation with megestrol acetate, mild physical exercise, relaxation exercises Minimize effects of nausea, vomiting, diarrhea, pain, fatigue, taste changes Incorporate high-protein foods to the extent possible in the diet Alter food seasonings

Assess for RUQ pain, discomfort, dyspepsia Assess color of urine and stool Assess for weight loss, malaise, nausea, vomiting, taste changes, anorexia Assess for pain, fever, chills Assess for signs and symptoms of liver failure (weakness, lethargy, encephalopathy, renal failure)

Facilitate diagnostic workup Interventions appropriate for pruritus As needed, instructions for management of percutaneous transhepatic biliary catheter As needed, preparation and postoperative care for internal stent and stent site Positioning to promote comfort Analgesic measures to promote comfort Promote optimal nutritional intake Minimize nausea and vomiting

Jaundice

Liver metastasis Biliary obstruction Primary cancers of liver, pancreas, gallbladder Hepatitis Cholecystitis Intrahepatic abscess

M E T A S T A S E S AND THE G A S T R O I N T E S T I N A L S Y S T E M

anticholinergics, and phenothiazines (methotrimeprazine, proehlorperazine, ehlorpromazine). 14,15,1s Selecting the optimal medications and route to treat nausea and vomiting often requires trial and error.

Pruritus is a common symptom associated with jaundice, which may develop when there is any interference in the ability of the liver to excrete conjugated bilirubin into the biliary system. This may occur with liver metastasis or biliary obstruction. Serum levels of bile acids increase and eventually accumulate in the tissues. Pruritus can cause significant distress, making it difficult to concentrate and interfering with sleep. Patients find it difficult not to scratch, and the skin may become excoriated and infected. Local measures may be helpful. Bathing in water that is not too hot for only 10 minutes a day and using mild soaps and oatmeal baths prevent drying of the skin. Loose-fitting cotton clothing reduces perspiration, lowering the itch threshold. Topical moisturizing creams, oils, and steroid creams may provide relief. When pruritus is severe, systemic drug treatment may be necessary. Antihistamines (eg, hydroxyzine, cyproheptadine) and phenothiazincs may reduce the sensation of itching. 27,32 If pruritus interferes with sleep despite these measures, hypnotic medication may be required. Bleeding may be a problem in patients with liver metastasis because of decreased synthesis of clotting factors and decreased clearance of fibrin degradation products. Patients may have petechiae, eeehymoses, and purpura of the skin. Bleeding may develop within the GI tract (eg, hematemesis, rectal bleeding, guiae-positive stools), genitourinary tract (eg, hematuria, vaginal bleeding), respiratory tract (eg, hemoptysis), and central nervous system (eg, mental status changes). Patients at risk must be instructed in measures to reduce the chance of injury. They should avoid trauma to the skin and mucous membranes by using only an electric razor, cleaning teeth with a soft-bristled toothbrush, and avoiding the insertion of anything into the rectum or vagina. In planning and administering care, invasive procedures should be avoided, and if punctures are required for drawing blood or administering medication, pressure should be applied for 5 minutes to puncture sites. Aspirin, nonsteroidal anti-inflammatory drugs, and eorticosteroids should be avoided, as these may impair platelet functioning and may cause gastric irritation or

197

ulceration. Bleeding may be life-threatening, and if rapid correction is required, fresh-frozen plasma or prothrombin complex concentrates may be administered. Subcutaneous injection of vitamin K also may be helpful. If patients are actively bleeding, red blood cell transfusions may be indicated. 33 Nutritional deficits may become significant in patients with metastasis involving the GI tract. Protein-calorie malnutrition ultimately may lead to eachexia, with weight loss and physical wasting. Patient manifestations include weakness, fatigue, decreased attention span, difficulty concentrating, and impaired immune function. Multiple factors may cause nutritional deficits in the patient with GI metastasis: impaired digestion and absorption, alterations in metabolism, loss of albumin, anorexia, and symptoms of pain, nausea, and vomiting.34, 3s Patients are at risk for malnutrition if they have been unable to take in adequate nutrients for 7 days or more, have had weight loss of 10% of their usual weight, or have a decrease in serum albumin. 35 Initial interventions should be focused on treating symptoms that may decrease appetite, such as pain, nausea, and vomiting. Decisions about nutritional support must be made based on the patient's response to antineoplastic therapy and long-term prognosis. Total parenteral nutrition is of little benefit to most patients with cancer and is associated with significant risk of mechanical, metabolic, and infectious complications. The enteral route of nutritional support is generally preferred to maintain gut mucosal mass and function. Measures to increase oral intake include frequent small meals, light exercise, and use of seasonings to enhance taste. Nutritional supplements that come in a variety of flavors and formulations may be administered orally or through feeding catheters. CONCLUSION aring for patients with metastasis involving the GI tract presents numerous challenges to ontology nurses. With an understanding of the disease process, nurses can effectively antieipate and manage symptoms that may develop. With knowledge of the alternative medical interventions available, nurses ean effectively educate patients and families so they can fully participate in making deeisions regarding their treatment.

C

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