Malignant bowel obstruction: Individualized treatment near the end of life
ABSTRACTMalignant bowel obstruction requires a highly individualized approach, tailored to the patient’s medical condition, prognosis, and goals of care. Surgery should not be routinely done. Less-invasive approaches such as gastric and colonic stenting are useful.
KEY POINTS
- Combinations of analgesics, antisecretory drugs, and antiemetics can provide acceptable symptom relief.
- A venting gastrostomy should be considered if drug therapy fails to reduce nausea and vomiting to an acceptable level.
- A nasogastric tube should be used only as a temporizing measure, until symptoms are controlled medically or a venting gastrostomy is placed.
- Total parenteral nutrition is beneficial only in patients with intermediate life expectancy who may otherwise die of starvation rather than the cancer itself.
WHEN TO CONSIDER A VENTING GASTROSTOMY
Patients with a poor performance status, rapidly progressive disease, peritoneal carcinomatosis, a life expectancy of less than 30 days, or multiple levels of obstruction benefit from placement of a percutaneous endoscopic gastrostomy tube (ie, a venting gastrostomy) rather than surgery if symptoms do not respond to drug therapy.7,48 There is compelling evidence that this procedure relieves nausea and vomiting in 80% to 90% of patients and restores some level of oral intake in many.5,6,48,49 A venting gastrostomy tube can be placed during surgical exploration, percutaneously with fluoroscopy, or endoscopically.9
There are no absolute contraindications to gastrostomy tube placement. It is feasible even in patients with tumors encasing the stomach, diffuse carcinomatosis, and ascites.48 However, massive ascites, previous upper abdominal surgery, or a large mass attached to the abdominal wall make tube placement difficult.
Complications are often local. Patients experience transient abdominal wall pain after the procedure. Dislodgement, bleeding, catheter migration, peritonitis, and necrotizing fasciitis are early complications. Others include skin excoriation from leakage of gastric contents, leakage of ascitic fluid from the site, and obstruction or dislodgement of the tube.48,49
Patients can be discharged from the hospital soon after the tube is placed, usually with fewer medications than for patients who undergo surgery.48 This is particularly important for patients with a short expected survival. Some patients at home benefit from hydration (less than 2 L/day) via an existing central venous port or peripherally inserted central catheter, or by hypodermoclysis.
WHEN IS A NASOGASTRIC TUBE APPROPRIATE?
Some patients with malignant bowel obstruction require a nasogastric tube early in their hospital course.12 Unfortunately, nasogastric tubes, if left in place, cause nose and throat pain, sinusitis, abscess formation, erosion of nasal cartilage, aspiration, esophageal erosion, pharyngitis, and social isolation.5,6
Nasogastric tubes should be a temporizing measure to vent gastrointestinal secretions, reduce abdominal distension, and improve nausea and vomiting while a decision about surgery is being made.13,24 If surgery is not feasible, one can avoid the long-term complications and discomfort of a nasogastric tube via medical management and earlier evaluation for venting gastrostomy in those with symptoms that respond poorly to optimal medical management.49
WHICH PATIENTS BENEFIT FROM TOTAL PARENTERAL NUTRITION?
The use of total parenteral nutrition in patients with incurable malignancies is controversial. Enteral and parenteral feeding can increase muscle mass and improve functional status and quality of life in a subset of patients who are not suffering from cancer-related cachexia.2,50,51 However, for those whose weight loss and malnutrition are consequences of tumor-mediated cachexia, as demonstrated by anorexia and an elevated C-reactive protein level, parenteral nutrition is unlikely to improve the outcome.51 For most terminally ill patients, retrospective studies have failed to show that parenteral nutrition improves overall survival, performance status, or quality of life.2,48,50–54
Total parenteral nutrition poses risks: it is invasive and requires central venous access, which predisposes to infection; it requires frequent monitoring of hydration and electrolytes; and it predisposes to thrombosis, diarrhea, hyperglycemia, and liver failure.50–56
Total parenteral nutrition may be justified in patients with minimal tumor burden who are candidates for definitive surgery, or in those with a good performance status early in the disease course who have not had chemotherapy or whose cancer responds to chemotherapy.2,50–56
The American College of Physicians discourages the routine use of parenteral nutrition in those with advanced cancer who are undergoing palliative chemotherapy, since few patients benefit and many experience side effects.53
Total parenteral nutrition is much like a medical intervention in that it should be offered or continued only if it provides benefit. Conversations at the time that it is begun must include adverse effects that will lead to its discontinuation, and criteria for response. In certain situations, a limited trial of parenteral nutrition may be considered for patients with an uncertain prognosis or for those who have potentially reversible conditions that limit oral intake.51 In such cases, there should be a clear understanding between patient and physician that parenteral nutrition will be discontinued if it fails to show benefit.53
ADDITIONAL CONCERNS OF PATIENTS AND FAMILIES
‘Will I starve to death?’
Starvation is a fear echoed by patients and families. Ethical discourse on the continuation of nutrition and hydration for the terminally ill has been polarizing.57–60 Withdrawal of nutrition can be perceived as euthanasia.
Advanced cancer patients in general do not experience hunger, and those who do require only small amounts of food for satiation.61 In one report, most patients died of their advanced cancer and not from starvation.52 Artificial hydration and nutrition will thus not influence survival and can even be a burden without benefit in the imminently dying.60 These patients should be encouraged to take food orally for pleasure, as long as it is tolerated, without consideration of end points such as weight gain, body mass index, or albumin levels.
Complaints of thirst and dryness of the mouth are relieved with mouth care, ice chips, lubrication to the lips, and sips of fluid, rather than by parenteral nutrition.59 Patients with a terminal illness experience relief from thirst with minimal intake. The symptom of thirst may be relieved without hydration.34,61 Adequate hydration requires smaller fluid volumes due to decreased body weight, decreased renal clearance of free water, and decreased insensible water losses from reduced physical activity.58
‘Can we continue intravenous hydration so he won’t die of thirst?’
Overzealous intravenous hydration may worsen the symptoms of malignant bowel obstruction. Overhydration can increase secretions in the gut lumen and worsen the secretion-distention-contraction cycle, leading to greater abdominal pain and to nausea and vomiting.7 There is a greater risk of fluid overload in these patients, since they have edema and excessive interstitial fluid. Most have a low serum albumin level, which results in movement of fluid from intravascular to interstitial spaces due to reduced colloid osmotic pressure. In these instances, overzealous hydration can lead to respiratory insufficiency and worsening edema.
In spite of numerous discussions in the medical literature of the benefits and burdens of continual hydration, there is no consensus or guideline. When a patient has limited oral intake, the decision to hydrate should be individualized, with careful assessment of the risks and benefits and in accordance with the patient’s or family’s wishes.57,58
