April '98
Patricia Cantwell BSc.N
Nurse Consultant Regional Palliative Care Program Capital Health Authority, Edmonton, Alberta, Canada.

Bowel obstruction is a fairly common problem in patients with advanced abdominal or pelvic cancer. Approximately 25% of patients with ovarian cancer will develop a bowel obstruction over the course of their illness. For patients with colo-rectal cancers the incidence is approximately 10-15%. Bowel obstruction can occur with other cancer primaries as well - i.e. cervical, gastric, pancreatic, uterine and lymphomas. As nurses, we are often the ones who will pick up the initial symptoms of an obstruction. By doing a good assessment we can present clear information to the physician to enable appropriate interventions in a timely manner.

What are the signs and symptoms?

• Nausea and vomiting will occur in 100% of patients with a complete bowel obstruction
  • small bowel obstruction
  • mesis will develop early
  • emesis large in volume
  • emesis frequent - (shortly after po. intake)
    
    
  • large bowel obstruction
  • emesis develops later
  • often fecal in content
• Abdominal/visceral pain - many patients will have this symptom
  • pain is colicky or cramping
  • pain is often near site of obstruction
• Abdominal distention is more common in obstruction of large bowel
• Bowel sounds - complete obstruction
  • absent bowel sounds
  • absent flatus
  • partial obstruction- bowel sounds can be high pitched or tympanic

• History of infrequent bowel movements

It is clinically useful to differentiate between a partial and a complete obstruction. ( Partial: continues to have flatus, occasional stools vs. complete: there is no flatus, no stools and there is usually severe vomiting). Their respective management may be slightly different.

What is pseudo- obstruction?
It is important to be aware that a patient can present with some of the symptoms of a bowel obstruction - i.e. nausea, vomiting, abdominal pain, distention etc. but the obstruction is secondary to fecal impaction/obstipation or to paralytic ileus. An abdominal x-ray (3 views) will help delineate if the patient's problem is due to ++ stool in the colon.

Treatment - Surgery should be considered if the obstruction is amenable to surgery and the patient is a surgical candidate. In some cases, the surgery may involve surgical bypass or ostomy rather than bowel resection. If the patrient is not a surgical candidate, then the treatment is medically oriented.

• if abdominal x-ray identifies stool impaction then -
  • vigorous enemas and oral laxatives are needed to clear out stool
  • often needs several "good BM's" to clear colon

• if the obstruction is inoperable, high dose dexamethasone may help reduce the obstruction by decreasing the swelling and inflammation at the site. The dose is tapered over time to the lowest effective dose. Dexamethasone is also a powerful anti-nauseant.

• Pro-kinetic agents such as metoclopramide or domperidone must not be used when there is a complete bowel obstruction. These agents will increase the patient's pain, nausea and emesis.

CONSERVATIVE MEDICAL MANAGEMENT OF COMPLETE OBSTRUCTION

• Control nausea/emesis - if dexamethasone sc alone is not effective add
  • haloperidol sc - 1-2 mg. Q8-12H
  • hyoscine butylbromide helps reduce G.I. secretions and peristalsis (if complete obstruction that cannot be overcome) .

• Drain G.I. contents and decompress bowel
  • NG tube to suction may be helpful for short period.
  • PEG tube may be needed if there is much fluid emesis and distention

• Control pain - opioid may be useful
  • hyoscine butylbromide helpful for colicky pain

• Prevent dehydration - clysis of 1-2 litres fluid/day.
• Monitor and correct electrolyte imbalances
• Good mouth care
• Initial trial of clear fluids once symptoms have been controlled.

With the above conservative measures, along with good patient/family teaching and support, a patient can live comfortably at home for several months even when there is a complete non-operable bowel obstruction.

References:

• Baines, M.J. (1994) Management of intestinal obstruction in patients with advanced cancer. Annals Academy of Medicine, 23 (2), 178-181.
• Cantwell,P., MacKay,S., Macmillan,K., Turco,S., Mckinnon,S., Read-Paul,L. (1997). 99 Questions (and Answers) about Palliative Care: A Nurses' Handbook. Regional Palliative Care Program, Capital Health Authority, Edmonton, Alberta, Canada.
• Doyle, D., Hanks, G., MacDonald,N. (Eds). (1993). Oxford Textbook of Palliative Medicine. Oxford: Oxford University Press.
• Ripamonti,C., (1994). Management of bowel obstruction in advanced cancer patients. Journal of Pain and Symptom Management, 9(3), 193-199.