Malignant Bowel Obstruction
KEYPOINTS
- Has been reported in 5-15% of cases of advanced cancer
- 5-40% of ovarian cancer and 5-24% of bowel cancer
- Signs and symptoms of bowel obstruction may not be ‘classic’ in advanced malignant disease
- May resolve spontaneously especially in early stages
- Oral administration of medications is unreliable
- The “goals of care” must be clear: “is this a patient that we would consider for surgery, oncological treatments or comfort only?”
- In children non malignant causes such as volvulus or intususception should be kept in mind
ASSESSMENT
(see Foreword)
- Clinical features may include pain, nausea, vomiting, abdominal distension and reduced or absent passing of faeces or flatus
- Investigations to consider for diagnosis may include:
- Abdominal x-rays to demonstrate fluid levels
- If surgical intervention is a possibility, consider imaging (CT or contrast plain films) to help define level of obstruction (gastrograffin is preferable as may be useful in restoring bowel function in some cases)
MANAGEMENT
Pharmacological Treatment
Symptom management or possible reversal of bowel obstruction
- In many cases, reversal of the bowel obstruction or marked reduction in symptoms may be possible by using a combination of corticosteroids, prokinetic, antiemetic and antisecretory drugs. A trial of
- Dexamethasone 16 mg/day SC/IV
- Metoclopramide 10-30 mg qid SC/IV and
- Haloperidol 1-2 mg/24 SC/IV is used for 3 to 5 days
- Octreotide may be added
- Hyoscine butylbromide can also reduce colic and secretions but is less effective
Pain control
- Use of appropriate opioid analgesics such as morphine SC/IV as outlined in the section on pain is the mainstay of treatment
- For colic add: hyoscine butylbromide 20 mg q6h/prn SC or hyoscine hydrobromide 0.4 mg sc q4h prn
Nausea and vomiting
- Haloperidol 2-4 mg/24hrs PO/SC/IV in divided doses
- Metoclopramide 10-30 mg qid SC/IV or as infusion
Metoclopramide may increase colic as it is a prokinetic agent and therefore should be monitored closely and discontinued if the patient experiences more pain
- Dexamethasone 16 mg/day SC/IV: can be helpful to reduce nausea and vomiting increase water and salt absorption form GI tract, reduce peritumoral oedema and alleviate obstruction. Give for a 5-day trial, reduce dose as tolerated or discontinue if not helpful
- Octreotide 200 mcg-500 mcg in divided doses (bid or tid) SC or 300-1200 mcg/24hrs by SC infusion. Can be useful especially in cases where there is high volume emesis
Non-Pharmacological Treatment
Nasogastric tube
- Will relieve some patients especially with high level obstruction
This is usually reserved for patients with frequent or severe symptoms. Usually short term use only while waiting to see if pharmacological management is effective.
If necessary for control of symptoms, conversion to a venting gastrostomy tube is beneficial
By-pass surgeries and stenting
- May be considered in selected patients depending on the nature of the obstruction, condition of the patient, prognosis and likely benefit
Hydration
- Administration daily of 1-1.5 L solution containing electrolytes (+/- glucose) IV or SC may be useful in maintaining electrolyte balance and preventing adverse effects such as opioid toxicity and delirium
- Hydration may also cause some symptoms to worsen due to increased third spacing and oedema
- Metoclopramide 0.1 to 0.2 mg/kg/dose q6h PO/SC/IV
- Haloperidol 0.05-0.15 mg/kg/day bid/tid PO/SC/IV
- Dexamethasone
- 2-5 years; 0.5-1 mg bid PO/IV (if IV give over 3-5 minutes)
- 5-12 years: 1-2 mg bid PO/IV (if IV give over 3-5 minutes)
- Octreotide 1-10 mcg/kg/24h SC/IV
PITFALLS/CONCERNS
- In patients in the final terminal phase – ie. hours to days, invasive treatments should be minimized
- Prolonged use of nasogastric tubes can cause considerable distress as well as medical complications
- Hydration should be tailored to individual needs; beware of over-hydration
- If the bowel obstruction does reverse it may recur at some point in the future
- Metoclopramide and haloperidol (and other neuroleptics) can cause extra pyramidal reactions in children and can be used in combination with diphenhydramine to reduce likelihood of this
PALLIATIVE TIPS
- Aggressive pharmacological management can be very effective in reversing obstruction and reducing gastrointestinal symptoms in inoperable bowel obstruction. A combination of drugs is usually necessary
- Treatment should be initiated early
- Hydration may be given by SC infusion (hypodermoclysis) up to 80 cc/h
- In cases of partial obstruction with constipation; continue stool softeners (docusate) but stop stimulants (senna and bisacodyl) if colic is a problem. Try rectal measures such as suppositories
REFERENCES
- Fainsinger RL, MacEachern T, Miller MJ, Bruera E, Spachynski K, Kuehn N et al. The use of hypodermoclysis for rehydration in terminally ill cancer patients. J Pain Symptom Manage 1994;9(5):298-302. http://www.ncbi.nlm.nih.gov/pubmed/7963780
- Laval G, Arvieux C, Stefani L, Villard ML, Mestrallet JP, Cardin N. Protocol for the treatment of malignant inoperable bowel obstruction. J Pain Symptom Manage 2006;31(6):502-512. http://www.ncbi.nlm.nih.gov/pubmed/16793490
- Mercadante S, Ferrera P, Villari P, Marrazzo A. Aggressive pharmacological treatment for reversing malignant bowel obstruction. J Pain Symptom Manage 2004;28(4):412-416. http://www.ncbi.nlm.nih.gov/pubmed/15471659
- Ripamonti C, Mercadente S. Pathophysiology and management of malignant bowel obstruction. In Doyle D, Hanks G, Cherny N, Calman K, editors. Oxford textbook of palliative medicine. 3rd ed. Oxford: Oxford University Press; 2005, p. 496-507.
- Twycross R. The use of prokinetic drugs in palliative care. Eur J Palliat Care 1995;2(4):143-145. http://www.ejpc.eu.com/ejpc/ejpcIssue.asp?Z=755794&IssueID=71
page revision: 40, last edited: 16 Oct 2009 08:45