Intestinal Obstruction
An approach to symptom management to guide decision-making in the management of patients with life-threatening illness
Appropriate assessment to identify cause and severity of symptoms
Explanation to patient and family at all stages
Consider disease-specific palliative therapy
Institute non-pharmacological interventions
Prescribe appropriate first-line treatment
Consider adjuvant/second-line treatment
Review assessment and management regularly
Intestinal obstruction is caused by an occlusion to the lumen of the bowel or a lack of normal propulsion, preventing or delaying intestinal contents from passing along the gastrointestinal tract. Obstruction may be the presenting symptom of cancer problem, but more commonly develops during the course of the disease. Any site in the bowel may be involved, from the gastro duodenal junction to the rectum and anus.
The incidence in cancer patients is 3%. The incident increases to 25-40% in advanced ovarian cancer.
Obstruction can be functional (paralytic) or organic (mechanical), or both.
It can also be:
- partial or incomplete
- transient (acute) or persistent (chronic)
Appropriate assessment to identify cause and severity of symptoms
Symptoms:
- Colicky pain
- nausea and vomiting
- abdominal distension
- constipation
Causes:
- Primary tumours of the large bowel
- Previous treatment e.g. adhesions, post radiation, ischaemic fibrosis
- Extra mural compression by tumour masses
- An unrelated benign condition e.g. a strangulated hernia
Confirm obstruction with abdominal X-ray and exclude pseudo-obstruction – faecal impaction/ ileus.
Explanation to patient and family at all stages
Explain goals of treatment, including the fact that vomiting may not be eliminated particularly with complete intestinal obstruction. A discussion about the possibility of surgery or the fact that surgery is not appropriate and the fact that this means the prognosis is poor should be held in a sensitive and compassionate way.
Correct reversible factors
Surgery may be indicated in a younger patient, relatively fit, single site of obstruction, no ascites, previous good response to chemotherapy.
In many patients surgery is not indicated because of multiple sites of obstruction, advanced disease with relatively short prognosis to death, additional problems such as ascites or obstructive nephropathy.
Consider disease-specific palliative therapy
In few patients, further chemotherapy may be an option but in general intestinal obstruction is a manifestation of advanced disease unlikely to improve with chemotherapy.
Institute non-pharmacological interventions
Good mouth care is essential. Patients eat and drink as they choose and there are no special diets. With adequate oral fluids, thirst is not usually a problem and the occasional dry mouth is treated with local measures such as crushed ice to suck. Nasogastric intubation is not appropriate unless surgery is planned.
Prescribe appropriate first-line treatment
Subcutaneous infusion of a combination of drugs is the preferred treatment. Nasogastric tube and IV fluids are rarely used. The preferred route of drug administration is by subcutaneous infusion using a syringe driver. The three major symptoms of intestinal obstruction are colic, abdominal pain and vomiting.
Drugs used in symptom control
Symptom | Drug | Dose | Comment |
Intestinal colic | Morphine | As required | Add antispasmodics |
Hyoscine butylbromide | 40-60mg | Avoid gastrokinetic drugs e.g. metoclopramide | |
Continuous abdominal pain | Morphine | As required | Anti-emetic or antispasmodic |
Nausea and vomiting | Haloperidol | 5-15mg | May cause sedation |
Cyclizine | 100-200mg | May crystallise in syringe driver | |
Hyoscine butylbromide | 40-60mg | Reduces gastrointestinal secretions and mobility | |
Octreotide | 0.3-0.6mg | A somatostatin analogue (0.1mg-0.6mg/day) Reduces gastrointestinal secretions and vomiting | |
Intestinal Obstruction | Dexamethasone may be added | 8-16mg | To reduce peritumoural oedema |
Avoid stimulant drugs such as metoclopramide and senna as these drugs may increase colic and pain.
Consider adjuvant/second-line treatment
Corticosteroids may be used for an anti-inflammatory effect, reducing oedema with resultant symptom relief.
Review regularly. If the patient is terminally ill, within 1 or 2 days of death, sedation may be necessary. Midazolam – 15-45mg / 24 hourly can be added to the syringe driver.
Review assessment and management regularly
Most patients with intestinal obstruction can be made reasonably comfortable with control of nausea for most of the time using a combination of a continuous infusion of appropriate drugs, careful mouth care and frequent small sips of water. Some patients may chose to take some food and fluids by mouth recognising that vomiting will occur. In few cases, it may be appropriate to perform a venting gastrostomy.
At all stages of management consider
- Involvement of interdisciplinary team
- Referral to appropriate service/more experienced clinician