The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [442]
Acute diarrhoea.
Legal and professional issues
Competencies and consent will be the same as those discussed in the Gastroscopy section.
Preprocedural considerations
Equipment
A colonoscope is a flexible endoscope that allows direct visualization of the rectum and colon (Smith and Watson 2005).
Pharmacological support
Bowel preparation agents, such as senna tablets and Citramag, are given to the patient to take 1 day prior to the colonoscopy to clear the bowel. A sedative and possibly an analgesic are usually administered before the procedure. This involves the administration of a benzodiazepine such as midazolam and an opioid such as fentanyl or pethidine which have been prescribed by a medical practitioner. Doses must be titrated for elderly patients or those with co-morbidities such as cardiac or renal failure. An antispasmodic may also be given. Oxygen therapy should also be administered during sedation. Generally 2 litres per minute is adequate for most circumstances to maintain oxygen saturation levels and prevent hypoxaemia (BSG 2003, Riley 2008, Swan 2005).
Specific patient preparations
To complete a successful colonoscopy, the bowel must be clean so that the physician can clearly view the colon. It is very important that the patient follows all the instructions given for bowel preparation well in advance of the procedure. Without proper preparation, the colonoscopy will not be successful and the test may have to be repeated. If the patient feels nauseated or vomits while taking the bowel preparation, they are advised to wait 30 minutes before drinking more fluid and start with small sips of solution. Some activity such as walking or a few cream crackers may help decrease the nausea (Smith and Watson 2005, Swan 2005).
Two days prior to the endoscopy, specific light foods may be eaten, such as steamed white fish, and others avoided, such as high-fibre foods. On the day before the colonoscopy, breakfast from the approved food groups may be eaten while drinking plenty of clear fluids. On the day of the procedure patients can drink tea/coffee with no milk 4 hours before and water up to 2 hours before (Smith and Watson 2005, Swan 2005).
A medical and nursing history and assessment must be undertaken to identify any care needs or concerns that may be significant. In particular, this should cover the patient’s current drug therapy, drug reactions or allergies, any organ dysfunctions such as cardiac and/or respiratory disease, and previous or current illnesses. It is also important to be aware of any coagulopathies as samples of tissue or biopsy may need to be taken during the procedure. This can be pre-empted by reviewing blood results prior to the colonoscopy. A set of observations including temperature, pulse, blood pressure, respiration rate and oxygen saturations should also be taken to identify any preprocedural abnormalities and to provide a baseline. If the patient has diabetes, a blood glucose level should also be checked (BSG 2003, Smith and Watson 2005).
Postprocedural considerations
Immediate care
Physiological monitoring and care post sedation should be the same as those for gastroscopy. However, larger doses of sedative and opioids may have been used so further observation is required. The patient may feel some cramping or a sensation of having gas, but this quickly passes on eating and drinking. Bloating and distension typically occur for about an hour after the examination until the air is expelled. Unless otherwise instructed, the patient may immediately resume a normal diet, but it is generally recommended that the patient waits until the day after the procedure to resume normal activities.
Ongoing care
If a biopsy was taken or a polyp was removed, the patient may notice light rectal bleeding for 1–2 days after the procedure; large amounts of bleeding, the passage of clots or abdominal pain should be reported immediately.
Complications
Perforation
During the procedure the greatest risk or possible complication is bowel perforation. This occurs in 1 in 1000 cases. The nurse