Page 135 - Registrar Orientation Manual 2016

Reference:
1257
Effective date:
7 July 2015
Expiry date:
6 July 2018
Page:
18 of 35
Title:
Imaging Guidelines
Type:
Clinical Guideline
Version:
02
Authorising initials:
These criteria are designed to cover the majority of indications for referral for colonoscopy by GPs and non-gastrointestinal specialists. We also use them to triage internal referrals to ensure equity of access.
The criteria include references to the option of CT colonograpy as an alternative to colonoscopy:
• “CT colonography is an acceptable alternative investigation to colonoscopy for many
indications in the ‘six week category’ where direct mucosal visualisation is not required” • “CT colonography may also be the most appropriate investigation for patients with
significant co-morbidities but who meet the criteria for investigation”
Unfortunately, at Waikato, we currently have limited capacity to do CT colonography. We are not able to accept all referrals and have to be selective. This may change in the future and we may offer CT colonography in lower risk cases but at the moment we are only able to offer a very limited service.
This means we will not offer CT colonography as an “alternative investigation” without a good reason. At Waikato we will:
• offer CT colonography to patients who have had a failed colonoscopy,
• consider CT colonography for patients who meet the National Referral Criteria for Direct
Access Outpatient Colonoscopy but have contraindications to colonoscopy.
CT colonography is not without significant morbidity from the bowel preparation and the procedure. Many frail patients do not tolerate CT colonography very well. Perforation is a potentially fatal risk. Referral implies a patient is well enough to tolerate both the test and treatment if a cancer is found. Referrers should always consider (taken from the National Criteria) whether the patient will benefit:
• “if they are frail, have multiple co morbidities or advanced malignancy” In a frail patient with multiple co-morbidities consider other management options.
For example, if a patient with iron deficiency anaemia due to presumed GI blood loss is not fit for colonoscopy or surgery, consider stopping the any antiplatelet therapy and treating with iron rather than further investigation.
The colonoscopy criteria also include the referrals that won’t be accepted shown in the following table and CT colonography will not be offered for any of these indications either.
In addition CT colonography will not be offered for the following:
• weight loss of uncertain cause with no gastrointestinal symptoms,
• possible malignancy (e.g. in idiopathic VTE) with no gastrointestinal symptoms
• screening for malignancy in IBD
• patient preference