The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [448]
— pulmonary embolism
— stroke, cerebral bleeds
perfusion CT.
Contraindications
Pregnancy: CT is not recommended unless clinical benefit outweighs radiation risk.
Patients with poor renal function or those having iodine therapy may have CT without intravenous contrast.
Previous CT within short timeframe unless clinically urgent.
Patients who are unable to lie down in order to pass through the machine (Royal College of Radiologists 2010).
Preprocedural considerations
Assessment and recording tools
Patients complete a questionnaire prior to CT in order to assess their suitability for CT and intravenous (IV) contrast. Intravenous contrast contains iodine, therefore patients with an iodine allergy or previous history of reaction to IV contrast should have a non-IV contrast CT.
Pharmacological support
The patient is cannulated for the intravenous injection of iodine-based contrast medium to enhance the blood vessels and bodily organs. During the injection it is normal for the patient to transiently feel warm over their whole body and to experience a metallic taste at the back of the throat, and some patients feel nauseous. CT examinations such as CT pulmonary angiograms demand contrast to flow at a fast rate and therefore a large gauge cannula (20 G) is required (Thomsen et al. 2009).
Non-pharmacological support
Although CT is a fast imaging technique (5–20 seconds), some patients are very concerned about being claustrophobic during scanning but with kind careful explanation, most patients manage to be scanned.
Specific patient preparations
Patients are prepared for CT by drinking an oral contrast, usually water, which shows the digestive tract. This serves to hydrate the patient which is beneficial post IV contrast and also it acts as a negative contrast agent in the digestive tract. Patients refrain from eating for 2 hours prior to CT in order to allow them to drink easily and to reduce nausea post IV contrast medium (Thomsen et al. 2009).
Patients lie on the CT scan couch and pass through the doughnut-shaped machine. The examination is painless and the majority of patients tolerate the examinations well. Small children require general anaesthetic for CT (Thomsen et al. 2009).
Websites
Diagnostic tests: www.library.wmuh.nhs.uk/pil/diagnostictests.htm.com
Blood tests: www.library.wmuh.nhs.uk/pil/diagnostictests.htm#BloodTests.com
Endoscopy: www.library.wmuh.nhs.uk/pil/diagnostictests.htm#endoscopy.com
Colonoscopy: www.patient.co.uk/health/Colonoscopy.htm.com
Cytoscopy: www.nhs.uk/Conditions/Cystoscopy/Pages/Introduction.aspx?url=Pages/What-is-it.aspx.com
X-ray: www.library.wmuh.nhs.uk/pil/diagnostictests.htm#xrays.com
MRI: www.library.wmuh.nhs.uk/pil/diagnostictests.htm#Magnetic Resonance Imaging.com
References
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AUA (2008) Best Practice Policy Statement on Urologic Surgery Antimicrobial Prophylaxis. American Urological Association Education and Research. www.auanet.org/content/media/antimicroprop08.pdf?CFID=2317518&CFTOKEN=12094021&jsessionid=8430364ab2795c3082622c78141f7b19487a.
Berreth, M. (2010) Minimising the risk of lymphodema: implications for the infusion nurses. INS Newsline, 32 (3), 6–7.
Blann, A.D. (2007) Routine Blood Results Explained, 2nd edn. M and K Update Ltd, Keswick, Cumbria.
BNF (2011) British National Formulary. BMJ Group and RPS Publishing, London.
Bouza, E., Munoz, P., Burillo, A. et al. (2005) The challenge of anticipating catheter tip colonization in major heart surgery patients in the intensive care unit: are surface cultures useful? Critical Care Medicine, 33 (9), 1953–1960.
BSG (2003) Guidelines on Safety and Sedation During Endoscopic Procedures. British Society of Gastroenterology, London. www.bsg.org.uk/clinical-guidelines/endoscopy/guidelines-on-safety-and-sedation-during-endoscopic-procedures.html.
Campbell, H., Carrington, M. and Limber, C. (1999) A practice guide to venepuncture and management of complications. British Journal of Nursing,