Minimising risk and improving the management of colonoscopic adverse events

Abstract

Introduction
Colonoscopy is the gold standard screening tool for colorectal cancer and is used as such in the English National Health Service Bowel Cancer Screening Programme (NHSBCSP). It does, however, carry a risk of adverse events that may compromise patient safety and the integrity of the screening programme. This thesis examined the colonoscopic adverse events perforation, post polypectomy bleeding (PPB) and post colonoscopy colorectal cancer (PCCRC) in the NHSBSCP.

Aims & Methods
1. Determine the frequency of perforation, PPB and PCCRC in the NHSBCSP.
2. Determine the impact of perforation and PPB on patients and colonoscopists.
3. Identify risk factors for perforation so that its risk can be minimised.
4. Improve the management of perforation and PPB to improve patient outcomes.

To achieve the aims of this thesis I used mixed methodology comprising both quantitative and qualitative health research methods.

Results
The frequency of the colonoscopic adverse events studied was 0.06% for perforation and 0.44% for post polypectomy bleeding.
Perforation led to hospital admission in 98.7% of patients, with 53.9% of admissions having surgery and 26.1% of admissions leaving hospital with a stoma. Only perforations that had surgery developed post perforation morbidity and were admitted to intensive care.
Perforation has a profound psychological impact on the colonoscopist involving four stages of reaction.
Risk factors for perforation include time pressure, colonoscopist fatigue, a longer procedure than the colonoscopist expected and equipment failure.
PPB led to hospital admission in 64.7% of patients studied with 27.9% of patients studied having a repeat endoscopic examination. 1.47% of the patients with PPB studied had surgery and 1.47% of the patients with PPB studied had radiological intervention.


Conclusions
1. The rates of perforation and PPB in the NHSBCSP are in line with other similarly sized studies reported globally. The robust system for capturing details of perforation and PPB in the NHS BCSP suggest the rates reported in these studies accurately reflect their true rate.
2. Perforation leads to hospital admission in nearly all patients. Of those perforations admitted to hospital, surgery occurred in approximately a half, with stoma formation in approximately a quarter and post perforation morbidity in approximately one fifth.
3. PPB leads to hospital admission in approximately two thirds of patients. Over half of the Post Polypectomy Bleeds are of minor severity
4. Colonoscopists should be aware that time pressure, colonoscopist fatigue, a longer procedure than the colonoscopist expected and equipment failure may be associated with perforation.