Prospective Evaluation of Pain Assessment and Management Protocol for Post-procedural Pain After Endoscopic Mucosal Resection of Colonic Polyps >20mm
Prospective Evaluation of Pain Assessment and Management Protocol for Post-procedural Pain After Endoscopic Mucosal Resection of Colonic Polyps >20mm
Endoscopic mucosal resection (EMR) of large (≥20 mm) laterally spreading colonic lesions
 (LSL) is safe, effective and superior to surgery. This advantage is based on a day stay model
 of care, however the most common adverse event is abdominal pain and this is a major
 impediment to this efficiency. No prospective data exist on the optimal selection of
 analgesics, the necessary recovery period or the triggers that should alert the practitioner
 to a more serious trajectory and the need for escalation of care.

 We aimed to characterise potential predictors for persistent (>5 minutes) post-procedural
 pain (PP) and develop a simple and effective management algorithm for patients with PP based
 on the need for analgesics in recovery.

 Data on consecutive patients with a LSL referred for EMR at a single, tertiary referral
 centre were included. Patient and lesion characteristics and peri-procedural data were
 prospectively collected. Standard post EMR care included 2 hours in first stage recovery
 followed by 1 hour in 2nd stage recovery where clear fluids were given and discharge after if
 the patients were well. PP was graded from 0 to 10 using a Visual Analogue Scale (VAS). If PP
 occurred >5 minutes, 1 gram of paracetamol was administered parenterally and outcomes were
 monitored. If pain settled the patient was transferred to second stage recovery after medical
 review. PP >30 minutes lead to clinical review and upgrade of analgesics to fentanyl, with a
 starting dose of 25 micrograms (mcg) up to a maximum of 100 mcg. Investigations, admission
 and interventions for PP are recorded.
Large, sessile, colonic polyps of ≥ 20 mm are at increased risk of progressing to colorectal
 cancer (CRC). Most colonic polyps are small and pedunculated and can be safely removed by
 conventional polypectomy. Treatment of large polyps however, is challenging but very
 important in preventing development of CRC, the second leading cause of cancer deaths
 worldwide. Early detection and treatment of these polyps, possible through vigilant CRC
 screening via colonoscopy, shows significant reduction in incidence of CRC.

 Over the last decade, endoscopic mucosal resection (EMR) has been recognised as a safe and
 reliable alternative to surgery to remove large, sessile colonic polyps of ≥ 20mm. The
 benefits of EMR over traditional surgery include reduced risk of peri- and post-operative
 complications from surgery (particularly in elderly patients with multiple co-morbidities),
 less health expenditure and reduced length of hospital admission. The majority of patients
 can be managed safely as outpatients post EMR.

 EMR has been proven to be a safer alternative to traditional surgery, but is a technically
 challenging procedure. The most common complication post procedure is non-specific abdominal
 pain, which occurs in 10-20% of cases. The cause is often innocent such as simple luminal
 distension during the procedure. The advent of improved EMR techniques, for example using
 carbon dioxide instead of air insufflation, significantly reduces incidence of abdominal pain
 and subsequently need for admission.

 Colonic perforation during colonoscopy rates range from 0.06 to 0.1%. Advanced age, female
 gender, having a colonoscopy indication of abdominal pain or Crohn's disease, result in a
 statistically higher risk of colonic perforation. In addition, ICU inpatients have
 substantially greater odds of perforation. A recent study, conducted over twelve years in a
 total of 110,785 patients undergoing diagnostic and therapeutic colonoscopies, showed one
 case of colonic perforation associated with EMR.

 Currently, it remains difficult to delineate innocent abdominal pain from more serious
 complications. There are no standard algorithms used in clinical practice to stratify risk
 post EMR according to patient's symptoms and there are no data supporting previously proposed
 pain algorithms. There is also a paucity of data regarding pain scales employed in the past
 to show significant correlation between pain level and risk of perforation or bleeding. The
 100mm Visual Analog Scale (VAS) has been documented to have sound correlation in patients
 presenting to the emergency department with an acute abdomen and could be a useful aid in a
 formal assessment based on pain post EMR.

 With the prospectively recorded data in this study, we aim to validate an algorithm to
 provide decision support in first stage recovery of Endoscopy Departments. This algorithm on
 assessment and management of post EMR pain, will identify patients at risk for more serious
 complications, and will allow health carers to recognize these complications and act more
 accurately. Ultimately, this will improve patient's outcomes.
Inclusion Criteria:

 -  All patients referred to Westmead Hospital Endoscopy Unit to undergo an EMR of a
 colonic lesion reported to be ≥20mm in size.

 -  Age ≥18 years.

 -  Patients able to give informed consent to involvement in the trial. For patients who
 do not speak English, an interpreter will be asked to translate the informed consent.

 Exclusion Criteria:

 Inability to sign informed consent.