Editing Colonoscopy complications

** '''Complications to sedation'''
** '''Complications from bowel prep'''
*** Nausea/vomiting/oesophageal tears
*** Electrolyte or fluid disturbances
** '''Bleeding'''
*** Usually a/w polypectomy, rarely accompanying diagnostic scope
*** Typically 1-2%, but higher with larger polyps or pro-bleeding risk factors
*** Immediate bleeding: 
**** a/w techniques not involving cautery
**** Usually recognised during procedure
**** Usually managed with repeat scope if not fixed at time
*** Delayed:
**** Typically 5-7 days, up to a month
**** Thought to occur when eschar sloughs off
**** Usually needs scope
*** Management
**** Resuscitate and correct coagulopathy
**** Usually scope again - don't need to prep, but if patient is stable, could do a rapid prep
**** Tattoo the bleeding site in case you need to operate later
**** Angiographic embolisation can be considered, as long as you won't need to resect bowel at the site in future
**** Persistent bleeding needs an operation - usually with intra-operative colonoscopy to localise, then colotomy and direct haemostasis, then closure. If a resection is going to be required in the future anyway, may be better off resecting.
** '''Perforation'''
*** Aetiology
**** Mechanical trauma from pressure (rectosigmoid region typically)
**** Barotrauma from excessive insufflation (typically caecum)
**** Electrocautery injury during polypectomy
**** Excessive looping
**** Overzealous stricture dilation
*** Incidence
***
*** Perforations from diagnostic scope are typically large (barotrauma or mechanical), whereas electrocautery perforations more often cause small localised perforations
*** Risk factors: (patient factors/technical factors)
**** Age
**** Multiple comorbidities
**** Diverticulosis
**** Obstruction
**** Resection of polyps >1cm in right colon
**** Inexperience
*** Presentation
**** Can become clear right afterwards, or days later with increasing abdominal sepsis (typically perforations that were initially contained, or polypectomy with cautery)
*** Investigation
**** Some say start with AXR - free air and local peritonitis are diagnostic, however small-volume pneumoperitoneum can be normal after colonoscopy (Schein's)!
**** CT - highly consider PO or rectal contrast
*** Treatment
**** Large perforations - usually surgery
***** Consider - would the patient require surgery for the colon lesion anyway? Might as well just do it…
**** Smaller can be managed non-op
***** Pneumoperitoneum is not necessarily an absolute indication for surgery
***** Good prognostic factors for non-op: 
****** Prepped colon
****** No peritonitis, tachycardia, or fever
****** Retroperitoneal contained perforation
****** Sustained perforation during therapeutic scope
**** Clip closure of small perforations has been reported - but ONLY if it is recognised at time of scope, you can't do a repeat scope on a patient after the perforation has occur red - risk blowing open a contained perforation and contaminating the abdomen
**** Peritoneal toilet and primary suture closure of the perforation is usually sufficient
***** Consider bypass/diversion/resection
**** In established infection, primary closure with covering loop ileostomy may be useful - note that diversion is less useful if the patient is not prepped, and there is faeces above the injury anyway. Ileostomy preferred to loop colostomy to avoid interfering with future potential conduit required to fix the problem.
** '''Post-polypectomy syndrome'''
*** Electrocoagulation injury to bowel wall, causing transmural burn and focal peritonitis without frank perforation
*** Can see fever, leucocytosis, focal tenderness up to 5 days later
*** Just needs antibiotics - can sometimes be treated as outpatient
** '''Infection'''
*** Very uncommon - contaminated instruments with BBV has been reported
** '''Gas explosion'''
*** APC can cause this
*** Incomplete prep, meaning methane is present
*** Incompletely absorbable carbohydrate preps such as lactulose, mannitol, sorbitol

[[Category:Endoscopy]]