Toxic Megacolon Flashcards
What is toxic megacolon?
Total or segmental nonobstructive colonic dilatation (>6cm) that occurs in the context of systemic toxicity
Incidence of toxic megacolon?
Unknown
Toxic megacolon affects what age groups?
Affects all ages
Etiologies of toxic megacolon?
Complications of IBD (Ulcerative colitis MC), Infectious colitis (C. difficile MC, CMV), Ischemic colitis, Volvulus, Diverticulitis, Radiation, Obstructive colorectal cancer
HPI for toxic megacolon?
Profound bloody diarrhea, abdominal pain & distention, nausea, vomiting, tenesmus (feeling of needing to pass stool even though bowels are empty)
Physical exam for toxic megacolon?
Lower abdominal tenderness & distention, dehydration (+/-) signs of peritonitis (rigidity, guarding, rebound tenderness)
Lab diagnostics fot toxic megacolon?
CBC w/ diff, CMP, Lactic acid, ESR & CRP, Lipase, TSH, Stool culture
Imaging diagnostics for toxic megacolon?
-Abdominal xr (Radiologic evidence of colon >6cm)
-Abdominal/pelvic CT to assess for complications
What is contraindicated with toxic megacolon?
Bowel prep, barium enema, complete colonoscopy (can cause colonic perforation)
What may be seen on radiologic imaging with toxic megacolon?
Gross dilatation of large and small intestines *Lead pipe appearance
-Small bowel dilatation: thin transverse folds of the valvulae conniventes (arrowhead)
-Large bowel dilatation: characteristic thick haustral markings that don’t extend cross the entire lumen
Diagnostic criteria for toxic megacolon?
Radiographic evidence
plus
3 or more of the following: Fever >38C, Pulse >120bpm, Neutrophilic leukocytosis >10,500/microL, anemia
plus
at least 1 of the following: Hypotension, Dehydration, Electrolyte abnormalities, Altered mental status (AMS)
Treatment of toxic megacolon?
MAINSTAY: supportive care (admit, bowel rest, NG tube, broad-spectrum abx (ceftriaxone + metronidazole), fluid/electrolyte repletion, serial labs /abdominal films
*treat underlying cause
When is surgery indicated for toxic megacolon?
In colonic perf, necrosis, full-thickness ischemia, intra-abdominal HTN, abdominal compartment syndrome, clinical signs of peritonitis or worsening abdominal pain despite adequate medical therapy, and end-organ failuire
What is another name for Ogilvie syndrome?
Acute colonic psuedo-obstruction
What is Ogilvie syndrome?
A disorder characterized by acute dilatation of the colon in the absence of an anatomic lesion that obstructs the flow of intestinal contents
Which part of the colon is usually involved in Ogilvie syndrome?
Cecum and right colon
Who does Ogilvie syndrome more commonly affect?
Men >60 y/o
Is the exact Patho physiology of Ogilvie syndrome known?
No
Usually Ogilvie syndrome occurs in hospitalized/institutionalized patients in association with what?
A severe illness, after surgery/in conjunction w/ metabolic imbalance, administration of culprit med
Which meds cause Ogilvie syndrome?
Opioids, anticholinergics, alpha-2-adrenergic agonists, antipsychotics, CCBs, cytotoxics, dopaminergics, epidural anesthesia
What kinds of trauma/ortho surgery can be associated with Ogilvie syndrome?
Fractures, hip and spine surgery
What kinds of obstetric and gynecological conditions are related to Ogilvie syndrome?
Pelvic surgery esp involving spinal anesthesia, c-section, vaginal (normal or instrumental) delivery
What cardiothoracic surgeries or diseases are associated with Ogilvie syndrome?
Cardiac surgery including transplants, myocardial infarction, heart failure, pneumonia
What neurological disorders are associated with Ogilvie syndrome?
Parkinson’s, stroke, dementia
What retroperitoneal diseases are associated with Ogilvie disease?
Malignancy, hemorrhage
Infection of which virus is associated with Ogilvie syndrome?
Herpes zoster
HPI for Ogilvie syndrome?
Abdominal distention (main sx), nausea, vomiting, abdominal pain, constipation, paradoxical diarrhea (overflow diarrhea)
Physical exam findings for Ogilvie syndrome?
Abdominal distention, tympanitic on percussion, high-pitched bowel sounds
What symptoms of Ogilvie syndrome are suggestive of colonic ischemia or perforation (or their impending development)?
Fever, marked abdominal tenderness, and presence of peritoneal signs (guarding, rigidity, rebound tenderness)
Lab diagnostics for Ogilvie syndrome?
CBC, CMP, LFTs, Serum lactate, TSH, stool cultures if diarrhea
Diagnostic scans for Ogilvie syndrome?
Abdominal radiographs, Abdominal CT is preferred
What may be seen on an abdominal CT of Ogilvie syndrome?
Proximal colonic dilatation, dilation may extend to rectum
Goal of management of Ogilvie syndrome?
To decompress the colon in order to minimize risk of colonic perforation/ischemia
Treatment for Ogilvie syndrome w/o ischemia/perforation/peritonitis (colon dilation <12cm)?
Supportive/conservative care: NPO, NG tube, IV fluid/electrolyte repletion, treat underlying disease, d/c offending meds
Serial exams, serial abdominal radiographs, serial labs every 12-24 hrs
Treatment for patients with Ogilvie syndrome, at risk for perforation (>12cm)/severe abdominal pain/failed conservative treatment?
Med: Neostigmine
Colonoscopic decompression: reserved for failed conservative tx, Neostigmine contraindications/failure
Serial exams, serial abdominal radiographs, serial labs ever 12-24 hrs
What is the perforation rate and risk of mortality for colonoscopic decompression?
Perf rate: ~2%
Mortality risk: 1%
*technically difficult procedure
