Saturday 25 January 2014

Colorectal Carcinoma

BMJ Learning modules
Colorectal Cancer
Lower GI Cancer

Doctors.net module
Diagnosing Colorectal Cancer  http://www.doctors.net.uk/ecme/wfrmNewIntro.aspx?moduleid=1334
Rectal Bleeding

A note on iron deficiency anaemia4-6% of cases are caused by coeliac disease
The British Society of Gastroenterologists recommends coeliac disease screening is performed in all cases of IDA. This is done either by testing for anti-endomysial antibodies (EMA) or tissue transglutaminase (tTG) antibodies.

CancerThe stats aren't good for cancer. 26% of colorectal cancers are not diagnosed until they present as an emergency.
28% present with metastatic disease
1 in 20 people develop colorectal cancer
Peak incidence is in the 7th decade
Increasing incidence

Risk Factors
    Meat consumption and a diet high in animal fat
    Obesity (association stronger in men than women)
    Lack of physical exercise
    Smoking or alcohol
    Type 2 diabetes mellitus or acromegaly
    Renal transplantation
    Previous abdominal radiation


Beneficial Factors
 A diet rich in fruit and vegetables
    Increased fibre
    Treatment with aspirin
    Treatment with non-steroidal anti-inflammatory drugs

2 week wait:
- > 40yrs with PR bleeding + looser stools for more than six weeks
- >60 years with PR bleeding for >6 weeks
- >60 years with looser or more frequent stools without bleeding
- RIF or palpable rectal mass.
- Men with unexplained iron deficiency anaemia (Hb <110)
- Non-menstruating women with an Hb <100
- Carcinoembryonic antigen (CEA) is a useful tumour marker in those patients with a raised CEA preoperatively and whose value drops post-resection.

Bleeding in General
Lower GI bleeding is defined as bleeding distal to the ligament of Treitz
The BLEED Criteria is useful



Sunday 5 January 2014

Diverticulitis

FOAM
http://academiclifeinem.com/paucis-verbis-outpatient-treatment-for-diverticulitis/
http://radiopaedia.org/articles/hinchey-classification-of-acute-diverticulitishttp://www.emlitofnote.com/2013/01/diverticulitis-sinusitis-of-colon.htmlhttp://www.alifeatrisk.com/2013/03/diagnosis-of-diverticulitis-with-hands.htmlhttp://www.bmj.com/content/346/bmj.f928
http://www.criticalultrasoundjournal.com/content/5/S1/S5
http://radiopaedia.org/cases/acute-meckels-diverticulitis
http://radiopaedia.org/articles/diverticulitishttp://www.sciencedirect.com/science/article/pii/S0735675700900044
http://www.bmj.com/content/332/7536/271
http://learning.bmj.com/learning/module-intro/colonic-diverticular-disease.html?moduleId=5003332&searchTerm=%E2%80%9Cdiverticulitis%E2%80%9D&page=1&locale=en_GB

Introduction
Diverticulosis—the presence of diverticula that are asymptomatic
Diverticular disease—diverticula associated with symptoms
Diverticulitis—evidence of diverticular inflammation (fever, tachycardia) with or without localised symptoms and signs (LIF pain). Normally caused by gram negative bacteria.
Complicated diverticulitis—perforation*, abscess, fistula, stricture/obstruction

Diverticulitis affects over half of the population over 65years, with a prevalence that increases with age. You can get diverticulitis in young people.
85% of colonic diverticulitis will recover with treatment but some patients may have complications such as abscesses, fistulas, obstruction and perforation.
Recurrent diverticulitis is observed in 7-42% of people with diverticular disease and there is a 3% yearly risk of a further attack following resolution of the initial episode. 

The pathogenesis incompletely understood. Inverse relationship between incidence and fibre content of the diet.
Once diverticula have formed, stool may become thickens within the neck. In a process similar to appendicitis, the obstructing faecalith promotes secretion of mucus and bacterial overgrowth, which distends and erodes the thin walled diverticulum. Localised ischaemia develops, enabling translocation of mucosal bacteria and eventual perforation.



Diverticulosis is the most common structural abnormality of the colon and in the Western world. It affects 5% of people in their fifth decade and up to 50% of those older than 80.

Diverticula arise mainly in the distal colon, with 90% of patients having sigmoid colon involvement compared with only 15% on the right side. In contrast, Asian populations show predominantly right sided involvement, this may have a genetic involvement


Symptoms
Colicky abdominal pain, normally left sided.
You can get a meckel's diverticulitis which causes right sided pain.
Patients get bloating, or flatulence, which is exacerbated by eating and relieved by passage of flatus or stool.

There is usually little to find on clinical examination of patients with diverticulosis.
  • Diverticular disease  mild left iliac fossa tenderness. 
  • Acute diverticulitis typically left iliac fossa tenderness + general signs of infection
  • Remember coeliac disease can cause diarrhoea and may be associated with other conditions such as dermatitis herpetiformis - this is an itchy vesicular rash on the extensor surfaces of the arms and legs
Diagnosis
Hinchey classification of acute diverticulitis:
    stage 1a - phlegmon
    stage 1b - diverticulitis with pericolic or mesenteric abscess
    stage 2 - diverticulitis with walled off pelvic abscess
    stage 3 - diverticulitis with generalised purulent peritonitis
    stage 4 - diverticulitis with generalised faecal peritonitis

CT as good as USS but has slightly higher diagnostic accuracy. CT should be done in critically unwell patient without delay to rule out complicatied diverticulitis.  


TreatmentUncomplicated diverticulitis might be treated as outpatient if:
 - can tolerate POs
 - no significant co-morbidities
 - able to obtain antibiotics
 - have adequate pain control
 - access to follow up and social support
The role of antibiotics is controversial. One small study suggests diverticulitis might be a self-limiting process rather than one that requires antibiotics?

Chronic Treatment
 - High fibre diet
- Exercise
- Laxatives (controversial evidence)
- Antispasmodics

Inflammatory Bowel Disease

IBD (not to be confused with IBS) is made up of Ulcerative Colitis and Crohn's Disease.

Ulcerative Colitis
- Young adults (15-40 years old)
- More common in males
- Environmental and genetic factors play a part, but mostly idiopathic
- Incidence: 10-20/100 000
- Prevalence: 100-200/100 00


Symptoms
- Chronic bloody diarrhoea with tenesmus, pain and fever
- Colicky abdominal pain, urgency


Categories

Distal disease is confined to the rectum (proctum) and sigmoid colon (proctosigmoiditis).
Extensive disease includes left sided colitis (up to the splenic flexure)
Extensive colitis is up to the hepatic flexure
Pancolitis affects the whole colon



Mild:
  • The patient produces fewer than four stools daily with or without blood
  • There is no systemic disturbance
  • The patient has a normal ESR or CRP test.
Moderate:
  • Produces four to six stools a day
  • Has minimal systemic disturbance.
Severe:
  • Produces more than six stools a day with blood
  • Has evidence of systemic disturbance (any of fever, tachycardia, anaemia, or hypoalbuminaemia).

Pathology
- Limited to the mucosa
- UC - needs macroscopic findings on sigmoidoscopy

Crohn's Disease

Incidence: 5-10/100 000
Prevalence: 50-100/ 100 000
Incidence increasing

Symptoms and Diagnosis
Abdominal pain, diarrhoea and weight loss
Systemic fever or malaise, anorexia or fever
May cause intestinal obstruction
Anaemia in Crohn's disease around 30% but ranges from 10% to 70%



Pathology
- Elevated malignancy risk
- Transmural disease ie. patchy inflammation
- 3 different patterns of disease - inflammatory, fistulating or stricturing-  Focal inflammation seen on histology



Treatment of Inflammatory Bowel Disease
  • Aminosalicylates
    • Mesalazine
      • 2-4g daily
    • Sulphasalazine main group. Newer modules have come out that are better tolerated. 
    • Pentasa has a time controlled release.
    • Sulphasalazine - causes side effects in 10 - 45%  of patients.
      • Headache
      • Epigastric pain
      • Diarrhoea
      • Steven-Johnson Syndrome
  • Steroids
    • Combination of oral and rectal steroids better than either alone
    • 40mg prednisolone optimal
    • Needs slow dose reduction
  • Thiopurines
    • Azathioprine, mercaptopurine
    • Need for two or more corticosteroid courses in a calendar year
    • Relapse of disease when the dose of prednisolone is <15 mg
    • Relapse within six weeks of stopping steroids
  • Methotrexate
    • Teratogenic
    • Can cause early toxicity - primarily GI
    • Toxicity reduced by co-administration of folic acid
  • Ciclosporin
    • Prevents clonal expansion of T-cell subsets
    • For severe, steroid refractory treatments
  • Infliximab
    • Chimeric anti-TNF monoclonal antibody with potent anti-inflammatory effects. 
  • Institution of a cinnamon and benzoate free diet has been shown to provide improvement in 54-78% of patients.


ED Management
  • Vital signs
  • Clinical examination
  • Low threshold for AXR 
  • FBC, U&E, ESR or CRP
  • s/c heparin
  • Intravenous corticosteroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day. 
  • Withdrawal of anticholinergic, antidiarrhoeal agents, NSAID and opioid drugs, which risk precipitating colonic dilatation
  • IV antibiotics if infection considered 
  • Immediate surgical referral if there is evidence of toxic megacolon (diameter >5.5 cm, or caecum >9 cm).
  • Stool cultures -50% of relapses in patients with ulcerative colitis are associated with pathogens.
Fistulating and perianal disease
  • Metronidazole 400 mg tds and/or ciprofloxacin 500mg bd (grade B) are appropriate first line treatments for simple perianal fistulae.
  • Azathioprine 1.5–2.5 mg/kg/day or mercaptopurine 0.75–1.5mg/kg/day are potentially effective for simple perianal fistula
  • Infliximab (three infusions of 5 mg/kg at 0, 2, and 6 weeks) for refractory illness only. 

http://learning.bmj.com/learning/module-intro/ulcerative-colitis.html?moduleId=5003315&searchTerm=%E2%80%9Canal%E2%80%9D&page=1&locale=en_GB
http://www.bmj.com/content/346/bmj.f432?sso=
http://radiopaedia.org/articles/crohns-disease-vs-ulcerative-colitis
http://www.bmj.com/content/335/7632/1260
http://gut.bmj.com/content/53/suppl_5/v1.full
http://learning.bmj.com/learning/module-intro/crohn%E2%80%99s-disease.html?moduleId=10014189&searchTerm=%E2%80%9Canal%E2%80%9D&page=1&locale=en_GB