Clinical infections - Gastrointestinal 1 Flashcards
Sterile sites:
peritoneal space, pancreas, gall bladder, liver (wouldn’t expect bacterial growth)
Non-sterile sites
intra-luminal so from top to the bottom end: mouth, oesophagus, stomach, small/large bowel
Normal Flora
- Enterococcus – found in the enteric tract
- Nose: staphylococcus aureus
- Mouth: streptococci viridans
- Pharynx: contain haemophilus
Angular Cheilitis definition
- Acute/chronic inflammation of skin and contiguous labial mucosa located at lateral commissures of mouth
Angular Cheilitis aetiology
- Caused by excessive moisture [maceration] from saliva and secondary infection with C albicans or less commonly S aureus
Angular Cheilitis treatment
Topical Antifungals or Antibiotics
Angular Cheilitis presentation
- Older people: Loss of vertical dimension of the mouth, drooling, saliva
- Erythema, maceration, scaling, fissuring at corners of mouth
Hairy Leucoplakia
- White plaques on the tongue seen in HIV patients who have not been treated
- caused by Epstein Barr Virus, cause of glandular fever
Dentoalveolar infections
- Caries - Bacterial plaques form on the tooth surface and form caries, Acid produced by Streptococcus mutans and lactobacillus spp
- Pulpitis: Require root canal treatment
- Periapical abscess - Streptococci and anaerobes
Periodontal infection
- Plaque beneath the gingival margin
- Gingivitis - requires improved oral hygiene
- Periodontitis -Progression of gingivitis - Antibiotics required
- Periodontal abscess - requires surgical draining
- Acute necrotizing ulcerative gingivitis - Can lead to DNSI’s - requires antibiotics
Peritonsillar abscess (quinsy abscess)
- Unilateral swellings of the tonsil; caused by Streptococcus pyogenes
- Signs: muffled voice, trismus: lock jaw
- Symptoms: dysphagia, unilateral sore throat
- Treatment: Surgical drainage and antibiotic management
Acute suppurative parotitis
- Non mumps; occurs in patients with poor oral hygiene and dehydration
- Almost always caused by Staphylococcus aureus
- Treatment: surgical drainage, antibiotics administered
Submandibular space infections (Ludwig’s angina)
- Bilateral infection of submandibular space, potential for airway obstruction
- Abscesses form: surgical drainage required, antibiotics administered
Helicobacter pylori infection definition
- Bacterial urease hydrolyses gastric luminal urea to form ammonia that helps neutralise gastric acid and form a protective cloud around the organism so it can penetrate the gastric mucus layer
Helicobacter pylori infection diagnosis
- Cause pain, bleeding, perforation, ulcers. Diagnosis:
- Urease breath test - research
- Faecal antigen test – Best way to diagnose
Helicobacter pylori infection treatment
- Triple antibiotic therapy plus PPI for 7-14 days – PPIs prevent acid secretion so conditions are no longer optimal for bacteria
Biliary Tract Infection: Cholangitis
- The classic presentation is fever, abdominal pain, and jaundice (Charcot’s triad)
- Site: common bile duct
Elevations in: - serum alkaline phosphatase (ALP)
- gamma-glutamyl transpeptidase
- bilirubin
- Colonic bacteria: Enterobacteriaceae
Biliary Tract Infection: Cholecystitis
- Abdominal pain, fever, history of fatty food ingestion
- Elevation in the serum total bilirubin and alkaline phosphatase concentrations
- Murphy’s signs: positive = pain on inspiration
- Site: Gall bladder - associated with stones
- Treatment: antibiotics +/- surgical
Bacterial overgrowth of small intestine
- Overgrowth of bacteria on small bowel is believed to be associated with malabsorption or chronic diarrhoea
- Overgrowth of bacteria may result from achlorhydria, impaired motility, blind loops of bowel
- Treatment: dietary changes, surgical, motility, non-absorbable antibiotics
Whipple’s Disease aetiology
- Tropheryma whipplei - found everywhere in environment
Whipple’s Disease symptoms
- Joint symptoms, chronic diarrhoea, malabsorption, and weight loss
- joint and GI “pain”
Whipple’s Disease pathology in distal duodenum
White plaques representing engorged lymph vessels
Liver abscess
- Occurs if cholangitis is not treated and bacteria travel up biliary tree, into liver
- Infection ascends biliary tract, enters the bloodstream via portal vein, Haematogenous spread
- Commonly entamoeba histolytica
Liver abscess investigations
- Serum alkaline phosphatase is elevated in 67 to 90 percent of cases and serum bilirubin and aspartate aminotransferase concentrations are elevated in about one-half of cases
- Protozoal infections and Viral hepatitis another cause
Mycobacterium Tuberculosis
- TB in GI tract, mainly respiratory illness
- Ileo-caecal tuberculosis is the most common GI site
- gastric ulcers giving gastric outflow obstruction
Complicated Intra-Abdominal Infection definition
Infection of the GI tract that extends beyond the hollow viscus of origin into the peritoneal space and is associated with either abscess formation or peritonitis
- complicated need rapid surgical intervention and treatment
Uncomplicated infections that can become complicated
o Cholecystitis o Diverticulitis o Appendicitis o Gastric/duodenal ulcer - C diff infection
Intra-peritoneal abscess
- Anaerobes most likely cause
- Localised area of peritonitis with build-up of pus/faeces
Intra-peritoneal abscess predisposing factors
- Perforation (may be result of surgery)
- Mesenteric ischemia/bowel infarction
- Pancreatitis/pancreatic necrosis
- Penetrating trauma
- Postoperative anastomotic leak
Intra-peritoneal abscess treatment
- Generally, require
drainage - Drainage: surgical or radiological; combined with antimicrobial therapy
Swinging pyrexia
- Fever (different to most infections), temperature going up and down, abscess get bigger and bigger and periodically release pus and then peak in temp
Subphrenic abscess
- between diaphragm, liver and spleen
- Pain in shoulder on affected side, persistent hiccup, intercostal tenderness, apparent hepatomegaly
Pelvic abscess
- Urinary frequency
- Tenesmus: continuation/recurrent inclination to evacuate the bowels, caused by disorder of the rectum or illness
Post-Operative Infection
- Superficial Surgical Site Infection: SSI-S
- Deep Surgical Site Infection: SSI-D
- Organ space SSI: SSI-O
o Within 30 days of surgery or 1 year if prosthetic infection
Spontaneous Bacterial Peritonitis (SBP) definition
- Ascitic fluid infection without an evident intra-abdominal surgically treatable source
Spontaneous Bacterial Peritonitis (SBP) diagnosis
- Positive ascitic fluid bacterial culture
- Elevated ascitic fluid absolute
- Polymorphonuclear leukocyte (PMN) count.
- Should be clear, milky appearance = infection
Spontaneous Bacterial Peritonitis (SBP) aetiology
- Bacteria within gut lumen cross intestinal wall into mesenteric lymph nodes
- Lymphatics carrying the contaminated lymph ruptures
Spontaneous Bacterial Peritonitis (SBP) Presentation
- The vast majority of patients with SBP have advanced cirrhosis with ascites
Spontaneous Bacterial Peritonitis (SBP) treatment
- Treatment is based upon antibiotics; antibiotic prophylaxis may be given
- Surgically treatable infections, e.g. perforated duodenal ulcer, that lead to ascitic fluid infection are called secondary bacterial peritonitis
Antibiotic prophylaxis for SPB be given to the following patients
o Patients with cirrhosis and GI bleeding
o Patients who have had one+ episodes of SBP
o Patients with cirrhosis and ascites along with either impaired renal function or liver failure
Colonic Malignancy
- Patients with bowel cancer can present with a bacteraemia caused by S. gallolyticus
Colonic Malignancy
- Patients with bowel cancer can present with a bacteraemia caused by S. gallolyticus
Abdominal conditions that require antibiotics
- Appendicitis
- Complicated diverticulitis- antibiotics and surgery
- Pancreatitis - Antibiotics should be withheld until infection is proven with positive cultures
- Oesophageal rupture
