Today, I had a mock OSCE. OSCE, being the clinical exam I’m going to have to do at the end of this academic year i.e. pretty soon. You have a rotation of different stations, 10 minutes each, and stations consist of examinations on patients, taking histories and performing clinical skills, like taking bloods and blood pressure. I did well overall, but have things that I need to improve on. It’s over 2 hours long, and a really tiring exam, and you keep introducing yourself at each station, and I almost always forget their name and always forget their age, especially when it is a student in the year above, who is meant to be in their 60s. Oh, and I was trying to take blood pressure today, without actually pushing the ‘on’ button, because all the manual blood pressure machines I have ever used, do not have ‘on’ buttons.
Definition: Liver infection resulting in a walled off collection of pus
Pyogenic- E.coli, Klebsiella, enterococcus, bacteroides, streptococci, staphylococci
Biliary tract disease (60%)- e.g. gallstones, strictures, cryptogenic
Protozoa- Entamoeba histolytica
Other bacteria- Clostridium perfringens (rare presentation, gas-forming liver abscess), Nocardia species, Brucellosis, Aeromonas hydrophilia, TB
Risk factors: travel, immunocompromised
Pyogenic- incidence = 0.8 in 100,000- most common liver abscess in industrialised world
Amoebic- most common type of liver abscess worldwide
-high swinging fever
-malaise, nausea, anorexia
-right upper quadrant pain or epigastric pain, which may radiate to the shoulder (if diaphragmatic irritation)
-chest pain (e.g. if intrapleural rupture)
-may have prior history of amoebic dysentery
-tender hepatomegaly (right lobe affected more commonly than left)
-pyrexia (continuous or spiking)
-dull percussion note and reduced breath sounds at right lung base (reactive pleural effusion)
Bloods: FBC- raised WCC, mild anaemia, eosinophilia if parasitic cause
LFTs- normal or deranged (raised conjugated bilirubin, raised AlkPhos)
Stool microscopy, cultures- for E.histolytica eggs
Liver ultrasound/CT- localises structure of mass
+/- Aspiration & culture of abscess material– most pyogenic liver abscesses are polymicrobial. Amoebic abscesses contain ‘anchovy sauce’ fluid of necrotic hepatocytes and trophozoites.
CXR- right pleural effusion or atelectasis, raised right hemidiaphragm
→Needle aspiration (U/S or CT guided) if ≤ 5cm or percutaneous catheter drainage if > 5cm.
→Surgical drainage for multiple/loculated abscesses, abscesses with viscous contents or inadequate response to percutaneous drainage within 7 days.
→IV broad-spectrum antibiotics until sensitivities are known (e.g. metronidazole and ceftriaxone), switching to oral when there is a clinical response. Complete a 4-6 wk course.
Amoebic liver abscess
→TINIDAZOLE (2g/24h) for 5 days +/- ultrasound guided aspiration if not improving within days.
-rupture and dissemination e.g. into biliary tract causing acute cholangitis. intrathoracic rupture or peritonitis
-untreated pyogenic abscesses are often fatal and complications have high mortality
-amoebic abscesses have a better prognosis and usually quick response to therapy
References: Rapid Medicine, Cheese & Onion