7/30/2019 Case 9 2007 Intra-Abdominal Focus Infection

1/3

Case 9: Bacteraemic infection with an intra-abdominal focus

Clinical outline

92 yr old man

Presented with RUQ pain and vomiting (x5) over one day.

Pain was severe, radiating across abdomen to LUQ.

Gave history of episodic yellowing for many years.

Acute dyspnoea developed while in ED: nebulisers given

Past history includes CVA, LVF (moderate), CAL, AAA repair 1979.

Medications: verapamil, diuretic, inhalers.

O/E: unwell, having rigors, mild jaundice, alert

HR 120/m regular, 140/80, Temp 38

O2sat 94% on 24% mask

Soft BS bilaterally; prolonged exp wheeze, some bi-basal creps

Soft abdomen, distended +, tender over RUQ . No stigmata of liver disease. No splenomegaly.

What is your provisional diagnosis and differential? Pause to think and compose your own answer

before proceeding.

Differential diagnosis

1. Ascending cholangitis with bacteraemia; probable gall stone in the common bile ductThe most likely diagnosis . This patient displays the syndrome called Charcots Triad.

2. Acute cholecystitis3. Alcoholic hepatitis: the degree of pain is out of keeping with this diagnosis. Rigors implies secondary

infection. Tenderness consistent.

4. Early RLZ pneumococcal pneumonia : may present with an acute abdomen, usually with UQ pain,usually pleuritic. Jaundice not infrequently occurs in pneumococcal pneumonia. Pneumonia may not

be clinically apparent at presentation. Absence of cough unusual.

In all likelihood decompensation of LVF and CAL probably responsible for dyspnoea.

Absence of signs of peritonism make perforation less likely though not impossible in an elderly person.

What investigations would be useful to confirm your clinical suspicions?

7/30/2019 Case 9 2007 Intra-Abdominal Focus Infection

2/3

Initial investigation results

Hb 142g/l WCC 13.6 Plt 127

Film comment: Left shift with mild toxic changes. Mild macrocytosis (102fL). Consistent with liver

disease.

bilirubin 69 GGT 223 Alk phos 185 ALT 294 AST 317

Blood cultures taken: Gram negative rods isolated after 2 hrs of incubation

CXR : increase interstitial markings c/w LVF

Abdominal U/S arranged: CBD 9mm in diameter (was 5mm on previous u/s in May 1998). No gall stones

seen.

What is your interpretation of these results?

Interpretation of initial results

The patient has moderately deranged LFTs with a mixed picture c/w cholangitis

Blood cultures confirm bacteraemia; there is a high incidence of bacteraemia in cholangitis

The ultrasound is very suggestive of CBD obstruction with diameter of CBD at the upper limit of normal.

CBD stones may easily be missed on u/s.

What are the management principles for this condition?

Management principles

1. EMPIRIC antibiotic therapy:Patient given gentamicin and ticarcillin/clavualate (Timentin).

More usual protocol is ampicillin/gentamicin with metronidazole (see Antibiotic guidelines).

Principle is to cover aerobic gram negatives and enteric streptococci (S. milleri group and others) well.

Anaerobic cover also important particularly in patients with malignant biliary obstruction. Usual protocol

also covers enterococci which may also contribute though these are seldom the major pathogens and

antibiotics such as timentin that do not cover enterococci usually work.

Temperature, pain and rigors settled over next 48 hrs.

Have a look at the relevant section of the antibiotic guidelines for cholangitis. Are there particular

problems with giving gentamicin in the presence of liver disease or jaundice?

7/30/2019 Case 9 2007 Intra-Abdominal Focus Infection

3/3

1. Early ERCP to relieve CBD obstruction:Relief of obstruction is as crucial as providing antibiotic therapy.

Patient underwent ERCP on day 2; the ampulla of vater was inflamed and after cholangiogram,

spincterotomy was performed. A small gall stone liberated together with dirty-looking bile. A gastric

ulcer, possibly malignant was also found and biopsied.

2. Supportive care: judicious hydration, monitor observations closely etc3. Modify antibiotic therapy in the light of susceptibility of cultures: = DIRECTED THERAPY

Culture from blood identified asE. coli resistant to ampicillin, timentin, cefotaxime and sensitive to

gentamicin, ciprofloxacin, imipenem.

Patient was changed to oral ciprofloxacin 500mg bd and did well. Note that gentamicin not advisable

beyond a few doses in elderly patients and does not penetrate well into bile. However it has a good initial

impact on the bacteraemic component of this disease which is most important. Ciprofloxacin was the

only oral choice available based on susceptibilities. However some elderly can develop an acute

confusional state or tremor while on ciprofloxacin, especially at higher doses, so beware.

This bacterial isolate is probably making an extended spectrum -lactamase (ESBL) enzyme that is able

to destroy ampicillin and third generation cephalosporins. Whilst this enzyme is inhibited by the

clavulanate in timentin, this bacteria is probably producing enough -lactamase to overcome the effect of

clavulanate. Only relatively simple mutations in the usual plasmid-mediated-lactamase (penicillinase

responsible for ampicillin resistance) ofE. coli is required to extend its spectrum to include cefotaxime.

Further reading Antibiotic guidelines 13th Edition