1. CLINICAL PROBLEM SOLVING
„Batteries not included”
Antea Topić MD, PhD

2. History
60-y-old man was admitted to hospital with a 30-d history of fever (up to 39° C), weakness, occasional diarrhea and coughing
medical history included PTSD and surgical treatment of a perforated duodenal ulcer
20 y ago a pacemaker was implanted because of extreme bradycardia and recurrent syncope
3 y ago an afunctional generator was removed
pacemaker lead was left in situ; it perforated the skin 6 m earlier

3. Patient examination
febrile (39.2° C), BP 100/65 mmHg, HR 92/min, respirations 18/min
a painless wound with a perforating lead under the right clavicle was present (no surrounding erythema or tenderness)
regular heart rhythm with a midsystolic murmur (2/6) left of the sternal border

4. Presumed clinical diagnosis
pneumonia
infectious diarrhea
bacteraemia
FUO
endocarditis/lead infection
More than one answer possible...

5. Correct answers: pneumonia infectious diarrhea bacteraemia FUO
endocarditis/lead infection

6. Next step(s)? chest X-ray blood cultures ECG echocardiogram
basic blood tests
all of the above

7. Correct answer: chest X-ray blood cultures ECG echocardiogram
basic blood tests
all of the above

8. Diagnostic test results
CRP – mg/l
tWBC count – 24.5×109/l with mature neutrophilia
RBC count – 3.75×1012/l, haemoglobin – 112 g/l
platelet count – 56×109/l

9. Diagnostic test results (continued)
ECG – normal
transthoracic echocardiogram – a mass (12 mm) attached to the pacemaker lead in the right ventricle
heart valve function – normal
Chest X-ray – abandoned pacemaker lead

10. Diagnostic test results (continued)
3 separate sets of blood cultures grew Staphylococcus lugdunensis susceptible to:
penicillin, oxacillin, vancomycin, gentamicin, cipro-floxacin, rifampicin, azithromycin, clindamycin, linezolid, tigecycline, co-trimoxazole, and mu-pirocin
the MICs were: penicillin mg/l, oxacillin 0.25 mg/l, and vancomycin 0.5 mg/l

11. Staphylococcus lugdunensis
is a Gram positive bacterium
is a separate species of coagulase negative staphylococci (CoNS)
is an important pathogen in the cardiovascular system infections
infections tend to have a more fulminant course, resembling that of S. aureus rather than those caused by CoNS
is a member of common skin flora
all of the above

12. Correct answer: is a Gram positive bacterium
is a separate species of coagulase negative staphylococci (CoNS)
is an important pathogen in the cardiovascular system infections
infections tend to have a more fulminant course, resembling that of S. aureus rather than those caused by CoNS
is a member of common skin flora
all of the above

13. S. lugdunensis was named after discovery in:
Lyon (France)
Lu’an (China)
Lugano (Switzerland)
Lug (Germany)
Luxembourg (Luxembourg)

14. Correct answer: Lyon (France): its Latin name – Lugdunum Lu’an (China)
Lugano (Switzerland)
Lug (Germany)
Luxembourg (Luxembourg)

15. Diagnosis is: S. lugdunensis endocarditis S. lugdunensis bacteraemia
S. lugdunensis pacemaker lead infection
S. lugdunensis blood contamination

16. Correct answer: S. lugdunensis endocarditis S. lugdunensis bacteraemia
S. lugdunensis pacemaker lead infection
S. lugdunensis blood contamination

17. Patient management: vancomycin gentamicin
penicillin/oxacillin/flucloxacillin
clindamycin
lead extraction

18. Correct answers: vancomycin gentamicin
penicillin/oxacillin/flucloxacillin
clindamycin
lead extraction

19. Pacemaker lead extraction
Lead removal is warranted in following circumstances:
TTE/TEE demonstrating valve or lead vegetation
positive blood culture with S. aureus, CoNS, Propionibacterium sp., Candida sp.
pocket infection
high-grade bacteraemia due to an organism that commonly causes endocarditis, i.e. streptococci or enterococci
transvenous extraction/surgical removal

20. Clinical course Treatment: flucloxacillin (2 g every 4 h i.v.)
percutaneous lead extraction performed with no complications during 1-d monitoring
microbiological analyses of the vegetation of the extracted pacemaker lead also yielded S. lugdunensis of same susceptibility
six days after admission the patient started complaining of chest pain above the right costal margin

21. Clinical course (continued)
Chest X-ray (supine)
The presumed diagnosis:
hospital pleuropneumonia
haematothorax
septic pulmonary embolism
heart failure

22. Correct answer: hospital pleuropneumonia haematothorax
septic pulmonary embolism
heart failure
Right-heart endocarditis can lead to septic pulmonary embolism (SPE). SPE has different imaging findings, such as nodules, patchy infiltrates, cavities, pleural effusions, gangrene, absceses and infarction.

23. Clinical course (continued)
CT pulmonary angiography confirmed a presumed pulmonary embolism
transthoracic echocardiogram – normal heart valve and systolic function, with mild tricuspid regurgitation
because of persisting fever and recurrent S. lugdunensis bacteraemia – treatment modified; linezolid (600 mg bid) added to flucoloxacillin for the next 10 days
therapeutic pleural puncture was performed

24. Clinical course (continued)
defervescence occurred after 2 weeks
the patient became afebrile with clinical and laboratory improvements
surveillance blood cultures – negative
patient finished 4 weeks of flucloxacillin therapy and has done well since discharge
follow-up 1 m since discharge – uneventful

25. Summary
Despite the clinical severity, the patient was managed successfully by an antimicrobial treatment. Pacemaker lead extraction was, most probably, crucial for his survival.