During hospitalization, he continued to have persistently elevated white
blood cell count, with no clear explanation on workup. He was needing
aggressive diuresis for his clinical picture of cardiogenic shock and
associated fluid overload. Multiple sets of blood cultures remained
negative after more than 72 hours of incubation. Computed tomography of
abdomen and pelvis scan revealed no abscess or foci of infection.
He was started on empiric intravenous ceftriaxone given his recent
history of K. oxytoca septicemia. Echocardiograms via both
transthoracic and transesophageal approaches were pursued which showed
preserved left ventricular ejection fraction however was concerning for
native aortic valve endocarditis with severely thickened aortic valve
and a pseudoaneurysm of aortic root.
Cardiothoracic surgery was consulted given findings of valvular
endocarditis with symptoms and signs of left ventricular failure. He
subsequently underwent surgical debridement of aortic annulus and left
ventricular outflow tract with aortic valve replacement.
Intraoperatively, chronic vegetation at the base of the right coronary
cusp with fibrosis of the left ventricular outflow tract was found.
Debrided valve tissue was sent for bacterial, acid-fast bacilli (AFB)
test, fungal cultures and direct DNA sequencing by PCR. Gram stain and
routine bacterial, mycobacterial and fungal cultures of the operative
specimens were negative. However, K. oxytoca specific DNA was
detected on the ribosomal DNA amplification by polymerase chain reaction
of diseased valve/tissue.
The patient clinically improved after a few days’ stay in the cardiac
care unit post-surgery and was continued on intravenous ceftriaxone. He
was able to be discharged home after eleven days of hospitalization and
was continued on intravenous antibiotics via a peripherally inserted
central catheter to complete a four-week course. On a post-hospital
discharge visit to the cardiology clinic, he clinically improved and
continued to participate in physical therapy sessions.