Bacteremia duration provesunreliable in identifying who will be affected.
Bacteremia duration does not accurately predict which hemodialysis(HD) patients will develop endocarditis, according to researchers.
The finding is based on a study of 443 HD patientshospitalized with Staphylococcus aureusbacteremia. All had at least one blood culture positive for S. aureus during their hospital stay.
Theinvestigators identified endocarditis in 85 patients (19%). The mean duration ofthe infection was 4.3 days and was longer for patients withmethicillin-resistant S. aureus thanfor those with methicillin-sensitive S.aureus (8.1 vs. 4.3 days).
Although the duration of bacteremia was associated with anincreased likelihood of developing endocarditis, it had poor sensitivity andspecificity for predicting the condition, the researchers reported. Sensitivitywas 74.1% at 72 hours and 55.3% at 96 hours. Specificity was 52.7% at 72 hoursand 64.0% at 96 hours.
“We were surprised because there were studies showing thatduration of bacteremia was associated with increased incidence ofendocarditis,” said study investigator Jyoti Gulia, MD, a resident atWashington Hospital Center in Washington, D.C.
“It was believed that the longerthe duration of bacteremia, the higher the risk of endocarditis, but about25.8% of the patients [with endocarditis] had a bacteremia duration of lessthan 48 hours, which is far below the clinical index of suspicion….So if youare going to wait for two to three days of bacteremia [before ordering anechocardiogram], you are going to miss this large fraction of patients.”
Staphylococcus aureusis the most common cause of bacteremia in chronic hemodialysis patients. It isassociated with a 20% higher risk of death compared with other organisms.Previous research has shown that one fourth of patients with S. aureus bacteremia may developendocarditis, leading to even higher morbidity and mortality.