Treatment and Outcomes of VTE in Children with Staphylococcus aureus Osteomyelitis

SAN DIEGO, CA— For children with Staphylococcus aureus osteomyelitis, the presence of venous thromboembolism is associated with a higher C-reactive protein at admission, longer hospital stay, and ICU admission, according to Kavita Patel, MD, from Baylor College of Medicine and Texas Children's Hospital, Houston, TX, at IDWeek 2012.

Dr. Patel and colleagues conducted a retrospective case series analysis to compare the clinical features, treatment, and outcomes of children with community-acquired Staphylococcus aureus osteomyelitis prospectively identified at Texas Children's Hospital from 2005–2010. Statistical methods included use of student T-tests and Fisher's exact tests using STATA 12.

Community-acquired Staphylococcus aureus osteomyelitis was identified in 227 children, of whom 31 (13.7%) had deep venous thrombosis (DVT) and 22 (9.7%) had septic pulmonary emboli (PE). Nineteen out of the 22 children with septic PE had concomitant DVT. Further findings showed that the DVT was adjacent to site of osteomyelitis in 28 of 31 (90%), with 23 of these cases occurring in the proximal lower extremity. In the three children with DVT not adjacent to the site of osteomyelitis, only one of the DVTs was associated with a central line.

DVTs were detected at a mean of 3.7 days (range: 0–21 days). Of those with DVT, more patients were infected with methicillin-resistant Staphylococcus aureus (n=20) compared with methicillin-sensitive Staphylococcus aureus (n=11) (odds ratio 1.9, P=0.11).

C-reactive protein at admission was significantly higher for those with DVT vs. those without DVT (mean 37.2mg/dL vs. 15.8mg/dL, P<0.0001). Also, those with DVT were more likely to be admitted to the intensive care unit (odds ratio 32.2, P=0.0001) and have longer hospital stays (mean 24 days for patients with DVT vs. 11 days for patients without DVT, P<0.0001).

The majority of children were treated with unfractionated heparin and/or enoxaparin. There were two non-life-threatening bleeding episodes. Anticoagulation was generally given for three months (per the American College of Chest Physicians' guidelines) or discontinued earlier if there was bleeding or other contraindication for anticoagulation. The majority of the children had clot resolution (23/31 complete, 4/31 partial, 4/31 lost to follow up). The mean duration of anticoagulation was 85 days (median 89 days, range 2–236 days). Overall survival was 99.6%.

Dr. Patel stated, “Though most DVTs were adjacent to the site of osteomyelitis, they may not be present at the time of osteomyelitis diagnosis and can occur at sites away from the infection. Affected children can then be anticoagulated safely and effectively.”