**11. Treatment**

74 Venous Thrombosis – Principles and Practice

shorter duration between the onset of admission for children with DVT compared to those without. (5.6 days versus 14.4 days).9 This lends further support to the possibility that children with musculoskeletal infection and DVT have a more abrupt onset and rapid clinical decline to the point where medical attention is sought. Pulmonary involvement with a variety of manifestations including pneumonia, septic pulmonary emboli, cavitary pneumatoceles, empyema, and various infiltrates was recorded in 36 of the 58 children with

The use of central venous catheters (CVCs) in the treatment of children with musculoskeletal infection has raised the concern that these catheters may be associated with risk including DVT development. Our review noted the concurrent presence of CVLs in several children with DVT, but the conclusions were generally that there was no clear relationship.5,6,9 Hollmig et al. found that CVCs were used in all eleven children with osteomyelitis and DVT in their series.9 However, there did not appear to be a relationship

We reviewed 19 articles (15 case reports1,2,4,5,7,10-19, three studies pertaining to musculoskeletal infection in general3,8,9, and one study focused on an osteomyelitis population6). In estimating the heterogeneity of the three musculoskeletal infection papers (k = 3), we measured the I2 index as our test of heterogeneity and found the I2 index to be 7.7%. The Cochran's Q value was found to be 2.153 (p = 0.3407). This statistic signifies a degree of heterogeneity between the three papers which makes it difficult to derive meaningful conclusions from the summary data from these studies. However, this level of heterogeneity is expected considering several factors such as different study methodology, different timing of the onset of disease, different disease

The incidence rate of DVT was calculated to compare the difference between an incidence rate specific to osteomyelitis and the incidence related to musculoskeletal infection in general. From our results, the number of DVTs in the three musculoskeletal infection papers was 23 with a sample size of 450.3,8,9 Therefore the incidence of DVT in children with musculoskeletal infection was 5.1%. However, in the one paper in which osteomyelitis alone was considered, the number of DVTs was 9 with a sample size of 116.6 Hence, the incidence of DVT with osteomyelitis was 7.8%. Although the differences in incidence could be due to different populations being studied, there does appear to be a higher incidence of DVT specifically with pediatric osteomyelitis as compared to pediatric musculoskeletal infection

Any child with deep musculoskeletal infection, particularly osteomyelitis caused by *Staphylococcus* aureus should be considered at risk for DVT. However, in light of the medical literature, a higher index of suspicion should be held for those children with severe clinical presentation, including: intensive care unit admission, markedly elevated inflammatory indices, lower extremity location of the musculoskeletal infection, need for repeated surgical debridement, and pulmonary involvement with infiltrates or septic pulmonary emboli. These

between the location or temporal onset of the DVT to the CVC in their experience.9

DVT (62.1%).1,2,4-7,9-11,13-19

**9. Statistical analysis** 

severity and different patient groups.

in general. Further research is required in this area.

**10. Evaluation recommendations** 

**8. Central venous catheters** 

Children with DVT and osteomyelitis can be effectively managed with low molecular weight heparin. Resolution of the DVT occurs at an average of ten to twelve weeks.5,9 Follow-up imaging is helpful to ensure resolution of the DVT. In cases refractory to low molecular-weight heparin, consideration may be given to placement of an intravascular filter. Warfarin is also an option, but requires additional effort in managing the prothrombin time (PT) and international normalized ratio (INR) effectively.

Because children with DVT and osteomyelitis may require repeat surgical procedures, care must be taken to appropriately withhold and resume the anticoagulant therapy around periods of surgery to avoid bleeding complications.

#### **12. Conclusions**

Pediatric musculoskleletal infection is associated with the risk for DVT. Risk factors include: osteomyelitis; lower extremity location of infection; *Staphylococcus aureus*, particularly MRSA, as the causative organism; age greater than 4 years; markedly elevated inflammatory indices; severe clinical illness often requiring intensive care unit admission, intubation, or inotrope support; and pulmonary involvement with infiltrates, pneumonia, or septic pulmonary emboli. A high index of suspicion should be maintained when risk factors are present and appropriate screening imaging should be obtained. One study demonstrated a 40% rate of DVT when the child was greater than 8 years of age with positive cultures for MRSA and an initial CRP of greater than 6 mg/dL.9 Consideration may be given to evaluating for the presence of PVL within the bacterial genetics to help further stratify the risk of DVT. Whenever DVT is identified, appropriate treatment should be administered in a timely manner and the child should be monitored until the point of resolution. The anticipated outcome is good.

#### **13. References**


**Part 2** 

**Management and Complications** 

susceptible staphylococcus aureus musculoskeletal infections in children. *The Pediatric Infectious Disease Journal, 23*, 701-706.

