Pulmonary embolism in the pediatric patient

Adolescent Fat Embolism Syndrome after Closed Tibial Shaft Fracture: Treatment with Emergent External Fixation

Case

An adolescent male developed fat embolism syndrome 24 hours after sustaining a closed right tibial shaft fracture in a football game. The patient was treated with emergent external fixator application due to declining respiratory and mental status and experienced swift recovery after stabilization. He was treated with an intramedullary nail within 1 week of injury.

Conclusion

Pediatric fat embolism syndrome is uncommon, and a high index of suspicion is required to facilitate appropriate orthopaedic involvement. External fixation can be performed emergently with minimal fracture manipulation. Rapid provisional fixation appears to have facilitated recovery in this example.

Fat Intravasation from Intraosseous Flush and Infusion Procedures

STUDY HYPOTHESIS

The primary study objective was to delineate the procedural aspects of intraosseous (IO) infusions responsible for fat intravasation by testing the hypothesis that the fat content of effluent blood increases during IO infusions.

METHODS

IO cannulas were inserted into the proximal tibiae of 35 anesthetized swine (Sus scrofa, 50.1 ± 3.5 kg) and intravasated fat was assessed using a lipophilic fluoroprobe (Nile red) and by vascular ultrasound imaging. Effluent blood bone marrow fat was assessed at baseline, during flush, and with regimens of controlled infusion pressures (73-300 mmHg) and infusion flow rates (0.3-3.0 mL per second). Fat intravasation was also assessed with IO infusions at different tibial cannulation sites and in the distal femur. In 7 animals, the lipid uptake of alveolar macrophages and lung tissue assessed for fat embolic burden using oil red O stain 24 hours post infusion. Additionally, bone marrow shear-strain was assessed radiographically with IO infusions.

RESULTS

Fat intravasation was observed during all IO infusion regimens, with subclinical pulmonary fat emboli persisting 24 hours post infusion. It was noted that initial flush was a significant factor in fat intravasation, low levels of intravasation occurred with infusions ≤300 mmHg, fat intravasation and bone marrow shear-strain increased with IO infusion rates, and intravasation was influenced by cannula insertion site. Ultrasound findings suggest that echogenic particles consistent with fat emboli are carried in fast and slow venous blood flow fields. Echo reflective densities were observed to rise to the nondependent endovascular margins and coalesce in accordance with Stoke's law. In addition, ultrasound findings suggested that intravasated bone marrow fat was thrombogenic.

CONCLUSION

Results suggest that in swine the intravasation of bone marrow fat is a common consequence of IO infusion procedures and that its magnitude is influenced by the site of cannulation and infusion forces. Although the efficacy and benefits of IO infusions for emergent care are well established, emergency care providers also should be cognizant that infusion procedures affect bone marrow fat intravasation.

Deep vein thrombosis and septic pulmonary emboli with MRSA osteomyelitis in a pediatric patient

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are relatively rare occurrences in the pediatric population. However, DVT and PE are associated with significant morbidity and mortality to the patient if not promptly diagnosed and treated. We describe the case of a 5-year-old boy that was diagnosed in our emergency department with DVT and PE. The underlying etiology was osteomyelitis of the left tibia caused by community-acquired methicillin-resistant Staphylococcus aureus. The patient had a prolonged hospital course with multiple complications but was eventually discharged in a good condition. In areas with a high prevalence of community-acquired methicillin-resistant S. aureus, it is important for physicians in the emergency department to be aware of the rare, but potentially fatal, complications of infection, including DVT with PE from septic emboli.

Pediatric cardiac emergencies: Children are not small adults

Compared with adults, cardiac emergencies are infrequent in children and clinical presentation is often quite variable. In adults, cardiac emergencies are most commonly related to complications of coronary artery disease; however, in pediatric cases, the coronaries are only rarely the underlying problem. Pediatric cardiac emergencies comprise a range of pathology including but not limited to undiagnosed congenital heart disease in the infant; complications of palliated congenital heart disease in children; arrhythmias related to underlying cardiac pathology in the teenager and acquired heart disease. The emergency room physician and pediatric intensivist will usually be the first and second lines of care for pediatric cardiac emergencies and thus it is imperative that they have knowledge of the diverse presentations of cardiac disease in order to increase the likelihood of delivering early appropriate therapy and referral. The objective of this review is to outline cardiac emergencies in the pediatric population and contrast the presentation with adults.

Anticoagulation therapy: indications, monitoring, and complications

Anticoagulation for thromboembolic disease and bleeding, the main complication of anticoagulation therapy, are uncommon but are potentially life- or limb-threatening conditions that may present in the pediatric emergency department. Thromboembolic disease in children usually occurs as a complication of vascular access, primarily in children with congenital heart disease or cancer. However, complications of anticoagulation therapy used in the treatment of venous thromboembolism, pulmonary embolism, and blocked central venous catheter; arterial thromboembolism, including arterial ischemic stroke, Kawasaki disease, and after cardiac surgery, may warrant a visit to n the pediatric emergency department. Anticoagulation therapy may take the form of unfractionated heparin, low-molecular weight heparin, vitamin K antagonists, acetylsalicylic acid, or thrombolytic therapy. Monitoring anticoagulation therapy in children is very important and follows adult guidelines. Anticoagulant dosing may be adjusted based on activated partial thromboplastin time, anti-factor Xa level, and international normalized ratio.

Approach to the child with chest pain

Children frequently present to a pediatric office or emergency department with the complaint of chest pain. Between 0.3% and 0.6% of visits to a pediatric emergency department are for chest pain. Unlike adult patients with chest pain, most studies have shown that children with chest pain rarely have serious organic pathology. Infrequently, a child with chest pain will present with significant distress and require immediate resuscitation. Most children with chest pain are not in extremis, and for many, the pain is not acute in nature.

Pneumothorax, pneumomediastinum, and pulmonary embolism

This article discusses pneumothorax, pneumomediastinum, and pulmonary embolism in pediatric practice. Although children appear to have better outcomes than adults, the risk factors are substantial. Topics covered include the pathophysiology incidence, presentation, diagnosis, and management of these diseases.

Calcified pulmonary thromboembolism in a child with sickle cell disease: value of multidetector CT in patients with acute chest syndrome

The incidence of pulmonary embolism in children is not clearly known, but is believed to be low. Risk factors for pulmonary thromboembolism include central venous catheter, malignancy, surgery, infection, trauma, and congenital hypercoagulable disorders. Children with sickle cell disease are prothrombotic and are at an increased risk of thromboembolism. The incidence of this event is unknown because these children are often not thoroughly imaged. We report here a case of a calcified pulmonary thromboembolism in a child with sickle cell disease and emphasize the use of multidetector CT in detection of pulmonary thromboembolism in children with sickle cell disease.

Venous thrombosis associated with staphylococcal osteomyelitis in children

BACKGROUND

Venous thrombosis (VT) in children with Staphylococcus aureus osteomyelitis occurs rarely. We describe clinical features of infections and molecular characterization of isolates of children at Texas Children's Hospital with S aureus osteomyelitis and VT.

METHODS

We reviewed records and imaging studies (chest radiographs, ultrasound, computed tomography, and MRI) of 9 patients at Texas Children's Hospital with acute S aureus osteomyelitis and new onset VT between August 1999 and December 2004. Isolates were fingerprinted by pulsed-field gel electrophoresis and tested for the presence of genes encoding selective virulence factors.

RESULTS

The mean age of the patients was 10.6 years. All 9 of the patients had osteomyelitis with sites of infection adjacent to the VT. The femoral and popliteal veins were most commonly affected. Two patients had VTs develop on the same side in which a central line had been in place. Four patients had chest radiographs consistent with septic emboli; inferior vena cava filters were placed in 3. Evaluation for hypercoagulable state revealed 3 patients with lupus anticoagulant, 1 with anticardiolipin IgG antibody, and 5 with no defect. Most laboratory abnormalities had resolved at follow-up. Seven patients had infections caused by methicillin-resistant S aureus belonging to the same clonal group (USA300); all were community acquired. Seven isolates carried the Panton-Valentine leukocidin (luk-S-PV and luk-F-PV) genes.

CONCLUSIONS

The predominant community-acquired, methicillin-resistant S aureus clone in Houston, Texas, (USA300) may have a unique propensity to cause VT in association with osteomyelitis. Management of the venous thrombosis in this setting may be complicated by the rapid evolution of septic emboli.