Title: VTE in Pediatrics<br/>Author: Megan Cobb<br/><a href='http://umem.org/profiles/resident/1244/'>[Click to email author]</a><hr/><p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Background:</span></span></p> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">There is an increased incidence of venous thromboembolic events (VTE) in pediatrics due to improved diagnosis and survival of children with VTE. </span></span></p> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"> <span><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">The mortality rate is estimated at 2%. </span></span></p> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"> <span><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">The most common etiologies vary by age - </span></span><span style="background-color: transparent; color: rgb(0, 0, 0); font-family: Calibri; font-size: 11pt; white-space: pre-wrap;">Central venous catheters in neonates and infants, and inherited thrombophilia in children and adolescents.</span></p> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; font-weight: 700; vertical-align: baseline; white-space: pre-wrap;">Learning Points: </span></span></p> <ol style="margin-top:0pt;margin-bottom:0pt;"> <li dir="ltr" style="list-style-type: decimal; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline;"> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">With neonates and infants, carefully assess medical history from neonatal period. Umbilical lines? PICC? Broviac? History of these is likely to be the cause.</span></span></p> </li> <li dir="ltr" style="list-style-type: decimal; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline;"> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">In children and adolescents, unprovoked VTE is most likely due to inherited thrombophilia, and can be DVT, PE, Portal venous thrombus, etc.</span></span></p> <ol style="margin-top:0pt;margin-bottom:0pt;"> <li dir="ltr" style="list-style-type: lower-alpha; font-size: 11pt; background-color: transparent; vertical-align: baseline;"> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">Antithrombin deficiency: The first discovered inherited thrombophilia. The result is a lack of inhibition of coagulation factors – IIa, IXa, Xa, XIIa. </span></span></p> </li> <li dir="ltr" style="list-style-type: lower-alpha; font-size: 11pt; background-color: transparent; vertical-align: baseline;"> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">Protein C or/and S deficiency: The result is lack of inhibition of activated Factor V. </span></span></p> </li> <li dir="ltr" style="list-style-type: lower-alpha; font-size: 11pt; background-color: transparent; vertical-align: baseline;"> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">Factor V Leiden: Most common inherited thrombophilic defect. Resultant activated Factor V is resistant to normal Protein C and S activity. </span></span></p> </li> <li dir="ltr" style="list-style-type: lower-alpha; font-size: 11pt; background-color: transparent; vertical-align: baseline;"> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">Prothrombin Mutation: Second most common inherited thrombophilia. The result is increased levels of prothrombin, which increases the half-life of factor Va. </span></span></p> </li> </ol> </li> <li dir="ltr" style="list-style-type: decimal; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline;"> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">Initial treatment of clinically significant VTE can start with enoxaparin (1-1.5 mg/kg q12-24h, while checking Anti-Xa levels 4 hours after administration for therapeutic dosing.) </span></span></p> </li> </ol> <p> </p> <p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"> <span style="background-color: transparent; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); vertical-align: baseline; white-space: pre-wrap;"><strong>Pearl:</strong> Testing for thrombophilia is not always appropriate when diagnosing pediatric patients with their first VTE, but in</span><span style="background-color: transparent; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); font-style: italic; vertical-align: baseline; white-space: pre-wrap;"> children and adolescents</span><span style="background-color: transparent; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); vertical-align: baseline; white-space: pre-wrap;"> with first diagnosed,</span><span style="background-color: transparent; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); text-decoration-line: underline; vertical-align: baseline; white-space: pre-wrap;"> unprovoked </span><span style="background-color: transparent; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); vertical-align: baseline; white-space: pre-wrap;">VTE, it is worthwhile to send off the initial hypercoaguability work up as this can affect the duration of treatment and need for testing or evaluation. <u>Enoxaparin </u></span><span style="background-color: transparent; font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); vertical-align: baseline; white-space: pre-wrap;">is a recommended medication to start therapeutic treatment of VTE, even in pediatric patients. </span></p> <fieldset><legend>References</legend>
<p dir="ltr" style="line-height: 1.295; margin-top: 0pt; margin-bottom: 8pt;"> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">Van Ommen CH, Nowak-Gottl U. </span><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; font-style: italic; vertical-align: baseline; white-space: pre-wrap;">Inherited Thrombophilia in Pediatric Venous Thromboembolic Disease: Why and Who to Treat.</span><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline; white-space: pre-wrap;"> Frontiers in Pediatrics. 2017: 5(20). </span></span></p> <p> <span id="docs-internal-guid-d36123eb-3dd0-e57a-6e46-6b43164a8d05"><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline; white-space: pre-wrap;">The Harriet Lane Handbook, 20</span><span style="font-size: 6.6pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: super; white-space: pre-wrap;">th</span><span style="font-size: 11pt; font-family: Calibri; color: rgb(0, 0, 0); background-color: transparent; vertical-align: baseline; white-space: pre-wrap;"> edition. Chapter 29: Drug Dosages. 2015</span></span></p> </fieldset>