1/4/13 Relevant Financial Relationships US in the Complex NICU Patient • I have no disclosures to make Harriet J. Paltiel, MD Boston Children’s Hospital Harvard Medical School US in the NICU US Diagnosis • US is a powerful, inexpensive and ubiquitous tool • Radiographic chest opacities • Particularly suitable for diagnosis and treatment of • Vascular thrombosis critically ill neonates • Diaphragmatic paralysis • Certain imaging procedures and operative • Neonatal sepsis management may be impractical or impossible due • Visceral anatomy in patients with heterotaxy to marginal clinical status of these patients • Minimally invasive bedside diagnostic and interventional techniques highly desirable Radiographic Chest Opacities Vascular Thrombosis • US used to distinguish pleural from parenchymal • Great vessels causes of opacification • Portal vein • Transudates anechoic or echogenic • Renal vein • Exudates more often complex collections with fibrin • Peripheral veins septations – associated pleural thickening and parenchymal abnormality – hemothorax and empyema appear complex with thick fluid and septations • Consolidated lung is echogenic and contains air- filled and/or fluid-filled bronchi 1 1/4/13 Aortic Thrombosis Vena Caval Thrombosis • Usually in neonates • Indwelling catheters • Complication of umbilical artery catheterization • Dehydration • Clotting and cardiovascular disorders • Sepsis • Associated with renal artery thrombosis • Tumor • Most patients symptomatic • Usually due to spread from veins in lower limb, – catheter dysfunction, hematuria, hypertension pelvis, kidney or liver • Duplex and color Doppler US determine extent of • Focal expansion of vessel lumen thrombosis and monitor changes in flow during • Echogenicity of thrombus depends on its age treatment – chronic thrombi may calcify • Flow reconstituted via collateral vessels • Color Doppler reveals intraluminal filling defect • Long-term sequelae: • Spectral analysis produces no signal – hypertension and lower extremity growth impairment Portal Vein Thrombosis Renal Vein Thrombosis • Dehydration • More common than renal artery thrombosis • Shock • Prematurity • Umbilical vein catheterization • Prothrombotic abnormalities • Coagulopathy • Central venous line • Diabetic mother • Cirrhosis • Asphyxia • Budd-Chiari syndrome • Infection • Tumor • Infants:! • Pylephlebitis – thrombosis initiated in interlobular and arcuate veins! • Older children: ! – thrombosis initiated in IVC and extends into renal vein! Renal Vein Thrombosis Peripheral Veins: Indications for US • Acute: • Chronic occlusion due to IV catheter use and venous – flank pain, hematuria thrombosis results in difficult central venous access • Chronic: in many hospitalized and chronically ill patients – venous collaterals, insignificant symptoms • Outcome varies from complete recovery to severe • US ideal for identifying renal atrophy: suitable sites for venous access – depends on rapidity and extent of venous occlusion – venous recanalization and/or collaterals result in decreased edema, arterial reperfusion and improved outcome 2 1/4/13 Diaphragmatic Paralysis Neonatal Sepsis • Phrenic nerve injury • Early-onset in first week of life – birth trauma, cardiac surgery, TE fistula repair, chemical – maternally transmitted prior to or during delivery injury from parenteral fluid extravasation – risk factors include group B streptoccocal infection during • Infants dependent on diaphragmatic function for pregnancy, preterm delivery, prolonged rupture of adequate ventilation membranes, chorioamnionitis – poorly developed intercostal muscles, mobile mediastinum • Late-onset between days 8 and 89 days of life • Prompt diagnosis permits early diaphragmatic – risk factors include prolonged hospitalization, indwelling catheters plication which reduces incidence of severe lung infections and mortality in selected patients • US useful in identifying focal sites of infection, including abscesses and fluid collections • Advantage of US diagnosis over fluoroscopy is lack of ionizing radiation and portability Visceral Anatomy in Heterotaxy Patients with Heterotaxy • Disordered development of left-right body axis with • Male-to-female ratio 2:1 abnormal arrangement of thoracic and/or abdominal • Known environmental risk factors: viscera – twin gestation, maternal diabetes, maternal cocaine use • Ciliopathy • Wide phenotypic spectrum and range of associated • Group of genetically and phenotypically congenital anomalies has hindered clinical care and heterogeneous disorders research • Ciliary dysfunction common pathological • Clinical evaluation focused on delineating anatomy mechanism and managing the congenital anomalies • Specific clinical features dictated by subtype, • Visceral situs anomalies, congenital heart defects, structure, distribution, and function of affected cilia asplenia or polysplenia, biliary atresia, midline defects Conclusion • US is a versatile, noninvasive tool that provides rapid anatomical and physiological information critical to the management of the fragile NICU patient 3 .