Comparisons of Continuous-wave Doppler Ultrasound Monitor and Echocardiography in Cardiac Postoperative Pediatric Patients.

RATIONAL AND OBJECTIVES: Non-invasive cardiac output (CO) measurements are essential during the immediate post-operative course of young, congenital heart repaired patients. The use of the Ultrasonic Cardiac Output Monitor (USCOM) in pediatric intensive care units (PICU) is increasing. The literature on accuracy of USCOM in young, critically ill, mechanically ventilated, hemodynamically supported patients is scarce. We aimed to assess agreement between the USCOM device and echocardiography for measurements of CO in this population. MATERIALS (PATIENTS) AND METHODS: A prospective observational study in a pediatric cardiac intensive care unit (PCICU). Paired CO measurements were taken in young, mechanically ventilated, immediate post-operative patients with exclusion of unrepaired or residual intra-cardiac shunt, using USCOM and echocardiography, by two separate senior performers. Agreement between echocardiography and USCOM was assessed by percentage error and Bland-Altman analysis. RESULTS: One hundred and thirteen comparison scans were performed on 61 patients: mean age 94 ± 111 d, weight 4.7 ± 2.1 kg, vaso-inotropic score 15.3 ± 11, and STAT score 3-4 (46%). Mean USCOM cardiac index (CI) percent difference was -9.6% (45.6) and velocity-time-integral (VTI) 8.9% (34.7). Bland-Altman analyzes demonstrated poor agreement comparing USCOM to echocardiography with regard to CI, stroke volume (SV), VTI and aortic diameter (AO) measurements. CONCLUSION: Our study shows that USCOM underestimates CI in comparison with echocardiography; therefore USCOM should be used with great caution as an absolute estimate or surrogate of CI in neonates and infants in the immediate post-operative, congenital heart surgery period.

Fluid Responsiveness Predictability in Immediate Postoperative Pediatric Cardiac Surgery. Is the Old Slandered Central Venous Pressure Back Again?

OBJECTIVE: Acute low cardiac output (CO) is a frequent scenario in pediatric cardiac intensive care units (PCICU). While fluid responsiveness has been studied extensively, literature is scarce for the immediate postoperative congenital heart surgery population admitted to PCICUs. This study analyzed the utility of hemodynamic, bedside ultrasound, and Doppler parameters for prediction of fluid responsiveness in infants and neonates in the immediate postoperative cardiac surgery period. DESIGN: A prospective observational study. SETTING: University affiliated, tertiary care hospital, PCICU. PARTICIPANTS: Immediate postoperative pediatric patients displaying a presumed hypovolemic low CO state were included. A clinical, arterial derived, hemodynamic, sonographic, Doppler-based, and echocardiographic parameter assessment was performed, followed by a fluid bolus therapy. INTERVENTIONS: Fifteen to 20 cc/kg crystalloid fluid bolus. MAIN OUTCOME MEASURES: Fluid responsiveness was defined as an increase in cardiac index >10% by echocardiography. RESULTS: Of 52 patients, 34 (65%) were fluid responsive. Arterial systolic pressure variation, continuous-Doppler preload parameters, and inferior vena-cava distensibility index (IVCDI) by bedside ultrasound all failed to predict fluid responsiveness. Dynamic central venous pressure (CVP) change yielded a significant but modest fluid responsiveness predictability of area under the curve 0.654 (P = 0.0375). CONCLUSIONS: In a distinct population of mechanically ventilated, young, pediatric cardiac patients in the immediate postoperative period, SPV, USCOM preload parameters, as well as IVC-based parameters by bedside ultrasound failed to predict fluid responsiveness. Dynamic CVP change over several hours was the only parameter that yielded significant but modest fluid responsiveness predictability.

Nitric oxide for post-liver-transplantation hypoxemia in pediatric hepatopulmonary syndrome: case report and review.

HPS is rare in the pediatric population. Liver transplantation is the ultimate treatment for severe HPS. There are only a few case reports and one series of children in whom HPS was the main indication for liver transplantation. Outcome was good in most of them, with full regression of the pulmonary process. However, hypoxemia in the early post-operative course can have severe consequences, and effective treatment modalities are needed. There are rare instances of the use of iNO for the treatment of post-operative hypoxemia. We describe a 10.5-yr-old boy with severe HPS owing to chronic liver disease after bone marrow transplantation. Liver transplantation from a living related donor (the same sister who donated the bone marrow) was complicated by severe hypoxemia on POD 2. iNO was administered via the ventilator circuit and, after extubation, through nasal prongs. It was slowly tapered down and stopped on POD 10. The child had an otherwise uneventful course and was discharged home on POD 21 with normal oxygen saturation. Liver transplantation should be offered to children with severe HPS. iNO can reverse the hypoxemia that may occur after the operation.