3-Dimensional sonographic volumetry of fetal brain, liver and myocardial mass--interdisciplinary clinical validation of the method and application in fetuses with and without structural heart disease.

BACKGROUND: Prenatal 3-dimensional (3D) ultrasound allows volumetry of the fetal brain, liver and measurement of myocardial mass (MM). We studied the reliability of this method in an interdisciplinary approach, defined the relation of the values throughout gestation, and evaluated the results in fetuses with congenital heart disease (CHD). METHODS: In 104 fetuses (39 with CHD) between 14 and 38 weeks of gestation 3D ultrasound was prospectively performed. Data sets of brain, abdomen and heart were stored for off-line analysis of volumes and MM. Descriptive statistics, coefficients of correlation and of variation (CV) were performed. RESULTS: Volumetric data set acquirement was feasible in all pregnancies, lasted approximately 10 min, but off-line analysis was feasible in only 66% lasting about 45 min. MM increased in a linear fashion during gestation. CV were 11.0 and 10.8 for the left, 14.39 and 12.66, respectively, for the right MM. Median ratio between right and left MM was 0.88 in normal fetuses, and 8.25 in fetuses with hypoplastic left heart syndrome. Intra- and interobserver variabilities revealed CVs of 2.46 and 11.80, respectively, for brain volumetry, and CVs of 3.16 and 29.2, respectively, for liver volumetry. Both brain and liver volumes were positively associated with gestational age, and did not show different growth patterns in fetuses with CHD. CONCLUSIONS: Prenatal volumetry is time-consuming, but reliable especially for left MM and brain volume. Linear growth of brain and liver volume is present in utero irrespective of CHD. Application of our reference graphs of MM growth allows early differentiation in CHD.

Cardiac index monitoring by pulse contour analysis and thermodilution after pediatric cardiac surgery.

OBJECTIVES: To validate a new device (PiCCO system; Pulsion Medical Systems, Munich, Germany), we compared cardiac index derived from transpulmonary thermodilution and from pulse contour analysis in pediatric patients after surgery for congenital heart disease. We performed a prospective clinical study in a pediatric cardiac intensive care unit of a university hospital. METHODS: Twenty-four patients who had had cardiac surgery for congenital heart disease (median age 4.2 years, range 1.4-15.2 years) were investigated in the first 24 hours after admission to the intensive care unit. A 3F thermodilution catheter was inserted in the femoral artery. Intracardiac shunts were excluded by echocardiography intraoperatively or postoperatively. Cardiac index derived from pulse contour analysis was documented in each patient 1, 4, 8, 12, 16, 20, and 24 hours after admission to the intensive care unit. Subsequently, a set of three measurements of thermodilution cardiac indices derived by injections into a central venous line was performed and calculated by the PiCCO system. RESULTS: The mean bias between cardiac indices derived by thermodilution and those derived by pulse contour analysis over all data points was 0.05 (SD 0.4) L x min x m(-2) (95% confidence interval 0.01-0.10). A strong correlation between thermodilution and contour analysis cardiac indices was calculated (Pearson correlation coefficient r = 0.93; coefficient of determination r2 = 0.86). CONCLUSIONS: Pulse contour analysis is a suitable method to monitor cardiac index over a wide range of indices after surgery for congenital heart disease in pediatric patients. Pulse contour analysis allows online monitoring of cardiac index. The PiCCO device can be recalibrated with the integrated transpulmonary thermodilution within a short time frame.

Cardiac output determination in children: equivalence of the transpulmonary thermodilution method to the direct Fick principle.

OBJECTIVE: To show the equivalence of the transpulmonary thermodilution method to the direct Fick principle in children. DESIGN: Prospective single-centre study. SETTING: A 16-bed paediatric cardiac ICU and a cardiac catheterisation laboratory at an university affiliated centre for paediatric cardiology and congenital heart disease. PATIENTS: We consecutively investigated 18 patients (mean age 12.1 +/- 6.4 years) during cardiac catheterisation and after corrective cardiac operation. METHODS AND RESULTS: We prospectively defined limits of equivalence for cardiac index (CI) for both methods of +/- 0.25 l/min x m(2). We measured oxygen consumption for determination of CI by Fick as the clinical "gold standard" and performed a set of three transpulmonary thermodilution measurements. The mean CI(Fick) was 2.88 +/- 1.07 l/min x m(2) (range 1.10-4.62 l/min x m(2)) and CI(TPID)was 2.85 +/- 1.03 l/min x m(2)(range 1.02-4.49 l/min x m(2)). The mean difference between CI(Fick) and CI(TPID)was 0.030 +/- 0.168 l/min x m(2), and limits of agreement -0.306 to 0.366 l/min x m(2)(90% confidence interval -0.040 to 0.099 l/min x m(2)). The regression equation was : CI(Fick)=1.0244 x CI(TPID)-0.040, r(2) = 0.976, P < 0.0001. The intraclass coefficient of reliability for three repeated measurements of CI(TPID) was 0.97, the corresponding lower limit of the 95% confidence interval was 0.94. CONCLUSION: We demonstrated the equivalence of CI measurement by transpulmonary thermodilution and the Fick principle in children. This new method may improve hemodynamic monitoring and management in seriously ill children.