Comparison of CVP Measurements in the Intrathoracic and the Intraabdominal Vena Cava in Pediatric Cardiac Surgical Patients

Abstract

Background: Although concerns exist as to the safety of placing central venous catheters via the internal jugular or subclavian veins, central venous catheterization is often performed in pediatric patients undergoing cardiac surgery and cardiopulmonary bypass. We hypothesized that central venous pressures (CVP) measured in the inferior vena cava by the femoral venous approach accurately reflect those in the superior vena cava. Methods: We simultaneously measured CVP at the superior vena cava and at the abdominal vena cava or common iliac vein in 56 children scheduled for cardiac surgery. A total of 133 data pairs were collected. A single lumen, femoral catheter and an intrathoracic catheter, according to patient weight were placed intraoperatively in all patients. Results: The ages of the patients ranged from 5 days to 84 months (mean 13.1 months), and heights from 44 to 111 cm (mean 71.8 cm). Measurements of the central venous pressure in the inferior vena cava and in the superior vena cava correlated well (r = 0.93 for spontaneous ventilation, r = 0.85 for mechanical ventilation with a closed sternum, r = 0.69 for mechanical ventilation with an open sternum). Conclusions: We conclude that while central venous pressures measured in the inferior and superior vena cava are not statistically identical, that differences between the two are well within clinically acceptable limits.