A comparison between continuous central venous pressure measurement from right atrium and abdominal vena cava or common iliac vein

Objective: To determine the accuracy of mean continuous central venous pressure (CVP) measurements in the abdominal vena cava. Design: We simultaneously measured the CVP at the superior vena cava or right atrium and at the abdominal vena cava or common iliac vein. The study was conducted at the pediatric intensive care unit of a major university-affiliated medical center. Patients: Nine patients, aged 6 months to 14 years, were included in our study. Measurements and results: Eleven continuous recordings of 12 to 68 min were taken, eight of them while the children were mechanically ventilated. Mean overall CVP ranged from 3 to 30 mmHg. A total of 519 simultaneous recordings were made, of which 515 (99.2%) were within the accepted limits of agreement of +/-2 mmHg: 301 (58%) with Delta CVP of +/-0 mmHg, 189 (36,4%) with Delta CVP of +/-1 mmHg, and 25 (4.8%) with Delta CVP of +/-2 mmHg. The mean pressure difference was -0.22+/-1.52 mmHg. Accuracy was maintained within all ranges of CVP (3-10, 11-20, and 21-30 mmHg) and was not influenced by mechanical ventilation or abdominal fluid collection. Conclusion: In children with no obstruction of blood flow from the abdominal vena cava to the right atrium, the pressure in the abdominal vena cava or common iliac vein accurately reflects the pressure in the right atrium.