Comparison of direct and intravesical measurement of intraabdominal pressure in children

PurposeThe aim of this study was to compare directly measured intraabdominal pressure with the pressure measured indirectly via urinary catheter using different bladder-filling volumes in children.MethodsProspective observational study in pediatric intensive care unit at a university children's hospital. Three simultaneous measurements of intraabdominal pressure were performed in 14 children, mean age 1.6 months (range, 0.2-56), after cardiac surgery requiring cardiopulmonary bypass directly via an intraperitoneal dialysis catheter and indirectly via indwelling urinary catheter with bladder volumes of 1, 1.5, 2, 2.5, and 3 mL/kg of physiological saline. Of the 14 patients, 9 were mechanically ventilated at the time of the intraabdominal pressure measurements.ResultsDirectly measured intraabdominal pressure ranged between 0 and 10 mm Hg and showed the highest correlation (r = 0.971, P < .0001) with the pressure measured via urinary catheter using bladder-filling volume of 1 mL/kg. The higher the bladder-filling volume, the higher was the overestimation of the intraabdominal pressure and the weaker was the correlation with the direct measurement. Overestimation of intraabdominal pressure was 1.3, 2.0, and 2.9 mm Hg, with bladder volume of 1, 2, and 3 mL/kg, respectively.ConclusionThese data suggest that intravesical pressure closely correlates with intraabdominal pressure in children. A bladder-filling volume of 1 mL/kg is recommended for the measurement of intraabdominal pressure in children with a risk of abdominal compartment syndrome.