Background and Goal of Study: Reliable measurements of the intraabdominal pressure are the basis for treatment of intraabdominal hypertension . The intraabdominal pressure (IAP) usually is assessed via the intra-bladder pressure (IBP). The aim of our study was to validate a continuous technique to measure the intraabdominal pressure via a balloon tipped gastric tube (GT, Spiegelberg) connected to an IAP Monitor.
We compared it with the current standard technique of measuring the intrabladder pressure (IBP).
Materials and Methods: We measured the intraabdominal pressure in 14 ICU patients after laparatomy (57.5a ± 19.3; 8m/6f; APACHE II 17.5 ± 6.3; in total 168 paired measurements were performed). All patients were ventilated (BIPAP) and under sedation. We evaluated the correlation of the GT with the intra-bladder pressure at different bladder-volumes (50 ml to 200 ml), the change of the correlation over time (90 minutes) and than we assessed the reaction to external pressure. All values are shown as mean plus/minus standard deviation (MEAN ± SD).
Results and Discussions: We found a good correlation between both methods with an intra-bladder volume of 50 ml (GT = −1.074 + 1.082 ⋆ IBP; R2 = 0.736; p < 0.001). After 60 minutes the correlation was as follows (GT = 1.929 + 0.908 ⋆ IBP; R2 = 0.957; p < 0.001). Bland Altman Analyses showed a good agreement (mean bias was 0.2 ± 4.2)
In each patient we measured the reaction to external pressure with both methods. Both systems reacted immediately to the external pressure. The pressure difference in both systems showed a good correlation (GT = −0.905 + 1.167 ⋆ IBP; R2 = 0.723; p < 0.001).
Conclusion: The balloon tipped gastric tube may be used for assessing reliable the intraabdominal pressure. The validity of the measurement over a longer period as well as the influence of the body position still has to be evaluated.
1 Malbrain, M.L., Different techniques to measure intra-abdominal pressure (IAP): time for a critical re-appraisal. Intensive Care Med, 2004. 30
(3): p. 357-71.