Related Experiment Video
Updated: Jul 18, 2025
Urinary Bladder Distention Evoked Visceromotor Responses as a Model for Bladder Pain in Mice
Published on: April 27, 2014
Abdominal Wall Movements Predict Intra-Abdominal Pressure Changes in Rats: A Novel Non-Invasive Intra-Abdominal
Deirdre Vincent1, Stefan Mietzsch1, Wolfgang Braun2
1Department of Pediatric Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Insights
This study explored a non-invasive method for monitoring intra-abdominal pressure (IAP) in rats. Abdominal surface tension measurements showed a high correlation with IAP, suggesting a potential new monitoring technique.
Area of Science:
- Critical care medicine
- Medical engineering
- Animal physiology
Background:
- Elevated intra-abdominal pressure (IAP) can cause irreversible tissue damage in critically ill patients.
- Current IAP monitoring via urinary bladder catheter has limitations, including complications and unsuitability for neonates.
- A need exists for non-invasive IAP monitoring methods.
Purpose of the Study:
- To develop and validate a non-invasive method for detecting changes in intra-abdominal pressure (IAP).
- To assess the feasibility of using abdominal surface tension measurements for IAP monitoring.
- To utilize an animal model for establishing this novel technique.
Main Methods:
- Intra-abdominal pressure (IAP) was induced in 19 Wistar rats by applying intra-abdominal air (up to 20 mmHg).
- IAP was measured using an intra-abdominally placed intracranial pressure probe.
- Abdominal surface tension was concurrently measured using a Graseby capsule (GC).
Main Results:
- A strong positive correlation (r = 0.9264) was observed between abdominal wall distension and IAP across all subjects.
- Abdominal surface tension measurements demonstrated high accuracy in reflecting IAP changes.
- The Graseby capsule effectively detected IAP variations in the animal model.
Conclusions:
- Intra-abdominal pressure (IAP) changes can be accurately detected non-invasively in rats using a Graseby capsule (GC) by measuring abdominal surface tension.
- This non-invasive method shows promise as an alternative to traditional IAP monitoring techniques.
- Further research is required to evaluate the efficacy of the GC method for IAP measurement in the neonatal population.
Abstract:
(1) Background: As increases in intra-abdominal pressure (IAP) result in irreversible tissue damage, monitoring IAP in critically ill patients using the common urinary bladder catheter method is essential. However, this method can result in complications and is not suitable for very low birth weight neonates. The aim of this study was to establish a non-invasive and accurate method to detect IAP changes using an animal model. (2) Methods: IAP changes via intra-abdominal air application (up to 20 mmHg) were measured in 19 Wistar rats via an intra-abdominally placed intracranial pressure probe. Concurrently, abdominal surface tension was measured using a Graseby capsule (GC). (3) Results: A high correlation between abdominal wall distension and IAP (r = 0.9264, CI 0.9249-0.9279) was found for all subjects. (4) Conclusions: IAP changes in rats can be detected non-invasively using a GC. However, further studies are necessary to assess whether IAP changes can be measured using a GC in the neonatal population.
