Validation of continuous intraabdominal pressure measurement: feasibility and accuracy assessment using a capsular device in in-vivo studies

BACKGROUND

Monitoring Intraabdominal Pressure (IAP) is essential in critical care, as elevated IAP can lead to severe complications, including Abdominal Compartment Syndrome (ACS). Advances in technology, such as digital capsules, have opened new avenues for measuring IAP non-invasively. This study assesses the feasibility and effectiveness of using a capsular device for IAP measurement in an animal model.

METHOD

In our controlled experiment, we anesthetized pigs and simulated elevated IAP conditions by infusing CO2 into the peritoneal cavity. We compared IAP measurements obtained from three different methods: an intravesical catheter (IAPivp), a capsular device (IAPdot), and a direct peritoneal catheter (IAPdir). The data from these methods were analyzed to evaluate agreement and accuracy.

RESULTS

The capsular sensor (IAPdot) provided continuous and accurate detection of IAP over 144 h, with a total of 53,065,487 measurement triplets recorded. The correlation coefficient (R²) between IAPdot and IAPdir was excellent at 0.9241, demonstrating high agreement. Similarly, IAPivp and IAPdir showed strong correlation with an R² of 0.9168.

CONCLUSION

The use of capsular sensors for continuous and accurate assessment of IAP marks a significant advancement in the field of critical care monitoring. The high correlation between measurements from different locations and methods underscores the potential of capsular devices to transform clinical practices by providing reliable, non-invasive IAP monitoring.

Differential Effects of Intra-Abdominal Hypertension and ARDS on Respiratory Mechanics in a Porcine Model

Background and Objectives: Intra-abdominal hypertension (IAH) and acute respiratory distress syndrome (ARDS) are common concerns in intensive care unit patients with acute respiratory failure (ARF). Although both conditions lead to impairment of global respiratory parameters, their underlying mechanisms differ substantially. Therefore, a separate assessment of the different respiratory compartments should reveal differences in respiratory mechanics. Materials and Methods: We prospectively investigated alterations in lung and chest wall mechanics in 18 mechanically ventilated pigs exposed to varying levels of intra-abdominal pressures (IAP) and ARDS. The animals were divided into three groups: group A (IAP 10 mmHg, no ARDS), B (IAP 20 mmHg, no ARDS), and C (IAP 10 mmHg, with ARDS). Following induction of IAP (by inflating an intra-abdominal balloon) and ARDS (by saline lung lavage and injurious ventilation), respiratory mechanics were monitored for six hours. Statistical analysis was performed using one-way ANOVA to compare the alterations within each group. Results: After six hours of ventilation, end-expiratory lung volume (EELV) decreased across all groups, while airway and thoracic pressures increased. Significant differences were noted between group (B) and (C) regarding alterations in transpulmonary pressure (TPP) (2.7 ± 0.6 vs. 11.3 ± 2.1 cmH2O, p < 0.001), elastance of the lung (EL) (8.9 ± 1.9 vs. 29.9 ± 5.9 cmH2O/mL, p = 0.003), and elastance of the chest wall (ECW) (32.8 ± 3.2 vs. 4.4 ± 1.8 cmH2O/mL, p < 0.001). However, global respiratory parameters such as EELV/kg bodyweight (-6.1 ± 1.3 vs. -11.0 ± 2.5 mL/kg), driving pressure (12.5 ± 0.9 vs. 13.2 ± 2.3 cmH2O), and compliance of the respiratory system (-21.7 ± 2.8 vs. -19.5 ± 3.4 mL/cmH2O) did not show significant differences among the groups. Conclusions: Separate measurements of lung and chest wall mechanics in pigs with IAH or ARDS reveals significant differences in TPP, EL, and ECW, whereas global respiratory parameters do not differ significantly. Therefore, assessing the compartments of the respiratory system separately could aid in identifying the underlying cause of ARF.

Intra-abdominal hypertension and increased acute kidney injury risk: a systematic review and meta-analysis

OBJECTIVE

The present meta-analysis aimed to determine the relationship between intra-abdominal hypertension (IAH) and an increased prevalence of acute kidney injury (AKI) and identify the associated risk factors in various patient populations, regardless of whether they were admitted to an intensive care unit.

METHODS

We used three databases for the following search terms: "IAH," "abdominal compartment syndrome," "AKI," "acute kidney failure," and others. The articles retrieved were compared to identify appropriate studies published until 7 May 2020. The main outcome was AKI.

RESULTS

Six studies with 344 individuals were included. The patients were divided into two main groups: the IAH and non-IAH groups. Compared with patients without IAH, patients with IAH had a higher risk of AKI (odds ratio = 2.57, 95% confidence interval: 1.55-4.26). In the subgroup and meta-regression analyses, body mass index, age, the presence or absence of burns, and cardiac surgery did not affect the risk of AKI.

CONCLUSION

IAH was associated with AKI risk, and this association was not influenced by age, body mass index, the presence or absence of burns, or cardiac surgery.