Pre-Clinical Validation of A Novel Continuous Intra-Abdominal Pressure Measurement Equipment (SERENNO)

Introduction: Increased intra-abdominal pressure (IAP) has an important impact on morbidity and mortality in critically ill patients. The SERENNO Sentinel system (Serenno Medical, Yokne'am Illit, Israel) is a novel device that allows automatic and continuous IAP measurements. Aims: Pre-clinical validation in a bench model study comparing the new device with the gold standard method and two other continuous IAP measurement devices. Methods: IAP measurement with the novel SERENNO device (IAP_SER) was compared with the gold standard IAP_H2O (water column height) and two other automatic and continuous IAP measurement devices: IAP_CiM measured via the CiMON device (Pulsion Medical Systems, Munich, Germany) and IAP_SPIE measured using the Spiegelberg device (Spiegelberg, Hamburg, Germany), which previously received the CE mark for clinical applications. The IAP measurement was performed six times (n = 6) at each pressure value (between 0 and 35 mmHg) with different methods and the height of the water column in a bench-top phantom was used as the reference IAP for further interpretations. In addition to the quadruple comparisons, intra- and inter-observer variability of IAP measurements were also calculated. Correlation studies and Bland and Altman's analyses were performed in addition to the concordance study. Results: The CiMON and Spiegelberg devices showed a greater dynamic range and standard deviation when recording IAP_CiM and IAP_SPIE compared with IAP_SER. In general, the maximum and minimum values of IAP recorded with each device (at each level of IAP_H2O) were significantly different from each other. However, the average values were in very good agreement. The highest correlation was observed between IAP_SER and IAP_H2O, and IAP_SER and IAP_SPIE (R = 0.99, p = 0.001 for both comparisons and intra- and inter-observer measurements). Although the CiMON and SERENNO systems were in very good agreement with each other, a slightly smaller correlation coefficient was found between them (R = 0.95, p = 0.001, and R = 0.96, p = 0.001 for intra- and inter-observer measurements, respectively). When compared to the gold standard (IAP_H2O), Bland and Altman's analysis showed a mean difference of +0.44, -0.25, and -0.04 mmHg for the intra-observer measurements and +0.18, -0.75, and -0.58 mmHg for the inter-observer measurements for IAP_SER, IAP_CiM, and IAP_SPIE, respectively. IAP_SER showed a small positive bias (overestimation), while IAP_CiM and IAP_SPIE showed a negative bias (underestimation) when compared to IAP_H2O. Further statistical analysis showed a concordance coefficient of 100% with an excellent ability of the SERENNO system in tracking IAP_H2O changes. Conclusions: Pre-clinical validation of a new IAP monitoring device (SERENNO) showed very promising results when compared with the gold standard and other continuous techniques; however, clinical trials should be followed as the next stage of the validation process. Based on the actual research guidelines, the SERENNO system can be used interchangeably with the gold standard.