Abstract 201: 3D-Printed Automated Pressure-Cycled Resuscitator Maintains Respiratory Homeostasis in Swine With Normal to Moderately Low Lung Compliance

Abstract

Background: During resuscitation, manual ventilation is commonly used. However, the effectiveness of this approach heavily relies on the skills of the individuals performing, often leading to inconsistent tidal volumes and respiratory rates. Such variations in ventilation can disrupt the removal of CO 2 resulting in altered pH. To address this problem, we leveraged advancements in fluidics and 3D printing to develop a miniature, automated, pressure-cycled resuscitator (inVent) that operates without any moving parts or settings. Hypothesis: The inVent will be able to maintain a pH of 7.2 or higher in swine with a dynamic compliance (Cdyn) of 25-50 ml/cmH 2 O. Goals/Aims: To assess the inVent’s performance in an animal model with normal to severe lung injury. Methods: Hybrid Landrace swine were studied under a protocol approved by the Institutional Animal Care and Use Committee. All swine were anesthetized, and underwent oral intubation. Breath by breath measurements were obtained using the NM3 Monitor (Phillips). All 3 inVent (fluidIQ) resuscitators pressure modules were used pre and post lung injury to fully characterize how each of the modules would react in different lung conditions. Lung injury was induced through a repeated bronchoalveolar lavage. ABG analysis was performed using the epoc system (Siemens). pH values 7.2 or less were considered acidotic while those over 7.2 were considered acceptable. Results: 8 swine with an average weight of 36 (5.8) Kg were studied. 7 swine contributed to 39,770 breaths of pulmonary mechanics and 33 ABGs recorded. Mean Cdyn was lower than anticipated at 25.8 (14.7) mL/cmH 2 O and a pH 7.32 (0.16). Figure 1 demonstrates a linear relationship with compliance and pH. Conclusions: The inVent resuscitator was able to maintain a pH of at least 7.2 in moderate compliance ranges, however struggled to maintain pH of 7.2 or higher in the severely injured. Higher lung compliance ranges are needed to explore possible hyperventilation events.