Structural characteristics of a novel catheter for esophageal pressure monitoring

Introduction: Esophageal pressure monitoring allows estimation of transpulmonary pressure and precise application of lung-protective ventilation. Aims and Objectives: We describe structural characteristics of a novel esophageal catheter comprising a polyurethane balloon in comparison with commercially available alternatives. Methods: We tested a novel catheter (AspisafeNG+, Aspisafe Solution, NY, USA), designed to monitor esophageal pressure and prevent gastro-esophageal reflux vs. four commercially available catheters. We used a caliper to measure esophageal balloon outer diameter (OD) and length. Balloon compliance was measured via 0.5-mL increments of air up to an internal pressure of 40 cmH2O. Minimum volume (Vmin) was defined as the inflated volume that caused a linear increase in balloon internal pressure. Each experiment was made in triplicate. Results: Balloon OD varied among catheters (N 15, p=0.012) and ranged from median (IQR) of 6.6 (0.5) mm (Cooper®), up to 25.2 (0.2) mm (AspisafeNG+). Balloon lengths as well differed among catheters (N 15, p=0.013) from median (IQR) of 39.1 (2.5) mm (Aspisafe NG+), up to 100.7 (0.7) mm (Nutrivent®). Vmin (N 15, p=0.010) varied among catheters, as reported in Fig.1, while compliance did not (N 103, p=0.714). Measurements and Main Results: The novel esophageal balloon is characterized by large OD and Vmin. Manufacturers produce highly heterogeneous catheters for esophageal pressure monitoring