Abstract Background In preterm infants, application of negative pressure ventilation (NPV) may offer advantages to traditional methods of nasal continuous positive airway pressure (nCPAP). In a pre-clinical model, we recently described the “NeoVest”, a system consisting of a sealed abdominal interface and a ventilator that applies NPV in synchrony and in proportion to the diaphragm electrical activity (Edi) (Beck 2022). In animals with loaded breathing, the Neovest allowed a 50% reduction in Edi, and demonstrated specific diaphragm unloading, without hemodynamic effects. The NeoVest system, and its interface, have yet to be evaluated in human infants. Objectives The aim of the study was to evaluate the feasibility of applying synchronized and proportional NPV with an abdominal interface in infants with respiratory distress. Design/Methods This is a prospective feasibility trial. The inclusion criteria were admission to the Neonatal Intensive Care Unit with respiratory distress, birthweight>1.5kg, <6 weeks of age, FiO2 <0.35, clinically stable with no recent apneas and bradycardias, nCPAP <8 cm H2O and at least 48 hrs old, or post-extubation. After parental consent, the feeding tube was exchanged for a 6F “Edi catheter” (for feeding and measuring Edi), and sensors were placed (heart rate, oxygen saturation, transcutaneous CO2, and non-invasive blood pressure (BP)). Figure 1 shows the Neovest interface on a manikin. The five protocol steps were: nCPAP ON/NeoVest OFF (10 min), nCPAP ON/NeoVest ON (10 min), NO ASSIST (1 min), NeoVest only medium (10 min), NeoVest high (5 min), NeoVest low (5 min). Results Eight babies have been included to this point. The principal diagnoses were Respiratory Distress Syndrome and/or Transient Tachypnea of the Newborn. Mean weight was 2186±480g and age 10±8 days old. All babies tolerated the physical application of the vest. As shown in Figure 2, there was no significant difference in Edipk when the vest was placed (12.4±5.5 vs. 11.1±3.5 uV). During the period of no assist, Edipk was higher (18.8 ±7.3 uV) than nCPAP or NeoVest periods (p= 0.012), which were not significantly different from each other. Neural respiratory rate was the same for all periods tested. As per its design, the Neovest system delivered negative pressure in synchrony and in proportion to the Edi. Negative pressures applied (□PVEST) were -9±4, -11±4, and -7±5 cmH2O (Figure 2) for the three NeoVest periods. All infants were clinically stable with no disruptions to vital signs. Conclusion Applying synchronized and proportional negative pressure with the NeoVest system was feasible and showed promise with regards to diaphragm unloading. Future studies are required to evaluate the NeoVest utility for longer periods and compared to other methods of respiratory support.
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