A Simulated Single Ventilator / Dual Patient Ventilation Strategy for Acute Respiratory Distress Syndrome During the COVID-19 Pandemic

Jose A. Solis-Lemus; Edward Costar; Denis Doorly; Eric C. Kerrigan; Caroline H. Kennedy; Frances Tait; Steven A Niederer; Peter E. Vincent; Steven E. Williams

To achieve balanced tidal volumes between mismatched patients we propose the inclusion of a variable flow restrictor (modelled as a variable resistor) in the inspiration arm of the splitter for both patients and one-way valves (modelled as diodes) in the exhalation arm to stop pressure equilibration. We demonstrate the function of this on the cases of a patient with healthy lungs (Lung Model A) paired with a patient with increasing severity of ARDS (Lung Models B, C and D). We first show in the case of an A-A pairing that inclusion of the resistors and diodes/valves, with the resistance set to 0 recovers the standard setup results of section (i). We then show that by adjusting the PIP from the ventilator and altering the resistance of the resistor for the healthy patient (Patient 1 in this setup) we can achieve tidal volume within 10 ml of 490 ml for each patient (Figure 5 and Table 4 ). This shows that by manipulating the inhalation pathway resistance and PIP it is possible to equilibrate the tidal volume delivered to both Patient 1 and Patient 2 even in the setting of patients with differing lung compliances.