Fig 1.
One-line diagram of the ACRA interface.
Inspiration and expiration circuits are colored in red and black, respectively. A dashed green line represents a bypass circuit of small diameter.
Fig 2.
Three-dimensional volume renderings of the ACRA interface.
(1) Connection for inspiratory limb from ventilator, (2) connection for expiratory limb to ventilator, (3) bypass circuit, (4) unidirectional valves, (5) and (5’) pinch valves, (6) adjustable PEEP valve, (7) and (7’) connection for expiratory tubes from paired units, (8) and (8’) connection for inspiratory tubes to paired units.
Table 1.
Proposed variations on the peak inspiratory pressure and positive end-expiratory pressure of the ventilator and the resulting values of peak inspiratory pressure, positive end-expiratory pressure, driving pressure and expired tidal volume on each lung unit.
Table 2.
Proposed variations of pressure on the pinch valves of both lung units (via adjustment of the flow restriction) and the positive end-expiratory pressure adjustable valve and the resulting values of peak inspiratory pressure, positive end-expiratory pressure, driving pressure and expired tidal volume on each lung unit.
Table 3.
Resulting variations of VTe (mL) in paired lung units after a sole modification of the respiratory rate in the ventilator using a fixed inspiratory time of 2 seconds, while applying a flow restriction of 0, 10 and 20 cm H2O in lung unit 1, which resulted in a PIP of 35, 25 and 15 cm H2O, respectively.
Table 4.
Resulting variations of VTe (mL) in paired lung units after a sole modification of the respiratory rate in the ventilator using a variable inspiratory time of 2 seconds, while applying a flow restriction of 0, 10 and 20 cm H2O in lung unit 1, which resulted in a PIP of 35, 25 and 15 cm H2O, respectively.
Table 5.
Simulation of progressively worsening acute respiratory distress syndrome conditions on breathing simulator 2 during dual ventilation using the ACRA device.
Table 6.
Comparison of the values of peak inspiratory, positive end-expiratory and plateau pressures, and global and individual expired tidal volumes recorded from the analog manometers and ventilator, respectively, with those values obtained from both simulators’ software during the five proposed acute respiratory distress syndrome conditions simulated on simulator 2.
Table 7.
Effect of dual ventilation with the ACRA interface of homogeneous (Step 1) and heterogeneous (Step 2) paired animal models on pH, partial pressure of arterial carbon dioxide, ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen, percentage of hemoglobin saturated with oxygen, heart rate, mean arterial pressure, stroke volume, respiratory system compliance, positive end-expiratory pressure, driving pressure and expired tidal volume.