MASI Ventilator: Implementing Peruvian Technology in Regions at High Altitude

The expanded use of the Masi ventilators to more regions of Peru is important, particularly for regions located at high altitudes, due to the ventilatory support latent need, which also represents a challenge in the calibration and the adjustment of metrological parameters to ensure its correct performance. In a previous study, in Puno city at 3800 m.a.s.l., it was found an error above 15.0% (minimum tolerance) in the tidal volume, for which a negative correction of 25.0% was applied. In the present study, a Masi ventilator was transported to Chachapoyas city, at an altitude of 2400 m.a.s.l. to continue evaluating the effect of altitude on the parameters of the device. Once there, ventilators were acclimated and calibrated. Tidal volume, inspiration-expiration ratio (I:E), positive end-expiratory pressure (PEEP), peak inspiratory flow (PIF) and peak inspiratory pressure (PIP) were tested, and the maximum percentages errors presented were 13.5% and 13.9% in the tidal volume and the PIF, respectively. For that reason, although errors were under 15.0%, an update of the software of Masi was needed, applying a negative correction of 14.0%. Then, the parameters were tested again obtaining results with errors below 6.0% and 8.0% in volume controlled an pressure controlled ventilation modes, respectively. These results allowed the use of the Masi ventilator at ICU area. Finally, a software update for the Masi ventilator is performed by applying a linear equation that relates altitudes and percentage errors tested.