Development and Safety Trial of the OstreaVent2™ Prototype for Mechanically Ventilated Adult Patients

Abstract

Background: With the surge of COVID-19 infections, there were concerns about shortage of mechanical ventilator in several countries including the Philippines.

Objective: To transform a locally made, low-cost, neonatal ventilator into a volume- and pressure-controlled, adult ventilator and to determine its safe use among ventilated, adult patients at the Philippine General Hospital.

Methods: The modification of the neonatal ventilator (OstreaVent1) to the adult OstreaVent2 was based on the critical need for adult ventilators, in volume or pressure mode, in the Philippines due to the COVID-19 pandemic. The adult ventilator settings were calibrated and tested for two days to check for consistency and tolerance and then submitted to a third party for certification. Once certified, a safety trial of 10 stable adult patients on mechanical ventilator was conducted. The patients were placed on the OstreaVent2 for four hours while ventilator parameters, patient's vital signs, and arterial blood gases were monitored at baseline, during, and after placement on the OstreaVent2. A post-study chest radiograph was also done to rule out pulmonary complications, particularly atelectasis and pneumothorax.

Results: The prototype OstreaVent2 received an FDA Certification for Medical Listing after passing its third-party certification. Ten patients (60% male) recruited in the study had a mean age of 39.1 ± 11.6 years. Half of the patients had a diagnosis of non-COVID-19 pneumonia. During the 4-hour study period, the patients while on the OstreaVent2, had stable ventilator settings and most of the variabilities were within the acceptable tolerances. Vital signs were stable and arterial blood gases were within normal limits. One patient developed alar flaring which was relieved by endotracheal tube suctioning. No patient was withdrawn from the study. One patient who was already transferred out of the ICU subsequently deteriorated and died three days after transfer to the stepdown unit from a non-ventilator related cause.

Conclusion: The new OstreaVent2 is safe to use among adults who need ventilator support. Variabilities in the ventilator's performance were within acceptable tolerances. Clinical and blood gas measurements of the patients were stable while on the ventilator.

Keywords: OstreaVent1; OstreaVent2; adult ventilator.

Figure 1

Pneumatic diagram of the OstreaVent2 prototype.

Figure 2

External hardware, ports, and accessories of the OstreaVent2.

Figure 3

Blending of oxygen and compressed air depending on the desired oxygen delivery and flow rate. (Paran AP, 2021).

Figure 4

Screen display of the OstreaVent2 showing actual ventilator parameters, bar graph (A), and Pressure-time scalar (B).

Figure 5

(A) First sub-screen display on safety shutdown of the OstreaVent2; (B) Second sub-screen display affirming shutdown of the OstreaVent2.

Figure 6

Median (±1 IQR) tidal volumes of the 10 adult patients before, during, and after placement on the OstreaVent2. * Blue circles are the actual tidal volumes delivered by the OstreaVent2 at 15-240 mins. ** Red circles are baseline (0) and +30- and +60-minutes values off the OstreaVent2 and on the commercial ventilator.

Figure 7

Median (±1 IQR) tidal volumes of individual patients during the 4-hour study period on the OstreaVent2.

Figure 8

Median (±1 IQR) PEEP of the 10 patients before, during, and after placement on the OstreaVent2. * Blue circles are the actual tidal volumes delivered by the OstreaVent2 at 15-240 mins. ** Red circles are baseline (0) and +30 and +60 minutes values off the OstreaVent2 and on the commercial ventilator.

Figure 9

Median (IQR) PEEP of individual patients during study period on the OstreaVent2.

Figure 10

Median (1 IQR) flow rate of the 10 patients before, during, and after placement on the OstreaVent2. * Blue circles are the actual tidal volumes delivered by the OstreaVent2 at 15-240 mins ** Red circles are baseline (0) and +30 and +60 minutes values off the OstreaVent2 and on the commercial ventilator.

Figure 11

Median (IQR) flow rate of individual patients during the 4-hour study period on the OstreaVent2.

Figure 12

Median (IQR) ventilator rate of the 10 patients before, during, and after placement on the OstreaVent2. * Blue circles are the actual tidal volumes delivered by the OstreaVent2 at 15-240 mins. ** Red circles are baseline (0) and +30 and +60 minutes values off the OstreaVent2 and on the commercial ventilator.

Figure 13

Median (IQR) PIP of individual patients during the 4-hour period on the OstreaVent2.

Figure 14

Median (1 IQR) inspiratory time of individual patients during the 4-hour OstreaVent2 study period.

Figure 15

Median vital signs of the 10 patients before, during, and after placement on the OstreaVent2. * Minutes 15 to 240 were the time period the patients were on the OstreaVent2 ** -60 and -30 were time periods prior to attaching to the OstreaVent2 *** +30 and +60 were 30 and 60 mins after removal from the OstreaVent2 and return to previous mechanical ventilator

Figure 16

Median (IQR) arterial blood gases of the 10 patients 1 hour before, 1 hour after placement on the OstreaVent2, and 1 hour after return to commercial ventilator.