An Investigation to Determine the Compatibility of the Hamilton Galileo Ventilator and the Jet Bunnell in a Neonatal Lung Model

Introduction: Our facility is in the process of reevaluating the standard of care ventilator for our level III NICU. The Bunnell Jet ventilator is often used in tandem with our current standard ventilator for patients meeting jet ventilation criteria. The reevaluation process must insure that whatever ventilator standard is chosen, that it is compatible with the Jet Bunnell. Hamilton Medical Inc. has recently come out with neonatal software upgrades for their Galileo ventilator. The package includes time-cycled pressure-limited modes with a neonatal flow sensor. Since this ventilator is one of many that is being considered we decided to do a bench test to determine its compatibility with the Jet Bunnell since it had not been previously reported in the literature.

Methods: Testing consisted of ventilating an IngMar Medical Neonatal test lung using the Galileo and the Jet in tandem under two test conditions. Each test condition was performed using a triple lumen 3.0 and 4.0 ETT. In test condition one, PIP was varied on the Galileo from 5 to 35 cmH20 in 5 cmH2O increments. The jet PIP was operated at 5 cmH2O higher than the Galileo and also increased in 5 cmH2O increments, along with the Galileo, to 40 cmH2O. All other ventilator settings remained the same. These setting were: Galileo: time cycled - pressure limited SIMV, rate: 5, Peep; 5, inspiratory time: 0.4 sec., flow: 6 Lpm, trigger 1.5 Lpm. Jet: rate 420 with an on-time of 0.02 sec. In test condition two the Jet rate was varied at rates of 300, 420, and 500. All other ventilator settings remained the same. These setting were: Galileo: time cycled - pressure limited SIMV, PIP: 20 cmH2O, rate: 5, Peep; 5, inspiratory time: 0.4 sec., flow: 6 Lpm, trigger 1.5 Lpm. Jet: PIP: 25 cm H2O with an on-time of 0.02 sec. Data was gathered for approximately 5 min. for each variable test condition. All measured and monitored Galileo data was captured using the Galileo Data Logger software package.

Results: Both ventilators operated efficiently under these test conditions. All measured and monitored data from the Galileo were consistent, reproducible, and within acceptable limits. Upon initial investigation under test condition one, it was discovered that the PIP of the Galileo must always be at least one cmH2O below the PIP of the Jet. If not, the Galileo would report a sensor malfunction. During the alarm condition the Galileo continued to function appropriately. This may be of concern, as some clinicians prefer to ventilate with conventional PIP?s the same or higher than the jet.

Discussion: When new neonatal ventilator technology becomes available it is important to consider all aspects of its operation. Those facilities that promote the use of Bunnell Jet ventilation must consider if the two devices are compatible. In addition, many NICU?s are recognizing the benefit of flow sensor monitoring technology. The sensor and often its location create more difficulties when the jet us used.

Conclusion: We feel that it is safe to use the Hamilton Galileo in tandem with the Bunnell jet as long as it is clinically acceptable to use jet PIP?s greater than the Galileo.