Comparison of the Pressure Support Mode of Anesthesic Respiratory and Resuscitation Ventilators

Abstract

The objective: Comparison of parameters characterizing the operation of the pressure support regime on modern anesthetic and intensive care ventilators.Subjects and Methods. The study included 5 anesthesia machines (Mindray WATO EX-65, Drӓger Primus, GE Avance S/5, GE Carestation 650, and GE Aisys CS2) and 5 intensive ventilators (Hamilton C1, Hamilton C2, GE Engstrӧm Carestation, Puritane Bennette 840, and Puritane Bennette 980). All devices were tested using the Ingmar medical ASL 5000 breathing device. The trigger delay time, the maximum pressure reduction below the PEEP level at the initiation of inspiration, PTP (pressure-time product), as well as the level of pressure achieved after 300 and 500 ms from the start of inspiration at different levels of pressure support and PEEP were evaluated.Results. The parameters characterizing operation of the trigger system and pattern of the inspiratory pressure set in ventilators used in intensive care and anesthesia ventilators had statistically significant differences. However, in terms of the response rate of the trigger system, modern anesthesia machines (GE Avance S/2, GE Caretation 650, and GE Aisys CS2) are not significantly inferior to traditional ventilators, their trigger delay time is about 100 ms. The maximum decrease in pressure below PEEP before the start of inhalation in the tested intensive ventilators was 1.0–1.5 cm H2O, in modern anesthesia machines this parameter was comparable and made approximately 1.5–2.0 cm H2O (GE Avance S/2, GE Caremation 650, and GE Aisys CS2). Assessment of the pressure level achieved after 300 and 500 ms showed that these parameters were closer to the target pressure for ventilators of the pneumatic compressor design, for turbine devices these parameters were approximately 25% less. Anaesthesia devices with a two-circuit pneumatic design had 40% less pressure values compared to devices with a pneumatic compressor design.Conclusion: The performance of the trigger system in modern anesthesia and intensive care ventilators does not differ significantly. Most of the anesthesia machines tested did not reach the target pressure within 500 ms, and by this parameter they differ significantly from intensive care respirators.

Keywords

• artificial lung ventilation
• ventilator
• anesthesia ventilators
• pressure support ventilation
• pressure support
• inhalation trigger