Delivering Low Tidal Volume With Anesthesia and ICU Ventilators in a Neonatal Lung Model

Area of Science:

• Biomedical Engineering
• Neonatal Physiology
• Respiratory Care

Background:

• Mechanical ventilation in neonates demands precise tidal volume (V_T) and PEEP delivery to prevent lung injury.
• Small neonatal V_T and endotracheal tube leaks complicate accurate V_T delivery.
• While neonatal ICU ventilators are validated for neonates, anesthesia ventilators lack thorough performance studies in this population.

Purpose of the Study:

• To evaluate the accuracy of anesthesia ventilators in delivering small tidal volumes (V_T) in neonates.
• To compare the performance of anesthesia ventilators with ICU ventilators under various simulated neonatal respiratory conditions.
• To assess the impact of gas leaks on V_T and PEEP delivery by different ventilator types.

Main Methods:

• Tested three anesthesia ventilators (Dräger Apollo, GE Avance, Getinge Flow-i) and two ICU ventilators (Medtronic PB980, Nihon Kohden NKV-550).
• Utilized volume control mode with set V_T of 5, 20, 40, and 60 mL.
• Employed a Servo ASL 5000 lung simulator with three combinations of lung compliance and airway resistance, including scenarios with and without leaks.

Main Results:

• Without leaks, Apollo and Flow-i showed >10% error in V_T delivery. Avance, PB980, and NKV-550 had <10% error.
• With leaks and varying respiratory mechanics, none of the anesthesia ventilators consistently delivered V_T within a 10% error margin.
• Ventilator bias in V_T delivery ranged from 4.27 mL to -10.59 mL. Apollo underdelivered PEEP with the largest leak.

Conclusions:

• Anesthesia ventilators did not significantly differ from tested neonatal ICU ventilators in V_T delivery accuracy when gas leaks were present.
• Challenges remain in achieving precise V_T delivery with anesthesia ventilators in neonates, particularly with leaks.
• Further research is needed to optimize anesthesia ventilator performance for neonatal mechanical ventilation.