The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts


Thomas Blakeman1, Richard Branson1

Background: Electrical power failure in the hospital represents a severe challenge in the intensive care unit (ICU). Ventilator dependent patients are at particular risk during power outage. Total electric power failure can occur, even when an emergency power system is in place. A reliable ICU ventilator back-up battery is needed to ensure patient safety. We tested the back-up internal battery system of four different ICU ventilators; Draeger Evita XL, Puritan Bennett 840, Viasys Avea, and Siemens Servo 300.

Methods: We used a single unit of each ventilator model. Each ventilator battery was charged per manufacturer instructions. The Evita XL has an internal battery and an optional external battery. We tested each separately. For each trial, the ventilator was attached to one chamber of a Michigan Instruments Training Test Lung. Lung compliance was set at 0.04 L/cmH2O and resistance at 5.0cm H2O/L/s. We evaluated four combinations of settings with each ventilator. At each setting, the respiratory rate was 20 breaths/min, inspiratory time was 1.0 second, and FIO2 was 0.6. PEEP was set at 0 cmH2O or 20 cmH2O. During volume control, VT was 500 ml and during pressure control, pressure was 14 cm H2O (delivered VT 500 ml). The data (mean ± SD) below shows the results of a minimum of 2 trials with each ventilator at 0 cm H2O PEEP.

Results: The range of battery life across all ventilators was 20.5 -170.5 minutes. The use of volume control ventilation vs pressure control ventilation and 20 cmH2O PEEP vs 0 cmH2O PEEP did not have any impact on the battery duration. Variables effecting duration of operation include battery capacity and ventilator operating characteristics.

Conclusion: Battery life varies widely among devices. Clinicians should be aware of these differences in the event of power interruption.