title: Battery performance of 4 intensive care ventilator models.
abstract: BACKGROUND
  Hospital electrical power failure represents an important challenge in the intensive care unit. Despite the presence of backup generators, total electrical power failure may still occur. Life-support equipment should have a reliable internal battery to ensure patient safety. We tested the duration of operation of the internal battery of 4 intensive care ventilators.
  
  
  METHODS
  In our laboratory we evaluated one each of 4 ventilator models available in our facility (Evita XL, Puritan Bennett 840, Avea, and Servo 300), with volume-control and pressure-control ventilation, and with positive end-expiratory pressure (PEEP) of zero and 20 cm H(2)O. We then randomly selected and tested 6 Evita XL and 4 Servo 300 ventilators from our inventory to determine the variability of internal battery duration among ventilators of the same model. The ventilator settings were identical to the previous tests, other than fraction of inspired oxygen, which was set at 0.6, and PEEP was 5 cm H(2)O.
  
  
  RESULTS
  The battery-duration range of the tested ventilators was 20.5-170.5 min, and the mean +/- SD battery duration was 80.4 +/- 49.3 min. Changes in breath type and PEEP did not significantly impact battery duration. Among the ventilators of the same model, the battery-duration range was 5-69 min and the mean +/- SD battery duration was 28.9 +/- 21.4 min. Use of a compressor significantly shortened battery duration. There was no correlation between battery duration and battery age (r = -0.263).
  
  
  CONCLUSIONS
  The duration of ventilator operation on internal battery ranged widely among the tested devices. Clinicians need to be aware of these differences in the event of power failure.
authors.affiliation: Division of Trauma and Critical Care, Department of Surgery, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0558, USA. thomas.blakeman@uc.edu
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Blakeman
authors.forename: Bryce R H
authors.initials: BR
authors.lastname: Robinson
authors.forename: Richard D
authors.initials: RD
authors.lastname: Branson
mesh_terms: D011211:Electric Power Supplies; D004867:Equipment Design; D006801:Humans; D007362:Intensive Care Units; D008422:Materials Testing; D012121:Respiration, Artificial / Q000295:instrumentation*; D013997:Time Factors