title: Actual performance of mechanical ventilators in ICU: a multicentric quality control study.
abstract: Even if the performance of a given ventilator has been evaluated in the laboratory under very well controlled conditions, inappropriate maintenance and lack of long-term stability and accuracy of the ventilator sensors may lead to ventilation errors in actual clinical practice. The aim of this study was to evaluate the actual performances of ventilators during clinical routines. A resistance (7.69 cmH(2)O/L/s) - elastance (100 mL/cmH(2)O) test lung equipped with pressure, flow, and oxygen concentration sensors was connected to the Y-piece of all the mechanical ventilators available for patients in four intensive care units (ICUs; n = 66). Ventilators were set to volume-controlled ventilation with tidal volume = 600 mL, respiratory rate = 20 breaths/minute, positive end-expiratory pressure (PEEP) = 8 cmH(2)O, and oxygen fraction = 0.5. The signals from the sensors were recorded to compute the ventilation parameters. The average ± standard deviation and range (min-max) of the ventilatory parameters were the following: inspired tidal volume = 607 ± 36 (530-723) mL, expired tidal volume = 608 ± 36 (530-728) mL, peak pressure = 20.8 ± 2.3 (17.2-25.9) cmH(2)O, respiratory rate = 20.09 ± 0.35 (19.5-21.6) breaths/minute, PEEP = 8.43 ± 0.57 (7.26-10.8) cmH(2)O, oxygen fraction = 0.49 ± 0.014 (0.41-0.53). The more error-prone parameters were the ones related to the measure of flow. In several cases, the actual delivered mechanical ventilation was considerably different from the set one, suggesting the need for improving quality control procedures for these machines.
authors.affiliation: TBM-Lab, Dipartimento di Bioingegneria, Politecnico di Milano University, Milano, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Govoni
authors.forename: Raffaele L
authors.initials: RL
authors.lastname: Dellaca'
authors.forename: Oscar
authors.initials: O
authors.lastname: Peñuelas
authors.forename: Giacomo
authors.initials: G
authors.lastname: Bellani
authors.forename: Antonio
authors.initials: A
authors.lastname: Artigas
authors.forename: Miquel
authors.initials: M
authors.lastname: Ferrer
authors.forename: Daniel
authors.initials: D
authors.lastname: Navajas
authors.forename: Antonio
authors.initials: A
authors.lastname: Pedotti
authors.forename: Ramon
authors.initials: R
authors.lastname: Farré
keywords: equipment and supplies; health care quality assessment; intravenous; medical devices; quality assurance; ventilation error; ventilator accuracy