All Servo ventilators 300 and 300A with automode function 를 위한 안전성 경고 / 현장 안전성 서한

Safety alert / Field Safety Notice

MDA/2009/020

CON041410

2009-03-24

United Kingdom

MHRA

https://webarchive.nationalarchives.gov.uk/20141206095400/http://www.mhra.gov.uk/PrintPreview/PublicationSP/CON041410

Risk of inadequate ventilation of neonatal or paediatric patients without warning by any alarm. the mhra is aware of an incident where a reduced inspiration time occurred, with no alarm, during ventilation of a neonate with a servo ventilator 300a. the automode was on with the trigger level set to the minimum and the patient had no spontaneous breathing. the reduced inspiration time resulted in inadequate ventilation. when pressure control (pc) or pressure regulated volume control (prvc) ventilation is used with automode set to ‘on’ the ventilator cycles to expiration in the controlled mode if the airway pressure exceeds the set/calculated inspiratory pressure by more than 3 cm h2o. the purpose of this cycle off criterion is to provide a smooth transition from controlled to supported ventilation when the patient starts to trigger the ventilator, since this increase in pressure is interpreted as the patient working against the ventilator. this phenomenon only occurs with neonatal or paediatric patients with small tidal volumes and set, short inspiratory rise times during either pc or prvc ventilation. the probability of occurrence increases with larger, compressible volumes in the tubing system (including humidifier chamber) and with a lower resistance of the patient’s airways (including tracheal tube). the manufacturer issued a field safety notice on 15 december 2008 (see appendix - in pdf only).

Identify if you have any Servo 300 or 300A ventilators that have an automode function. When using the automode function with either pressure control (PC) or pressure regulated volume control ventilation (PRVC) mode in the neonatal or paediatric patient range, ensure that: the set inspiratory rise time is in the range 7-10% the water level of the humidifier chamber is maintained according to the manufacturer’s recommendations. Ensure that users are aware of and act on Maquet’s Field Safety Notice.