Increase in resistance of in-line breathing filters in humidified air.
A study has been performed to measure the resistance of Pall Ultipor BB50 filters when exposed to humidified air for 48 h during artificial ventilation by an Engstrom Erica ventilator fitted with a Bennett Cascade Mk2 humidifier. A marked increase in resistance was demonstrated. A hypothesis is presented as to the aetiology of these findings together with details of minor modifications to the system which allow the use of these filters under clinically acceptable conditions.
D004869:Equipment Safety; D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D006813:Humidity; D011312:Pressure; D012121:Respiration, Artificial; D012212:Rheology; D013997:Time Factors; D012122:Ventilators, Mechanical