title: The impact of aerosolized mucolytic agents on the airflow resistance of bacterial filters used in mechanical ventilation.
abstract: OBJECTIVE
  In order to reduce the contamination in the ventilator, bacterial filters were placed on the expiratory limb of a ventilator circuit. Aerosolized mucolytic agents may increase the resistance of the ventilator. The goal of this study is to determine the impact of aerosolized mucolytic agents on the pressure change during mechanical ventilation.
  
  
  METHODS
  A lung model was investigated with mucolytic inhaled agents of 10% acetylcysteine and 2% hypertonic saline. The agents were administered using a jet nebulizer every 45 minutes for 15 minutes. The pressure drop was measured after nebulization. The end point was referred to the 45(th) dose or obstruction of the filter. Furthermore, the pressure drop after steam autoclaving was also measured.
  
  
  RESULTS
  The maximum pressure was significantly higher with 10% acetylcysteine than with 2% sodium chloride (39.32 ± 7.22 cmH2O vs. 3.53 ± 0.90 cmH2O, p < 0.001). With acetylcysteine filters, the pressure drop over 4 cmH2O occurred earlier and had a good relationship between the degree of pressure drop and doses. The acetylcysteine group yielded a significant difference in the pressure drop compared to the newly autoclaved and the end point of inhalation (p = 0.043).
  
  
  CONCLUSIONS
  This study demonstrated the aerosolized mucolytic agents could increase the pressure drop of the bacterial filters during mechanical ventilation. The pressure drop of the bacterial filters was higher with 10% acetylcysteine. It is critical to continuously monitor the expiration resistance, auto-positive end-expiratory pressure, and ventilator output waveform when aerosolized 10% acetylcysteine was used in mechanical ventilation patients.
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Han-Chung
authors.initials: HC
authors.lastname: Hu
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Hsin-Chun
authors.initials: HC
authors.lastname: Liu
authors.affiliation: Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Yen-Huey
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Chung-Chi
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Gwo-Hwa
authors.initials: GH
authors.lastname: Wan
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Lan-Ti
authors.initials: LT
authors.lastname: Chou
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Meng-Jer
authors.initials: MJ
authors.lastname: Hsieh
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Ning-Hung
authors.initials: NH
authors.lastname: Chen
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Cheng-Ta
authors.initials: CT
authors.lastname: Yang
authors.affiliation: Department of Respiratory Therapy, Chang Gung Memorial Hospital at Linkou, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan. Electronic address: kck0502@adm.cgmh.org.tw.
authors.forename: Kuo-Chin
authors.initials: KC
authors.lastname: Kao
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry*; D000280:Administration, Inhalation; D004866:Equipment Contamination / Q000517:prevention & control*; D004867:Equipment Design; D005100:Expectorants / Q000737:chemistry*; D016014:Linear Models; D008422:Materials Testing; D009330:Nebulizers and Vaporizers; D012121:Respiration, Artificial; D012122:Ventilators, Mechanical / Q000382:microbiology*
chemical_list: D005100:Expectorants; D000111:Acetylcysteine
keywords: acetylcysteine; aerosols; bacterial filters; mechanical ventilation; mucolytic agents