title: Long-term mechanical ventilation with hygroscopic heat and moisture exchangers used for 48 hours: a prospective clinical, hygrometric, and bacteriologic study.
abstract: OBJECTIVE
  To determine whether use of a hygroscopic heat and moisture exchanger (HME) for 48 hrs without change affects its efficiency and the level of bacterial colonization in long-term mechanically ventilated medical intensive care unit patients.
  
  
  METHODS
  Prospective, randomized clinical study evaluating two hygroscopic HMEs.
  
  
  METHODS
  Medical intensive care unit at a university teaching hospital.
  
  
  METHODS
  Long-term mechanically ventilated medical intensive care unit patients, including chronic obstructive pulmonary disease patients.
  
  
  METHODS
  Patients were randomly allocated to one of the two HMEs studied (Hygrolife and EdithFlex) and changed every 48 hrs. Devices in both groups could be changed if hygrometric measurements indicated insufficient humidity delivery.
  
  
  RESULTS
  Daily measurements of inspired gas temperature and relative and absolute humidity. In addition, cultures of tracheal aspirations and both patient and ventilator sides of the device were performed after 48 hrs of use. Ventilatory variables and clinical indicators of efficient humidification were also recorded. Prolonged use of both HMEs was safe and efficient (no tracheal tube occlusion occurred). Mean duration of mechanical ventilation was 20 days. Both clinical indicators and hygrometric measurements showed that both devices performed well during 48 hrs. Absolute humidity with EdithFlex was significantly higher on day 0 and day 1 than with Hygrolife. Absolute humidity measured in chronic obstructive pulmonary disease patients was identical to that measured in the rest of the study population. Tracheal colonization and HME colonization were similar with both HMEs. Bacterial contamination of the ventilator side of both devices was markedly low.
  
  
  CONCLUSIONS
  These two purely hygroscopic HMEs provided safe and efficient humidification during a 48-hr period of use in long-term mechanically ventilated medical intensive care unit patients, including chronic obstructive pulmonary disease patients. In addition, they maintained ventilatory circuits clean, despite the absence of filtering media. The cost of mechanical ventilation is consequently reduced.
authors.affiliation: Services de Réanimation Médicale, Hôpital Louis Mourier (Assistance Publique-Hôpitaux de Paris), Colombes, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Boyer
authors.forename: Guillaume
authors.initials: G
authors.lastname: Thiéry
authors.forename: Serge
authors.initials: S
authors.lastname: Lasry
authors.forename: Etienne
authors.initials: E
authors.lastname: Pigné
authors.forename: Amar
authors.initials: A
authors.lastname: Salah
authors.forename: Arnaud
authors.initials: A
authors.lastname: de Lassence
authors.forename: Didier
authors.initials: D
authors.lastname: Dreyfuss
authors.forename: Jean-Damien
authors.initials: JD
authors.lastname: Ricard
mesh_terms: D000368:Aged; D015169:Colony Count, Microbial; D003363:Cost Control; D004209:Disposable Equipment / Q000191:economics / Q000592:standards; D004866:Equipment Contamination / Q000706:statistics & numerical data; D004867:Equipment Design / Q000592:standards; D005260:Female; D006801:Humans; D006813:Humidity; D017053:Infection Control; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers / Q000191:economics / Q000592:standards*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000628:therapy*; D012121:Respiration, Artificial / Q000191:economics / Q000295:instrumentation*; D012131:Respiratory Insufficiency / Q000150:complications / Q000628:therapy*; D012449:Safety; D013183:Sputum / Q000382:microbiology; D013997:Time Factors; D014132:Trachea / Q000382:microbiology; D016896:Treatment Outcome; D017155:Wettability