title: In vitro performance of spacers for aerosol delivery during adult mechanical ventilation.
abstract: BACKGROUND
  During mechanical ventilation, different aerosol generators are employed with various interfaces. The objective of this study was to evaluate the performance of a range of spacers, including a new device called Combihaler® designed for connection with both nebulizers and pressurized Metered-Dose Inhalers (pMDIs).
  
  
  METHODS
  To assess the spacers, we used a ventilator and the Dual Adult Training and Test Lung (model 5600i, Michigan Instruments). Ventilation parameters were measured with and without spacers in volume-controlled and pressure-controlled mode. A filter was placed at the end of the endotracheal tube to measure aerosol delivery. Amikacin (1 g/8 mL) and salbutamol (5 mg/5 mL) were nebulized with an Aeroneb Solo® connected to its T-adapter or the Combihaler® spacer. Salbutamol (100 μg/actuation with 10 actuations) and beclomethasone (250 μg/actuation with 10 actuations) were delivered with a pMDI connected to a Minispacer®, an ACE® spacer, or a Combihaler® spacer. Drug delivery measurements were performed in volume-controlled mode in dry and humidified conditions. Drug deposits on the filter were assayed.
  
  
  RESULTS
  The use of spacers and the T-adapter did not change the ventilation parameters (p>0.9). Aerosol delivery of salbutamol and Amikacin by nebulization increased up to three-fold with the Combihaler® compared with the T-adapter in humidified and nonhumidified conditions (p<0.05). Aerosol delivery of salbutamol and beclometasone by pMDI increased up to three-fold with the Combihaler® and the ACE® spacer compared with the Minispacer® in humidified and nonhumidified conditions (p<0.05). Aerosol delivery by pMDIs and vibrating mesh nebulizers using either a T-adapter or spacers was reduced by up to 62.5% in a humidified circuit compared with a nonhumidified circuit.
  
  
  CONCLUSIONS
  Aerosol delivery via pMDIs and vibrating mesh nebulizers is greater with large spacers (Combihaler® and ACE®) than with smaller spacers (Minispacer®) or a T-adapter, in both humidified and nonhumidified conditions. In humidified conditions, the aerosol delivery decreased with all spacers.
authors: 1 Centre d'Etude des Pathologies Respiratoires INSERM, Université François Rabelais de Tours , F-37032 Tours, France .
authors: Nabile
authors: N
authors: Boukhettala
authors: Thierry
authors: T
authors: Porée
authors: Patrice
authors: P
authors: Diot
authors: Laurent
authors: L
authors: Vecellio
mesh_terms: D000280:Administration, Inhalation; D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage*; D000328:Adult; D000336:Aerosols; D000420:Albuterol / Q000008:administration & dosage*; D000583:Amikacin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001507:Beclomethasone / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D004867:Equipment Design; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D036501:Metered Dose Inhalers; D008953:Models, Anatomic; D009330:Nebulizers and Vaporizers; D012121:Respiration, Artificial / Q000295:instrumentation*; D012122:Ventilators, Mechanical; D014732:Vibration
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D000336:Aerosols; D000900:Anti-Bacterial Agents; D001993:Bronchodilator Agents; D000583:Amikacin; D001507:Beclomethasone; D000420:Albuterol
keywords: aerosol delivery; mechanical ventilation; nebulizer; pMDI; spacer; vibrating mesh