title: Surfactant and perfluorocarbon aerosolization during different mechanical ventilation strategies by means of inhalation catheters: an in vitro study.
abstract: BACKGROUND
  Aerosol delivery of surfactant and perfluorocarbon (PFC) is a desirable therapeutic approach for the treatment of various lung diseases in patients undergoing mechanical ventilation. However, the behavior of these substances during aerosolization differs significantly from that of aqueous solutions. In particular, the high vapor pressure of many PFCs tends to result in greater evaporation during mechanical ventilation.
  
  
  METHODS
  Three PFCs and surfactant were aerosolized during mechanical ventilation by means of three intratracheal inhalation catheters (IC) with different air flow rates (IC-1.23, IC-1.1, and IC-1.4), with their aerosol generating tip placed at the distal end of the endotracheal tube (i.d. 4 mm). The influence of four different ventilation strategies on aerosol production rate and PFC and surfactant recovery was studied. The changes in intrapulmonary pressure produced by the air jets of each IC were measured.
  
  
  RESULTS
  With IC-1.23 and IC-1.1, the highest rates of aerosol production were achieved using FC75 (2.27±0.18 and 0.76±0.01, respectively) followed by PFOB (1.74±0.06 and 0.56±0.04), PFD (0.82±0.01 and 0.21±0.01), and surfactant (0.42±0.05 and 0.092±0.01). With IC-1.4 modest aerosol production was obtained irrespective of the aerosolized compound. Mechanical ventilation influenced aerosol recovery, with the trend being toward recovering higher percentages of the compounds with lower peak inspiratory pressure (PIP) and lower respiratory rate (RR) settings. The highest percentages of the initial volume were recovered with IC-1.23 (between 65.43%±4.2 FC75 and 90.21%±4.71 surfactant) followed by IC-1.1 (between 46.48%±4.46 FC75 and 73.19%±2.82 PFOB) and IC-1.4 (between 4.65%±4.36 FC75 and 63.24%±9.71 surfactant). Each of three of the ICs were found to increase the intrapulmonary pressure by about 2-3 cmH₂O during mechanical ventilation.
  
  
  CONCLUSIONS
  Despite of mechanical ventilation, IC-1.23 and IC-1.1 were able to deliver significant amounts of surfactant and perfluorocarbon to the lung model. Changes in PIP and RR directly influence the percentage of surfactant and perfluorocarbon recovered.
authors: Experimental Neonatal Respiratory Physiology Research Unit, Hospital de Cruces, Plaza de Cruces, Barakaldo E-48903, Bizkaia, Spain. xabier.murgiaesteve@osakidetza.net
authors: Xabier
authors: X
authors: Murgia
authors: Elena
authors: E
authors: Gastiasoro
authors: Victoria
authors: V
authors: Mielgo
authors: Estibaliz
authors: E
authors: Ruiz-Del-Yerro
authors: Francisco José
authors: FJ
authors: Alvarez-Diaz
authors: Hector
authors: H
authors: Lafuente
authors: Adolf
authors: A
authors: Valls-I-Soler
authors: Miguel Angel
authors: MA
authors: Gomez-Solaetxe
authors: Carmen
authors: C
authors: Rey-Santano
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D057785:Catheters; D005466:Fluorocarbons / Q000008:administration & dosage*; D011312:Pressure; D011663:Pulmonary Surfactants / Q000008:administration & dosage*; D012119:Respiration; D012121:Respiration, Artificial
chemical_list: D000336:Aerosols; D005466:Fluorocarbons; D011663:Pulmonary Surfactants