Recruitment maneuver: RAMP versus CPAP pressure profile in a model of acute lung injury

Respir Physiol Neurobiol. 2009 Oct 31;169(1):62-8. doi: 10.1016/j.resp.2009.08.010. Epub 2009 Aug 25.

Abstract

We examined whether recruitment maneuvers (RMs) with gradual increase in airway pressure (RAMP) provide better outcome than continuous positive airway pressure (CPAP) in paraquat-induced acute lung injury (ALI). Wistar rats received saline intraperitoneally (0.5 mL, CTRL) or paraquat (15 mg/kg, ALI). Twenty-four hours later lung mechanics [static elastance, viscoelastic component of elastance, resistive, viscoelastic and total pressures] were determined before and after recruitment with 40cmH2O CPAP for 40s or 40-s-long slow increase in pressure up to 40cmH2O (RAMP) followed by 0 or 5 cmH2O PEEP. Fractional area of alveolar collapse and PCIII mRNA were determined. All mechanical parameters and the fraction area of alveolar collapse were higher in ALI compared to CTRL. Only RAMP-PEEP maneuver significantly improved lung mechanics and decreased PCIII mRNA expression (53%) compared with ALI, while both RMs followed by PEEP decreased alveolar collapse. In conclusion, in the present experimental ALI model, RAMP followed by 5cm H2O PEEP yields a better outcome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Lung Injury / chemically induced
  • Acute Lung Injury / metabolism
  • Acute Lung Injury / pathology
  • Acute Lung Injury / physiopathology*
  • Analysis of Variance
  • Animals
  • Collagen Type III / genetics
  • Collagen Type III / metabolism
  • Disease Models, Animal
  • Gene Expression Regulation
  • Lung / metabolism
  • Lung / pathology*
  • Lung Volume Measurements
  • Paraquat
  • Positive-Pressure Respiration / methods*
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Wistar
  • Recruitment, Neurophysiological / physiology*
  • Respiratory Mechanics / physiology*

Substances

  • Collagen Type III
  • RNA, Messenger
  • Paraquat