title: Proportional assist ventilation in low birth weight infants with acute respiratory disease: A comparison to assist/control and conventional mechanical ventilation.
abstract: OBJECTIVE
  To compare the physiologic efficacy and safety aspects of proportional assist (PA), assist/control (A/C), and intermittent mandatory ventilation (IMV) in very low birth weight infants with acute respiratory illness and to test the hypothesis that ventilatory pressure requirements are lower and arterial oxygenation is improved during PA when compared with IMV or A/C at an equivalent inspired oxygen fraction.
  
  
  METHODS
  Randomized, 3-period, crossover design.
  
  
  METHODS
  Thirty-six infants were stratified by birth weight (600 to 750, 751 to 900, and 901 to 1200 g) and exposed to consecutive 45-minute epochs of the 3 modalities in a sequence chosen at random. Tidal volumes of 4 to 6 mL/kg were targeted during A/C and IMV. The IMV rate was matched to the rate during an A/C test period. PA was adjusted to unload the resistance of the endotracheal tube and the disease-related increase in lung elastic recoil.
  
  
  RESULTS
  Compared with A/C and IMV, PA maintained similar arterial oxygenation with lower airway and transpulmonary pressures (15% to 44% reduction depending on the index variable). The oxygenation index decreased by 28% during PA. No adverse events were observed. The number and severity of apneic episodes and periods of arterial oxygen desaturations were similar with the 3 modes. Similar results were obtained within each birth weight subgroup.
  
  
  CONCLUSIONS
  PA safely maintains gas exchange with smaller transpulmonary pressure changes compared with A/C and IMV. It may therefore offer a way of reducing the incidence of chronic lung disease in low birth weight infants.
authors.affiliation: Department of Pediatrics, Division of Neonatology and Epidemiology and Public Health, University of Miami, Florida, USA.
authors.forename: A
authors.initials: A
authors.lastname: Schulze
authors.forename: T
authors.initials: T
authors.lastname: Gerhardt
authors.forename: G
authors.initials: G
authors.lastname: Musante
authors.forename: P
authors.initials: P
authors.lastname: Schaller
authors.forename: N
authors.initials: N
authors.lastname: Claure
authors.forename: R
authors.initials: R
authors.lastname: Everett
authors.forename: O
authors.initials: O
authors.lastname: Gomez-Marin
authors.forename: E
authors.initials: E
authors.lastname: Bancalari
mesh_terms: D000208:Acute Disease; D000403:Airway Resistance; D001794:Blood Pressure; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007385:Intermittent Positive-Pressure Ventilation / Q000379:methods*; D008170:Lung Compliance; D008297:Male; D011659:Pulmonary Gas Exchange; D011669:Pulmonary Wedge Pressure; D012121:Respiration, Artificial / Q000379:methods*; D012127:Respiratory Distress Syndrome, Newborn / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D013990:Tidal Volume