title: Postnatal changes of extracellular volume, atrial natriuretic factor, and diuresis in a randomized controlled trial of high-frequency oscillatory ventilation versus intermittent positive-pressure ventilation in premature infants <30 weeks gestation.
abstract: OBJECTIVE
  High-frequency oscillatory ventilation (HFOV) with a high lung volume strategy is an experimental mode of ventilating preterm infants aimed at achieving maximal alveolar recruitment Higher mean airway pressures are used during HFOV than during intermittent positive-pressure ventilation (IPPV), and the intrathoracic volume increase is relatively constant. Both factors increase the risk to depress organ blood flow and diuresis. Our objective was to test the hypothesis that high lung volume HFOV attenuates the postnatal reduction of extracellular volume in preterm infants by reducing plasma atrial natriuretic factor and diuresis.
  
  
  METHODS
  Prospective, randomized, controlled clinical trial.
  
  
  METHODS
  University hospital, Level III neonatal intensive care unit.
  
  
  METHODS
  Premature infants <30 wks gestation requiring intubation for respiratory distress syndrome within the first 6 hrs of life; 15 infants (gestational age, 26 [24-29] wks, birth weight 814 [452-1340] g) were randomized to HFOV, 19 infants (gestational age 27 [24-39] wks, birth weight 930 [644-1490] g) to IPPV.
  
  
  METHODS
  The randomized mode of ventilation was assigned within 1 hr after intubation. During HFOV mean airway pressure was increased as long as oxygenation improved and no lung overinflation was seen on chest radiograph. IPPV rates were > or =60/min.
  
  
  RESULTS
  We measured extracellular volume (sucrose dilution) and atrial natriuretic factor on Day 1 and Day 3. Mean airway pressure, body weight, diuresis, and fluid intake were measured daily. During HFOV mean airway pressure was higher at 12 hrs (median 7 cm H2O vs. 4 cm H2O; p = .001) and 24 hrs (median 6 cm H2O vs. 3 cm H2O; p = .01). In both groups, extracellular volume decreased between Day 1 and Day 3 (HFOV from 428 +/- 126 mL to 344 +/- 145 mL [p = .003], IPPV from 466 +/- 108 mL to 414 +/- 124 mL [p = .01]) and diuresis increased (HFOV, from 2.5 +/- 1.7 to 4.6 +/- 0.9 mL/kg/hr [p = .001]; IPPV, from 2.8 +/- 1.6 to 4.2 +/- 1.0 mL/kg/hr [p = .01]). Plasma atrial natriuretic factor was not decreased in the HFOV group.
  
  
  CONCLUSIONS
  High lung volume HFOV as primary mode of ventilation in preterm infants <30 wks gestation did not result in unwanted fluid retention and a decrease in diuresis in the first days of life.
authors.affiliation: Department of Pediatrics, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Bauer
authors.forename: S
authors.initials: S
authors.lastname: Buschkamp
authors.forename: M
authors.initials: M
authors.lastname: Marcinkowski
authors.forename: H
authors.initials: H
authors.lastname: Kössel
authors.forename: U
authors.initials: U
authors.lastname: Thome
authors.forename: H T
authors.initials: HT
authors.lastname: Versmold
mesh_terms: D009320:Atrial Natriuretic Factor / Q000097:blood*; D004231:Diuresis / Q000502:physiology*; D005110:Extracellular Space; D005865:Gestational Age; D006612:High-Frequency Ventilation; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007385:Intermittent Positive-Pressure Ventilation; D011446:Prospective Studies; D012127:Respiratory Distress Syndrome, Newborn / Q000097:blood / Q000503:physiopathology / Q000628:therapy*
chemical_list: D009320:Atrial Natriuretic Factor