title: A new method for continuous monitoring of chest wall movement to characterize hypoxemic episodes during HFOV.
abstract: BACKGROUND
  Monitoring ventilated infants is difficult during high-frequency oscillatory ventilation (HFOV). This study tested the possible causes of hypoxemic episodes using a new method for monitoring chest wall movement during HFOV in newborn infants.
  
  
  METHODS
  Three miniature motion sensors were attached to both sides of the chest and to the epigastrium to measure the local tidal displacement (TDi) at each site. A >20% change in TDi was defined as deviation from baseline.
  
  
  RESULTS
  Eight premature infants (postmenstrual age 30.6 ± 2.6 weeks) were monitored during 10 sessions (32.6 h) that included 21 hypoxemic events. Three types of such events were recognized: decrease in TDi that preceded hypoxemia (n = 11), simultaneous decrease in TDi and SpO2 (n = 6), and decrease in SpO(2) without changes in TDi (n = 4). In the first group, decreases in TDi were detected 22.4 ± 18.7 min before hypoxemia, and were due to airway obstruction by secretions or decline in lung compliance. The second group resulted from apnea or severe abdominal contractions. In the third group, hypoxia appeared following a decrease in FiO2.
  
  
  CONCLUSIONS
  Monitoring TDi may enable early recognition of deteriorating ventilation during HFOV that eventually leads to hypoxemia. In about half of cases, hypoxemia is not due to slowly deteriorating ventilation.
authors.affiliation: Department of Neonatology, Carmel Medical Center and Faculty of Medicine, 7 Michal St, 34362, Haifa, Israel. dwaisman@netvision.net.il
authors.forename: Dan
authors.initials: D
authors.lastname: Waisman
authors.forename: Carmit
authors.initials: C
authors.lastname: Levy
authors.forename: Anna
authors.initials: A
authors.lastname: Faingersh
authors.forename: Fatmi Ifat Colman
authors.initials: FI
authors.lastname: Klotzman
authors.forename: Eugene
authors.initials: E
authors.lastname: Konyukhov
authors.forename: Irena
authors.initials: I
authors.lastname: Kessel
authors.forename: Avi
authors.initials: A
authors.lastname: Rotschild
authors.forename: Amir
authors.initials: A
authors.lastname: Landesberg
mesh_terms: D005260:Female; D006612:High-Frequency Ventilation / Q000009:adverse effects*; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D015656:Respiratory Mechanics / Q000502:physiology*; D035441:Thoracic Wall / Q000502:physiology*