Mechanisms of hypoxemia episodes in spontaneously breathing preterm infants after mechanical ventilation

Cristian Esquer, Nelson R Claure, Carmen D'Ugard, Yoshiro Wada, Eduardo Bancalari

Research output: Contribution to journalArticle

17 Scopus citations


Background: Preterm infants often present with recurrent episodes of hypoxemia after mechanical ventilation. Objective: To evaluate the role of abdominal muscle activity and central apnea on the frequency and severity of hypoxemia episodes (HEs) in preterm infants with a history of mechanical ventilation. Methods: Continuous recordings of arterial oxygen saturation (SpO2), gastric pressure, respiratory inductance plethysmography and abdominal surface electromyography were obtained during 4 h from spontaneously breathing preterm infants who had recently been extubated and presented with frequent HEs. Results: Ten infants (gestational age 26.4 ± 1.1 weeks, body weight 816 ± 128 g, age 44 ± 21 days, FiO2 0.31 ± 0.09, mechanically ventilated for 33 ± 37 days) were studied 12 ± 7 (mean ± SD) days after extubation. These infants presented with 10.2 ± 9.3 HEs/h (SpO2 <88%, ≥10 s). Of these, 8.2 ± 6.2 HEs/h were associated with abdominal muscle contraction while only 2.0 ± 4.5 HEs/h were associated with ≥10 s apnea (p < 0.05). Of the more severe HEs (SpO2 <75%, ≥10 s), 2.7 ± 3.1 HEs/h were associated with abdominal contraction and only 0.7 ± 2.1 HEs/h with apnea (p < 0.05). Resting lung volume decreased by 69 ± 16% of tidal volume in HEs associated with abdominal contraction. Conclusions: In this group of premature infants who presented with frequent HEs after mechanical ventilation, most HEs were associated with abdominal muscles contraction and a loss in lung volume. These findings provide an alternate mechanism to explain these episodes in spontaneously breathing preterm infants with a history of mechanical ventilation.

Original languageEnglish
Pages (from-to)100-104
Number of pages5
Issue number2
StatePublished - Aug 1 2008



  • Apnea
  • Hypoxemia episodes
  • Hypoxia
  • Intermittent hypoxemia
  • Premature infants

ASJC Scopus subject areas

  • Developmental Biology
  • Pediatrics, Perinatology, and Child Health

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