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Effects of continuous positive airway pressure on diaphragm dimensions in preterm infants

V K Rehan1, J Laiprasert, J M Nakashima

  • 1Department of Pediatrics, Memorial Hospital of Rhode Island, Pawtucket, RI, USA.

Journal of Perinatology : Official Journal of the California Perinatal Association
|January 5, 2002
PubMed

Insights

Continuous positive airway pressure (CPAP) improves oxygen saturation in preterm infants despite shortening the diaphragm. This suggests other mechanisms offset CPAP

Area of Science:

  • Neonatal Medicine
  • Pediatric Respiratory Physiology
  • Medical Imaging and Diagnostics

Background:

  • Continuous positive airway pressure (CPAP) is vital for treating neonatal respiratory distress.
  • CPAP improves oxygenation and survival but its effect on diaphragm mechanics is unclear.
  • Increased end-expiratory lung volume (EEV) from CPAP may alter diaphragm length.

Purpose of the Study:

  • To quantify diaphragm shortening caused by CPAP in preterm infants.
  • To examine the relationship between diaphragm dimensions, excursion, and arterial oxygen saturation.
  • To assess the impact of varying CPAP levels on diaphragm function.

Main Methods:

  • Ultrasonography (7.5 MHz transducer) measured diaphragm thickness and excursion.
  • Measurements were taken in 12 stable preterm infants across three CPAP levels (low, medium, high).
  • Heart rate, respiratory rate, and arterial oxygen saturation were recorded concurrently.

Main Results:

  • Higher CPAP levels significantly increased diaphragm thickness and arterial oxygen saturation.
  • Diaphragm excursion decreased significantly with increasing CPAP levels.
  • Diaphragm shortening was 36% at EEV and 31% at end-inspiratory volume at high CPAP.

Conclusions:

  • Improved oxygen saturation with CPAP occurs despite diaphragm shortening and reduced mobility.
  • Other physiological changes associated with CPAP likely compensate for negative effects on diaphragm function.
  • Excessive CPAP may lead to diaphragm dysfunction, potentially outweighing oxygenation benefits.
Abstract

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