Removal of excessive bronchial secretions by asymmetric high-frequency oscillations

L. Freitag, W. M. Long, C. S. Kim, Adam Wanner

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The present study evaluated whether high-frequency oscillations (HFO) with biased flow profiles applied at the airway opening are capable of altering mucus clearance. In eight anesthetized sheep, artificial mucus (100 P) was infused continuously (1 ml/min) into the left main bronchus via a cannula inserted through the dorsal wall of the left main bronchus after thoracotomy. Outcoming mucus was collected every 10 min from the end of a cuffed orotracheal tube. Animals were ventilated with a Harvard respirator at a low frequency with superimposed HFO at 14 Hz with asymmetrical waveforms generated by a digitally controlled electromagnetic piston pump (expiratory bias: peak expiratory flow 3.8 l/s, peak inspiratory flow 1.3 l/s; inspiratory bias: reverse of expiratory bias). The influence of posture and of HFO airflow bias on mucus clearance was determined. In the horizontal position, mucus clearance with expiratory biased HFO was 3.5 ± 2 (SD) ml/10 min. Head-down tilt produced a clearance of 3.1 ± 3 ml/10 min; addition of HFO with expiratory bias increased clearance to 11.0 ± 2.0 ml/10 min (P < 0.05). No clearance occurred with inspiratory biased HFO during head-down tilt. These results indicate that expiratory biased HFO at the airway opening can clear excessive airway secretions and augment clearance by postural drainage.

Original languageEnglish
Pages (from-to)614-619
Number of pages6
JournalJournal of Applied Physiology
Volume67
Issue number2
StatePublished - Jan 1 1989

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Mucus
Head-Down Tilt
Bronchi
Postural Drainage
Electromagnetic Phenomena
Thoracotomy
Mechanical Ventilators
Posture
Sheep

ASJC Scopus subject areas

  • Endocrinology
  • Physiology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Removal of excessive bronchial secretions by asymmetric high-frequency oscillations. / Freitag, L.; Long, W. M.; Kim, C. S.; Wanner, Adam.

In: Journal of Applied Physiology, Vol. 67, No. 2, 01.01.1989, p. 614-619.

Research output: Contribution to journalArticle

Freitag, L. ; Long, W. M. ; Kim, C. S. ; Wanner, Adam. / Removal of excessive bronchial secretions by asymmetric high-frequency oscillations. In: Journal of Applied Physiology. 1989 ; Vol. 67, No. 2. pp. 614-619.
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