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Maximal expiratory flows generated by rapid chest compression following end-inspiratory occlusion or expiratory
1Pulmonary and Cystic Fibrosis Clinic, Shaare Zedek Medical Center, Jerusalem, Israel.
Insights
This study found that modifying the rapid chest compression technique by adding end-inspiratory airway occlusion or expiratory clamping significantly improves maximal expiratory flow in infants and young children, enhancing pulmonary function assessment.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
Background:
- Partial forced expiratory flow-volume curves using rapid chest compression are common for infant pulmonary function testing.
- The effectiveness of this technique in achieving flow limitation in young children requires further investigation.
Purpose of the Study:
- To evaluate if flow limitation is achieved with partial forced expiratory flow-volume curves using rapid chest compression in infants and young children.
- To compare the impact of different pre-compression maneuvers on expiratory flow rates.
Main Methods:
- Eight infants and young children underwent pulmonary function testing using three techniques: regular rapid chest compression, end-inspiratory occlusion followed by rapid chest compression, and expiratory clamping followed by rapid chest compression.
- Cuff pressure was incrementally increased from 20 to 90 cmH2O for each technique to generate maximal flow-volume curves.
Main Results:
- End-inspiratory occlusion prior to rapid chest compression increased expiratory flows (V50 by 34%, V75 by 31%) compared to the regular technique.
- Expiratory clamping prior to compression resulted in even higher expiratory flows.
- Maximal flow-volume curves were successfully generated using all tested techniques.
Conclusions:
- Modifications to the rapid chest compression technique, specifically end-inspiratory occlusion and expiratory clamping, enhance expiratory flow rates in pediatric subjects.
- These modified techniques may offer a more effective method for assessing pulmonary function and achieving flow limitation in infants and young children.
Abstract:
Partial forced expiratory flow-volume curves obtained by the rapid chest compression technique are being widely used to assess pulmonary function in infants and young children. The aim of this study is to assess whether in this age group flow limitation is achieved with the partial forced expiratory flow-volume curve with rapid chest compression. In eight infants and young children sedated with chloral hydrate, flow-volume curves were obtained by regular rapid chest compression technique, end-inspiratory airway occlusion prior to rapid chest compression, and expiratory clamping prior to rapid chest compression. In each technique, beginning with a cuff pressure of 20 cmH2O, the cuff pressure was increased by 10 cmH2O increments until the compression pressure reached 90 cmH2O. Maximal flow-volume curves were generated by each technique. End-inspiratory occlusion prior to rapid chest compression caused higher flows over the entire phase of expiration than the regular rapid chest compression. This increase could be observed over the entire phase of expiration. Forced expiratory flow at 50% and at 75% of vital capacity (V50 and V75) with regular rapid chest compression were 207 +/- 44 ml.s-1 (mean +/- SD) and 138 +/- 59 ml.sec-1, respectively. When end-inspiratory occlusion preceded rapid chest compression, V50 and V75 increased to 283 +/- 114 and 206 +/- 61 ml.sec-1 respectively, with a mean increase in V50 of 34% and in V75 of 31%. When expiratory clamping preceded the compression, even higher expiratory flows resulted.(ABSTRACT TRUNCATED AT 250 WORDS)