Multiple breath washout cannot be used for tidal breath parameter analysis in infants

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology

Background:

• Multiple breath washout (MBW) using sulfur hexafluoride (SF6) is standard for infant ventilation assessment.
• The impact of SF6 on infant tidal breathing parameters during MBW is not well understood.
• Investigating these changes is crucial for accurate respiratory assessments in infants.

Purpose of the Study:

• To determine if SF6 gas mixture alters tidal breathing parameters in infants during MBW testing.
• To assess the necessity of a separate tidal breathing measurement in room air prior to MBW.

Main Methods:

• Comparison of tidal breathing in room air versus during MBW with SF6 in healthy, preterm, and cystic fibrosis infants.
• Analysis of key respiratory parameters: inspiratory/expiratory times, time to peak flows, tidal volume, respiratory rate, and minute ventilation.

Main Results:

• Significant increases in breath times (inspiratory and expiratory) were observed in healthy and cystic fibrosis infants during MBW wash-in.
• Decreased respiratory rate and minute ventilation were noted in healthy and cystic fibrosis infants during MBW wash-in.
• Preterm infants showed reduced minute ventilation during both wash-in and wash-out phases of MBW.

Conclusions:

• SF6 gas mixture significantly alters tidal breathing parameters in infants during MBW testing.
• Measuring a separate tidal breathing trace in room air before MBW is essential.
• This pre-MBW measurement ensures the rigor and accuracy of derived tidal breath indices for clinical analysis.