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Effect of maturity on maximal transdiaphragmatic pressure in infants during crying
G Dimitriou1, A Greenough, G F Rafferty
1Department of Child Health, King's College Hospital, London, United Kingdom.
Insights
Infant diaphragm function improves with maturation. Noninvasive maximal inspiratory pressure (PImax) correlates with invasive measures, suggesting it can assess infant diaphragm strength.
Area of Science:
- Pediatric Pulmonology
- Neonatal Physiology
- Respiratory Mechanics
Background:
- Diaphragmatic function is crucial for infant respiration.
- Assessing diaphragmatic strength in neonates is challenging.
- Maturation-related changes in respiratory muscle function require investigation.
Purpose of the Study:
- To evaluate the impact of maturation on infant diaphragmatic function.
- To compare invasive and noninvasive methods for assessing diaphragmatic strength.
- To determine if noninvasive measurements correlate with invasive assessments.
Main Methods:
- Invasive measurement of maximal transdiaphragmatic pressure during crying (cPdi) using esophageal (Pes) and gastric (Pgas) balloons.
- Noninvasive measurement of maximal inspiratory pressure (PImax) in a subset of infants.
- Correlation analysis between cPdi, PImax, gestational age (GA), and postconceptional age (PCA).
Main Results:
- Median cPdi and cPes were lower in infants studied at a postconceptional age (PCA) less than term.
- cPdi and cPes showed significant correlations with PCA and gestational age (GA).
- PImax correlated significantly with cPdi (r = 0.79, p < 0.01), indicating a strong relationship.
Conclusions:
- Infant diaphragm function is significantly affected by maturation.
- Maximal inspiratory pressure (PImax) shows potential as a noninvasive index for assessing infant diaphragm strength.
- Noninvasive PImax offers a viable alternative to invasive methods for evaluating respiratory muscle function in neonates.
Abstract:
The aim of this study was to determine the effect of maturation on diaphragmatic function. In addition, we investigated whether noninvasive assessment yielded similar results to invasive measurement. Twenty-eight infants, median gestational age (GA) 35.5 wk (range, 25 to 42 wk) and postconceptional age (PCA), 37.6 wk (range, 32 to 44 wk), were examined. Diaphragmatic function was assessed by measuring the maximal transdiaphragmatic pressure during crying (cPdi) using balloon catheters in the midesophagus (Pes) and the stomach (Pgas). In 14 of the infants, a noninvasive measurement of inspiratory muscle strength, maximal inspiratory pressure (PImax), was also made. cPdi and PImax were recorded during a crying effort with the airway occluded at end-expiration. The median cPdi and Pes during crying (cPes), but not Pgas during crying (cPgas), were significantly lower in those studied at a PCA of less than term compared with those studied at an older age (p < 0.05). cPdi and cPes, but not cPgas, correlated significantly with PCA (r = 0.44, p < 0.02; r = 0.43, p < 0.03; respectively) and gestational age (r = 0.46, p < 0.02 and r = 0.56, p < 0.01; respectively). In the 14 infants, the median PImax was lower, but it correlated significantly with cPdi (r = 0.79, p < 0.01). We conclude maturation does affect diaphragm function, and PImax may provide a noninvasive index of diaphragm strength.