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Influence of maturation on infant diaphragm function assessed by magnetic stimulation of phrenic nerves
Author(s) -
Dimitriou Gabriel,
Greenough Anne,
Moxham John,
Rafferty Gerrard F.
Publication year - 2003
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.10209
Subject(s) - medicine , diaphragm (acoustics) , phrenic nerve , stimulation , esophagus , anesthesia , gestational age , diaphragmatic breathing , functional residual capacity , respiratory system , surgery , lung volumes , lung , pregnancy , pathology , physics , alternative medicine , biology , acoustics , loudspeaker , genetics
Infant diaphragm function may be adversely affected in a variety of disorders and conditions. Key to establishing an accurate diagnosis are appropriate control data. The aim of this study was to determine the effect of maturation on diaphragm function, using a nonvolitional test. Diaphragm function was assessed by measuring the transdiaphragmatic pressure (Pdi) generated by magnetic stimulation of the phrenic nerves. Ballon catheters were positioned in the lower third of the esophagus and stomach. Esophageal (Pes) and gastric (Pgas) pressure changes were measured using differential pressure transducers. The pressure signals were amplified and displayed in real time on a computer (running Labview™ software) and Pdi derived by online subtraction of Pes from Pgas. Twenty‐nine infants (14 born preterm), at a median gestational age of 37 (range, 25–42) weeks, were studied at a median postconceptional age (PCA) of 39 (range, 32–44) weeks. At time of measurement, none had respiratory problems or were hyperinflated (functional residual capacity ranged from 23–35 mL/kg). The preterm infants had significantly lower transdiaphragmatic pressures responses following median left (4.0, range 2.5–6.8 cmH 2 O vs. 4.8, range 2.8–7.2 cmH 2 O) and median right phrenic nerve stimulation (3.6, range 2.6–4.8 cmH 2 O vs. 4.3, range 2.7–6.8 cmH 2 O) ( P < 0.05) than term infants. Following left and right phrenic nerve stimulation, Pdi correlated significantly with gestational age (r = 0.4, P < 0.05, and r = 0.4, P < 0.05, respectively) and PCA (r = 0.37, P = 0.05, and r = 0.56, P < 0.01, respectively). We conclude that gestational age at birth and postconceptional age at time of measurements must be taken into account when interpreting the results of infant diaphragm function tests. Pediatr Pulmonol. 2003; 35:17–22. © 2003 Wiley‐Liss, Inc.