Elsevier

The Journal of Pediatrics

Volume 164, Issue 2, February 2014, Pages 283-288.e3
The Journal of Pediatrics

Original Article
Volumetric Capnography in Infants with Bronchopulmonary Dysplasia

https://doi.org/10.1016/j.jpeds.2013.09.034Get rights and content

Objectives

To assess the feasibility of using volumetric capnography in spontaneously breathing small infants and its ability to discriminate between infants with and without bronchopulmonary dysplasia (BPD).

Study design

Lung function variables for 231 infants (102 term, 52 healthy preterm, 77 BPD), matched for post-conceptional age of 44 weeks, were collected. BPD was defined as supplemental oxygen requirement at 36 weeks post-menstrual age. Tidal breath-by-breath volume capnograms were obtained by mainstream capnography. The capnographic slope of phase II (SII) and slope of phase III (SIII) were calculated and compared between study groups. The effect of BPD, tidal volume (VT), respiratory rate (RR), and prematurity on the magnitude of the slopes was assessed.

Results

SII was steeper in infants with BPD (100 ± 28/L) compared with healthy preterm (88 ± 22/L; P = .007) and term infants (79 ± 18/L; P < .001), but this finding was attributed to differences in VT, RR, and gestational age. SIII was steeper in the BPD group (26.8 ± 14.1/L) compared with healthy preterm (16.2 ± 6.2/L; P < .001) and term controls (14.8 ± 5.4/L; P < .001). BPD was a significant predictor of SIII independently of VT, RR, and gestational age. The ability of SIII to discriminate between BPD and controls was significantly higher compared with lung clearance index (area under the curve 0.83 vs 0.56; P < .001).

Conclusions

Volumetric capnography may provide valuable information regarding functional lung alterations related to BPD and might be considered as an alternative to more involved lung function techniques for monitoring chronic lung disease during early infancy.

Section snippets

Methods

This cross-sectional observational study was based on previously-collected lung function data from healthy term and preterm infants with and without BPD, matched for a post-conceptional age of 44 weeks and recruited from 1999-2007 within the region of Bern, Switzerland. The study protocol was approved by the Bernese Cantonal Ethics Committee and written informed parental consent was obtained for each subject prior to enrollment.

Term-born participants were infants without postnatal respiratory

Results

Term-born infants (n = 102), healthy preterm infants (n = 52), and infants with BPD (n = 77) fulfilled the inclusion criteria. Therefore, data from 231 infants (129 preterm; 77 with BPD) were included in the final analysis. All subjects had complete tidal breathing, MBW, and volume-based capnographic measurements. After application of quality control criteria, all capnographic series were suitable for further analysis with an available number of breaths between 82 and 95 (88 ± 3 in average). No

Discussion

Volumetric capnography has not been extensively studied in spontaneously breathing infants. Previous reports on sidestream time-based measurements have suggested the existence of an ‘immature’ capnographic pattern in preterm neonates26 and outlined the differences in capnographic shapes between infants with and without BPD.27 Volume-based capnographic data from unsedated infants are sparse and derived solely from studies aiming to estimate deadspace ventilation.20, 23 We present volume-based

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    S.F. is the recipient of the European Respiratory Society Fellowship (STRTF 53-2012). The authors declare no conflicts of interest.

    Contributed equally.

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