Postnatal Respiratory Compliance among Premature Ventilated Neonates Associated with Variable Timing and Dosing of Antenatal Steroids

Abstract

Background Antenatal steroids (ANSs) improve the respiratory compliance of premature infants. Many premature neonates are born before the administration of a complete course of ANS.

Objective The objective of this study was to evaluate the respiratory system compliance (Crs) of premature (≤ 32 weeks gestation), intubated neonates in relation to the dose, and timing of ANS administration.

Study Design Neonates (n = 61) were divided into four groups based on the dose and timing of ANS exposure: Group 1: no ANS; Group 2: partial course (one dose of betamethasone); Group 3: complete course (two doses of betamethasone administered within 2 weeks of delivery); and Group 4: remote course (two doses of betamethasone administered > 2 weeks before delivery). Crs was measured by single-breath occlusion technique.

Results Indexed respiratory compliance ± standard error of the mean (mL/cmH₂O/kg) adjusted for gestational ages were 0.359 ± 0.074, 0.366 ± 0.080, 0.625 ± 0.038, and 0.505 ± 0.060 for Groups 1 to 4, respectively. The mean indexed Crs in complete ANS was significantly higher than that of no ANS (0.266 ± 0.085; p = 0.016) as well as partial ANS group (0.259 ± 0.086; p = 0.025).

Conclusions Crs after birth was significantly higher among premature intubated neonates born to mothers who received a complete course of ANS within 2 weeks, compared with no ANS or a partial course of ANS.

Keywords

respiratory compliance - antenatal steroids - premature

Note

This article was presented as a poster at: Chawla S, Natarajan G, Chen X, Gelmini M, and Lua J. Respiratory compliance in premature infants in relation to ANSs and postnatal surfactant. Pediatric Academic Society Meeting; May 2–5, 2009; Baltimore, MA. Abstract E-PAS2009:3860.177 and Chawla S, Natarajan G, and Lua J. Respiratory compliance in premature infants; effect of ANSs. 29th Annual Meeting of Society of Maternal Fetal Medicine Annual Conference; January 26–31, 2009; San Diego, CA.

• References

• 1 NIH Consensus Development Panel on the Effect of Corticosteroids for Fetal Maturation on Perinatal Outcomes. Effect of corticosteroids for fetal maturation on perinatal outcomes. JAMA 1995; 273 (5) 413-418
• 2 Liggins GC, Howie RN. A controlled trial of antepartum glucocorticoid treatment for prevention of the respiratory distress syndrome in premature infants. Pediatrics 1972; 50 (4) 515-525
• 3 Bunton TE, Plopper CG. Triamcinolone-induced structural alterations in the development of the lung of the fetal rhesus macaque. Am J Obstet Gynecol 1984; 148 (2) 203-215
• 4 Schellhase DE, Shannon JM. Effects of maternal dexamethasone on expression of SP-A, SP-B, and SP-C in the fetal rat lung. Am J Respir Cell Mol Biol 1991; 4 (4) 304-312
• 5 McEvoy C, Bowling S, Williamson K, Stewart M, Durand M. Functional residual capacity and passive compliance measurements after antenatal steroid therapy in preterm infants. Pediatr Pulmonol 2001; 31 (6) 425-430
• 6 Boggaram V, Smith ME, Mendelson CR. Regulation of expression of the gene encoding the major surfactant protein (SP-A) in human fetal lung in vitro. Disparate effects of glucocorticoids on transcription and on mRNA stability. J Biol Chem 1989; 264 (19) 11421-11427
• 7 Ikegami M, Polk D, Jobe A. Minimum interval from fetal betamethasone treatment to postnatal lung responses in preterm lambs. Am J Obstet Gynecol 1996; 174 (5) 1408-1413
• 8 Vermillion ST, Soper DE, Newman RB. Is betamethasone effective longer than 7 days after treatment?. Obstet Gynecol 2001; 97 (4) 491-493
• 9 Chawla S, Natarajan G, Rane S, Thomas R, Cortez J, Lua J. Outcomes of extremely low birth weight infants with varying doses and intervals of antenatal steroid exposure. J Perinat Med 2010; 38 (4) 419-423
• 10 Sehdev HM, Abbasi S, Robertson P , et al. The effects of the time interval from antenatal corticosteroid exposure to delivery on neonatal outcome of very low birth weight infants. Am J Obstet Gynecol 2004; 191 (4) 1409-1413
• 11 Peaceman AM, Bajaj K, Kumar P, Grobman WA. The interval between a single course of antenatal steroids and delivery and its association with neonatal outcomes. Am J Obstet Gynecol 2005; 193 (3 Pt 2) 1165-1169
• 12 Ring AM, Garland JS, Stafeil BR, Carr MH, Peckman GS, Pircon RA. The effect of a prolonged time interval between antenatal corticosteroid administration and delivery on outcomes in preterm neonates: a cohort study. Am J Obstet Gynecol 2007; 196 (5) e1-e6
• 13 Roberts D, Dalziel S. Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth. Cochrane Database Syst Rev 2006; 3 (3) CD004454
• 14 McEvoy C, Schilling D, Peters D , et al. Respiratory compliance in preterm infants after a single rescue course of antenatal steroids: a randomized controlled trial. Am J Obstet Gynecol 2010; 202 (6) e1-e9
• 15 Ballard RA, Truog WE, Cnaan A , et al; NO CLD Study Group. Inhaled nitric oxide in preterm infants undergoing mechanical ventilation. N Engl J Med 2006; 355 (4) 343-353
• 16 Olinsky A, Bryan MH, Bryan AC. Influence of lung inflation on respiratory control in neonates. J Appl Physiol 1974; 36 (4) 426-429
• 17 Kramer HC, Thiemann S , eds. How Many Subjects? Statistical Power Analysis in Research. Newbury Park: Sage Publications; 1987
• 18 Baisch SD, Wheeler WB, Kurachek SC, Cornfield DN. Extubation failure in pediatric intensive care incidence and outcomes. Pediatr Crit Care Med 2005; 6 (3) 312-318
• 19 Salhab WA, Hynan LS, Perlman JM. Partial or complete antenatal steroids treatment and neonatal outcome in extremely low birth weight infants < or =1000 g: is there a dose-dependent effect?. J Perinatol 2003; 23 (8) 668-672
• 20 McEvoy C, Schilling D, Spitale P, Peters D, O'Malley J, Durand M. Decreased respiratory compliance in infants less than or equal to 32 weeks' gestation, delivered more than 7 days after antenatal steroid therapy. Pediatrics 2008; 121 (5) e1032-e1038