Background: Delayed postnatal removal of lung liquid may result in respiratory distress, which is more common in infants born by cesarean section. Vertical artefacts (B-lines) arising from the lung surface in lung ultrasound have been shown to correlate with the liquid content of the lungs. Objectives: We studied whether lung ultrasound could be used for the assessment of postnatal lung liquid in healthy term infants born vaginally and by cesarean section. Methods: Lung ultrasound was performed 1, 3 and 24 h after birth to 22 vaginally born infants and 20 infants born by elective cesarean section. The abundance of B-lines was scored for each infant and time point by two independent observers blinded to the mode of delivery and time point on the examination on a five-step scale. Results: In both groups, a significant decrease in abundance of B-lines, indicative of lung liquid absorption, was observed during the first 24 h. 3 h after birth cesarean section was associated with significantly higher lung liquid content than vaginal delivery. Conclusion: The noninvasive bedside ultrasound method for estimation of lung liquid is a promising tool for the early identification of infants at risk for pulmonary maladaptation.

1.
Helve O, Pitkanen O, Janer C, Andersson S: Pulmonary fluid balance in the human newborn infant. Neonatology 2009;95:347-352.
2.
Ramachandrappa A, Jain L: Elective cesarean section: its impact on neonatal respiratory outcome. Clin Perinatol 2008;35:373-393, vii.
3.
Jain L: Morbidity and mortality in late-preterm infants: more than just transient tachypnea! J Pediatr 2007;151:445-446.
4.
Gargani L: Lung ultrasound: a new tool for the cardiologist. Cardiovasc Ultrasound 2011;9:6.
5.
Copetti R, Cattarossi L: The ‘double lung point': an ultrasound sign diagnostic of transient tachypnea of the newborn. Neonatology 2007;91:203-209.
6.
Lichtenstein D, Meziere G: A lung ultrasound sign allowing bedside distinction between pulmonary edema and COPD: the comet-tail artifact. Intensive Care Med 1998;24:1331-1334.
7.
Copetti R, Cattarossi L, Macagno F, Violino M, Furlan R: Lung ultrasound in respiratory distress syndrome: a useful tool for early diagnosis. Neonatology 2008;94:52-59.
8.
Kitterman JA, Ballard PL, Clements JA, Mescher EJ, Tooley WH: Tracheal fluid in fetal lambs: spontaneous decrease prior to birth. J Appl Physiol 1979;47:985-989.
9.
Pfister RE, Ramsden CA, Neil HL, Kyriakides MA, Berger PJ: Volume and secretion rate of lung liquid in the final days of gestation and labour in the fetal sheep. J Physiol 2001;535:889-899.
10.
Bland RD, Bressack MA, McMillan DD: Labor decreases the lung water content of newborn rabbits. Am J Obstet Gynecol 1979;135:364-367.
11.
Bland RD, Hansen TN, Haberkern CM, Bressack MA, Hazinski TA, Raj JU, Goldberg RB: Lung fluid balance in lambs before and after birth. J Appl Physiol 1982;53:992-1004.
12.
Siew ML, Wallace MJ, Kitchen MJ, Lewis RA, Fouras A, Te Pas AB, Yagi N, Uesugi K, Siu KK, Hooper SB: Inspiration regulates the rate and temporal pattern of lung liquid clearance and lung aeration at birth. J Appl Physiol 2009;106:1888-1895.
13.
Bland RD, McMillan DD, Bressack MA, Dong L: Clearance of liquid from lungs of newborn rabbits. J Appl Physiol 1980;49:171-177.
14.
Hummler E, Barker P, Gatzy J, Beermann F, Verdumo C, Schmidt A, Boucher R, Rossier BC: Early death due to defective neonatal lung liquid clearance in alpha-ENaC-deficient mice. Nat Genet 1996;12:325-328.
15.
O'Brodovich H, Hannam V, Seear M, Mullen JB: Amiloride impairs lung water clearance in newborn guinea pigs. J Appl Physiol 1990;68:1758-1762.
16.
Brown MJ, Olver RE, Ramsden CA, Strang LB, Walters DV: Effects of adrenaline and of spontaneous labour on the secretion and absorption of lung liquid in the fetal lamb. J Physiol 1983;344:137-152.
17.
Olver RE, Ramsden CA, Strang LB, Walters DV: The role of amiloride-blockable sodium transport in adrenaline-induced lung liquid reabsorption in the fetal lamb. J Physiol 1986;376:321-340.
18.
Baines DL, Folkesson HG, Norlin A, Bingle CD, Yuan HT, Olver RE: The influence of mode of delivery, hormonal status and postnatal O2 environment on epithelial sodium channel (ENaC) expression in perinatal guinea-pig lung. J Physiol 2000;522:147-157.
19.
Gowen CW Jr, Lawson EE, Gingras J, Boucher RC, Gatzy JT, Knowles MR: Electrical potential difference and ion transport across nasal epithelium of term neonates: correlation with mode of delivery, transient tachypnea of the newborn, and respiratory rate. J Pediatr 1988;113:121-127.
20.
Faxelius G, Hagnevik K, Lagercrantz H, Lundell B, Irestedt L: Catecholamine surge and lung function after delivery. Arch Dis Child 1983;58:262-266.
21.
Eisler G, Hjertberg R, Lagercrantz H: Randomised controlled trial of effect of terbutaline before elective caesarean section on postnatal respiration and glucose homeostasis. Arch Dis Child Fetal Neonatal Ed 1999;80: F88-F92.
22.
Hjalmarson O, Sandberg KL: Effect of antenatal corticosteroid treatment on lung function in full-term newborn infants. Neonatology 2011;100:32-36.
23.
Oh SY, Romero R, Shim SS, Park JS, Jun JK, Yoon BH: Fetal plasma cortisol and dehydroepiandrosterone sulfate concentrations in pregnancy and term parturition. J Matern Fetal Neonatal Med 2006;19:529-536.
24.
Mears K, McAuliffe F, Grimes H, Morrison JJ: Fetal cortisol in relation to labour, intrapartum events and mode of delivery. J Obstet Gynaecol 2004;24:129-132.
25.
Vogl SE, Worda C, Egarter C, Bieglmayer C, Szekeres T, Huber J, Husslein P: Mode of delivery is associated with maternal and fetal endocrine stress response. BJOG 2006;113:441-445.
26.
Bagnoli F, Bruchi S, Garosi G, Caniggia I, Inaudi PA: Phenomenon of neonatal adaptation: progesterone, ACTH and cortisol during the 1st 24 hours of life. Boll Soc Ital Biol Sper 1988;64:317-322.
27.
Stutchfield P, Whitaker R, Russell I, Antenatal Steroids for Term Elective Caesarean Section (ASTECS) Research Team: Antenatal betamethasone and incidence of neonatal respiratory distress after elective caesarean section: pragmatic randomised trial. BMJ 2005;331:662.
28.
Gowen CW Jr, Lawson EE, Gingras J, Boucher RC, Gatzy JT, Knowles MR: Electrical potential difference and ion transport across nasal epithelium of term neonates: correlation with mode of delivery, transient tachypnea of the newborn, and respiratory rate. J Pediatr 1988;113:121-127.
29.
Janer C, Pitkanen OM, Helve O, Andersson S: Airway expression of the epithelial sodium channel alpha-subunit correlates with cortisol in term newborns. Pediatrics 2011;128:e414-e421.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.