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Saad SMI, Policova Z, Acosta EJ, Neumann AW. Effect of surfactant concentration, compression ratio and compression rate on the surface activity and dynamic properties of a lung surfactant. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:103-16. [PMID: 22020010 DOI: 10.1016/j.bbamem.2011.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 09/17/2011] [Accepted: 10/03/2011] [Indexed: 01/20/2023]
Abstract
This paper reports dynamic surface tension experiments of a lung surfactant preparation, BLES, for a wide range of concentrations, compression ratios and compression rates. These experiments were performed using Axisymmetric Drop Shape Analysis-Constrained Sessile Drop (ADSA-CSD). The main purpose of the paper is to interpret the results in terms of physical parameters using the recently developed Compression-Relaxation Model (CRM). In the past, only the minimum surface tension was used generally for the characterization of lung surfactant films; however, this minimum value is not a physical parameter and depends on the compression protocol. CRM is based on the assumption that the dynamic surface tension response is governed by surface elasticities, adsorption and desorption of components of the lung surfactant. The ability of CRM to fit the surface tension response closely for a wide variety of parameters (compression ratio, compression rate and surfactant concentration) and produce sensible values for the elastic and kinetic parameters supports the validity of CRM.
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Affiliation(s)
- Sameh M I Saad
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario, Canada
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2
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Frey SL, Pocivavsek L, Waring AJ, Walther FJ, Hernandez-Juviel JM, Ruchala P, Lee KYC. Functional importance of the NH2-terminal insertion sequence of lung surfactant protein B. Am J Physiol Lung Cell Mol Physiol 2009; 298:L335-47. [PMID: 20023175 DOI: 10.1152/ajplung.00190.2009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lung surfactant protein B (SP-B) is required for proper surface activity of pulmonary surfactant. In model lung surfactant lipid systems composed of saturated and unsaturated lipids, the unsaturated lipids are removed from the film at high compression. It is thought that SP-B helps anchor these lipids closely to the monolayer in three-dimensional cylindrical structures termed "nanosilos" seen by atomic force microscopy imaging of deposited monolayers at high surface pressures. Here we explore the role of the SP-B NH(2) terminus in the formation and stability of these cylindrical structures, specifically the distribution of lipid stack height, width, and density with four SP-B truncation peptides: SP-B 1-25, SP-B 9-25, SP-B 11-25, and SP-B 1-25Nflex (prolines 2 and 4 substituted with alanine). The first nine amino acids, termed the insertion sequence and the interface seeking tryptophan residue 9, are shown to stabilize the formation of nanosilos while an increase in the insertion sequence flexibility (SP-B 1-25Nflex) may improve peptide functionality. This provides a functional understanding of the insertion sequence beyond anchoring the protein to the two-dimensional membrane lining the lung, as it also stabilizes formation of nanosilos, creating reversible repositories for fluid lipids at high compression. In lavaged, surfactant-deficient rats, instillation of a mixture of SP-B 1-25 (as a monomer or dimer) and synthetic lung lavage lipids quickly improved oxygenation and dynamic compliance, whereas SP-B 11-25 surfactants showed oxygenation and dynamic compliance values similar to that of lipids alone, demonstrating a positive correlation between formation of stable, but reversible, nanosilos and in vivo efficacy.
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Affiliation(s)
- Shelli L Frey
- Department of Chemistry, Institute for Biophysical Dynamics and James Franck Institute, The University of Chicago,929 E. 57 St., Chicago, IL 60637, USA
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Schmiedl A, Vieten G, Mühlfeld C, Bernhard W. Distribution of intracellular and secreted surfactant during postnatal rat lung development. Pediatr Pulmonol 2007; 42:548-62. [PMID: 17469149 DOI: 10.1002/ppul.20623] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pulmonary surfactant prevents alveolar collapse via reduction of surface tension. In contrast to human neonates, rats are born with saccular lungs. Therefore, rat lungs serve as a model for investigation of the surfactant system during postnatal alveolar formation. We hypothesized that this process is associated with characteristic structural and biochemical surfactant alterations. We aimed to discriminate changes related to alveolarization from those being either invariable or follow continuous patterns of postnatal changes. Secreted active (mainly tubular myelin (tm)) and inactive (unilamellar vesicles (ulv)) surfactant subtypes as well as intracellular surfactant (lamellar bodies (lb)) in type II pneumocytes (PNII) were quantified before (day (d) 1), during (d 7), at the end of alveolarization (d 14), and after completion of lung maturation (d 42) using electron microscopic methods supplemented by biochemical analyses (phospholipid quantification, immunoblotting for SP-A). Immunoelectron microscopy determined the localization of surfactant protein A (SP-A). (1) At d 1 secreted surfactant was increased relative to d 7-42 and then decreased significantly. (2) Air spaces of neonatal lungs comprised lower fractions of tm and increased ulv, which correlated with low SP-A concentrations in lung lavage fluid (LLF) and increased respiratory rates, respectively. (3) Alveolarization (d 7-14) was associated with decreasing PNII size although volume and sizes of Lb continuously increased. (4) The volume fractions of Lb correlated well with the pool sizes of phospholipids in lavaged lungs. Our study emphasizes differential patterns of developmental changes of the surfactant system relative to postnatal alveolarization.
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Affiliation(s)
- Andreas Schmiedl
- Department of Anatomy, Hannover Medical School, Hannover, Germany.
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Sokol GM, Ehrenkranz RA. Inhaled nitric oxide therapy in neonatal hypoxic respiratory failure: insights beyond primary outcomes. Semin Perinatol 2003; 27:311-9. [PMID: 14510322 DOI: 10.1016/s0146-0005(03)00043-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Neonatal Research Network developed and initiated 3 multicenter randomized controlled clinical trials evaluating inhaled nitric oxide therapy. Additional projects evolved from these efforts including basic science research and observational investigations. This article provides a historical prospective of the Network's investigations related to the diagnosis and management of neonatal hypoxic respiratory failure, especially those related to inhaled nitric oxide therapy. It will review the Network's contributions toward advancing the clinical care of the newborn with severe hypoxic respiratory failure.
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Affiliation(s)
- Gregory M Sokol
- Section of Neonatal-Perinatal Medicine, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202-5271, USA.
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Lalani S, Remmers JE, Green FH, Bukhari A, Ford GT, Hasan SU. Effects of vagal denervation on cardiorespiratory and behavioral responses in the newborn lamb. J Appl Physiol (1985) 2001; 91:2301-13. [PMID: 11641375 DOI: 10.1152/jappl.2001.91.5.2301] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recently, Wong et al. (Wong KA, Bano A, Rigaux A, Wang B, Bharadwaj B, Schurch S, Green F, Remmers JE, and Hasan SU, J Appl Physiol 85: 849-859, 1998) demonstrated that fetal lambs that have undergone vagal denervation prenatally do not establish adequate alveolar ventilation shortly after birth. In their study, however, vagal denervation was performed prenatally and the deleterious effects of vagal denervation on breathing patterns and gas exchange could have resulted from the prenatal actions of the neurotomy. To quantify the relative roles of pre- vs. postnatal vagal denervation on control of breathing, we studied 14 newborn lambs; 6 were sham operated, and 8 were vagally denervated below the origin of the recurrent laryngeal nerve. Postoperatively, all denervated animals became hypoxemic and seven of eight succumbed to respiratory failure. In vagally denervated lambs, expiratory time increased, whereas respiratory rate, minute ventilation, and lung compliance decreased compared with the sham-operated animals. In the early postoperative period, the frequency of augmented breaths was lower but gradually increased over time in the denervated vs. sham-operated group. The dynamic functional residual capacity was significantly higher than the passive functional residual capacity among the sham-operated group compared with the denervated group. No significant differences were observed in the prevalence of various sleep states and in the amount of total phospholipids or large- and small-aggregate surfactants between the two groups. We provide new evidence indicating that intrauterine actions of denervation are not required to explain the effects of vagal denervation on postnatal survival. Our data suggest that vagal input is critical in the maintenance of normal breathing patterns, end-expiratory lung volume, and gas exchange during the early neonatal period.
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Affiliation(s)
- S Lalani
- Department of Pediatrics, Respiratory Research Group, Faculty of Medicine, The University of Calgary, Calgary, Alberta, Canada T2N 4N1
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Angus DC, Linde-Zwirble WT, Clermont G, Griffin MF, Clark RH. Epidemiology of neonatal respiratory failure in the United States: projections from California and New York. Am J Respir Crit Care Med 2001; 164:1154-60. [PMID: 11673202 DOI: 10.1164/ajrccm.164.7.2012126] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We wanted to determine the incidence, cost, outcome, and patterns of care for neonates requiring mechanical ventilation (MV) in the United States. Using 1994 state hospital discharge data from California and New York, we conducted an observational study of all neonatal hospitalizations (n = 16,405) with MV, comparing outcomes at centers of different technological capability, and generating national projections using census and natality reports. The MV rate was 18 per 1,000 live births. Although the incidence was much higher in lower birth weight (BW) babies, one-third had normal BW. The incidence was higher in boys (20 versus 15.6 per 1,000) and in blacks (29 per 1,000). Hospital mortality was 11.1%, higher in minority groups, and associated with low BW, congenital anomalies, and major hemorrhage. Mean hospital length of stay and costs were 31.1 d and $51,700. Half of all deaths occurred at lower level centers. There are 80,000 cases per year in the United States with 8,500 deaths and total hospital costs of $4.4 billion. We conclude neonatal respiratory failure is common, expensive, and frequently fatal. There are a surprisingly large number of normal BW cases and there are large racial differences.
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Affiliation(s)
- D C Angus
- Critical Care Medicine Division, Department of Anesthesiology and Critical Care Medicine, and the Center for Research on Health Care, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
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Göthberg S, Parker TA, Griebel J, Abman SH, Kinsella JP. Lung volume recruitment in lambs during high-frequency oscillatory ventilation using respiratory inductive plethysmography. Pediatr Res 2001; 49:38-44. [PMID: 11134489 DOI: 10.1203/00006450-200101000-00011] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Monitoring lung volume is important in the treatment of acute hypoxemic respiratory failure. However, there are no tools available for lung volume measurement to guide ventilator management during high-frequency oscillatory ventilation (HFOV) and during dynamic changes in conventional ventilation (CV). We studied the performance of a new respiratory inductive plethysmograph (RIP) with modified software. We measured Delta changes in lung volume above end-expiratory volume (V(RIP)) during HFOV and studied whether changes in V(RIP) parallel changes in mean airway pressure. Calibration of the plethysmograph was made by serial injections of a known gas volume in six term (140 d gestation) and eight preterm (125 d gestation) lambs. Linear regression analysis of the relationship between injected gas volume and V(RIP) showed strong correlation (r(2) = 0.93-1.00 term animals, r(2) = 0.86-1.00 preterm animals). The pressure volume curves from the calibration with the injected gas volumes also correlated well with the pressure volume curves extrapolated from changes in V(RIP). Lung hysteresis was clearly demonstrated with RIP after changes in mean airway pressure during HFOV and after changes in positive end-expiratory pressure during CV. We conclude that measurements of lung volume in term and preterm lambs by use of modified RIP correlate well with changes in mean airway pressure during HFOV, with static pressure volume curves and with changes in positive end-expiratory pressure during CV. We speculate that this technique may provide clinically useful information about changes in lung volume during HFOV and CV. However, evaluation of the precision and chronic stability of RIP measurements over prolonged periods will require further studies.
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Affiliation(s)
- S Göthberg
- Department of Pediatric Anesthesia and Intensive Care, The Queen Silvia Children's Hospital, 416 85 Göteborg, Sweden
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Kinsella JP, Parker TA, Galan H, Sheridan BC, Abman SH. Independent and combined effects of inhaled nitric oxide, liquid perfluorochemical, and high-frequency oscillatory ventilation in premature lambs with respiratory distress syndrome. Am J Respir Crit Care Med 1999; 159:1220-7. [PMID: 10194169 DOI: 10.1164/ajrccm.159.4.9807150] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Acute lung injury caused by tidal volume ventilation in the premature lamb with respiratory distress syndrome (RDS) is characterized by progessive deterioration in gas exchange and lung inflammation. Inhaled nitric oxide (iNO) improves gas exchange and decreases lung neutrophil accumulation in premature lambs with RDS. Mechanical lung recruitment techniques such as high-frequency oscillatory ventilation (HFOV) and partial liquid ventilation (PLV) also decrease lung injury and improve gas exchange in experimental models of neonatal respiratory failure. We hypothesized that two lung recruitment strategies (HFOV and PLV) would have similar effects on gas exchange and lung inflammation, and would augment the response to iNO. We studied the individual and combined effects of iNO, HFOV, and PLV (perflubron) in 31 extremely premature lambs (115 d, 0.78 term) using seven mechanical ventilation protocols. Four groups were treated with conventional ventilation (control CV, CV + iNO, CV + PLV, and CV + PLV + iNO). Three groups were treated with HFOV (control HFOV, HFOV + iNO, HFOV + PLV). Control CV animals had progressive deterioration in gas exchange over the 4-h study period (a/AO2 at 4 h = 0.06 +/- 0.01). In contrast, both HFOV and CV + PLV caused sustained improvements in oxygenation at 4 h (HFOV a/AO2 = 0. 27 +/- 0.06, CV + PLV a/AO2 = 0.25 +/- 0.04; p < 0.01 versus CV). Both lung recruitment strategies improved oxygenation when combined with iNO (5 ppm). Lung neutrophil accumulation was reduced by HFOV, PLV, and iNO compared to CV. We conclude that HFOV and PLV with perflubron cause similar improvements in gas exchange and lung inflammation in the premature lamb with severe RDS, and both strategies augment the oxygenation response to iNO.
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Affiliation(s)
- J P Kinsella
- Department of Pediatrics, Sections of Neonatology, Pulmonary and Critical Care Medicine, University of Colorado School of Medicine, Denver, Colorado, USA
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Ivy DD, Parker TA, Kinsella JP, Abman SH. Endothelin A receptor blockade decreases pulmonary vascular resistance in premature lambs with hyaline membrane disease. Pediatr Res 1998; 44:175-80. [PMID: 9702910 DOI: 10.1203/00006450-199808000-00006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Endothelin (ET)-1 is a potent vasoconstrictor peptide that modulates basal pulmonary vascular resistance (PVR) in the normal ovine fetus and contributes to high PVR after chronic intrauterine pulmonary hypertension. Although high PVR is present in premature lambs with severe hyaline membrane disease (HMD), whether ET-1 plays a role in the pathophysiology of experimental HMD is unknown. To test the hypothesis that ET-1 activity contributes to high PVR in the premature lamb with HMD, we studied the hemodynamic effects of a selective ET(A) receptor antagonist, BQ 123, in 10 animals (gestational age 125 d; 147 d=term). After baseline measurements, animals were intubated, treated with surfactant (Infasurf), and mechanically ventilated with a fraction of inspired oxygen of 1.00 for 8 h. Animals were treated with continuous infusions of either BQ 123 (1 mg/h; treatment group, n=5) or 1% DMSO (control; n=5). Plasma ET-1 levels progressively increased during prolonged ventilation with hyperoxia (0.8+/-0.1 pg/mL, baseline to 6.8+/-2.5 pg/mL, 8 h, p < 0.05). In comparison with control lambs, BQ 123 treatment caused a sustained reduction in pulmonary vascular resistance (0.55+/-0.04 mm Hg mL-(-1) min(-1), control versus 0.18+/-0.04 mm Hg mL(-1) min(-1), BQ 123, p < 0.05), increased left pulmonary artery blood flow (70+/-12 mL/min, control versus 194+/-28 mL/min, BQ 123, p < 0.05), and increased arterial PaO2 (53+/-14 mm Hg, control versus 174+/-71 mm Hg, BQ 123, p < 0.05) 8 h after the onset of ventilation. We conclude that circulating levels of ET-1 increase after delivery of premature lambs with severe HMD, and that selective ET(A) receptor blockade causes sustained improvement in hemodynamics in severe experimental HMD. These studies suggest that ET-1 contributes to the hemodynamic abnormalities in this model of pulmonary hypertension and severe HMD.
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Affiliation(s)
- D D Ivy
- The Pediatric Heart Lung Center, University of Colorado School of Medicine and The Children's Hospital, Denver 80218, USA
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10
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Abstract
Inhaled nitric oxide (iNO) is an effective adjuvant therapy for term newborns with persistent pulmonary hypertension. However, its role in treating hypoxemic respiratory failure in premature newborns has not been established. Laboratory experiments have shown the importance of endogenously produced NO in fetal and neonatal pulmonary vasoregulation in the premature lamb. Moreover, low-dose iNO improves oxygenation and reduces pulmonary vascular resistance in the premature lamb with hyaline membrane disease. Preliminary studies have suggested the potential role of low-dose iNO in premature newborns with hyaline membrane disease, sepsis, and pulmonary hypoplasia. However, prematurity poses unique risks that must be carefully addressed with clinical trials designed to measure both safety and efficacy of this promising new therapy.
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Affiliation(s)
- J P Kinsella
- Department of Pediatrics, Children's Hospital, Denver, CO 80218-1088, USA
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11
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Kinsella JP, Parker TA, Galan H, Sheridan BC, Halbower AC, Abman SH. Effects of inhaled nitric oxide on pulmonary edema and lung neutrophil accumulation in severe experimental hyaline membrane disease. Pediatr Res 1997; 41:457-63. [PMID: 9098845 DOI: 10.1203/00006450-199704000-00002] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To determine the effects of inhaled NO (iNO) on pulmonary edema and lung inflammation in experimental hyaline membrane disease (HMD), we measured the effects of iNO on pulmonary hemodynamics, gas exchange, pulmonary edema, and lung myeloperoxidase (MPO) activity in extremely premature lambs (115 d of gestation, 0.78 term). In protocol 1, we measured the effects of iNO (20 ppm) on lung vascular endothelial permeability to 125I-labeled albumin (indexed to blood volume using 57Cr-tagged red blood cells) during 1 h (n = 10) and 3 h (n = 14) of conventional mechanical ventilation with FiO2 = 1.00. In comparison with controls, iNO improved pulmonary hemodynamics and gas exchange, but did not alter lung weight-to-dry weight ratio or vascular permeability to albumin after 1 or 3 h of mechanical ventilation. To determine whether low dose iNO (5 ppm) would decrease lung neutrophil accumulation in severe HMD, we measured lung MPO activity after 4 h of mechanical ventilation with or without iNO (protocol 2). Low dose iNO improved gas exchange during 4 h of mechanical ventilation (PaO2 at 4 h: 119 +/- 35 mm Hg iNO versus 41 +/- 7 mm Hg control, p < 0.05), and reduced MPO activity by 79% (p < 0.05). We conclude that low dose iNO increases pulmonary blood flow, without worsening pulmonary edema, and decreases lung neutrophil accumulation in severe experimental HMD. We speculate that in addition to its hemodynamic effects, low dose iNO decreases early neutrophil recruitment and may attenuate lung injury in severe HMD.
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Affiliation(s)
- J P Kinsella
- Department of Pediatrics, University of Colorado School of Medicine, Denver 80218, USA
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Nicholas TE, Doyle IR, Bersten AD. Surfactant replacement therapy in ARDS: white knight or noise in the system? Thorax 1997; 52:195-7. [PMID: 9059486 PMCID: PMC1758490 DOI: 10.1136/thx.52.2.195] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Although one would predict that surfactant replacement therapy would be effective in acute respiratory distress syndrome (ARDS), a recent large trial proved unsuccessful, possibly reflecting the nature of the surfactant used. Given the importance of the unique proteins in the action of surfactant, these would seem vital components of any exogenous surfactant. The ability to identify patients at risk of ARDS and to characterise their surfactant might allow prophylactic treatment with a nebulised, complementary, tailor-made preparation of surfactant. Advanced cases might undergo bronchoscopic focal lavage to remove plasma proteins and inflammatory mediators prior to focal instillation of surfactant to areas of greatest need. Ventilation regimens might be adjusted both to minimise trauma and to conserve endogenous surfactant.
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Affiliation(s)
- T E Nicholas
- Department of Human Physiology, School of Medicine, Flinders University, Adelaide, Australia
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Suske G, Oestreich K, Varnholt V, Lasch P, Kachel W. Influence of early postnatal dexamethasone therapy on ventilator dependency in surfactant-substituted preterm infants. Acta Paediatr 1996; 85:713-8. [PMID: 8816210 DOI: 10.1111/j.1651-2227.1996.tb14132.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We examined 26 preterm infants with respiratory distress syndrome in a randomized controlled prospective study to determine whether early postnatal dexamethasone therapy (< 2 h; 0.5 mg/kg per day) over 5 days in addition to substitution of surfactant (100 mg/kg) facilitates extubation and the course of RDS. Control (n = 12) and treated (n = 14) groups were comparable in birthweight (mean +/- SD: 1219 +/- 292 versus 1446 +/- 442 g), gestational age (29.3 +/- 2.2 versus 30.6 +/- 2.7 weeks), prenatal characteristics and initial respiratory and blood gas parameters. In both groups one infant died. Infants in the dexamethasone group responded better to surfactant (12/14 versus 3/12; p < 0.01), were extubated earlier (6.6 versus 14.2 days; p < 0.02) and required less time on supplemental oxygen (4.2 versus 12.5 days; p < 0.02). Pulmonary complications tended to be lower in the dexamethasone group (1/14 versus 4/12), as was the frequency of retinopathy (2/14 versus 6/12; p < 0.05). We conclude that early postnatal dexamethasone therapy improves response to surfactant therapy resulting in better weaning and earlier extubation in premature infants.
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Affiliation(s)
- G Suske
- University Children's Hospital, Mannheim, Germany
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Cornfield DN, Abman SH. Inhalational nitric oxide in pulmonary parenchymal and vascular disease. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1996; 127:530-9. [PMID: 8648257 DOI: 10.1016/s0022-2143(96)90143-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- D N Cornfield
- Department of Pediatrics, University of Minnesota Hospital and Clinics, Minneapolis 55455, USA
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Kinsella JP, Abman SH. Recent developments in the pathophysiology and treatment of persistent pulmonary hypertension of the newborn. J Pediatr 1995; 126:853-64. [PMID: 7776084 DOI: 10.1016/s0022-3476(95)70197-4] [Citation(s) in RCA: 172] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Successful management of severe PPHN depends on the application of appropriate strategies to manage the cardiopulmonary interactions that characterize this syndrome. Manifestations of PPHN often involve dysfunctional pulmonary vasoregulation, with suprasystemic pulmonary vascular resistance causing extrapulmonary shunting, pulmonary parenchymal disease causing intrapulmonary shunting, and systemic hemodynamic deterioration. Inhaled NO can cause marked improvement in oxygenation when optimal lung inflation is achieved and systemic blood volume and vascular resistance are adequate. Although concern has been expressed regarding potential increases in costs associated with this new therapy, we have found that the successful application of inhaled NO in PPHN has reduced costs of hospitalization and duration of hospital stay by approximately 50% and 40%, respectively. However, inhaled NO alone is unlikely to cause sustained improvement in oxygenation in neonatal hypoxemic respiratory failure associated with severe parenchymal lung disease without extrapulmonary shunting. Inhaled NO may be an important tool in the management of severe PPHN when its application is limited to patients with severe extrapulmonary shunting and vigilant attention is given to changes in the clinical course.
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Affiliation(s)
- J P Kinsella
- Department of Pediatrics, Children's Hospital, Denver, CO 80218-1088, USA
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