-
Neonatal Network : NN 2015Respiratory development is crucial for all newborn infants. Premature infants may be born at an early stage of development and lack sufficient surfactant production.... (Review)
Review
Respiratory development is crucial for all newborn infants. Premature infants may be born at an early stage of development and lack sufficient surfactant production. This results in respiratory distress syndrome. This article reviews the normal fetal development of the lung as well as the disorder that develops because of an early birth.
Topics: Child Development; Disease Management; Humans; Infant, Newborn; Infant, Premature; Lung; Pulmonary Surfactants; Respiratory Distress Syndrome, Newborn; Term Birth
PubMed: 26802638
DOI: 10.1891/0730-0832.34.4.231 -
Annals of Anatomy = Anatomischer... Nov 2016Lung surfactant is a complex with a unique phospholipid and protein composition. Its specific function is to reduce surface tension at the pulmonary air-liquid... (Review)
Review
Lung surfactant is a complex with a unique phospholipid and protein composition. Its specific function is to reduce surface tension at the pulmonary air-liquid interface. The underlying Young-Laplace equation, applying to the surface of any geometrical structure, is the more important the smaller its radii are. It therefore applies to the alveoli and bronchioli of mature lungs, as well as to the tubules and saccules of immature lungs. Surfactant comprises 80% phosphatidylcholine (PC), of which dipalmitoyl-PC, palmitoyl-myristoyl-PC and palmitoyl-palmitoleoyl-PC together are 75%. Anionic phosphatidylglycerol and cholesterol are about 10% each, whereas surfactant proteins SP-A to -D comprise 2-5%. Maturation of the surfactant system is not essentially due to increased synthesis but to decreased turnover of specific components. Molecular differences correlate with resting respiratory rate (RR), where PC16:0/16:0 is the lower the higher RR is. PC16:0/14:0 is increased during alveolar formation, and decreases immune reactions that might impair alveolar development. In rigid bird lungs, with air-capillaries rather than alveoli, and no surface area changes during the respiratory cycle, PC16:0/16:0 is highest and PC16:0/14:0 absent. As there is no need for a surface-associated surfactant reservoir, SP-C is absent in birds as well. Airflow is lowest and particle sedimentation highest in the extrapulmonary air-sacs, rather than in the gas-exchange area. Consequently, SP-A and -D for particle opsonization are absent in bird surfactant. In essence, comparative analysis is consistent with the concept that surfactant is adapted to the physiologic needs of a given vertebrate species at a given developmental stage.
Topics: Animals; Birds; Elastic Modulus; Humans; Lung; Models, Biological; Phospholipids; Pulmonary Surfactants; Respiratory Mechanics
PubMed: 27693601
DOI: 10.1016/j.aanat.2016.08.003 -
Archives of Disease in Childhood. Fetal... Nov 2019Non-invasive ventilation and especially the application of continuous positive airway pressure (CPAP) has become standard for the treatment of premature infants with... (Review)
Review
Non-invasive ventilation and especially the application of continuous positive airway pressure (CPAP) has become standard for the treatment of premature infants with respiratory problems. However, CPAP failure may occur due to respiratory distress syndrome, that is, surfactant deficiency. Less invasive surfactant administration (LISA) aims to provide an adequate dose of surfactant while the infant is breathing spontaneously, thus avoiding positive pressure ventilation support. Using a thin catheter for surfactant application allows infants to maintain function of the glottis and continue spontaneous breathing, whereas the INtubate-SURfactant-Extubate (INSURE) procedure is connected with sedation/analgesia, regular intubation and a (brief) period of positive pressure ventilation. Individual studies and meta-analyses summarised in this review point in the direction that LISA is more effective than standard treatment or INSURE both in terms of short-term (avoidance of mechanical ventilation) and long-term (intracerebral haemorrhage and bronchopulmonary dysplasia) outcomes. Open questions include exact treatment thresholds for different gestational ages, the usefulness of devices/catheters that have recently been purpose-built for the LISA technique and especially the question of analgesia/sedation during the procedure. The current technology still demands laryngoscopy with all its unpleasant effects for infants. Therefore, studies with pharyngeal surfactant deposition immediately after delivery, the use of laryngeal airways for surfactant administration and attempts to nebulise surfactant are under way. Finally, LISA is not simply an isolated technical procedure for surfactant delivery but rather part of a comprehensive non-invasive approach supporting the concept of a gentle transition to the extrauterine world enabling preterm infants to benefit from the advantages of spontaneous breathing.
Topics: Gestational Age; Humans; Infant, Newborn; Infant, Premature; Noninvasive Ventilation; Pulmonary Surfactants; Respiratory Distress Syndrome, Newborn
PubMed: 31296694
DOI: 10.1136/archdischild-2018-316557 -
Zhongguo Dang Dai Er Ke Za Zhi =... Sep 2018Acute respiratory distress syndrome (ARDS) is a common clinical critical disease and is one of the main causes of death and disability in neonates. The etiology and... (Review)
Review
Acute respiratory distress syndrome (ARDS) is a common clinical critical disease and is one of the main causes of death and disability in neonates. The etiology and pathogenesis of neonatal ARDS are complicated. It is an acute pulmonary inflammatory disease caused by the lack of pulmonary surfactant (PS) related to various pathological factors. It is difficult to distinguish neonatal ARDS from other diseases. At present, there is no specific treatment method for this disease. Respiratory support, PS replacement, extracorporeal membrane oxygenation, nutrition support and liquid management are main treatment strategies. This paper reviews the research advance in etiology, clinical characteristics, diagnosis and treatment strategies of neonatal ARDS.
Topics: Dyspnea; Extracorporeal Membrane Oxygenation; Humans; Infant, Newborn; Pulmonary Surfactants; Respiratory Distress Syndrome, Newborn
PubMed: 30210023
DOI: 10.7499/j.issn.1008-8830.2018.09.006 -
NEJM Evidence Dec 2023In August of 1963, Patrick Bouvier Kennedy, the fourth child of Jackie Onassis Kennedy and John F. Kennedy, died less than 48 hours after his birth from respiratory...
In August of 1963, Patrick Bouvier Kennedy, the fourth child of Jackie Onassis Kennedy and John F. Kennedy, died less than 48 hours after his birth from respiratory distress syndrome (RDS) of the newborn. His tragic death inspired research into the physiology of RDS, one product of which was the development of surfactant replacement therapies which have saved millions of neonates from a similar fate. Shortly after the demonstration of its efficacy in 1980, exogenous surfactant replacement therapy became the mainstay intervention for RDS. Exogenous surfactant was originally administered via an endotracheal tube in mechanically ventilated neonates, a practice which may lead to ventilator-induced injury to the immature lung.
Topics: Humans; Infant, Newborn; Pulmonary Surfactants; Respiration, Artificial; Respiratory Distress Syndrome, Newborn; Surface-Active Agents
PubMed: 38320509
DOI: 10.1056/EVIDe2300297 -
Chemical Reviews Dec 2023Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing... (Review)
Review
Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing for breathing with minimal effort. The prevailing thinking is that low surface tension is attained by a compression-driven squeeze-out of unsaturated phospholipids during exhalation, forming a film enriched in saturated phospholipids that achieves surface tensions close to zero. A thorough review of past and recent literature suggests that the compression-driven squeeze-out mechanism may be erroneous. Here, we posit that a surfactant film enriched in saturated lipids is formed shortly after birth by an adsorption-driven sorting process and that its composition does not change during normal breathing. We provide biophysical evidence for the rapid formation of an enriched film at high surfactant concentrations, facilitated by adsorption structures containing hydrophobic surfactant proteins. We examine biophysical evidence for and against the compression-driven squeeze-out mechanism and propose a new model for surfactant function. The proposed model is tested against existing physiological and pathophysiological evidence in neonatal and adult lungs, leading to ideas for biophysical research, that should be addressed to establish the physiological relevance of this new perspective on the function of the mighty thin film that surfactant provides.
Topics: Infant, Newborn; Humans; Pulmonary Surfactants; Phospholipids; Surface-Active Agents; Surface Tension; Chemical Phenomena
PubMed: 37862151
DOI: 10.1021/acs.chemrev.3c00146 -
Biochimica Et Biophysica Acta Oct 2016Lung surfactant lines the gas-exchange interface in the lungs and reduces the surface tension, which is necessary for breathing. Lung surfactant consists mainly of... (Review)
Review
Lung surfactant lines the gas-exchange interface in the lungs and reduces the surface tension, which is necessary for breathing. Lung surfactant consists mainly of lipids with a small amount of proteins and forms a monolayer at the air-water interface connected to bilayer reservoirs. Lung surfactant function involves transfer of material between the monolayer and bilayers during the breathing cycle. Lipids and proteins are organized laterally in the monolayer; selected species are possibly preferentially transferred to bilayers. The complex 3D structure of lung surfactant and the exact roles of lipid organization and proteins remain important goals for research. We review recent simulation studies on the properties of lipid monolayers, monolayers with phase coexistence, monolayer-bilayer transformations, lipid-protein interactions, and effects of nanoparticles on lung surfactant. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg.
Topics: Computer Simulation; Lipid Bilayers; Membrane Lipids; Membrane Proteins; Nanoparticles; Pulmonary Surfactants; Surface Tension
PubMed: 26922885
DOI: 10.1016/j.bbamem.2016.02.030 -
Frontiers in Immunology 2022Pulmonary surfactant constitutes an important barrier that pathogens must cross to gain access to the rest of the organism the respiratory surface. The presence of... (Review)
Review
Pulmonary surfactant constitutes an important barrier that pathogens must cross to gain access to the rest of the organism the respiratory surface. The presence of pulmonary surfactant prevents the dissemination of pathogens, modulates immune responses, and optimizes lung biophysical activity. Thus, the application of pulmonary surfactant for the treatment of respiratory diseases provides an effective strategy. Currently, several clinical trials are investigating the use of surfactant preparations to treat patients with coronavirus disease 2019 (COVID-19). Some factors have been considered in the application of pulmonary surfactant for the treatment COVID-19, such as mechanical ventilation strategy, timing of treatment, dose delivered, method of delivery, and preparation utilized. This review supplements this list with two additional factors: accurate measurement of surfactants in patients and proper selection of pulmonary surfactant components. This review provides a reference for ongoing exogenous surfactant trials involving patients with COVID-19 and provides insight for the development of surfactant preparations for the treatment of viral respiratory infections.
Topics: Humans; Lung; Pulmonary Surfactants; Respiration, Artificial; Surface-Active Agents; COVID-19 Drug Treatment
PubMed: 35592339
DOI: 10.3389/fimmu.2022.842453 -
European Journal of Pediatrics Aug 2020Preterm neonates with respiratory distress syndrome (RDS) are commonly treated with surfactant by intubate surfactant extubate (InSurE) technique. Mode of surfactant... (Comparative Study)
Comparative Study Randomized Controlled Trial
Minimally invasive surfactant therapy versus InSurE in preterm neonates of 28 to 34 weeks with respiratory distress syndrome on non-invasive positive pressure ventilation-a randomized controlled trial.
Preterm neonates with respiratory distress syndrome (RDS) are commonly treated with surfactant by intubate surfactant extubate (InSurE) technique. Mode of surfactant administration has evolved towards less invasive technique in the last few years. We randomised 58 preterm infants of 28-34 weeks of gestation with RDS within 6 h of birth to receive surfactant by InSurE or minimally invasive surfactant therapy (MIST). Non-invasive positive pressure ventilation (NIPPV) was used as primary respiratory support. The main objective was to compare the need of invasive mechanical ventilation (IMV) in first 72 h of life and secondarily hemodynamically significant patent ductus arteriosus (hsPDA), intraventricular haemorrhage (IVH) (> grade 2), bronchopulmonary dysplasia (BPD) and composite outcome of BPD/mortality. We did not find any difference in need of IMV in first 72 h between MIST and InSurE (relative risk with MIST, 0.62; 95% confidence interval, 0.22 to 1.32). No difference was observed in terms of hs PDA, IVH (> grade 2), BPD and composite outcome of BPD/mortality.Conclusion: There is no difference between MIST and InSurE in preterm neonates with RDS with NIPPV as a primary mode of respiratory support. Larger multicentre studies are needed to further explore differences in treatment failure and other secondary outcomes.Trial registration: www.ctri.nic.in id CTRI/2019/03/017992, registration date March 8, 2019. What is Known • InSurE is commonly used for many years for treatment of RDS in preterm neonates. • MIST has been introduced as a newer tool. What is New • MIST with feeding tube is comparable with InSurE in preterm infants with RDS in developing countries. •NIPPV can be used as primary respiratory support for MIST.
Topics: Combined Modality Therapy; Female; Humans; Infant, Newborn; Infant, Premature; Intubation, Intratracheal; Male; Noninvasive Ventilation; Positive-Pressure Respiration; Prospective Studies; Pulmonary Surfactants; Respiratory Distress Syndrome, Newborn; Treatment Outcome
PubMed: 32462483
DOI: 10.1007/s00431-020-03682-9 -
Physiological Research Sep 2017The respiratory system is constantly exposed to pathogens which enter the lungs by inhalation or via blood stream. Lipopolysaccharide (LPS), also named endotoxin, can... (Review)
Review
The respiratory system is constantly exposed to pathogens which enter the lungs by inhalation or via blood stream. Lipopolysaccharide (LPS), also named endotoxin, can reach the airspaces as the major component of the outer membrane of Gram-negative bacteria, and lead to local inflammation and systemic toxicity. LPS affects alveolar type II (ATII) cells and pulmonary surfactant and although surfactant molecule has the effective protective mechanisms, excessive amount of LPS interacts with surfactant film and leads to its inactivation. From immunological point of view, surfactant specific proteins (SPs) SP-A and SP-D are best characterized, however, there is increasing evidence on the involvement of SP-B and SP-C and certain phospholipids in immune reactions. In animal models, the instillation of LPS to the respiratory system induces acute lung injury (ALI). It is of clinical importance that endotoxin-induced lung injury can be favorably influenced by intratracheal instillation of exogenous surfactant. The beneficial effect of this treatment was confirmed for both natural porcine and synthetic surfactants. It is believed that the surfactant preparations have anti-inflammatory properties through regulating cytokine production by inflammatory cells. The mechanism by which LPS interferes with ATII cells and surfactant layer, and its consequences are discussed below.
Topics: Acute Lung Injury; Animals; Biological Products; Humans; Lipopolysaccharides; Lung; Phospholipids; Pulmonary Surfactants; Swine
PubMed: 28937231
DOI: 10.33549/physiolres.933672