the day and, with the passage of time, the former has slipped into 13. There's no question about that. In addition to perinatal asphyxia, it was Cummings notes, again, the apparent advantages of natural over synthetic surfactant with regard to inactivation. in Infants with HMD, Influence of Steroid Therapy (2012) found that the magnetization of SPIONs was enhanced near to magnetization of bulk nanoparticles due to the satisfaction of orbitals occupations of surface atoms of SPIONs by the surfactants (oleic acid) … Conclusion: Minimal invasive surfactant administration was no clear benefits on the incidence of BPD, but it was associated with reduced incidence of patent ductus arteriosus. During both direct and indirect lung injury, initially active surfactant can be rendered dysfunctional by a number of mechanisms (Fig. problem with the pulmonary circulation in the pathogensis of HMD has 4. Found insideThis book provides an overview of pulmonary hypertensive diseases, the current understanding of their pathobiology, and a contemporary approach to diagnosis and treatment. Surfactant replacement therapy has been the mainstay of treatment for preterm infants with respiratory distress syndrome for more than twenty years. For the most part, surfactant is administered intratracheally, followed by mechanical ventilation. Clinical studies documenting the efficacy of surfactant therapy in pneumonia are less extensive than for meconium aspiration syndrome, but those that are available have been positive.196–198 An initial uncontrolled study by Auten et al196 reported significant improvements in oxygenation in term infants with pneumonia following instillation of calfactant (calf lung surfactant extract [CLSE]). Found insideThe animal models have also been instrumental in the evaluation of delivery techniques for surfactant administration to the airways. Recent advances in molecular genetics have provided the ability to develop transgenic animal models in ... 19. Exogenous surfactant has now been in use for nearly a decade. Soll RF. The resulting loss of surface-active function contributes to decreased lung volume, decreased compliance, severe ventilation-perfusion mismatching, and acute respiratory failure. References 1. 2014;11(8):1183–1201. Astrup technique introduced in the early 60's at last made it We know that lung injury occurs rapidly, in a matter of a couple of hours.. The first question I want to answer is how do we best administer it? In women with threatening preterm delivery, a single course is advocated between 24 and 34 weeks' gestation with either betamethasone (two doses of 12 mg 24 h apart) or dexamethasone (four doses of 6 mg at 12-h intervals). cause HMD even in the term fetus. infants who died with HMD were more likely to have low Apgar The classic studies of Avery and Mead reported in 1959 clearly Am. Experience with clinical surfactant therapy in adults with ALI/ARDS has been much less encouraging than in younger patients. The use of exogenous surfactant in conjunction with other modalities to simultaneously attack different aspects of the pathophysiology of ALI/ARDS may prove to be synergistic—not unlike the use of combination chemotherapy for various types of cancer. [7] Thus, An incomplete surfactant to say the least. We do not capture any email address. Tension and the Mucous Lining of the Lungs: Some Theoretical Doug, I'm intrigued by the concept of administering dilute surfactant via lung lavage. Neonates may have insufficient surfactant due to immaturity of the Type II cells. Morley C. J., Miller N., Bangham A. D., et al. : As the famous philosopher Yogi Berra so eloquently stated, “Predictions are difficult, particularly about the future.” Nonetheless, surfactant therapy has in fact already been shown to be beneficial in several lung-injury applications in term infants and children, in addition to its life-saving use in pre-term infants with RDS. Recent Advances in Management of Bronchiolitis. 5:00 PM to 6:30 PM. The magnificent contributions of J. Med. Kotas R. V., Avery M. E.: The Influence of Sex on Fetal Rabbit surfactant replacement therapy Initial reports of significant improvement in the clinical course of infants with severe HMD, following the installation of surfactant, are most encouraging. Exogenous surfactant therapy and mucus rheology in chronic obstructive airway diseases. 2000;2:CD000141. (Cstat). are most encouraging. Some models, such as saline lavage (one of the most commonly used ALI/ARDS models), resemble RDS more than ALI/ARDS. In general, surfactants with an adequate percentage of SP-B appear to be the most resistant to inhibition. My guess is not, but we'll see. Top authors were selected to write clinical review articles devoted to Advances in Respiratory Care of the Newborn. Biol Neonate. Improved compliance and better aeration at lower pressures and volumes with early surfactant administration may prevent a vicious circle of ventilator-induced injury that leads to increasingly and more injurious levels of ventilator support, leading to further iatrogenic lung injury. Dr. Stahlman has addressed this subject in detail in this book. shunt through the ductus or foramen ovale, a low pH, or because of a possibility of prevention of HMD.[16,18,19,20]. Journal 89:995, 1963. However, it is purified through a two-dimensional gel electrophoresis, to such an extent that the end product has almost twice the DPPC as any other surfactant. Other aspects of surfactant therapy that have been explored in animal studies include the volume and dose of surfactant,182 rapidity of administration,183 and method of respiratory support during surfactant administration.163,184 As a general rule, a larger instillation volume and/or higher dose results in more uniform distribution.182 Unfortunately, a larger instilled volume can also cause severe hypoxia and hypotension, due to transient ETT obstruction.154,185 The same trade-off is true for giving surfactant as a rapid bolus, as opposed to over a longer period; that is, a more homogeneous distribution is achieved with a rapid bolus, but this also risks obstructing the ETT. Category III synthetic lung surfactants have conceptual advantages in purity, reproducibility, manufacturing quality control efficiency, and scale-up economy compared to animal-derived surfactants. Fujiwara [28] instilled a liquid surfactant into the trachea of infants with HMD which was obtained from tracheal washings of cow lung and modified to exclude most of the protein (Fujisurf). 8. Am. Upon extremities and edema. Expert Opin Drug Deliv. Crit Care Med. also correctly concluded that the membrane was "an eosinophilic red Some of that will depend on how many different patients you enroll in the study. blood with two different PCO's, the infant's PCO2 and Spragg et al,127 using synthetic SP-C surfactant (recombinant protein C surfactant), also reported improved oxygenation but no long-term benefits, relative to placebo, in adults with ARDS. This would allow the best possible distribution and the possibility of avoiding some of the positive-pressure-associated lung injury, and would be the best test of whether instilled surfactant is helpful. and intravenous urokinase activated fibrinolysin was apparently Some sites, as you can imagine, only had one. These issues are addressed by the authors who are experts in their respective fields. the book will be valuable not only to healthcare providers but also to educators and policy makers. It appears that in infants born at 24-28 weeks gestation, steroids may not prevent RDS, but they do seem to reduce its severity. E-mail: Copyright © 2011 by Daedalus Enterprises Inc. Although manufacturers suggest that only half the regular dose is needed, no data support the idea that giving less volume provides a better treatment. artificial ventilation as the therapy of choice in the future, Lancet 11:469, 1962. in the Respiratory Distress Syndrome. Recent advances in liposome surface modification for oral drug delivery. Unfortunately, the pharmaceutical company sponsoring that trial has kept all the data under wraps, as they concentrated on the RDS population in their attempt to get FDA approval of their surfactant. The researchers found that, contrary to results in animal studies, there were no beneficial effects of aerosolized surfactant. I. A controlled study by Moller et al199 also reported that children with ARDS showed immediate oxygenation improvement and less need for rescue therapy following treatment with beractant, but the trial was underpowered to assess more definitive longer-term outcomes. Maybe it's in the biological processes, and we just don't know enough about the processes that we're administering the product in? If it were my own child, that's what I would do. With the increasing use of non-invasive ventilation as the primary mode of respiratory support for preterm infants at delivery, prophylactic surfactant is no longer beneficial. The consequence of a decreased blood volume, Fujiwara T., Maeta H., Chida S., et al. Usher R.: The Respiratory Distress Syndrome of Prematurity. replacement therapy should be the major approaches to treatment in In summary, animal studies have helped to elucidate several aspects of surfactant efficacy and administration, and remain indispensible for investigating surfactant therapy and its optimization going forward. Maternal antenatal corticosteroid treatment has … What volume? However, among the survivors treated with currently available surfactants (which do not contain SP-A or SP-D) there is a significant percentage of infants who grow up with recurrent pulmonary infection and chronic inflammation. Braudo M., Keith J. D.: The Value of Digitalis in the Surfactant replacement therapy in RDS makes intuitive sense, because surfactant is deficient in the premature lung and exogenous surfactant directly corrects this deficiency. Moss A. J., Duffie E. R., Fagan L. M.: Respiratory Distress Berg T. J., Pagtakhan R. D., Reed M. H., et al. Would you consider using a laryngeal mask airway and then putting them back on noninvasive ventilation? I was subsequently involved in a small trial in which we directly lavaged the lungs, via the ETT, of neonates with meconium aspiration syndrome.2 We also had some glimmers there.