Surfactant replacement therapy

There are also several examples of natural surfactants and foams in the human body. The understanding of the pulmonary surfactant system, although discovered in 1929, has only been applied clinically since about 1990 for the treatment of respiratory distress syndrome. Surfactant replacement therapy may also be used in treating other forms of lung disease, such as meconium aspiration syndrome, neonatal pneumonia and congenital diaphragmatic hernia [881]. Lung surfactant, composed of phospholipids and proteins [882,883], is necessary to maintain a low surface tension at the alveolar air-liquid interface. When there is a deficiency of surfac-... 

Foam film formation by three preparations used as surfactant replacement therapy by injection into the lungs in neonatal infants with surfactant insufficiency (RDS) has been... 

The surfactant replacement therapy treatment used may be either natural or artificial. Natural surfactants are derived from bovine or porcine animal lungs or human amniotic fluid. Synthetic or artificial surfactants are composed of DPPC and spreading agents such as unsaturated phosphatidylglycerol or tyloxapol and hexadecanol. ... 

Surfactant replacement therapy (SRT) is widely accepted as the most clinically acceptable and cost-effective approach to the treatment of RDS. Clinical trials have been carried out worldwide using an array of artificial, modified natural, and natural surfactants. Natural surfactants are either processed extracts of minced lungs or extracts of lavaged surfactant, which affects the surfactant protein makeup of the preparation. The differences in preparations can be discerned from key components and dosing strategies, which are summarized in Table 28-6. 

Maniscalco WM, Kendig JW, Shapiro DL. Surfactant replacement therapy Impact on hospital charges for premature infants with respiratory distress syndrome. Pediatrics 1989 83 1-6. 

Baughman et al. (72) also studied the changes in BAL IL-8 over time in patients with ARDS who were part of a study of surfactant replacement therapy. In 28 comparison patients who were not treated with surfactant replacement, the IL-8 concentration at the onset of ARDS was similar to that reported in other studies (median = 1186 pg/mL). The IL-8 concentration at the beginning of ARDS did not separate patients who lived or died. In survivors the IL-8 concentration fell between days 1 and 4, whereas in patients who died the IL-8 concentrations increased. This study did not confirm the value of the IL-8 as a predictor of survival, but it did support the observation of Meduri et al. that a persistent increase in BAL IL-8 (and other cytokines) was associated with persistent pulmonary inflammation and a poor prognosis (71). 

Espinosa, F. F and R. D. Kamm, Bolus dispersal through the lungs in surfactant replacement therapy, J. Appl. Physiol., 86 391-410, 1999. 

Shapiro DL, Hotter RH, (eds) (1989) Surfactant Replacement Therapy. Liss, New York... 

Greenough A. Expanded use of surfactant replacement therapy. Eur J Pediatr2001 159 635-640. 

SpraggRG. Surfactant replacement therapy. Clin Chest Med 2001 21 531-541. 

Notter RH, Shapiro DL. Lung surfactants for replacement therapy biochemical, biophysical, and clinical aspects. Clin Perinatol 1987 14(3) 433-479. 

Surfactant prophylaxis and replacement therapy markedly reduce RDS-related pulmonary morbidity and mortality. 

Efficient breathing requires a special lipid mixture known as pulmonary surfactant which contains exceptionally high proportions of dipalmitoyl-phosphatidylcholine. The secretion of pulmonary surfactant is carefully controlled and, when this secretion is impaired, as in premature babies, acute respiratory stress is found. Efforts are now being made to treat such respiratory distress either by hormones to hasten the development of the type II epithelial cells which make surfactant or by replacement therapy with artificial lipid mixtures. 

Today s high potency drugs, intended for local and systemic treatments, depend on reliable delivery systems. As an alternative to squeeze bottles and pipettes, propellant-driven or mechanical-dispensing systems are often used. Aerosol systems are well known in inhalation therapy. They are ready to use and easy to handle. While new propellants will replace the old ones, the environmental and pharmacological discussions will continue. The switch to new propellants must be supported by sufficient clinical and toxicological data. In particular, compatibility problems must be addressed. Furthermore, attention must be paid to the surfactants not under dispute. 

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