Premature infants lungs

Other specialized appHcations of cardiac arrest devices include extracorporeal membrane oxygenation (ECMO) which occurs when the lungs of a premature infant caimot function properly. The market segments for cardiopulmonary support devices are potentially significant. 

There is a clinical need for non-natural, functional mimics of the lung surfactant (LS) proteins B and C (SP-B and SP-C), which could be used in a biomimetic LS replacement to treat respiratory distress syndrome (RDS) in premature infants [56]. An effective surfactant replacement must meet the following performance requirements (i) rapid adsorption to the air-liquid interface, (ii) re-spreadabihty... 

Antioxidant therapy might be promising medication for the treatment of some lung disorders. For example, lecithinized phosphatidylcholine-CuZnSOD suppressed the development of bleomycin-induced pulmonary fibrosis in mice [284] these findings could be of relevance for the treatment of bleomycin-stimulated pulmonary fibrosis in humans. Davis et al. [285] recently demonstrated that the treatment of premature infants with recombinant human CuZnSOD may reduce early pulmonary injury. 

Artificial surfactant, which contains dipalmitoylphosphati-dyl choline and some palmitic acid to provide for spreadability, is now commercially available for instillation into the lung. Adminishation of steroids to the mother prior to birth of the premature infant is also carried out. 

Palivizumab is used to prevent serious lower respiratory tract infection due to RSV. It is used only in high-risk children who are younger than 24 months of age and have bronchopulmonary dysplasia or chronic lung disease that required treatment in the previous 6 months. It is also indicated for premature infants (less than 32 weeks gestation) until the age of 6 to 12 months. Palivizumab can reduce the incidence of RSV-related hospitalization by approximately half. The safety and efficacy of palivizumab in the treatment of RSV disease have not been established. 

When air is exhaled the small alveoli of the lungs could collapse if it were not for the surface active material (surfactant) present in the fluid that coats the lungs. e In fact, the lack of adequate surfactant is the cause of respiratory distress syndrome, a major cause of death among premature infants and a disease that may develop in acute form in adults. The surfactant material forms a thin film of high fluidity at the air-liquid interface and lowers the surface tension from the 72 mN/m of pure water to <10 mN/mfs (Pay attention to the definition of surface tension.11)... 

A systematic review of randomized controlled trials has been performed to determine whether dexamethasone therapy in the first 15 days of life prevents chronic lung disease in premature infants (14). Studies were identified by a literature search using Medline (1970-97) supplemented by a search of the Cochrane Library (1998, Issue 4). Inclusion criteria were (a) prospective randomized design with initiation of dexamethasone therapy within the first 15 days of life (b) report of the outcome of interest and (c) less than 20% crossover between the treatment and control groups during the study period. The primary outcomes were mortality at hospital discharge and the development of chronic lung disease at 28 days of life and 36 weeks postconceptional age. The secondary outcomes were the presence of a patent ductus... 

The use of postnatal glucocorticoids in very premature infants is controversial although dexamethasone reduces bronchopulmonary dysplasia, it has been associated with severe adverse effects (407). In 220 infants with a birth-weight of 501-1000 g randomized to placebo or dexamethasone (0.15 mg/kg/day for 3 days and tapering over a period of 7 days) the relative risk of death or chronic lung disease... 

Arias-Camison JM, Lau J, Cole CH, Frantz ID 3rd. Metaanalysis of dexamethasone therapy started in the first 15 days of life for prevention of chronic lung disease in premature infants. Pediatr Pulmonol 1999 28(3) 167-74. 

Caffeine is approved as a prescription drug for treating premature infants who are born before their lungs and brain are mature enough for automatic breathing. These babies may have a condition called apnea, in... 

Dipalmitoyl phosphatidyl choline is one component of human lung surfactant, which coats the inner surfaces of the lung membranes and prevents them from clinging together and collapsing. Premature infants often produce little or no lung surfactant, which can lead to collapsed alveoli and other symptoms of infant respiratory distress syndrome (IRDS). 

Reproductive toxicity Effects that may alter the normal reproductive processes of an animal—for instance, loss of fertility Residue The pesticide remaining in a product after natural or other processes Respiratory distress syndrome A lung disease that occurs primarily in premature infants the newborn must struggle for each breath and blueing of its skin reflects the baby s inability to get enough oxygen can also affect adults Restricted-use pesticide (RUP) A pesticide that can be sold to or used by only certified applicators... 

G-4) Respiratory distress syndrome. Lecithin (phosphatidylcholine) is an important membrane phos-phoglyceride. In the lung, one of the lecithins (they come in a variety of forms) reduces surface tension in the pul-monaiy alveoli. Lecithin deficiency in the premature infant results in the respiratory distress syndrome, in which the alveoli are collapsed and there is difficulty with air exchange. 

Respiratory distress syndrome is a pathological condition resulting from a failure in the biosynthetic pathway for dipalmitoyl phosphatidyl choline. This phospholipid, in conjunction with specific proteins and other phospholipids, is found in the extracellular fluid that surrounds the alveoli of the lung, where it decreases the surface tension of the fluid to prevent lung collapse at the end of the expiration phase of breathing. Premature infants may suffer from respiratory distress syndrome because their immature lungs do not synthesize enough dipalmitoyl phosphatidyl choline. 

Strange RC, Cotton W, Fryer AA, Jones P, Bell J, Hume R. Lipid peroxidation and expression of copper-zinc and manganese superoxide dismutase in lungs of premature infants with hyaline membrane disease and bronchopulmonary dysplasia. J Lab Clin Med 116 (1990) 666-673. 

Dexamethasone is widely used for the prevention and treatment of chronic lung disease in premature infants, in whom follow-up studies have raised the possibility of an association with alterations in neuromotor function and somatic growth. In 159 survivors (mean age 53 months) of a previous placebo-controlled study, the children who had received dexamethasone had a significantly higher incidence of cerebral palsy (39/80 versus 12/79 OR = 4.62 95% Cl = 2.38, 8.98) (36). The most common form of cerebral palsy was spastic diplegia. Developmental delay was more frequent in the dexamethasone group (44/80 versus 23/79 OR = 2.9 Cl = 1.5, 5.4). 

A theory has been proposed regarding a possible mechanism by which parenteral Upid solutions injure preterm infants namely, by free radical-induced lipid peroxidation in the lipid solution (142,143). How this happens is not explained. The result can be pulmonary damage and chronic lung disease. Premature infants are thought to be at particularly high risk. However, others (144,145) have suggested that Cooke s interpretation (142) was not based on solid clinical evidence, and that the data that he derived from his observations should be tested in controlled studies before parenteral nutrition is prescribed for infants of very low birth weights. 

Dipalmitoylphosphatidylcholine serves as the lung surfactant in adults, allowing the lungs to function normally. This phospholipid develops in the fetus after week 30 of gestation. Premature infants do not have an adequate amount of this phospholipid. As a result, acute respiratory distress syndrome is a leading cause of morbidity and death in premature infants. 

Beractant, a bovine lung extract (administered by intratracheal instillation), is indicated in prevention and treatment (rescue) of respiratory distress syndrome (hyaline membrane disease) in premature infants. 

Calfactant is a lung surfactant. It is an extract of natural surfactant from calf lungs that restores lung surfactant in premature infants with lung surfactant deficiency causing respiratory distress syndrome (RDS). Calfactant is indicated in RDS in premature infants under 29 weeks of gestational age at high risk for RDS and for the treatment rescue of premature infants under 72 hours of age who develop RDS and require endotracheal inmbation. 

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