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- Tashiro, K, et al.
(författare)
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Modified protocols for surfactant therapy in experimental meconium aspiration syndrome
- 2003
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Ingår i: Biology of the neonate. - : S. Karger AG. - 0006-3126. ; 83:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- In adult rats with experimental meconium aspiration syndrome, we investigated whether the therapeutic effect of exogenous surfactant was increased by addition of dextran or preceding airway lavage with diluted surfactant. Animals (n = 72) ventilated with pure oxygen were given human meconium suspension (50–75 mg kg<sup>–1</sup>) through the airways. When the PaO<sub>2</sub> had decreased to <20 kPa (mean ± SD 12 ± 3.9 kPa), the rats were randomly allocated to ten groups (G). G 6–10 underwent lung lavage with diluted Curosurf (5 mg ml<sup>–1</sup>, 20 ml kg<sup>–1</sup>), whereas G 1–5 did not. G 1 and 6 received no additional material through the airways. G 2 and 7 received Curosurf (100 mg kg<sup>–1</sup>), and G 3 and 8 received Curosurf (100 mg kg<sup>–1</sup>) plus dextran (75 mg kg<sup>–1</sup>); G 4 and 9 received Curosurf (200 mg kg<sup>–1</sup>), and G 5 and G 10 received Curosurf (200 mg kg<sup>–1</sup>) plus dextran (75 mg kg<sup>–1</sup>). All rats in G 1 died before 180 min after randomization. In G 2, 3, 6, 7, and 8, the PaO<sub>2</sub> transiently increased to 30–40 kPa. In G 4, 5, 9, and 10, the PaO<sub>2</sub> remained >30 kPa for 180 min. Both airway lavage and supplementation with dextran improved the therapeutic effects of surfactant; however, a large dose (200 mg kg<sup>–1</sup>) was nevertheless required to optimize gas exchange.
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| 8. |
- Johansson, J, et al.
(författare)
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A synthetic surfactant based on a poly-Leu SP-C analog and phospholipids: effects on tidal volumes and lung gas volumes in ventilated immature newborn rabbits
- 2003
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Ingår i: Journal of applied physiology (Bethesda, Md. : 1985). - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 95:5, s. 2055-2063
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Tidskriftsartikel (refereegranskat)abstract
- Available surfactants for treatment of respiratory distress syndrome in newborn infants are derived from animal lungs, which limits supply and poses a danger of propagating infectious material. Poly-Val→poly-Leu analogs of surfactant protein (SP)-C can be synthesized in large quantities and exhibit surface activity similar to SP-C. Here, activity of synthetic surfactants containing a poly-Leu SP-C analog (SP-C33) was evaluated in ventilated premature newborn rabbits. Treatment with 2.5 ml/kg body wt of 2% (wt/wt) SP-C33 in 1,2-dipalmitoyl- sn-3-glycero phosphoryl choline (DPPC)-1-palmitoyl-2-oleoyl- sn-3-glycero phosphoryl choline (POPC)-1-palmitoyl-2-oleoyl- sn-3-glycero phosphoryl glycerol (POPG), 68:0:31, 68:11:20, or 68:16:15 (wt/wt/wt) suspended at 80 mg/ml gave tidal volumes (Vt) of 20-25 ml/kg body wt, with an insufflation pressure of 25 cmH2O and no positive end-expiratory pressure (PEEP), comparable to the Vt for animals treated with the porcine surfactant Curosurf. Nontreated littermates had a Vt of ∼2 ml/kg body wt. The Vt for SP-C33 in DPPC-egg phosphatidylglycerol-palmitic acid [68:22:9 (wt/wt/wt)], DPPC-POPG-palmitic acid [68:22:9 (wt/wt/wt)], and DPPC-POPC-POPG [6:2:2 (wt/wt/wt)] was 15-20 ml/kg body wt. Histological examination of lungs from animals treated with SP-C33-based surfactants showed incomplete, usually patchy air expansion of alveolar spaces associated with only mild airway epithelial damage. Lung gas volume after 30 min of mechanical ventilation were more than threefold larger in animals treated with Curosurf than in those receiving SP-C33 in DPPC-POPC-POPG, 68:11:20. This difference could be largely counterbalanced by ventilation with PEEP (3-4 cmH2O). An artificial surfactant based on SP-C33 improves Vt in immature newborn animals ventilated with standardized peak pressure but requires PEEP to build up adequate lung gas volumes.
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