Surfactant with and without bronchoalveolar lavage in an experimental model of meconium aspiration syndrome.

OBJECTIVES: To assess the effect of surfactant administration, preceded or not by bronchoalveolar lavage (BAL) with dilute surfactant, on pulmonary function in experimental severe meconium aspiration syndrome. METHODS: Twenty-one newborn pigs received 20% meconium in saline intratracheally and were randomly allocated to one of three groups: I, control; II, surfactant only (poractant alfa, 200 mg/kg); or III, dilute surfactant BAL followed by 125 mg/kg surfactant. Arterial blood gases (ABGs), lung compliance, and resistance were assessed. RESULTS: Thirty minutes after treatment, mean PaO2 (mm Hg) increased to 72 in group I, to 106 in group II and to 172 in group III (P=0.01). After 3 h, mean PaO2 (mm Hg) was 70 in group I, 95 in group II and 198 in group III (P<0.01). After 6 h, it was 79 in group I, 110 in group II, and 217 in group III (P=0.01). From the 30-min point onward, there were significant differences among treatment groups in all other parameters and at every point of assessment, except for compliance and resistance 3 h after treatment. CONCLUSIONS: BAL with dilute surfactant, followed by an additional dose of surfactant, produced significant improvements in ABGs and pulmonary mechanics as compared with a single dose of surfactant.

Experimental model of atelectasis in newborn piglets.

BACKGROUND: There are few studies using animal models in chest physical therapy. However, there are no models to assess these effects in newborns. This study aimed to develop a model of obstructive atelectasis induced by artificial mucus injection in the lungs of newborn piglets, for the study of neonatal physiotherapy. METHODS: Thirteen newborn piglets received artificial mucus injection via the endotracheal tube. X-rays and blood gas analysis confirmed the atelectasis. RESULTS: The model showed consistent results between oxygenation parameters and radiological findings. Ten (76.9%) of the 13 piglets responded to the intervention. This did not significantly differ from the expected percentage of 50% by the binomial test (95% CI 46.2-95%, P = .09). CONCLUSIONS: Our model of atelectasis in newborn piglets is both feasible and appropriate to evaluate the impact of physical therapies on atelectasis in newborns.