Cerebral oxygenation associated with INSURE versus LISA procedures in surfactant-deficient newborn piglet RDS model.

BACKGROUND: Nasal continuous-positive airway pressure (nCPAP) with the INSURE (INtubation-SURfactant-Extubation) or LISA (Less-Invasive Surfactant Administration) procedures are increasingly being chosen as the initial treatment for neonates with surfactant deficiency. Our objective was to compare the effects on cerebral oxygenation of different methods for surfactant administration: INSURE and LISA, using a nasogastric tube (NT) or a LISAcath® catheter, in spontaneously breathing SF-deficient newborn piglets. METHODS: Eighteen newborn piglets with SF-deficient lung injury produced by repetitive bronchoalveolar lavages were randomly assigned to INSURE, LISA-NT, or LISAcath® groups. We assessed pulmonary (gas exchange, lung mechanics, lung histology) and hemodynamic (mean arterial blood pressure, heart rate) changes, cerebral oxygenation (cTOI) and cerebral fractional tissue extraction (cFTOE), with near-infrared spectroscopy, carotid blood flow and brain histology. RESULTS: SF-deficient piglets developed respiratory distress (FiO2 = 1, pH <7.2, PaCO2 >70 mmHg, PaO2 <70 mmHg, Cdyn <0.5 mL/cmH2 O/kg). Rapid improvements in pulmonary status were observed in all surfactant-treated groups without hemodynamic alterations. In the INSURE group, a transient decrease in cTOI occurred during and immediately after surfactant administration, while cTOI only decreased during surfactant administration in the LISA-NT group and did not change significantly in the LISAcath® group. Brain injury scores were low in all surfactant-treated groups. CONCLUSION: In spontaneously breathing SF-deficient newborn piglets, short-lasting decreases in cerebral oxygenation are associated with surfactant administration by the INSURE method or LISA using an NT, while no cerebral oxygenation changes occurred with LISA using a LISAcath®. Notably, none of treatments studied seems to have a negative impact on the neonatal brain.

Non-invasive ventilation and surfactant treatment as the primary mode of respiratory support in surfactant-deficient newborn piglets.

BackgroundNasal continuous positive airway pressure (NCPAP) and nasal intermittent positive pressure ventilation (NIPPV), forms of non-invasive ventilation (NIV) for respiratory support, are increasingly being chosen as the initial treatment for neonates with surfactant (SF) deficiency. Our objective was to compare NCPAP with NIPPV with or without SF administration as a primary mode of ventilation.MethodsTwenty-four newborn piglets with SF-deficient lung injury produced by repetitive bronchoalveolar lavages were randomly assigned to NCPAP or NIPPV, with or without SF administration (InSurE method). We evaluated pulmonary, systemic (hemodynamic and oxygen metabolism), and cerebral effects.ResultsSF-deficient piglets developed respiratory distress (FiO2:1, pH<7.2, PaCO2>70 mm Hg, PaO2<70 mm Hg, and Cdyn<0.5 ml/cmH2O/kg). Gradual improvements in pulmonary status were observed in both NIV groups, with NIPPV achieving lower lung inflammation markers and injury scores. Both SF-treated groups obtained significantly better respiratory outcomes than groups not treated with SF before NIV. All NIV-treated groups showed low brain injury scores.ConclusionIn spontaneously breathing SF-deficient newborn piglets, NIPPV is a suitable NIV strategy. SF administration in combination with NCPAP or NIPPV improves pulmonary status providing extra protection against pulmonary injury. No injury to the developing brain was observed to be associated with these NIV strategies, with or without SF therapy.

Cerebral and lung effects of a new generation synthetic surfactant with SP-B and SP-C analogs in preterm lambs.

BACKGROUND: Though natural surfactants (SF) are clinically superior to protein-free synthetic preparations, CHF-5633, a synthetic SF containing SP-B and SP-C analog peptides is a potential alternative to natural SF for treating neonatal respiratory distress syndrome (RDS). Nevertheless, information is lacking regarding the safety of this new treatment for the neonatal brain. We sought to compare the cerebral and pulmonary effects of this new synthetic surfactant (CHF5633) with those of natural porcine surfactant (Cursosurf) in premature lambs with RDS. METHODS: Twenty-one preterm lambs were randomly assigned to receive CHF5633, Curosurf, or no treatment (control). Pulmonary (gas exchange, lung mechanics) and cerebral (carotid artery blood flow, cerebral oxygen metabolism) effects were measured every 30 min for 6 h. Pulmonary and cerebral histological analysis were also performed. RESULTS: After delivery, lambs developed severe RDS (FIO2 :1, pH < 7.15, PaCO2 > 70 mmHg, PaO2 < 40 mmHg, Cdyn < 0.1 mL/cmH2 O/kg). By 30 min after treatment, animals in both SF-treated groups had consistently better gas exchange and lung mechanics than controls. After CHF5633 administration, PaCO2 , carotid artery blood flow, and cerebral oxygen delivery tended to slowly decrease compared to other groups. By 2 h, SF-treated groups had similar values of all parameters studied, these remaining steady for the rest of the experiment. Lambs administered CHF5633 obtained better lung and brain injury scores than controls. CONCLUSION: Intratracheal administration of a bolus of CHF5633 improves pulmonary status in preterm lambs with severe RDS, obtaining better lung and brain injury scores than controls and favorable cerebral hemodynamics, comparable to those with gold standard Curosurf treatment.