Exogenous surfactant administration by asymmetric high-frequency jet ventilation in experimental respiratory distress syndrome.
OBJECTIVE
To evaluate the efficacy of surfactant administration using the instillation technique by means of asymmetric high-frequency jet ventilation (HFJV).


METHODS
Experiments were carried out on tracheotomized, anaesthetized, and paralyzed rabbits. Animals were lung-lavaged with saline and conventionally ventilated with 100% oxygen. After respiratory failure, they were ventilated for additional 2 hours with conventional ventilation (f=30/min) or HFJV (f=300/min). Subgroups were treated with porcine surfactant (Curosurf; 80 mg/mL, dose 200 mg/kg) as a bolus followed by conventional ventilation or instilled into the jet of the ventilator during asymmetric HFJV (inspiration time Ti=30%). In controls, no material was instilled.


RESULTS
Bolus administration of Curosurf followed by conventional ventilation in comparison with conventionally ventilated animals without surfactant improved gas exchange (at 60 minutes: PaO(2)/FiO(2), 9.8-/+3.6 vs 22.3-/+8.5 kPa, P=0.020), reduced right-to-left pulmonary shunts (at 60 minutes: 47.8-/+13.8 vs 23.9-/+6.7 %, P<0.006), and reduced inflammatory response in the lungs. Surfactant administration by HFJV in comparison with bolus instillation resulted in even better gas exchange (at 90 minutes: 20.7-/+8.8 vs 39.1-/+10.9 kPa, P=0.005) and reduction of right-to-left pulmonary shunts (at 90 minutes: 29.1-/+7.2 vs 8.0-/+2.2 %, P=0.008). High-frequency jet ventilation with or without surfactant treatment significantly increased pressure-volume recordings and reduced intraalveolar edema in comparison with conventional ventilation-only group. There were no significant differences in inflammatory response between the two tested methods.


CONCLUSIONS
The response to surfactant therapy in experimental lung injury depends on the surfactant delivery method and may be potentiated by high-frequency jet ventilation.
Calkovska
Andrea
A
Department of Physiology, Comenius University, Jessenius Faculty of Medicine, Mala Hora 4, 03754 Martin, Slovakia. Calkovska@jfmed.uniba.sk
Sevecova-Mokra
Daniela
D
Javorka
Kamil
K
Petraskova
Maria
M
Adamicova
Katarina
K
D000818:Animals; D005260:Female; D006611:High-Frequency Jet Ventilation; D008297:Male; D023421:Models, Animal; D011663:Pulmonary Surfactants / Q000008:administration & dosage*; D011817:Rabbits; D012128:Respiratory Distress Syndrome / Q000188:drug therapy*; D016896:Treatment Outcome
D011663:Pulmonary Surfactants