Surfactant lung lavage using asymmetric high-frequency jet ventilation followed by conventional ventilation in rabbits with meconium aspiration.
BACKGROUND
Severe impairment of lung functions in meconium aspiration syndrome (MAS) often needs the application of combined therapeutic approach. In our recent study, surfactant lung lavage during asymmetric high-frequency jet ventilation (HFJV) removed more meconium than surfactant lavage during conventional ventilation, however, after the lavage excessive CO2 elimination was observed during HFJV.


OBJECTIVE
We hypothesized that the combination of asymmetric HFJV during surfactant lung lavage and conventional ventilation in the post-lavage period may be of benefit in a rabbit model of MAS.


METHODS
Suspension of human meconium in saline (25 mg/ml, 4 ml/kg) was instilled into the tracheal tube of conventionally ventilated (frequency, f, 30/min, inspiration time, Ti, 50%) anesthetized rabbits to cause a respiratory failure. Animals were then lavaged (10 ml/kg in 3 portions) with diluted surfactant (Curosurf, 100 mg of phospholipids/ml) or saline during asymmetric HFJV (f, 300/min, Ti, 70%). After the lavage, animals were ventilated conventionally (f, 30/min, Ti, 50%) for next 1 hour.


RESULTS
Surfactant lung lavage during asymmetric HFJV removed more meconium pigments and solids than saline with HFJV (p < 0.05 or p < 0.01, respectively). Moreover, application of asymmetric HFJV facilitated the lavage fluid removal in both groups. In the post-lavage period, improved oxygenation, lung compliance, right-to-left pulmonary shunts, and reduced ventilatory requirements were found in the surfactant group (p < 0.05), while pCO2 was kept in the normal range.


CONCLUSIONS
Surfactant lung lavage by asymmetric HFJV followed by conventional ventilation is advantageous combination in rabbits with MAS and may be tested in neonatal MAS (Tab. 2, Fig. 2, Ref. 12).
Mokra
D
D
Department of Physiology, Comenius University, Jessenius Faculty of Medicine, Martin, Slovakia. sevecova@jfmed.uniba.sk
Calkovska
A
A
Drgova
A
A
Javorka
K
K
D000818:Animals; D001688:Biological Products / Q000008:administration & dosage*; D018893:Bronchoalveolar Lavage; D006611:High-Frequency Jet Ventilation; D006801:Humans; D007231:Infant, Newborn; D008471:Meconium Aspiration Syndrome / Q000628:therapy*; D010743:Phospholipids / Q000008:administration & dosage*; D011663:Pulmonary Surfactants / Q000008:administration & dosage*; D011817:Rabbits; D012121:Respiration, Artificial
D001688:Biological Products; D010743:Phospholipids; D011663:Pulmonary Surfactants; C068291:poractant alfa