Effects of single and multiple doses of perfluorocarbon in comparison with continuous partial liquid ventilation on gas exchange and lung pathology in newborn surfactant-depleted pigs.
OBJECTIVE
To compare the efficacy of single, multiple, and continuous application of perfluorocarbon (PFC) FC-77 on gas exchange and lung pathology in a prolonged 24-hr study.


METHODS
Controlled animal trial.


METHODS
Research laboratory in a university setting.


METHODS
Twenty-one newborn piglets (mean weight 1.94 kg).


METHODS
After intubation and instrumentation, the anesthetized animals were randomized in three groups: a) animals receiving one 1-hr session of partial liquid ventilation (PLV) followed by 23 hrs of conventional ventilation (CV), designated as the single PLV (S-PLV) group; b) animals receiving multiple 1-hr sessions of PLV with intermittent CV, designated as the multiple PLV (M-PLV) group; and c) animals receiving continuous PLV over 24 hrs, designated as the continuous PLV (C-PLV) group. After lung injury was induced with repeated saline lavage, specific ventilatory treatment was initiated. The oxygenation index, Pao2/Fio2 ratio, and ventilatory efficacy index were determined before and after lung injury and during the 24-hr course. After 24 hrs, the lungs were removed for histopathologic examination.


RESULTS
Gas exchange variables improved within 60 mins in all groups after the initiation of the specific ventilatory treatment (p < .01). The best outcome was observed in the C-PLV group, which provided a continuously stable gas exchange over the 24-hr period. S-PLV initially improved gas exchange, but after 6 hrs all variables were impaired when compared with C-PLV (p < .01). M-PLV transiently improved gas exchange variables after each PFC application; however, M-PLV was associated with a significant deterioration of all pulmonary variables during the 24-hr course. The lungs of the animals in the M-PLV group demonstrated an increased lung injury score (p < .01) and increased morphometric values (p < .05) when compared with C-PLV.


CONCLUSIONS
In surfactant deficient lungs, single and multiple applications of PFC only transiently improved oxygenation. Multiple PFC fillings with intermittent gas ventilation led to a deterioration of gas exchange during the 24-hr study and severe lung damage. Continuous PLV provides the best gas exchange and the most favorable histopathologic outcome.
Merz
U
U
Children's Hospital, Neonatal Intensive Care, Aachen University of Technology, Pauwelsstr. 30, 52057 Aachen, Germany. umerz@post.klinikum.rwth-aachen.de
Klosterhalfen
B
B
Kellinghaus
M
M
Peschgens
T
T
Pluschke
S
S
Hoernchen
H
H
D000818:Animals; D000831:Animals, Newborn; D001784:Blood Gas Analysis; D004195:Disease Models, Animal; D005466:Fluorocarbons / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007231:Infant, Newborn; D021061:Liquid Ventilation / Q000009:adverse effects / Q000379:methods*; D008297:Male; D010100:Oxygen / Q000097:blood; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D011663:Pulmonary Surfactants / Q000172:deficiency*; D011897:Random Allocation; D012127:Respiratory Distress Syndrome, Newborn / Q000209:etiology / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy*; D012965:Sodium Chloride; D013552:Swine; D007507:Therapeutic Irrigation; D013997:Time Factors; D016896:Treatment Outcome
D005466:Fluorocarbons; D011663:Pulmonary Surfactants; C429307:fluorocarbon 77; D012965:Sodium Chloride; D010100:Oxygen