Evaluation of lung recovery after static administration of three different perfluorocarbons in pigs.
Résumé
Background: The respiratory properties of perfluorocarbons (PFC) have been widely studied for liquid ventilation in
humans and animals. Several PFC were tested but their tolerance may depend on the species. Here, the effects of a
single administration of liquid PFC into pig lungs were assessed and compared. Three different PFC having distinct
evaporative and spreading coefficient properties were evaluated (Perfluorooctyl bromide [PFOB], perfluorodecalin
[PFD] and perfluoro-N-octane [PFOC]).
Methods: Pigs were anesthetized and submitted to mechanical ventilation. They randomly received an intra-tracheal
administration of 15 ml/kg of either PFOB, PFD or PFOC with 12 h of mechanical ventilation before awakening and
weaning from ventilation. A Control group was submitted to mechanical ventilation with no PFC administration. All
animals were followed during 4 days after the initial PFC administration to investigate gas exchanges and clinical
recovery. They were ultimately euthanized for histological analyses and assessment of PFC residual concentrations
within the lungs using dual nuclei fluorine and hydrogen Magnetic Resonance Imaging (MRI). Sixteen animals were
included (4/group).
Results: In the PFD group, animals tended to be hypoxemic after awakening. In PFOB and PFOC groups, blood gases
were not significantly different from the Control group after awakening. The poor tolerance of PFD was likely related to
a large amount of residual PFC, as observed using MRI in all lung samples (≈10% of lung volume). This percentage was
lower in the PFOB group (≈1%) but remained significantly greater than in the Control group. In the PFOC group, the
percentage of residual PFC was not significantly different from that of the Control group (≈0.1%). Histologically, the
most striking feature was an alveolar infiltration with foam macrophages, especially in the groups treated by PFD or
PFOB.
Conclusions: Of the three tested perfluorocarbons, PFOC offered the best tolerance in terms of lung function, gas
exchanges and residuum in the lung. PFOC was rapidly cleared from the lungs and virtually disappeared after 4 days
whereas PFOB persisted at significant levels and led to foam macrophage infiltration. PFOC could be relevant for short
term total liquid ventilation with a rapid weaning.
Domaines
ToxicologieOrigine | Fichiers éditeurs autorisés sur une archive ouverte |
---|
Loading...