COMBINED GAS VENTILATION AND PERFLUOROCHEMICAL TRACHEAL INSTILLATION AS AN ALTERNATIVE TREATMENT FOR LETHAL CONGENITAL DIAPHRAGMATIC-HERNIAIN LAMBS

Tracheal instillation of perfluorochemical liquid (PFC) lowers surface tension in the lung and thus might reduce barotrauma commonly associa ted with conventional gas ventilation (GV) in highly immature and hypo plastic lungs. It could be a promising alternative treatment for conge nital diaphragmatic hernia (CDH) when GV alone is proving inefficient. The authors compared data for eight newborn lambs with surgically ind uced CDH. The animals had GV and were studied (in 2 groups) for up to 3.5 hours. Group 1 (GV, n = 4) had gas ventilation only. In group 2 (P FC, n = 4), after 30 minutes of GV, 10 to 12 mL/kg of warmed, oxygenat ed PFC liquid (LiquiVent) was instilled into the lung via the trachea under pressure-volume curve monitoring. Arterial pressure, blood chemi stry, and pulmonary mechanics were evaluated serially; histological an alysis was performed. One preassigned animal in group 1 died after 15 minutes. After 30 minutes of life, the cardiopulmonary profile of surv ivors was indicative of severe respiratory distress (Pao(2) < 72 mm Hg with FIO2 at 1.0, Paco(2) > 90 mm Hg, compliance < 0.10 mL/cm H2O(kg) and not different between groups; the severity of pulmonary hypoplasi a was further confirmed postmortem; the ratio of lung weight to body w eight was 41% of that observed in control lambs, in both gas only and combined gas/PFC-ventilated animals, compared with their respective co ntrols. After instillation of PFC, there were dramatic improvements in acid base status and pulmonary compliance in group 2. Survival at 3.5 hours also was markedly different (4 of 4 PFC animals and 1 of 3 GV a nimals). Perivascular emphysema was present on morphometric analysis i n all animals, and the mean perivascular compression index (PCI = % pe rivascular emphysema/% vessels x 100) was not different between the gr oups at this point. Conventional GV for the first 30 minutes in all la mbs may be the cause of a preexisting barotrauma. The average period o f ventilation was longer in the PFC group, and cure with long-term ven tilation appears to be possible because the lower pressures required w ould imply less risk of increasing PCI. Based needed to define the opt imal ventilatory strategy to avoid pulmonary trauma. Copyright (C) 199 5 by W.B. Saunders Company