Perfluorocarbon (PFC) liquids have high oxygen carrying capacity and relatively low surface tension allowing them to spread evenly through the diseased lung, especially in the case of adult respiratory distress syndrome. But few studies have demonstrated the effects of PFC on a bronchoconstriction model. The aim of this study was to investigate the effects of PFC on pulmonary mechanics and gas exchange in methacholine-induced bronchoconstricted cats using a flow interruption technique.

Twenty male cats were divided into four groups; control group (group C, n = 5), PFC group (group P, PFC 5 ml/kg, n = 5), methacholine group (group M, 25 µg/kg/min, n = 5), PFC and methacholine group (group MP, n = 5). Respiratory pressure using a flow interruption technique was measured immediately after stabilizing the heart rate and blood pressure 0, and 15, 30 and 60 min after the start of the intratracheal administration of PFC and/or methacholine infusion, depending on the group. Arterial blood gas analysis was done to compare arterial partial oxygen pressure among the groups at the time of measuring the pressure values. The pressure data was transferred to a personal computer and analyzed using ANADAT software program. Respiratory, airway and tissue viscoelastic pressure were calculated. Statistical analysis was done by ANOVA and statistical significance was defined as P <0.05.

Group M and MP showed significantly increased airway pressures compared with group C (P <0.05), but there was no difference among the groups in terms of viscoelastic pressure. Arterial blood gas analysis showed that group P and MP had lower arterial partial oxygen pressures than group C (P <0.05).

This study demonstrates that the intratracheal administration of PFC in a bronchoconstriction cat model increases airway pressure more than tissue viscoelastic pressure, and decreased arterial oxygen partial pressure. We conclude that the intratrachel administration of PFC is not to be recommended in bronchoconstrictive situations.