The effects of Partial Liquid Ventilation (PLV) on cerebrovascular hemodynamics in newborn pigs

PLV has been evaluated in different respiratory diseases in experimental and, recently, human studies. No report exists on effects of PLV on cerebral hemodynamics. We hypothesized that PLV by influencing intrathoracic pressure, venous return, and thus cerebral blood volume could result in an alteration of cerebrovascular hemodynamics. In anesthetized newborn pigs closed cranial windows were placed over the parietal cortices. An RDS model was produced by multiple lung lavage with warm normal saline. PLV was initiated by intratracheal instillation of 30 ml/kg perflurocarbon (FC-77, 3M Specialty Chemical Division, St.Paul, Minnesota). Pial arteriolar and venular diameters were measured. Cerebral vascular reactivities to 10 min hypercapnia (PaCO₂ >70 mm Hg) and 10 min topical isoproterenol (10^-6M) were evaluated before and during PLV. Hypercapnia Isoproterenol Periods Arlerioles Venules Arterioles Venules Before PLV +35±6% +12±4% +28±3% +3±1% During PLV +32±5% +16±4% +33±4% +7±2% In newborn pig model of mild RDS, pial arteriolar and venular diameters and, vascular reactivities to hypercapnia and isoproterenol are preserved after PLV.