Rationale: Earlier work has shown that experimental conditions calling for improved tissue oxygenation could be assisted by i.v. infusion of a dodecafluoropentane emulsion (DDFPe) forming oxygen-transporting microbubbles.
Objectives: The present work investigated the effect of DDFPe on hypoxia due to experimental shunts in the pig lung.
Methods: Nineteen O(2) breathing, anesthetized pigs had glass beads administered into the trachea so as to significantly depress arterial oxygen tension (PaO(2)). PaO(2) was recorded for up to 12 hrs while 0.1 ml/kg DDFPe was administered 1-3 times.
Main results: The animals were divided into two groups based on arterial oxygen saturation (SaO(2)) after shunt induction, combined with oxygen breathing: the "SaO(2) >90% group" (n=6) and the "SaO(2) <90% group" (n=13). In the "SaO(2) <90% group," the PaO(2) increased stepwise with each infusion from 56.6+/-2.9 to 88.6+/-14.6 mmHG (P<or=0.001); improvements lasted about 2 hrs after each infusion. Mixed venous oxygenation also increased with the infusions, e.g. (1(st) infusion) from a PvO(2) of 41.4+/-2.3 to 49.9+/-4.2 mmHg (P<or=0.05) and SvO(2) 58.0+/-2.9% (P<or=0.01), the venous changes supporting arterial oxygenation. At the same time, arterial CO(2) levels fell. Arterial O(2) and CO(2) levels were paralleled by similar changes in muscle tissue. Pulmonary arterial pressures did not indicate any pulmonary embolization by bubbles. Toxic effects of the treatment were not observed.
Conclusion: These results suggest that, on condition of successful toxicity testing, intravascular administration of a DDFPe and oxygen breathing may be beneficial in severe right-to-left shunting in humans.