PUMPLESS RESPIRATORY ASSISTANCE USING A MEMBRANE-OXYGENATOR AS AN ARTIFICIAL PLACENTA - A PRELIMINARY-STUDY IN NEWBORN AND PRETERM LAMBS

Newborns suffering from severe respiratory difficulties and not respon ding to conventional methods have been successfully treated by extraco rporeal circulation with a membrane oxygenator (ECMO). However, the te chnique needs a highly specialized staff excellent laboratory support, and continuous surveillance of the procedure to prevent complications . In a series of experiments on newborn and preterm lambs, we have inv estigated a relatively simpler technique of respiratory support that i nvolves a pumpless arteriovenous bypass by cannulating both umbilical arteries and the umbilical vein. A highly efficient microporous membra ne oxygenator (MO) with very low resistance was selected. This type of perfusion that mimics the placental circulation, besides providing an additional amount of oxygen to the blood, has proven to be very effec tive for CO2 extraction. Before its application in humans, however, im provements in the catheters to be inserted in the umbilical vessels, s ome modifications in the design of the MO, and improvements in the blo od compatibility of all foreign surfaces in contact with blood are nee ded.