Membrane versus bubble oxygenator in hyperthermic regional perfusion: a prospective randomized clinical study

In a prospective randomized clinical study a routinely used bubble oxygenator (Bentley-5) was compared with a hollow fiber membrane oxygenator (D 701 Masterflo 34) during hyperthermic isolated extremity perfusion. This was done to find out whether there were differences between the two oxygenators in hemolysis, cellular damage, oxygenation and temperature achieved during extremity perfusion. In 30 perfusions blood samples were obtained at defined times: plasma hemoglobin (Hb), serum lactate dehydrogenase (s-LDH), number of erythrocytes, mean corpuscular volume (MCV), hemoglobin and bilirubin were determined for hemolysis, leukocyte count (neutrophils, lymphocytes, monocytes) and platelets as a check for cellular damage, and PO2, PCO2, O2 saturation and pH to define blood oxygenation and CO2 elimination. Maximal increase in temperature after 30 min and perfusion time until maximum tissue temperature were also recorded. The membrane oxygenator yielded better results from the aspect of hemolysis: s-LDH and plasma Hb were significantly different (p < 0.001). Cellular damage was less with the membrane oxygenator: platelet differences were significant (p < 0.01). Oxygenation and hyperthermia were obtained more quickly and were better controllable in membrane oxygenator. Further advantages for the patient were the smaller volume of blood needed for priming in a membrane oxygenator (750 vs. 1,200 ml) and improved safety resulting from a 'closed' perfusion system. On the basis of the clinical prospective randomized trial conducted, we conclude that membrane oxygenators must be adopted as the new standard in isolated hyperthermic extremity perfusion.