Disease relevance of Oxygenators

• The present study was designed to determine if the addition of albumin or mannitol to the priming solution of the pump oxygenator would diminish edema in organs, without diminishing some of the beneficial effects of hemodilution on blood flow and renal function [1].
• In a series of 100 patients with postischemic ventricular fibrillation (group P), 20 mmol of potassium chloride (plus 10 mmol later if necessary) was added to the oxygenator reservoir and perfused through the arterial line into the proximal aorta [2].
• Data on postoperative blood loss and transfusions were collected from two groups: one comprising 49 patients perfused with the Travenol TMO membrane oxygenator (MO group) and the other composed of 25 patients with the Polystan VT 5000 bubble oxygenator (BO group) [3].
• Experimental and clinical use of the intravascular oxygenator (IVOX), an intravenacaval gas exchange device, in acute respiratory failure yielded a CO2 transfer of 40-70 ml/min (approximately 30% of adult CO2 production) at normocapnia [4].
• Nicotinamide has been shown to be an effective tumor oxygenator in preclinical studies and is part of a promising clinical protocol for the treatment of cancer of the larynx [5].

High impact information on Oxygenators

• Thirty anesthetized dogs were placed on CPB using bubble oxygenators with 50% O2 (n = 10) or 100% O2 (n = 10) to produce a wide range in the number of gaseous microemboli or membrane oxygenators with 50% O2 (n = 10) to avoid microemboli [6].
• The cells were recovered from the oxygenator membrane by washing with EDTA [7].
• The extracorporeal circuit was nonpulsatile with a bubble oxygenator administering 3-5% CO2 in the main group of hypercapnic patients (n = 59) and no CO2 in a second group of hypocapnic patients [8].
• The 16 dogs given adenosine deaminase were further subdivided into those perfused with blood deoxygenated by a donor canine lung (group 1, n = 11) and those perfused with blood from a paediatric oxygenator (group 2, n = 5) [9].
• CONCLUSIONS: The uptake of isoflurane into blood via PMP oxygenators during CPB is severely limited [10].

Chemical compound and disease context of Oxygenators

• Parabiotic experiments developed a refractory acidosis (pH at 120 min: parabiotic 7.31 +/- 0.14 versus oxygenator 7.42 +/- 0.4, P = 0.01) related to a progressive rise in lactate (at 120 min: parabiotic 4.0 +/- 2.6 mmol/L versus oxygenator 0.71 +/- 1.3 mmol/L, P < 0.01) [11].
• The gaseous microemboli (GME) production and gas transfer characteristics of two series of bubble oxygenators (Harvey H-1500 and Bentley BOS-10) were evaluated during clinical perfusion in 33 adult patients during open heart surgery for acquired valvular and ischaemic heart disease [12].
• In this preliminary study, samples of blood for plasma histamine were drawn from a mixed group of congenital cardiac patients featuring varying degrees of cyanosis, differing hypothermic operative conditions and utilising two oxygenator systems [13].

Biological context of Oxygenators

• RESULTS: The uptake of isoflurane, expressed as AUC of isoflurane blood concentration and a function of F(E), was significantly reduced in PMP oxygenators compared to PPL oxygenators (P < 0.01) [10].
• Complement activation during extracorporeal circulation. In vitro comparison of Duraflo II heparin-coated and uncoated oxygenator circuits [14].
• We have evaluated the effect of prostaglandin E1 (PGE1) on renal function after cardiac surgery with cardiopulmonary bypass in 20 patients, ten of whom received 0.02 microgram.kg-1.min-1 of PGE1 by infusion into the oxygenator during bypass; ten patients served as controls [15].
• After 5 minutes of blood circulation bradykinin levels significantly increased in all three groups (p < 0.01); however, the group with the PMEA coated oxygenators showed the lowest values [16].
• Nitric oxide gas infusion significantly (p < 0.05) reduced both platelet adherence to the oxygenator and in vitro platelet aggregation [17].

Anatomical context of Oxygenators

• The left anterior descending coronary artery was perfused via either of two pressurized (80 mmHg) reservoirs; reservoir 1 (control) was supplied with arterial blood free of isoflurane, and reservoir 2 was supplied with blood from an extracorporeal oxygenator, which was provided with 95% O2/5% CO2 gas that passed through calibrated vaporizer [18].
• Cranial venous blood was drained into a bubble oxygenator in which an isoflurane vaporizer was placed in line with the gas flow, and arterial blood was infused into a carotid artery with a roller pump [19].
• However, further reduction of heparin administration may not be advisable, since monocytes were still activated in the coated oxygenator [20].
• Free radical production, granulocyte activation, and hypoxanthine metabolism were assessed separately in the circulations drained by the inferior and superior venae cavae, as well as in the oxygenator [21].
• The degree of activation by poly HEMA, when corrected for surface area, was quite similar to that observed for dialysis and oxygenator membranes [22].

Associations of Oxygenators with chemical compounds

• Scavenging enflurane from extracorporeal pump oxygenators [23].
• The concentration of halothane in the oxygenator exhaust correlated reasonably well with the arterial halothane concentration (r = 0.82, P < 0.001) [24].
• METHODS: Two identical extracorporeal circulation circuits were primed with fresh human blood and circulated for 2 h at 37 degrees C. Nitric oxide at a 40-ppm concentration was added to one of the oxygenators in each pair [25].
• Paired serum tobramycin concentrations obtained pre- and postmembrane oxygenator demonstrated no drug removal [26].
• An in vitro model of a cardiopulmonary bypass (CPB) circuit using a bubble oxygenator was developed to assess the potential of this system to extract nitroglycerin (NTG) [27].

Gene context of Oxygenators

• Our laboratory measured the upregulation of the neutrophil-adhesion molecules CD11b and CD18 during CPB but did not demonstrate significant differences between membrane and bubble oxygenators [28].
• Leucocyte cound and PMN-elastase concentration rose significantly during ECC irrespective of oxygenator tested of flow type applied [29].
• A new oxygenator the Shiley S-100-A has been evaluated [30].
• Thirty patients had bypass with a bubble oxygenator (Harvey H1700) and 34 patients had bypass with a flat sheet membrane oxygenator (COBE CML) [31].
• CPB utilized a Travenol disposable bubble oxygenator and the prime consisted of 3 L. of Ringer's lactate [32].

Analytical, diagnostic and therapeutic context of Oxygenators

• Washin and washout of isoflurane administered via bubble oxygenators during hypothermic cardiopulmonary bypass [33].
• Paired serum tobramycin concentrations were obtained pre- and postmembrane oxygenator during ECMO in six sheep [26].
• The left anterior descending coronary artery (LAD) of 11 anesthetized and mechanically ventilated dogs was perfused at constant perfusion pressure (80 mm Hg) with enflurane-free blood or with blood equilibrated in an extracorporeal oxygenator with enflurane (1.1%, 2.2%, 4.4%) [34].
• PATIENTS AND METHODS: A simplified extracorporeal cardiopulmonary life support (ECLS) system was assembled consisting of a centrifugal pump head, heat exchanger, membranous oxygenator, percutaneous cannulas, and heparin-bonded circuitry [35].
• In this article, the authors discuss extracorporeal CO2 removal, venovenous intravena caval oxygenator, and tracheal gas insufflation as adjuncts to CO2 removal and nitric oxide, surfactant replacement therapy, perfluorocarbon-associated gas exchange, and prone positioning as adjuncts to oxygenation [36].

References