acetylcellulose and Hypertension--Pulmonary

Pulmonary hypertension (PHT) increases mortality rate in hemodialysis (HD) patients. Numerous clinical, hemodynamic, and metabolic abnormalities have been suggested to be associated with the development of PHT in HD patients. We aimed to investigate the acute effects of two different dialyzer membranes on pulmonary arterial pressure (PAP) throughout a HD session in maintenance HD patients. Seventy-four HD patients dialyzed through permanent tunneled jugular central venous catheter were enrolled. A first-use cellulose acetate and high-flux polysulfone dialysis membrane were tested using a crossover design. For each membrane, pre- and post-dialysis pulmonary artery pressures were measured echocardiographically. Elevated pulmonary artery pressure was observed in 68.8% of patients (n = 51), whereas mild PHT was observed in 28.3% of patients (n = 21) and moderate PHT in 40.5% (n = 30). Decrease in pulmonary artery pressure following HD procedure performed using high-flux polysulfone membrane was significantly higher than the decrease observed following HD procedure performed using cellulose acetate membrane (p < 0.05). Significant decrease in pulmonary artery pressures was observed only after HD procedures performed using high-flux polysulfone membrane (p < 0.05). Ultrafiltered volume was only significantly correlated with the decrease in pulmonary artery pressure observed after HD procedure performed through high-flux polysulfone membrane (β = 0.411, p < 0.05). PHT seems to be prevalent among HD patients even in the absence of AV fistula and abnormal cardiac functions. Membrane composition seems to be important, which may overwhelm the improving effects of ultrafiltration.

Topics: Adult; Biocompatible Materials; Cellulose; Cross-Over Studies; Female; Humans; Hypertension, Pulmonary; Kidney Failure, Chronic; Male; Membranes, Artificial; Middle Aged; Polymers; Pulmonary Artery; Renal Dialysis; Sulfones; Ultrafiltration

A sheep model is described that reliably produces acute pulmonary hypertension after blood, previously in contact with a number of different dialysis membranes including Cuprophan, enters the animal's circulation. This hemodynamic manifestation is associated with myocardial ischemia and arrhythmias and coincides in time with neutropenia but precedes maximal hypoxemia. The resulting pulmonary vascular response occurs following both exposure of flowing blood to a dialyzer in an extracorporeal circuit and reinjection of blood previously in static contact with a number of different devices for varying periods of time. Increasing volumes (1-15 ml) previously in static contact (10 min) with regenerated cellulose, saponified cellulose ester, and Cuprophan (hollow fiber and sheet form) caused varying increments in mean pulmonary artery pressure. Contact with either polyacrylonitrile or cellulose acetate resulted in little response. This effect was magnified with all the surfaces, even polyacrylonitrile and cellulose acetate, by prolonging the duration of contact up to 30 min. The hemodynamic events that occurred with this model are similar to those reported in the clinical entity of "dialyzer hypersensitivity." This model may be of value in the quest for elucidation of the mechanisms involved in this syndrome.

Topics: Acrylic Resins; Animals; Cellulose; Disease Models, Animal; Hemodynamics; Hypersensitivity; Hypertension, Pulmonary; Kidneys, Artificial; Leukocyte Count; Membranes, Artificial; Oxygen; Pulmonary Wedge Pressure; Renal Dialysis; Sheep