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Congestive heart failure afflicts 4 million people in the United States, with 400,000 deaths annually. Very little can be done for individuals with this condition, which is increasing in prevalence. The only hope is the promise of intervention with permanent circulatory support systems. Can we as a society afford the $3.1 billion that would be required to support every patient needing such a system? This cost represents an increase of 1/2 of 1% of the $662 billion per year expended for medical care. Fortunately, circulatory support systems do not necessarily represent an expense, but rather an investment that has a reasonable payback period. An investment in an individual of $100,000 for the device and implantation cost, coupled with an ongoing maintenance cost of $4,000 per year, can return to society an income greater in value than the investment. The payback period is strongly dependent on the earning power of the individual, as well as the amount of medical attention or complications experienced. An individual with an annual salary of $40,000 per year becomes a positive financial force in our society and increases the gross national product (GNP) within 5 years. The same individual with extensive medical complications and intermittent loss of salary can extend the payback period by an additional 2 years. Circulatory support systems have the potential of increasing our GNP, leading to a higher standard of living for the populace.

In the past few years, dialyzer reuse has gained increased clinical acceptance. This has been due both to the availability of automated reconditioning machines and powerful chemical cleaning and disinfecting agents. In this study the authors evaluated the effectiveness of a newly available peroxyacetic acid solution (PAS) (Dialox) as the dual cleaning and disinfecting agent in the reuse of highly permeable dialyzers. An in vivo study was conducted with ten patients already involved in our center's reuse program using the Renatron reprocessing machine and PAS at various dilutions. One hundred forty dialyzers of three different brands and membrane types (HF80 used for hemodiafiltration [HDF], Filtral 16 used for hemodialysis [HD], and FH88 used for hemofiltration [HF]) were employed for a total of 1182 treatments, giving an average 8.4 uses per module. Significantly more uses were obtained with the HF80 and Filtral 16 dialyzers (9.7 and 9.4, respectively) than for the FH88 modules used by the HF patients (6.7 uses per module). Compromised cleaning by backfiltration due to the lack of a second dialysate port on the FH88 may be a possible explanation. Greater membrane plugging due to higher ultrafiltration rates in HF may be another factor. Patient variability was found to be another factor in dialyzer reuse. The cleaning effectiveness of various dilutions of PAS was also tested in this study. The number of uses achieved was not found to vary significantly with PAS strength; however, a greater frequency of second or third reprocessing was required with more dilute cleaning solution. The authors found the dilution achieved on the Renatron reprocessing machine using the currently marketed PAS concentrate to be the most cost effective.

The authors reviewed the clinical usefulness of routine comprehensive skeletal surveys in monitoring renal osteodystrophy in 66 patients on chronic maintenance hemodialysis. Only fourteen (22%) of the 66 patients had roentgenographic evidence of hyperparathyroid bone disease. There were no significant differences in serum calcium, phosphate, or aluminum levels between patients with and without evidence of phalangeal subperiosteal bone resorption in the hands. However, serum levels of parathyroid hormone (PTH) (both intact and mid-molecule) and alkaline phosphatase values were significantly higher in the group with subperiosteal bone resorption (p less than 0.01 and p less than 0.02, respectively). Serum intact PTH correlated with alkaline phosphatase better than the mid-molecule assay. Neither intact nor mid-molecule PTH values correlated with serum calcium, phosphate, or aluminum. Hand roentgenograms were most sensitive in detecting early changes of hyperparathyroidism; symphysis pubis was the next best. Other skeletal roentgenographic findings were less revealing, and in a subset of 20 patients, roentgenograms correlated poorly with bone histology. During this study the authors found an 8% prevalence of vertebral compression fractures; all in postmenopausal white women.

A retrospective investigation was undertaken in which the rate of decline of residual renal function (RRF), estimated from creatinine clearance, was compared in 55 continuous ambulatory peritoneal dialysis (CAPD) and 57 hemodialysis (HD) patients for whom a minimum of four (mean of 7.6) well-spaced historic measurements of residual clearance were available. Because of the intrinsic variability that attends such data, specialized nonlinear, growth curve statistical methods were employed. Residual function was found to decline exponentially after the onset of therapy in both cohorts. The rate of decline in the HD group was twice that of the CAPD group (5.8% +/- 0.4% per month for HD vs 2.9% +/- 0.3% per month for CAPD; difference significant at p less than 0.0001). This difference remained highly significant (p less than 0.01) when corrected for other potential risk factors such as age, gender, hypertensive status, and use of angiotensin converting enzyme inhibitors in patients with diabetic or other forms of glomerular nephropathy. Differences between cohorts were not significant for patients with other diagnoses (p greater than 0.1) although the size of some of these subsets was very small. The physiologic mechanism for the more rapid fall-off of RRF on HD remains speculative, but could be related to renal ischemia secondary to intratreatment hypovolemia and/or to nephrotoxic effects of the inflammatory mediators of extracorporeal circulation.

To test the hypothesis that temporary platelet inhibition during cardiopulmonary bypass (CPB) with surface heparinized systems may result in platelet preservation, nine Yorkshire pigs were placed on CPB for 3 hours. Platelet labeling was done in all pigs with Indium-111 tropolone. CPB was instituted with a roller pump, a hollow fiber membrane oxygenator (Bentley CM-50 [Baxter-Bentley Laboratories, Irvine, CA]), and an arterial filter. The extracorporeal perfusion systems were surface-coated with the Duraflo-II heparin complex. Group A pigs (n = 5) were systemically heparinized (activated coagulation time longer than 400 sec). Group B pigs (n = 4) were placed on CPB without systematic heparinization, but have received the stable prostacyclin-analog Iloprost (ZK36374) at 1 ng/kg/min i.v. from 30 min before and during CPB. Platelet counts declined in group A pigs at 5 min, 1 hr, 2 hr, and 3 hr of CPB to 79.8% (mean), 66.5%, 71.3%, and 69.0% of pre-CPB values, respectively (p less than 0.05). In group B pigs, mean platelet count during CPB was higher than 90% of control value. Percentage of injected radioactivity detected in the oxygenator was 2.82% in group A pigs versus 0.73% in group B pigs (p = 0.0541). Surface heparinization with the Duraflo II heparin coating complex in combination with Iloprost-induced temporary platelet inhibition resulted in platelet count preservation during CPB in the pig model.

In September 1987, patients at an outpatient dialysis center were exposed to chloramine contaminated dialysate when the carbon filter in a recently modified water treatment system failed. Forty-one patients required transfusion to treat the resultant hemolytic anemia. Epidemiologic investigation demonstrated that the mortality rate among dialysis center patients increased during the 5 months after chloramine exposure when compared with the 12 months before chloramine exposure, but no deaths could be attributed to the exposure. Chloramine is commonly used as a disinfectant in municipal water supplies, and has previously been reported to cause hemolytic anemia in patients undergoing dialysis. Hemodialysis centers in cities that use chloramine in water supplies must design water treatment systems with adequate means for removing chloramine and must monitor processed water closely to ensure that chloramine contamination does not occur. Dialysis centers that make changes in their water processing systems should evaluate all components of the system before changes are made, and must ensure that after modifications are made, processed water meets the standards set by the Association for Advancement of Medical Instrumentation.

The clinical evaluation of investigational circulatory support devices has, for the most part, been financed with private funds. St. Louis University initiated a system in 1986 to bill for investigational circulatory support devices and care related to their use. Charges for hospitalization and rates of reimbursement were reviewed in 32 patients who received Thoratec (Thoratec Laboratories Corp., Berkeley, CA [N = 26]), Novacor (Baxter Healthcare Corp., Oakland, CA [N = 4]), or Symbion (Symbion Inc., Tempe, AZ [N = 2]) total artificial heart devices. Duration of support ranged from 0.2 to 440 days (mean 32). Total charges ranged from $43,115 to $1,335,691 (mean $221,716). Charges for the devices and technical support relating directly to their use ranged from $10,305 to $96,030 (mean $28,246). The mean percentage of reimbursement (total charges/total paid) was 67%. Whereas it was uncertain in some patients whether or not the devices were paid for, commercial insurers are willing to reimburse at a high percentage for the total cost of care.

The correction of acid-base balance during hemodialysis, especially in high-efficiency techniques, could present some problem related to the lack of an adequate monitoring of pH and blood gases. During hemodiafiltration (HDF), performed with the two-chamber technique (paired filtration dialysis, PFD), the ultrafiltrate (Uf) is continuously available, unmixed with the dialysate. Connecting a pH electrode (as Ag/C1Ag) to the Uf circuit, the authors made 40 determinations on 16 different PFD patients, and they correlated the Uf values obtained with those measured on arterial blood with standard methods. The one sample analysis gave a t = 10.145 (p = 0.0), and the linear regression analysis an r = 0.931 (p = 0.0). At 30 min, in 8 PFD patients, the HCO3 values obtained from Uf, pH and transcutaneous PCO2, gave a t = 6.37 (p = 0.0004), and an r = 0.939 (p = 0.00052). In conclusion, during HDF performed with PFD, continuous pH monitoring of the patient is possible without blood sampling. Moreover, correlation with the transcutaneous PCO2 measurement could provide HCO3 values in real time.

A single center experience of 160 cyclosporine-treated renal allografts that survived longer than 1 year was reviewed in an attempt to analyze the contribution of selected parameters to long-term survival. Sixty-one grafts were lost between 1 and 5 years, with the remaining functioning for longer than 5 years. Parameters with a significant influence on long-term survival included both quality of early graft function, with 13% of long-term survivors having delayed function, compared to 52% among the short-term survival group, and the incidence of acute rejection in the first year posttransplant (31% in long-term survivors compared to 63% in the short-term survival group). A marker for long-term survival (greater than 5 years) was a lower serum creatinine at 1 year (1.9 +/- 0.1 mg/dl, compared with 2.6 +/- 0.2 mg/dl in the short-term survival group). Recipient race, original renal disease, number of transplants and/or transfusions, panel reactive antibodies, and human leukocyte antigens matching did not appear to influence long-term outcome.