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Biomedical subjects

K D Nolph

Publications and source records attributed to K D Nolph.

At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

Protein catabolic rate calculations in CAPD patients.

Four different approaches to calculating the protein catabolic rate (PCR, in g/kg/day) were investigated in 28 stable continuous ambulatory peritoneal dialysis (CAPD) patients and compared to the dietary protein intake (DPI) from a 3 day diet history. The modified Borah technique is based on the hemodialysis correlation, with the addition of measured effluent protein losses. The Randerson technique is a correlation similar to the Borah hemodialysis correlation, but it was established in a CAPD population. The Teehan technique estimates total nitrogen loss by adding the measured urea nitrogen loss to average values from the literature for protein, amino acid, and non-urea nitrogen losses. The Kjeldahl technique measures total nitrogen loss. All four techniques yielded similar PCR values (0.85-0.92 g/kg/day), none of which was significantly different from the DPI (0.89 g/kg/day). Based on the simplicity of the measurements and calculations, the Randerson technique is recommended for routine monitoring of PCR in CAPD patients.

Adult↗
PubMedDate not supplied

The influence of dialysis treatment modality on the decline of remaining renal function.

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.

Female↗
PubMedDate not supplied

Long-term experience with Swan Neck Missouri catheters.

The Swan Neck Missouri catheters are designed to reduce major complications including 1) exit/tunnel infections, by a downward directed exit hole; 2) pericatheter leaks, by placement of the deep cuff in the rectus muscle; 3) catheter tip migration, by caudal direction of the intraperitoneal segment; and 4) outer cuff extrusion, by a permanent bend between the 5 cm or 3 cm spaced cuffs in SN-M2 and SN-M3 catheters, respectively. Between April 1986 and April 1990, 103 swan neck catheters were implanted. Comparison of prospective data from 103 swan neck catheters and retrospective data from 148 standard (Tenckhoff and Toronto Western Hospital) catheters implanted between January 1982 and June 1985 showed reduced complication rates with swan neck catheters. An overall survival of 64% at 36 months for swan neck catheters is significantly better than that of 29% for standard catheters.

Catheters, Indwelling↗
PubMedDate not supplied

Chronic nightly tidal peritoneal dialysis.

Nightly tidal peritoneal dialysis (NTPD) is a technique in which, after an initial fill of the peritoneal cavity, only a portion of dialysate is rapidly cycled. Five anuric, stable, PD patients entered a 4 month study to determine the NTPD session length necessary for clinically adequate dialysis and creatinine clearance similar to those on four daily 2 L CAPD exchanges. NTPD was performed using a modified PAC-X-2 cycler, with the drain phase regulated by a target volume. One patient completed 3.5 months of study, one 4 months, three 6 months, and one patient each continued on NTPD for 13, 14, and 32 months. The mean NTPD session time was 9 hr 24 min (range 8 hr 35 min to 9 hr 55 min) at the end of 4 months. All patients had clinically adequate dialysis. Three patients preferred NTPD over CAPD, particularly because of an empty abdomen during the daytime. One patient required an increase in NTPD time, and an addition of one daytime exchange, because of low creatinine clearance. In conclusion, NTPD provides weekly creatinine clearances comparable to CAPD, with an acceptable duration of nightly dialysis sessions in most anuric patients. A new PD machine providing inexpensive dialysis solution in large quantities, as well as safe and false alarm free dialysis sessions, is needed for practical NTPD implementation.

Blood Urea Nitrogen↗
PubMedDate not supplied

Leukocyte kinetics in patients with peritonitis on long-term peritoneal dialysis.

Dialysate and blood leukocyte counts were measured during 130 episodes of peritonitis in 91 hospitalized patients on long-term peritoneal dialysis (CPD). The authors found that the blood/dialysate leukocyte count can be less than 1.0, and this is usually the case when dialysate leukocyte count exceeds 20,000/mm3. Dialysate leukocyte removal in a single 2 L drain bag can approach the leukocyte number in the entire circulating blood volume. Daily drainage can remove leukocytes in amounts exceeding the blood leukocyte pool 2 to 3 fold. The observed blood leukocyte counts throughout a range of 2,700 to 10,000 at dialysate leukocyte counts greater than 20,000 per mm3 may reflect: 1) leukocyte removal approaching maximum bone marrow output of leukocytes, and/or 2) increasing microcirculatory margination of leukocytes in those episodes of peritonitis associated with very high dialysate leukocyte counts.

Cells, Cultured↗
PubMedDate not supplied

Continuous ambulatory peritoneal dialysis with a high flux membrane.

The standard peritoneal equilibration test (PET) was performed in 66 patients on CAPD. Patients were classified as low (n = 5), low average (n = 22), high average (n = 27), and high (n = 12) transporters based on the dialysate/plasma creatinine (D/P Cr) after 4 hour dwells. After an average time interval of 14 months on CAPD, indices of dialysis adequacy and nutrition were assessed. Based on monitoring of patient chemistries and drain volumes, peritoneal transport was considered stable during the interval. Instilled volumes and exchange tonicity were individualized in each patient to achieve combined renal and dialysis weekly creatinine clearance and KT/V urea that were not significantly different between groups. Overall, there were significant positive correlations of PET D/P Cr with dialysate albumin concentrations (r = 0.30, p < 0.02) and dialysate albumin losses (g/wk, r = 0.27, p < 0.04). There were significant inverse correlations with lean body mass (r = -0.26, p < 0.03), drain volumes (r = -0.025, p < 0.04), and KT urea by dialysis (L/wk, r = -0.24, p < 0.05). High transporters had significantly (p < 0.05) lower mean serum albumin, net protein catabolic rate (nPCR), lean body mass calculated from creatinine kinetics, and daily creatinine production (and presumably lower muscle mass) compared with one or more lower transport groups. In conclusion, we hypothesize that, in high transporters, use of more hypertonic exchanges with greater glucose absorption may inhibit appetite and nPCR; also, protein losses in drain volumes are increased. High transporters may require increased clearance and protein intake targets compared with other groups to maintain nutrition.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Transport↗
PubMedDate not supplied

Continuous ambulatory peritoneal dialysis with a high flux membrane. A preliminary report.

The standard peritoneal equilibration test (PET) was performed in 66 patients on continuous ambulatory peritoneal dialysis (CAPD). Patients were classified as low (n = 5), low average (n = 22), high average (n = 27), and high (n = 12) transporters based on the dialysate/plasma creatinine (D/P Cr) after 4 hr dwells. After an average time interval of 14 months on CAPD, indices of dialysis adequacy and nutrition were assessed. Based on monitoring of patient chemistries and drain volumes, peritoneal transport was considered stable during the interval. Instilled volumes and exchange tonicity were individualized in each patient to achieve combined renal and dialysis weekly creatinine clearance and KT/V urea that were not significantly different between groups. High transporters had significantly (p < 0.05) lower mean serum albumin, net protein catabolic rate (nPCR), lean body mass calculated from creatinine kinetics, and daily creatinine production (and presumably lower muscle mass), and higher albumin clearances compared to one or more lower transport groups. In conclusion, we hypothesize that high transporters are prone to protein malnutrition related to increased dialysate protein losses, and perhaps suppression of appetite, with increased use of hypertonic exchanges. High transporters are candidates for protein supplementation on CAPD or transfer to nightly intermittent peritoneal dialysis where short cycles provide more ultrafiltration with less glucose absorption.

Creatinine↗
PubMedDate not supplied

Peritoneal transfer during maximal hyperosmotic ultrafiltration in the rat.

Peritoneal transfer parameters were estimated in rats (n = 24) while maximal net ultrafiltration rate (nUFR) was achieved with 15% dextrose dialysis solution (1,153 mOsm/kg) and compared with those obtained with 0.37% dextrose solution (301 mOsm/kg). Experiments were carried out with dialysis solutions of pH approximately 6.5 and approximately 7.6, respectively, for 15% dextrose dialysis solution and 0.37% dextrose solution. Increases in both convective and diffusive transfer resulted in more than 70% greater peritoneal clearances of urea, potassium, and phosphate with hyperosmotic solutions at both pH values. Protein removal was increased only with a hyperosmotic solution of pH approximately 6.5 compared with isosmotic conditions at the same pH. Results support the hypothesis that increased peritoneal transfer parameters under hyperosmotic conditions depend not only upon enhanced convection but also on factors promoting diffusive transfer.

Animals↗
PubMedDate not supplied

Why are reported relative mortality risks for CAPD and HD so variable? (inadequacies of the Cox proportional hazards model)

The relative risks of death for CAPD and HD reported in the literature and at recent meetings most likely reflect case-mix differences and varying percentages of adequately dialyzed patients within the compared populations. A prospective randomized comparison of CAPD and HD patients will be unlikely because of the expense. Therefore, we should attempt to improve the way that both CAPD and HD are practiced. There is no conclusive evidence that the choice of CAPD or HD per se yields a specific modality advantage for survival.

Humans↗
PubMedDate not supplied

Peritoneal dialysis update 1994.

Each year there are over 400 papers published in the field of peritoneal dialysis. In this review I have touched on only a few highlights of some of the more active areas of investigation and development. The advances in controlling peritonitis rates with the Y-set have been dramatic and have resulted in peritonitis rates in many centers less than one episode per 24 patient months. Technique survivals have also improved with lower peritonitis rates. The enormous literature on new approaches to treatment and new understandings of host defenses are beyond the scope of this review. There are also many advances in peritoneal access. We now have many new types of catheters under investigation such as the Swan-Neck Missouri catheter and the Moncrief-Popovich catheter, with complete burial of the catheter until eventual externalization for CAPD training. There have been major advances in understanding the normal healing of exit sites and the early diagnosis and treatment of exit-site infections. All the extensive literature on catheter development in the management of exit sites will be reviewed elsewhere. I have focused primarily on an update of worldwide demographics, some of the new findings in peritoneal transport, the use of low-calcium solutions, experiences with EPO, new thinking about adequacy and nutrition, and finally, on recent comparisons of CAPD and hemodialysis.

Humans↗
PubMedDate not supplied

Recommended clinical practices for maximizing peritoneal dialysis clearances.

Data from the Canada-U.S.A. (CANUSA) Study have recently confirmed a long-suspected linkage between total clearance and patient survival in peritoneal dialysis (PD). Recognizing that what we have historically accepted as adequate PD simply is not, the Ad Hoc Committee on Peritoneal Dialysis Adequacy met in January, 1996. This committee of invited experts was convened by Baxter Healthcare Corporation to prepare a consensus statement that provides clinical recommendations for achieving clearance guidelines for peritoneal dialysis. Through an analysis of 806 PD patients, the group concluded that adequate clearance delivered with PD can be achieved in almost all patients if the prescription is individualized according to the patient's body surface area, amount of residual renal function, and peritoneal membrane transport characteristics. Use of 2.5 L to 3.0 L fill volumes, the addition of an extra exchange, and giving automated peritoneal dialysis patients a "wet" day are all options to consider when increasing weekly creatinine clearance and KT/V. Rather than specify a single clearance or KT/V target, the recommended clinical practice is to provide the most dialysis that can be delivered to the individual patient, within the constraints of social and clinical circumstances, quality of life, life-style, and cost. The challenge to PD practitioners is to make prescription management an integral part of everyday patient management. This includes assessment of peritoneal membrane permeability, measurement of dialysis and residual renal clearance, and adjustment of the dialysis prescription when indicated.

Body Surface Area↗