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Biomedical subjects

K D Nolph

Publications and source records attributed to K D Nolph.

At least 19 recordsLinked to original sources
PubMed1997

Hypokalemic metabolic alkalosis with hypomagnesuric hypermagnesemia and severe hypocalciuria: a new syndrome?

Bartter's and Gitelman's syndromes are characterized by hypokalemia, urinary potassium wasting, elevated plasma renin activity and aldosterone levels, normotension, and prostaglandinuria. They differ in that hypomagnesemia and hypocalciuria are universal in Gitelman's syndrome; 20% of cases of Bartter's syndrome have hypomagnesemia and hypercalciuria. We present a 44-year-old white man referred for hypokalemia. Clinical evaluation was unremarkable. He had hypokalemia (P(K), 2.8 to 3.0 mEq/L), hypochloremic metabolic alkalosis, mild azotemia (serum creatinine, 1.4 to 1.8 mg/dL; creatinine clearance, 59 mL/min), normocalcemia, marked persistent hypocalciuria (FE(Ca), 0.08% to 0.09%), and normal intact parathyroid hormone levels (51 pg/mL) and glucosuria. He had persistent hypermagnesemia (P(Mg), 2.1 to 2.8 mEq/L) with relative hypomagnesuria (FE(Mg), 3.2% to 5.2%) given the level of renal impairment and hypermagnesemia. Supine plasma renin activity and aldosterone levels were high (11 ng/mL/hr and 43 ng/dL, respectively). An excessive dietary intake of magnesium, including medications, was excluded. Studies were performed after withdrawing all medications for 8 days. A maximum water diuresis was established (an oral load of 20 mL/kg; stable Uosm, 120 mOsm/kg), and free water and solute clearances were studied at baseline and after sequential intravenous injections of 125 mg chlorothiazide and 40 mg furosemide. The patient had moderate renal impairment (technetium diethylene triamine pentacetic acid [DTPA] clearance, 35.4 mL/min/1.73 m2) and, in contradistinction to Bartter's and Gitelman's syndromes, sodium and water handling in the thick ascending limb of the loop of Henle and the distal tubule (fractional distal solute reabsorption) was normal, but there was evidence of a defect in the proximal tubule reabsorption (glucosuria, supranormal C(H2O) and high distal delivery). Hypomagnesuria and hypocalciuria appeared to be secondary to an increase in their absorption in the loop of Henle (increased excretion following furosemide). In conclusion, this combination of metabolic abnormalities has never been described. We postulate a proximal tubular defect in the absorption of NaCl leading to hypocalciuria, hypomagnesuria, and potassium wasting. Whether the tubular defect is primary or secondary to a renal parenchymal disease is, however, unclear.

Acute Disease↗
PubMed1996

Four-year experience with swan neck presternal peritoneal dialysis catheter.

The swan neck presternal catheter is composed of two flexible (silicon rubber) tubes joined by a titanium connector at the time of implantation. The exit site is located in the presternal or parasternal area. The catheter located on the chest was designed to reduce the incidence of exit site infections compared with peritoneal dialysis catheters with abdominal exit sites. From August 1991 to May 1995, 24 swan neck presternal catheters have been implanted in 24 patients for the following reasons: obesity nine patients, ostomies three patients, a suprapubic catheter one patient, previous problems with abdominal catheters two patients, desire to use a bathtub five patients, need to use a whirlpool one patient, need to wear sweatpants with an elastic waistband one patient, and body image two patients. In the same period, 47 abdominal swan neck catheters were implanted in 44 patients who preferred catheters with the exit on the abdomen. Presternal catheters tended to perform better regarding exit and tunnel infections, even though they were implanted in several patients in whom regular catheters with the exit on the abdomen would be difficult or impossible to implant. Two-year survival probability of presternal catheters was 0.88 +/- 0.14 (+/- SE). Recurrent/refractory peritonitis was the only reason of catheter failure. The differences in results between presternal and abdominal catheters were statistically insignificant; only the use of antibiotics to treat exit site infection was significantly higher with abdominal catheters. Patient acceptance of the exit position was good; at least seven patients preferred presternal catheter for psychological or body image reasons. We conclude that the swan neck presternal catheters provide excellent results comparable to those achieved with swan neck abdominal catheters. The catheter seems suitable for any patient commencing peritoneal dialysis and is particularly useful in extremely obese patients (body mass index > 40 kg/m2) and those with ostomies. The catheter exit location in the chest may be preferred by some patients, both men and women, for psychological or body image reasons. No specific contraindications to the presternal catheter implantation have been identified.

Abdomen↗
PubMed1996

Effects of bicarbonate dialysis solution on peritoneal transport in rats.

We studied the effects of bicarbonate dialysis solution (TB 1.36) on the peritoneum in our rat model of dialysis. Twenty-four male Sprague-Dawley rats were divided into two groups (n = 12 each). One group was dialyzed with standard 1.36% Dianeal PD-2 (L-group); the other group was dialyzed with TB 1.36 (B-group). After break-in dialysis after catheter insertion, the animals were dialyzed twice daily with 30 mL of the designated dialysis solution for four weeks. White blood cell count with differentials and microbiological culture of the dialysate were examined once a week to detect peritonitis. A peritoneal equilibration test (PET) was performed on the eighth and thirty-sixth days. The dialysate was obtained at 0, 2, and 4 hours; a blood sample was taken at 0 hour. Peritoneal tissue specimens were obtained after the second PET. Histological score was calculated based on the degree of thickening of the peritoneum. Five rats in L-group and three rats in B-group suffered from peritonitis. Two other rats in B-group had complications and did not complete the experiment. Therefore, seven rats from each group finished the experiment, and the PET data was analyzed. The peritoneal transport property of B-group did not change over time, while, in L-group it became less permeable on the thirty-sixth day. Fibrotic thickening of the peritoneum was observed in both groups, however, the histological score was slightly lower in B-group. These results suggest that the bicarbonate dialysis solution may be less harmful to the peritoneum.

Animals↗
PubMed1996

The effect of peritonitis on the peritoneal membrane transport properties in patients on CAPD.

Peritonitis is known to acutely affect the transport characteristics of the peritoneal membrane, however, the long-term effects are not known. We studied the effect of peritoneal inflammation on mean dialysate-to-plasma creatinine concentration ratio (D/P), dialysate protein losses (DPL, g/week), and dialysate albumin losses (DAL, g/week), done at six weeks or more postepisode, in 152 patients [102 (67%) males, mean age 57 years (range 21-91)]. These patients were on continuous ambulatory peritoneal dialysis for a mean of twelve months (range 1-97). A total of 94 distinct peritonitis episodes were managed in 47 patients (31%). The number of patients with 0, 1, 2, 3, 4, and 5 episodes of peritonitis were 105, 29, 3, 6, 4, and 5. These episodes were treated with a standard protocol. There were no statistically significant differences between the D/P, DPL, or DAL between the groups. The parameters did not show any correlation to time on dialysis. Thus, in conclusion, peritonitis, if promptly treated, does not cause any permanent change in D/P, DAL, or DPL.

Adult↗
PubMed1996

Protein catabolic rate in CAPD patients: comparison of different techniques.

Protein intakes of patients on continuous ambulatory peritoneal dialysis (CAPD) are estimated by protein catabolic rate (PCR) or dietary protein intake assessments (DPI). In this study we compared two approaches suggested by Randerson et al. for calculating PCR. One method incorporates urea generation rate (UG) and estimated dialysate protein losses (PCR), while the other includes UG and measured dialysate protein losses (PCR). We feel that calculating PCR2 is more convenient in practice. We studied 95 patients on CAPD, 49 men and 46 women, with a mean age of 56.5 years (range 26.6-84.5 years) and lean body mass of 41 kg (range 19-71 kg). Mean +/- SEM of PCR1, PCR2, and DPI were: 0.89 +/- 0.02, 0.86 +/- 0.02, and 0.90 +/- 0.04 g/kg standard weight (std wt)/day, respectively. PCR1 and PCR2 were highly and significantly correlated (r = 0.94, p = 0.0001). The difference of PCR1-PCR2 is plotted against dialysate protein loss, which reveals that PCR2 often underestimates PCR1 if dialysate protein loss is > 10 g/day, but this difference is minimum (< 0.1 g/kg standard weight/day) when the dialysate protein loss is < 15 g/day. We conclude that PCR2 is an easy and effective method to monitor nutritional status in the majority of CAPD patients as very few will have dialysate protein losses > 15 g/day.

Adult↗
PubMed1995

A proposed glossary for dialysis kinetics.

Quantification of the dialysis dose and assessment of nutritional status and response to nutritional therapy have become standard parts of the management of the chronic dialysis patient. Although advances in these areas have led to a more rational basis for therapy, certain misconceptions and points of confusion appear to have occurred. Recognizing the importance of a standard nomenclature to the development of concepts and the communication of research findings, we have attempted to compile a list of terms that are commonly used in the field of dialysis. New terms have been proposed for current ones that do not seem adequate. In addition, we have discussed potential methodologies for obtaining more accurate data for dialysis kinetics and for precise monitoring of nutritional intake and status. It is hoped that this glossary will stimulate discussion that will lead to refinements in terminology and concepts that will, in turn, improve research and practice in nephrology. It is anticipated that many of these definitions and recommendations will be modified or superseded as the management of patients with renal failure continues to advance.

Adolescent↗
PubMed1995

Expected white blood cell counts and differentials in a rat model of peritoneal dialysis.

OBJECTIVE: The purpose of this study was to establish baseline dialysate white blood cell (WBC) counts and differentials in noninfected rats on peritoneal dialysis (PD). DESIGN: Sixteen male Sprague-Dawley rats underwent PD in the first protocol, and eight from the 16 continued PD in the second through fourth protocols. At the beginning of the experiments, all animals had a PD catheter implanted and were initiated on PD with 1.5% dextrose dialysis solution twice daily. In the first protocol, WBC counts and differentials were assessed from day 4 to day 15 of dialysis in noninfected animals to establish "normal values" for such a rat model. In protocol 2, WBC counts and solute concentrations in small aliquots of dialysate obtained from the catheter were compared to values in well-mixed total drainage. Protocol 3 was designed to assess effects of dwell time on WBC counts. Protocol 4 examined the effect of glucose concentration of dialysis solution on WBC counts. RESULTS: In the first protocol, the mean dialysate WBC counts were significantly higher on the fourth day of dialysis, but stabilized below 2500 cells/mm3 by the eighth day. The percentage of neutrophils was stable around 20%-25%. In the second protocol, we found aliquots < 1 mL might underestimate the dialysate WBC count compared to the complete drainage. In the third protocol, WBC counts increased as cycle time became longer, but the percentage of neutrophils remained below 50%. In the fourth protocol, we did not find any effects of glucose concentration of instilled solutions on WBC counts and differentials. CONCLUSION: This study of WBC counts and differentials in noninfected rats on peritoneal dialysis establishes the range above which infection should be suspected. WBC counts increase with cycle time. Small dialysate aliquots may underestimate WBC counts. Glucose concentration does not effect WBC counts.

Animals↗
PubMed1995

Predicted and measured daily creatinine production in CAPD: identifying noncompliance.

OBJECTIVE: To evaluate the ratio of measured creatinine (Cr) production to predicted creatinine production as an index of noncompliance in patients on continuous ambulatory peritoneal dialysis (CAPD). DESIGN: A cross-sectional analysis. PATIENTS: One hundred and twenty-one patients on CAPD. MEASUREMENTS: We have calculated Cr production from measured Cr outputs in 24-hour collections of urine and dialysate. Predicted Cr productions were calculated from standard tables. Weekly KT/V urea and weekly Cr clearances were determined from the same 24-hour urine and dialysate collections. Lean body mass (LBM) was calculated from the Cr production. Serum albumin concentration was measured. RESULTS: The ratio of measured/predicted Cr production correlated positively and significantly with weekly KT/V urea, the protein equivalent of nitrogen appearance (PNA), weekly Cr clearance, and LBM. There was a decline in serum albumin concentration at ratios greater than 1.24, supporting the opinions of previous authors who have suggested that ratios greater than 1.24 are highly suggestive of noncompliance with the dialysis prescription. Defining noncompliance as a ratio greater than 1.24 implied that at least 5% of the female and 17% of the male patients were noncompliant. CONCLUSIONS: Declining serum albumin concentrations at higher ratios of measured/predicted Cr production support the opinion that this is an index of noncompliance. However, not all noncompliant patients necessarily have a ratio greater than 1.24. Weekly KT/V urea, weekly Ccr and LBM are all artifactually increased by "washout effects" if all exchanges are done only or mainly on the collection day.

Body Mass Index↗
PubMed1995

Continuous ambulatory peritoneal dialysis and the heart.

OBJECTIVE: To review clinical research pertaining to continuous ambulatory peritoneal dialysis (CAPD) and the heart. DATA SOURCES: A Medline computer search was employed to identify appropriate references from 1970 - 1994. Indexing terms were: continuous ambulatory peritoneal dialysis, hemodialysis, heart or cardiac, left ventricle, coronary artery disease, and survival. English and non-English language abstracts were scrutinized. STUDY SELECTION: Forty-six studies were reviewed and utilized. Numerical data extracted are reported in this review as they were reported in the original article. RESULTS: This review provides a broad-based survey of studies pertaining to CAPD and the heart. Most of the studies relate to CAPD and left ventricular structure or function. Little information exists concerning CAPD and coronary artery disease, valvular disease, pericardial disease, and cardiac arrhythmias. Studies pertaining to patient survival on CAPD identify coronary artery disease and congestive heart failure as major risk factors, but in-depth quantification of these cardiovascular disorders is lacking in the literature. CONCLUSIONS: CAPD is capable of decreasing left ventricular (LV) volume and improving LV systolic function in patients with LV enlargement and those with LV systolic dysfunction. The effect of CAPD on left ventricular hypertrophy (LVH) and LV diastolic function is variable. CAPD produces symptomatic improvement in patients with refractory congestive heart failure, but its effect on survival in such patients is uncertain. Atherogenic lipid abnormalities occur in CAPD patients. The clinical significance of these abnormalities is uncertain. Coronary artery bypass surgery can be performed safely and effectively on CAPD patients. CAPD is not arrhythmogenic. Survival of CAPD patients is similar to that of hemodialysis patients except in elderly diabetics for whom it is slightly lower.

Arrhythmias, Cardiac↗
PubMed1995

Modification of creatinine clearance by estimation of residual urinary creatinine and urea clearance in CAPD patients.

The use of creatinine clearance for adequacy of continuous ambulatory peritoneal dialysis (CAPD) requires consideration of the fact that a significant fraction of residual renal creatinine clearance is contributed by tubular secretion. We analyzed 123 peritoneal dialysis (PD) patients and corrected the residual renal creatinine clearance by averaging renal creatinine and urea clearance to estimate the glomerular filtration rate (GFR). Modified total creatinine clearance (peritoneal plus estimated renal GFR) was compared with total creatinine clearance (peritoneal plus total renal creatinine clearance). Modified and total creatinine clearances were not significantly different in patients with a total creatinine clearance less than 60 L/week/1.73 m2 body surface area (BSA), but a significantly lower modified total creatinine clearance was seen with patients having greater than 60 L/week/1.73 m2 BSA of total creatinine clearance. The correlation was better between KT/V and modified total creatinine clearance (r = 0.74) as compared to KT/V and total creatinine clearance (r = 0.67). We suggest that if creatinine clearance is used for peritoneal dialysis (PD) adequacy, the contribution of residual renal function should be calculated as the average of renal creatinine and urea clearance, thus estimating creatinine clearance only by the GFR. Further long-term studies are needed to confirm that modification of total creatinine clearance will better predict clinical outcome.

Creatinine↗
PubMed1995

Rat model of peritoneal fibrosis: preliminary observations.

The aim of this study was to establish a rat model of peritoneal fibrosis. After insertion of peritoneal catheters into 18 rats, the rats were divided into three groups. All animals were dialyzed twice a day with 4.25% Dianeal containing heparin. Group 1 rats (control) received antibiotics (vancomycin and gentamicin) in each exchange: group 2 rats were inoculated with Escherichia coli (5 x 10(6) in 5 mL of saline) at the beginning of the study; group 3 rats were treated with antibiotics after Escherichia coli inoculation; they also received a second inoculation of Escherichia coli after the second week of the study. By the end of the second week, group 2 rats were sacrificed because of catheter problems. Group 1 and 3 rats were sacrificed after 4 weeks of dialysis. A weekly peritoneal equilibration test (PET) was performed in each rat. The comparison of the PET results from the beginning and end of the study showed an increased permeability to glucose (p < 0.05) and total protein (p < 0.05) in group 3, which was not noted in group 1. In histology samples there was only delicate fibrosis with cellular infiltration in the peritoneum in group 1 rats. These changes were much more prominent in group 3 rats. This study suggests that E. coli peritonitis causes peritoneal fibrosis in rats, but to have a sclerosing encapsulating peritonitis (SEP) model this experiment must be carried out for a longer time.

Animals↗
PubMed1995

Spontaneous peritonitis and peritoneal fibrosis in rats on peritoneal dialysis for 9 weeks.

To investigate characteristics of peritonitis in rats on peritoneal dialysis (PD), we retrospectively studied 36 cases of peritonitis in 23 rats. After breakin dialysis postcatheter insertion, the animals were dialyzed twice daily with 1.5% or 4.25% Dianeal for 8 weeks. White blood cell (WBC) count with differentials and microbiological culture of the dialysate were examined twice weekly. Peritonitis was treated with cefazolin and tobramycin until the tenth day after the dialysate became clear. The peritoneal equilibration test (PET) was performed at weeks 2, 6, and 10. The dialysate was obtained at 0, 2, and 4 hours for glucose assay. The peritoneal cavity was inspected, and peritoneal tissue specimens were taken. There were 10 single episodes of peritonitis, 7 recurrences, and 6 reinfections. The organisms isolated were Staphylococcus aureus in 24 cases of peritonitis and Escherichia coli in 6 cases of peritonitis. The average treatment period was 16 days. The glucose absorption ratio became higher over time in single episodes of peritonitis, but was unchanged in recurrences and reinfections. Sixteen adhesions, 1 abscess, and 12 sclerotic retractions of the mesentery were observed. Fibrotic thickening of the peritoneum was found histologically in all animals. In spontaneous peritonitis in rats, we often found complicated clinical courses, catheter closure, intraperitoneal adhesion, and fibrotic thickening of the peritoneum.

Animals↗
PubMed1995

Absorption of iron dextran from the peritoneal cavity of rats.

We investigated the absorption rate and acute toxicities of intraperitoneal iron dextran in rats. Eighteen Sprague-Dawley rats were divided into three groups (n = 6). The animals were given standard 1.5% Dianeal (group 1) or 1.5% Dianeal containing iron in a concentration of 2 mg/L (group 2) or 10 mg/L (group 3) as iron dextran. First, a predialysis blood sample was obtained, and 25 mL of the designated dialysis solution was instilled into the peritoneal cavity. After a 6-hour cycle the dialysate was drained, and a postdialysis blood sample and specimen of the peritoneum were obtained. The iron concentrations of the dialysis solution, the dialysate, and both serum samples were determined. Histological samples were processed by hematoxylin and eosin and Prussian blue stain. Results of the iron concentration (mg/L) of the dialysis solution, the dialysate, and the percent of the absorbed iron were as follows: group 1: 0.00, 0.20 +/- 0.15, N/A; group 2: 2.24, 0.66 +/- 2.8, 73.8 +/- 11.0; group 3: 9.84, 2.12 +/- 0.62, 80.8 +/- 5.7. The serum iron concentration did not change. No abnormal findings were found histologically. More than 70% of the iron dextran was absorbed from the peritoneal cavity of the rats during a 6-hour peritoneal dialysis exchange. Intraperitoneal iron dextran may be an alternative route of iron delivery.

Absorption↗
PubMed1994

Idiopathic focal segmental glomerulosclerosis in a patient with systemic lupus erythematosus: an unusual combination.

Renal involvement is a major cause of morbidity in patients with systemic lupus erythematosus (SLE). Histologic examination of renal tissue using light microscopy, immunofluorescent staining, and electron microscopy permit identification of glomerular immune complex deposits in virtually all patients with SLE. We report a patient who fulfilled four American College of Rheumatology criteria for the classification of SLE whose clinical course was consistent with SLE, yet whose renal failure resulted from focal glomerulosclerosis that was not mediated by immune complexes. The characteristics of this case of focal glomerulosclerosis that differentiate it from healed focal proliferative glomerulonephritis are discussed.

Biopsy↗