Original Papers Nephron 15: 8-16 (1975)
Prognosis of Chronic Renal Failure III. Survival After One Peritoneal Dialysis1
J ohn F. M aher, D aniel J. A hearn, C edric W. Bryan and K arl D. N olph Division of Nephrology, Department of Medicine, University of Missouri Medical Center and Veterans Administration Hospital, Columbia, Mo.
Key Words. Peritoneal dialysis • Renal failure, prognosis • Creatinine • Reversible renal failure • Urine volume • Urinary tract infection ■Sodium depletion Abstract. Survival after serum creatinine exceeded 10.0 mg/100 ml was increased if one peritoneal dialysis was performed. After one peritoneal dialysis ‘survival’ of 62 patients to the present time, death or the next dialysis averaged 119 days; median survival was 28 days. Characteristics of prolonged survivors were persistent reduction of serum creatinine below the predialysis concentration, tubulointerstitial diseases, i.e. polycystic kidneys, pyelo nephritis or obstructive nephropathy, potentially reversible complications such as urinary tract infection or extracellular volume depletion, and high urine volume, and low blood pressure. Occasional patients with survival exceeding 2 years suggest the possibility of prolonged benefit after a single dialysis at least in those with characteristics favoring longer survival.
Often one peritoneal dialysis is used for patients with chronic renal failure, hoping for sustained benefit. Since lower plasma concentration after dialysis will decrease urinary excretion from residual nephrons, the improvement in azotemia should be brief unless there follows an increase in renal function. Such an increase could result from dialysis, e. g. toxin removal, but more often follows recognition and treatment of a reversible cause of renal failure or a reversible incidental complication, occurring preterminally. Since there has been no evaluation of factors affecting survival of patients with chronic renal failure after treatment by one peritoneal dialysis, this study was undertaken. The results show a variable, occasionally prolonged survival
Received: April 3, 1974; accepted: September 30, 1974.
Downloaded by: King's College London 137.73.144.138 - 1/16/2019 1:32:36 PM
1 Supported in part by University of Missouri Nephrology Research Fund.
M aher et at.
9
after one peritoneal dialysis. Survival was longer in patients with obstructive nephropathy, pyelonephritis or polycystic kidneys, and in those with recent infection, extracellular fluid volume depletion or higher urine volumes. Serum creatinine of most prolonged survivors did not return promptly to predialysis concentrations.
Between August 1, 1969 and June 30, 1972, 62 patients with chronic renal failure, diagnosed by criteria previously described underwent peritoneal dialysis [1]. Chronic renal failure was characterized by persistent azotemia, and usually renal atrophy and a known cause of chronic disease. Peritoneal dialysis was performed because of manifestations of uremia cither because maintenance dialysis had to be delayed or was unavailable, or in anti cipation of reversible uremia. Maintenance dialysis was started when uremia could not be controlled by other therapy. Serum creatinine concentration in each patient exceeded 10 mg/ 100 ml before peritoneal dialysis and never fell below 2.5 mg/100 ml during the period of observation. A comparison was made of the interval after serum creatinine was recognized to exceed 10 mg/100 ml and death between patients that underwent one peritoneal dialysis and 36 who were never treated by dialysis. Subsequent analyses are only of subgroups of peritoneal dialysis patients. The interval between starting peritoneal dialysis and death (26 patients) the present time (2) or the next dialysis (34) was measured for each patient. For simplicity this is called ‘survival’ but does not imply that initiation of maintenance dialysis is the temporal equiv alent of death. The median, mean and variance of survival was then calculated. Because of the variability in survival, further analyses were made seeking determinants of survival. Since the survival curves of subgroups were nonparametric, comparisons were made between curves, not between the means; subgroups are illustrated by the median (m). All peritoneal dialyses were technically satisfactory as reflected by at least a 50% decrease in serum urea nitrogen. The anticipated serum creatinine concentration at any given time after dialysis, was calculated by assuming that 12 h after dialysis, serum creatinine should be about 50% of the predialysis concentration. Urinary creatinine excretion during the first 24 h after dialysis would then be about 50% of the predialysis value leading to creatinine retention and an asymptotic increase in the serum concentration reaching 98% of the predialysis concentration within 7 days, assuming that creatinine production remains constant. Thereafter, the rate of increase in serum creatinine was assumed to equal our previously reported data for patients with chronic renal failure, a mean doubling time of 376 days [2], If serum creatinine remained below 80% of the predicted value, it was assumed that renal failure was partially reversible. Patients who ‘survived’ for 60 or more days after one peritoneal dialysis were compared to those who did not, with regard to the incidence of infection, extracellular volume depletion, rate of increase of serum creatinine concentration, congestive heart failure, persistent hematuria and cylindruria suggesting active glomerulonephritis, and accelerated hyperten sion.
Downloaded by: King's College London 137.73.144.138 - 1/16/2019 1:32:36 PM
Materials and Methods
10
M aher et at.
Using the Kolmogrov-Smimov test [3] survival was compared among groups sub divided by age, etiology of renal disease, blood pressure, predialysis serum creatinine con centration, urinary volume, 24 h urine sodium excretion (after salt loading with or without diuretics); and by the presence or absence of extracellular fluid volume depletion, urinary infection or congestive heart failure.
After serum creatinine exceeded 10 mg/100 ml the control group that did not undergo peritoneal dialysis had a shorter (p0.1) or those above and below age 40 (p >0.2). Figure 2 correlates median survival (days) after one peritoneal dialysis with the etiology of renal failure. Survival of patients with glomerulonephritis was shorter than that of the group with all other etiologies (p < 0.01). Other causes of renal failure were seen too infrequently to establish significant group dif ferences in survival. When patients with diabetes, amyloidosis, myeloma or
Downloaded by: King's College London 137.73.144.138 - 1/16/2019 1:32:36 PM
Results
Prognosis of Chronic Renal Failure
11
Fig. 1. Survival after a single peritoneal dialysis. Solid dots indicate survival and open circles indicate patients who underwent subsequent dialyses.
Table /. Chronic renal failure. Incidence of variables affecting prognosis Survival >60 days fit = 20) P
0.31 0.07 0.07 0.17 0.07 0.07 0.02
0.55 0.45 0.35 0.15 0.00 0.05 0.00
180/110 mm Hg]), survival was significantly longer only in the low blood pressure group (p < 0.05). Despite a tendency toward decreased survival as predialysis serum cre atinine concentration increased group differences were not significant. Survival of those with a predialysis serum creatinine concentration below 17 mg% was not longer than those with values above 24 mg% (p >0.2). Urinary volume was measured in 60 patients before dialysis. The mean of three daily volumes was determined if possible, otherwise the only available complete 24 h volumes were used. Higher volumes correlated with longer sur vival. Those with urine volumes below 500 ml/day (m = 8 days) had shorter survival than those with volumes above 500 ml/day (p
Prognosis of Chronic Renal Failure III. Survival After One Peritoneal Dialysis1
J ohn F. M aher, D aniel J. A hearn, C edric W. Bryan and K arl D. N olph Division of Nephrology, Department of Medicine, University of Missouri Medical Center and Veterans Administration Hospital, Columbia, Mo.
Key Words. Peritoneal dialysis • Renal failure, prognosis • Creatinine • Reversible renal failure • Urine volume • Urinary tract infection ■Sodium depletion Abstract. Survival after serum creatinine exceeded 10.0 mg/100 ml was increased if one peritoneal dialysis was performed. After one peritoneal dialysis ‘survival’ of 62 patients to the present time, death or the next dialysis averaged 119 days; median survival was 28 days. Characteristics of prolonged survivors were persistent reduction of serum creatinine below the predialysis concentration, tubulointerstitial diseases, i.e. polycystic kidneys, pyelo nephritis or obstructive nephropathy, potentially reversible complications such as urinary tract infection or extracellular volume depletion, and high urine volume, and low blood pressure. Occasional patients with survival exceeding 2 years suggest the possibility of prolonged benefit after a single dialysis at least in those with characteristics favoring longer survival.
Often one peritoneal dialysis is used for patients with chronic renal failure, hoping for sustained benefit. Since lower plasma concentration after dialysis will decrease urinary excretion from residual nephrons, the improvement in azotemia should be brief unless there follows an increase in renal function. Such an increase could result from dialysis, e. g. toxin removal, but more often follows recognition and treatment of a reversible cause of renal failure or a reversible incidental complication, occurring preterminally. Since there has been no evaluation of factors affecting survival of patients with chronic renal failure after treatment by one peritoneal dialysis, this study was undertaken. The results show a variable, occasionally prolonged survival
Received: April 3, 1974; accepted: September 30, 1974.
Downloaded by: King's College London 137.73.144.138 - 1/16/2019 1:32:36 PM
1 Supported in part by University of Missouri Nephrology Research Fund.
M aher et at.
9
after one peritoneal dialysis. Survival was longer in patients with obstructive nephropathy, pyelonephritis or polycystic kidneys, and in those with recent infection, extracellular fluid volume depletion or higher urine volumes. Serum creatinine of most prolonged survivors did not return promptly to predialysis concentrations.
Between August 1, 1969 and June 30, 1972, 62 patients with chronic renal failure, diagnosed by criteria previously described underwent peritoneal dialysis [1]. Chronic renal failure was characterized by persistent azotemia, and usually renal atrophy and a known cause of chronic disease. Peritoneal dialysis was performed because of manifestations of uremia cither because maintenance dialysis had to be delayed or was unavailable, or in anti cipation of reversible uremia. Maintenance dialysis was started when uremia could not be controlled by other therapy. Serum creatinine concentration in each patient exceeded 10 mg/ 100 ml before peritoneal dialysis and never fell below 2.5 mg/100 ml during the period of observation. A comparison was made of the interval after serum creatinine was recognized to exceed 10 mg/100 ml and death between patients that underwent one peritoneal dialysis and 36 who were never treated by dialysis. Subsequent analyses are only of subgroups of peritoneal dialysis patients. The interval between starting peritoneal dialysis and death (26 patients) the present time (2) or the next dialysis (34) was measured for each patient. For simplicity this is called ‘survival’ but does not imply that initiation of maintenance dialysis is the temporal equiv alent of death. The median, mean and variance of survival was then calculated. Because of the variability in survival, further analyses were made seeking determinants of survival. Since the survival curves of subgroups were nonparametric, comparisons were made between curves, not between the means; subgroups are illustrated by the median (m). All peritoneal dialyses were technically satisfactory as reflected by at least a 50% decrease in serum urea nitrogen. The anticipated serum creatinine concentration at any given time after dialysis, was calculated by assuming that 12 h after dialysis, serum creatinine should be about 50% of the predialysis concentration. Urinary creatinine excretion during the first 24 h after dialysis would then be about 50% of the predialysis value leading to creatinine retention and an asymptotic increase in the serum concentration reaching 98% of the predialysis concentration within 7 days, assuming that creatinine production remains constant. Thereafter, the rate of increase in serum creatinine was assumed to equal our previously reported data for patients with chronic renal failure, a mean doubling time of 376 days [2], If serum creatinine remained below 80% of the predicted value, it was assumed that renal failure was partially reversible. Patients who ‘survived’ for 60 or more days after one peritoneal dialysis were compared to those who did not, with regard to the incidence of infection, extracellular volume depletion, rate of increase of serum creatinine concentration, congestive heart failure, persistent hematuria and cylindruria suggesting active glomerulonephritis, and accelerated hyperten sion.
Downloaded by: King's College London 137.73.144.138 - 1/16/2019 1:32:36 PM
Materials and Methods
10
M aher et at.
Using the Kolmogrov-Smimov test [3] survival was compared among groups sub divided by age, etiology of renal disease, blood pressure, predialysis serum creatinine con centration, urinary volume, 24 h urine sodium excretion (after salt loading with or without diuretics); and by the presence or absence of extracellular fluid volume depletion, urinary infection or congestive heart failure.
After serum creatinine exceeded 10 mg/100 ml the control group that did not undergo peritoneal dialysis had a shorter (p0.1) or those above and below age 40 (p >0.2). Figure 2 correlates median survival (days) after one peritoneal dialysis with the etiology of renal failure. Survival of patients with glomerulonephritis was shorter than that of the group with all other etiologies (p < 0.01). Other causes of renal failure were seen too infrequently to establish significant group dif ferences in survival. When patients with diabetes, amyloidosis, myeloma or
Downloaded by: King's College London 137.73.144.138 - 1/16/2019 1:32:36 PM
Results
Prognosis of Chronic Renal Failure
11
Fig. 1. Survival after a single peritoneal dialysis. Solid dots indicate survival and open circles indicate patients who underwent subsequent dialyses.
Table /. Chronic renal failure. Incidence of variables affecting prognosis Survival >60 days fit = 20) P
0.31 0.07 0.07 0.17 0.07 0.07 0.02
0.55 0.45 0.35 0.15 0.00 0.05 0.00
180/110 mm Hg]), survival was significantly longer only in the low blood pressure group (p < 0.05). Despite a tendency toward decreased survival as predialysis serum cre atinine concentration increased group differences were not significant. Survival of those with a predialysis serum creatinine concentration below 17 mg% was not longer than those with values above 24 mg% (p >0.2). Urinary volume was measured in 60 patients before dialysis. The mean of three daily volumes was determined if possible, otherwise the only available complete 24 h volumes were used. Higher volumes correlated with longer sur vival. Those with urine volumes below 500 ml/day (m = 8 days) had shorter survival than those with volumes above 500 ml/day (p
