Serum and urinary insulin-like growth factor-1 and tumor necrosis factor in neonates with and without acute renal failure

Acute renal failure (ARF) in neonates may occur after renal ischemia. Growth factors participate in the tubular regeneration process. Insulin-like growth factor-1 (IGF-1) is produced in the kidney during the recovery phase of ARF. Tumor necrosis factor-alpha (TNFα) may play a role in renal apoptosis. We examined serum and urinary IGF-1 and TNFα in neonates with or without ARF after asphyxia, in order to assess their possible use as markers of renal damage and recovery. We studied 20 full-term asphyxiated neonates, 10 with ARF and 10 without ARF, and compared them with 13 normal newborns for 7 days after birth. Blood urea, creatinine, pH, base deficit, and serum and urine IGF-1 and TNFα were assessed. Neonates with ARF had more-severe acidosis than patients without ARF. All patients had lower serum IGF-1 values immediately after birth than control children. Serum IGF-1 remained low in the ARF patients. The initial urinary IGF-1 was higher in all patients compared with control newborns, and remained elevated for the rest of the study only in the ARF neonates. Serum and urinary TNFα concentrations were similar for all healthy and diseased neonates. Measurement of serum and urinary IGF-1 levels in ARF neonates might be of additional value for clinical assessment of ARF. Received: 31 January 2001 / Revised: 30 October 2001 / Accepted: 7 January 2002     

Acute renal failure in the neonatal period

Acute renal failure (ARF) is a common problem in the neonatal intensive care unit (NICU). In most cases, ARF is associated with a primary condition such as sepsis, metabolic diseases, perinatal asphyxia and/or prematurity. This retrospective study investigated the course of illness, therapeutic interventions, early prognosis and risk factors associated with development of ARF in the neonatal period. A total of 1311 neonates were treated in our NICU during the 42-month study period, and 45 of these babies had ARF. This condition was defined as serum creatinine level above 1.5 mg/dL despite normal maternal renal function. The data collected for each ARF case were contributing condition, cause and clinical course of ARF, gestational age and birth weight, age at the time of diagnosis, treatment, presence of perinatal risk factors and need for mechanical ventilation. The frequency of ARF in the NICU during the study period was 3.4%. Premature newborns constituted 31.1% of the cases. The mean birth weight in the group was 2863 +/- 1082 g, and the mean age at diagnosis was 6.2 +/- 7.4 days. The causes of ARF were categorized as prerenal in 29 patients (64.4%), renal in 14 patients (31.1%) and postrenal in 2 patients (4.4%). Forty-seven percent of the cases were nonoliguric ARF. Asphyxia was the most common condition that contributed to ARF (40.0%), followed by sepsis/metabolic disease (22.2%) and feeding problems (17.8%). Therapeutic interventions were supportive in 77.8% of the cases, and dialysis was required in the other 22.2%. The mortality rate in the 45 ARF cases was 24.4%. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were associated with significantly increased mortality (p<0.05). There were no statistical correlations between mortality rate and perinatal risk factors, oliguria, prematurity or blood urea nitrogen and creatinine levels. The study showed that, at our institution, ARF in the neonatal period is frequently associated with preventable conditions, specifically asphyxia, sepsis and feeding problems. Supportive therapy is effective in most cases of neonatal ARF. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were identified as indicators of poor prognosis in these infants. Early recognition of risk factors and rapid effective treatment of contributing conditions will reduce mortality in neonatal ARF.     

Acute Renal Failure in the Neonatal Period

Acute renal failure (ARF) is a common problem in the neonatal intensive care unit (NICU). In most cases, ARF is associated with a primary condition such as sepsis, metabolic diseases, perinatal asphyxia and/or prematurity. This retrospective study investigated the course of illness, therapeutic interventions, early prognosis and risk factors associated with development of ARF in the neonatal period. A total of 1311 neonates were treated in our NICU during the 42‐month study period, and 45 of these babies had ARF. This condition was defined as serum creatinine level above 1.5 mg/dL despite normal maternal renal function. The data collected for each ARF case were contributing condition, cause and clinical course of ARF, gestational age and birth weight, age at the time of diagnosis, treatment, presence of perinatal risk factors and need for mechanical ventilation. The frequency of ARF in the NICU during the study period was 3.4%. Premature newborns constituted 31.1% of the cases. The mean birth weight in the group was 2863 ± 1082 g, and the mean age at diagnosis was 6.2 ± 7.4 days. The causes of ARF were categorized as prerenal in 29 patients (64.4%), renal in 14 patients (31.1%) and postrenal in 2 patients (4.4%). Forty‐seven percent of the cases were nonoliguric ARF. Asphyxia was the most common condition that contributed to ARF (40.0%), followed by sepsis/metabolic disease (22.2%) and feeding problems (17.8%). Therapeutic interventions were supportive in 77.8% of the cases, and dialysis was required in the other 22.2%. The mortality rate in the 45 ARF cases was 24.4%. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were associated with significantly increased mortality (p < 0.05). There were no statistical correlations between mortality rate and perinatal risk factors, oliguria, prematurity or blood urea nitrogen and creatinine levels. The study showed that, at our institution, ARF in the neonatal period is frequently associated with preventable conditions, specifically asphyxia, sepsis and feeding problems. Supportive therapy is effective in most cases of neonatal ARF. Acute renal failure of renal origin, need for dialysis, and need for mechanical ventilation were identified as indicators of poor prognosis in these infants. Early recognition of risk factors and rapid effective treatment of contributing conditions will reduce mortality in neonatal ARF.     

Nonoliguric and oliguric acute renal failure in asphyxiated term neonates

The purpose of this study was to determine the prevalence and types of acute renal failure in asphyxiated full-term neonates and to evaluate the accuracy of an asphyxia morbidity score in predicting acute renal failure. Neonates admitted to one institution from 1990 through 1993 with a gestational age 36 weeks and 5-min Apgar score 6, without congenital malformations or sepsis, were studied retrospectively for acute renal failure in the 1st week of life. Acute renal failure was defined as serum creatinine >1.5 mg/dl (133 mol/l) with normal maternal renal function. Nonoliguric renal failure was defined as renal failure with urine output >1 ml/kg per hour after the 1st day. An asphyxia morbidity scoring system was used to distinguish severe from moderate asphyxia. The score ranged from 0 to 9 and was based upon fetal heart rate, Apgar score at 5 min, and base deficit in the 1st h of life. The score for severe asphyxia was defined as 6–9 and for moderate asphyxia as 1–5. Sixty-six neonates fulfilled study criteria. Acute renal failure was present in 20 of 33 (61%) infants with severe asphyxia scores and 0 of 33 with moderate asphyxia scores (P<0.0001). Acute renal failure was nonoliguric in 12 of 20 (60%), oliguric in 5 of 20 (25%) and anuric in 3 of 20 (15%). In conclusion 1) acute renal failure occurred in 61% of infants with severe asphyxia, 2) acute renal failure associated with severe asphyxia was predominantly nonoliguric and 3) an asphyxia morbidity score, which can be determined at 1 h of age, predicted acute renal failure in full-term infants with 100% sensitivity and 72% specificity.     

Exercise-induced acute renal failure with renal hypouricemia: a case report and a review of the literature

A previously healthy 16-year-old boy developed acute renal failure following a track race at a local athletic meeting. Several hours after the run, he expressed pain in the loins with nausea and vomiting. After 3 sessions of hemodialysis, he was referred to our hospital. On admission, serum creatinine was elevated to 2.3 mg/dl without an increase in serum uric acid level. After recovery from acute renal failure (ARF), hypouricemia (0.7 mg/dl) became evident in the patient. One year later, he suffered from ARF after a track race with the highest creatinine levels of 1.1 mg/dl. In order to clarify the cause and prognosis of ARF with renal hypouricemia, we summarized the clinical features in 18 patients previously described and our patient. Serum uric acid levels after recovery from ARF were below 1.0 mg/dl in all patients. Renal biopsy in 9 patients showed acute tubular necrosis in 8 patients and uric acid nephropathy in 1. The short-term prognosis of these patients seemed good, although 5 patients needed to undergo hemodialysis in their ARF courses. However, the recurrence of ARF episodes occurred in 6 patients (31.6%) including our patient, indicating that prevention of ARF might be necessary in these patients. More information is required to establish guidance for prevention of ARF.     

Rhabdomyolysis: clinical analysis of 20 patients

Twenty patients with rhabdomyolysis with and without acute renal failure (ARF) were studied. The patients consisted of 9 males and 11 females with a mean age of 64.5 +/- 3.2 years. Infection, compression and metabolic derangement were implicated as the most common etiologic factors. While 7 patients developed ARF during hospitalization, renal functions were normal in the remaining 13. While the mean ages, serum ARF, significant increases in potassium, phosphate, blood urea nitrogen, creatinine and uric acid were observed. While the mean blood pressure was similar, significant increases in hematocrit and total protein were observed in the patients with ARF. The detailed results indicated that infection, compression and metabolic derangement were the most common etiology factors of rhabdomyolysis, and plasma volume contraction might be responsible for the development of ARF.     

Prophylactic theophylline to prevent renal dysfunction in newborns exposed to perinatal asphyxia—a study in a developing country

Renal damage frequently complicates perinatal asphyxia. Renal vasoconstriction due to adenosine metabolite leads to a fall in glomerular filtration rate (GFR) and filtration fraction. This might be inhibited by the nonspecific adenosine receptor antagonist, theophylline. This study was designed to determine whether theophylline could prevent and/or ameliorate renal dysfunction in term neonates with perinatal asphyxia. We randomized 40 severely asphyxiated term infants to receive intravenously a single dose of either theophylline (5 mg/kg; study group: n=20) or placebo (control group: n=20) during the first hour of life. Fluid intake, urine output, serum creatinine, creatinine clearance, GFR, urinary 2 microglobulin (2 M) and sodium excretion were recorded during the first 5 days of life. The two groups were comparable. No significant difference was reported regarding mechanical ventilatory support, respiratory complications and seizures. Severe renal dysfunction was significantly higher in the control group. Serum creatinine values were less, and creatinine clearance and GFR were significantly higher in the theophylline group from the second day onwards. 2 M excretion was significantly less in the theophylline group, while sodium excretion and hematuria showed no significant difference. Prophylactic theophylline treatment, given early after birth, has beneficial effects in reducing the renal involvement in asphyxiated full-term infants, with no significant changes in central nervous system involvement.     

Purine enzyme defects as a cause of acute renal failure in childhood

Acute renal failure (ARF) is not listed as a usual form of presentation in hypoxanthineguanine phosphoribosyltransferase deficiency, despite the gross uric acid overproduction in the defect. We found that a third of such patients may present in ARF when the urinary uric acid/creatinine ratio may be normal, not raised, and the defect may be suspected from the disproportionate increase in plasma uric acid. This is important in view of the potential confusion of uric acid with 2,8-dihydroxyadenine, the even more insoluble purine excreted in the other salvage enzyme disorder, adenine phosphoribosyltransferase deficiency. In that disorder, presentation in ARF is well recognised, the uric acid/creatinine ratio is also normal, but plasma urate is not raised. Our combined experience in these two disorders underlines the importance of early recognition and treatment with carefully adjusted doses of allopurinol, which may reverse or postpone renal failure.     

Azotaemia in severe head injury — central dysregulation or renal failure?

Summary We have investigated serum urea, uric acid, and creatinin crealinine levels in 39 patients with craniocerebral trauma. The most impressive observation was a change in serum urea, which was found significantly increased up to 237 mg% on the seventh day (mean value) after severe injury, and turned out to be of great prognostic value. Patients with a serum urea above 100 mg% did not survive the acute stage. Uric acid and creatinine were only significantly increased in patients with lethal outcomes, the first beingelevated by about 300% in the first week, the second remaining normal for four days and increasing thereafter. It is concluded from these first data that a hypercatabolic state due to shock, central dysregulation, or both, is responsible for the dissociated behaviour of urea, uric acid and creatinine during the first four days, after which renal failure as a secondary change is shown by the rise in serum creatinine.     

Decreased fractional excretion of urate as an indicator of prerenal azotemia

Although the fractional excretion of uric acid (FEUA) is known to reflect extracellular fluid volume changes, the diagnostic significance of decreased FEUA in dehydration has not been previously reported. We studied the possible association between low FEUA and acute prerenal azotemia, and its diagnostic value, compared with other traditional indices, in discriminating prerenal azotemia from renal parenchymal causes of acute renal failure. In 65 chronic renal disease patients, 174 FEUA measurements were obtained from 24-hour urine collections. FEUA levels increased as reciprocal serum creatinine levels decreased. All 8 patients with prerenal azotemia showed significantly decreased FEUA values compared with chronic renal disease patients with a comparable degree of serum creatinine elevation, whereas all 7 patients with acute renal failure had FEUA values higher than those of chronic renal disease patients with comparable creatinine levels. FEUA values in prerenal azotemia were distinctly lower than those in acute renal failure (p less than 0.001). Patients with prerenal azotemia showed a lower fractional excretion of sodium, a lower fractional excretion of chloride and renal failure index, and a higher urine-to-plasma creatinine ratio than those with acute renal failure (p less than 0.05). However, these traditional indices were not useful in discriminating between the two conditions. The urine-to-plasma urea nitrogen ratio and the ratio of plasma urea nitrogen to creatinine showed no statistical difference between prerenal azotemia and acute renal failure. We conclude that, in acute azotemia, a decreased FEUA value may represent a reliable indicator of prerenal azotemia in the differential diagnosis of acute renal failure.     

Partial deficit of hypoxanthine guanine phosphoribosyl transferase presenting as acute renal failure

A 12-year-old boy presented with acute renal failure (ARF) accompanied by a disproportionate increase of serum uric acid level and massive uric acid crystalluria. After alkalinization and allopurinol therapy, serum uric acid and renal function returned to normal values. A further enzymatic study showed the existence of a partial hypoxanthine-guanine phosphoribosyl transferase (HPRT) deficit (less than 1% of HPRT normal activity). Although ARF is an exceptional form of presentation of HPRT deficiency, this possibility should be considered whenever an ARF is accompanied by disproportionate high levels of serum uric acid.     

Exercise-induced acute renal failure associated with renal hypouricaemia: results of a questionnaire-based survey in Japan.

BACKGROUND: A retrospective investigation was conducted to define the clinical features of exercise-induced acute renal failure (ARF) associated with renal hypouricaemia with the aim of clarifying further the clinical features of the disease entity. METHODS: A questionnaire was mailed to 43 institutions in Japan that had experienced case(s) of exercise-induced ARF associated with renal hypouricaemia. Fifty-four patients (48 males and six females) were identified from 38 institutions. RESULTS: Median age at the first episode of ARF was 17 years (range 11-46). The maximal serum uric acid and creatinine levels were 4.40+/-2.49 (range 0.4-13.3) and 5.45+/-3.33 mg/dl (range 1.10-17.7), respectively. The serum uric acid level after recovery was 0.70+/-0.25 mg/dl (range 0.1-1.4). The short-term prognosis seemed to be good and histological findings in 28 patients showed minimal change or acute tubular necrosis except for one patient with chronic lesions. ARF episodes occurred predominantly in September, October and May, mostly after strenuous exercise such as a short-distance race. The first symptoms were nausea/vomiting in 51 episodes, loin pain in 35, abdominal pain in 22, general fatigue in 16 and low-grade fever in seven. Thirteen patients (24.1%) experienced recurrent ARF at various intervals. Univariate and multivariate analyses failed to demonstrate any risk factor of ARF recurrence, although no female patients experienced ARF recurrence. CONCLUSIONS: The reason for the heterogeneity in ARF associated with renal hypouricaemia remains unknown. Further studies, especially on molecular mechanisms, are required to establish the best guidance against ARF recurrence.     

Acute renal failure after exercise in a child with renal hypouricaemia

We describe a 12-year-old boy with renal hypouricaemia who presented with acute renal failure after a 6-h sports training session. Back and loin pain were noted at presentation. Although serum creatinine and blood urea nitrogen were elevated, the serum uric acid concentration was normal (2.6 mg/dl). This decreased to 0.3 mg/dl after recovery. The pyrazinamide and probenecid tests revealed that the cause of renal hypouricaemia in this patient was totally defective uric acid reabsorption. Acute renal failure after exercise is a rare but serious complication in paediatric patients with renal hypouricaemia.     

Influence of calcium antagonists on renal function and secondary hyperparathyroidism in acute renal failure in rats

Glycerol-induced acute renal failure (ARF) is characterized by an increase in serum creatinine, urea, and phosphate concentration, and severe impairment of creatinine clearance. Secondary hyperparathyroidism develops rapidly during ARF. The calcium antagonist nisoldipine clearly improves renal function, which becomes evident by an improvement of creatinine clearance and attenuation of the increase of serum creatinine, urea, and phosphate concentrations. Further secondary hyperparathyroidism is ameliorated by nisoldipine treatment. In spite of normalization of the hypocalcemia in ARF by nisoldipine, weak hyperparathyroidism persists, suggesting that hypocalcemia is not exclusively responsible for elevated parathyroid hormone serum levels in ARF.     

Acute spontaneous tumor lysis presenting with hyperuricemic acute renal failure: clinical features and therapeutic approach

BACKGROUND: Acute spontaneous tumor lysis syndrome (STLS) presenting with hyperuricemic acute renal failure (ARF) is a rare disease which can be overlooked in patients with neoplasic disorders, requiring prompt recognition and aggressive management. This study examined the incidence, clinical characteristics and prognosis of this condition. METHODS: A retrospective study was performed, reviewing the records of all patients who developed ARF at Chang Gung Memorial Hospital between 1st July 1999 and 30th October 2002. Acute STLS was diagnosed based on pretreatment hyperuricemic ARF, ratio of urinary uric acid to creatinine (Cr) >1.0, and significantly elevated lactate dehydrogenase (LDH) (>500 units/L), together with a pathologically proven malignancy. Clinical course, metabolic parameters, response to therapeutics and outcome were assessed in all patients. RESULTS: STLS-induced acute uric acid nephropathy was identified in 10 out of 926 ARF patients (1.08%) studied. Most presentations were non-specific or related to malignancy symptoms. All patients had advanced tumors with large tumor burden, and abdominal organ involvement in 80% of patients. The 10 hyperuricemic patients became oliguric despite conservative therapy, and remained hyperuricemic (mean +/- SD: 20.7 +/- 5.0 mg/dL) until dialysis initiation. Seven patients (70%) developed diuresis, with an associated resolution of hyperuricemia, azotemia and metabolic derangements following dialysis initiation. The patients who developed diuresis had mean serum uric acid levels 9.3 +/- 3.1 mg/dL and median levels 9.8 mg/dL. Three patients (30%) survived, with two patients suffering residual renal function impairment. CONCLUSIONS: Acute STLS presenting with hyperuricemic ARF is a rare cause of acute uric acid nephropathy in patients with bulky or occult neoplastic disorders. The tumors that developed STLS had advanced stage or large tumor burden. Frequent abdominal organ involvement and non-specific initial presentations can obscure the nature of the disease and delay diagnosis. Unlike hyperuricemia and oliguria, which are constant findings, azotemia or impaired renal function is not always manifest on initial presentation. Poor outcomes in patients with STLS developing acute uric acid nephropathy make early recognition, aggressive management and prompt dialysis mandatory.     

Evolution and predictive power of serum cystatin C in acute renal failure

AIMS: The serum concentration of cystatin C has recently been proposed as a better indicator of glomerular filtration rate (GFR) than plasma creatinine. Little is known about cystatin C in critical illness. We assessed serum cystatin C as a marker of renal function in acute renal failure (ARF) and its power in predicting survival of ARF patients. MATERIAL: 202 consecutive adult patients admitted into the intensive care unit (ICU) during a period of 9 months. METHOD: Serum cystatin C, plasma creatinine and plasma urea were measured on admission, daily during the first 3 days, and 5-7 times a week during the rest of the ICU stay. The patients with and without ARF were compared by the Mann-Whitney U-test. The correlation between different variables was calculated by Spearman's correlation. Forward stepwise multiple regression analysis was performed to test independent predictors of mortality. The positive predictive value of serum cystatin C and plasma creatinine for ARF and mortality was calculated by ROC analysis. RESULTS: ARF occurred in 54 patients (27%). Serum cystatin C showed excellent positive predictive value for ARF in critical illness by ROC analysis. In acute renal dysfunction, abnormal values of serum cystatin C and plasma creatinine appeared equally quickly (median 3 days). The diagnosis of ARF, the day 1 Apache II score and admission plasma creatinine appeared as independent predictors of hospital mortality. ROC analysis showed only weak predictive power for serum cystatin C and plasma creatinine regarding hospital mortality. CONCLUSIONS: Serum cystatin C was as good as plasma creatinine in detecting ARF in intensive care patients. Neither marker was clinically useful in predicting mortality.     

Renal hypouricemia in school-aged children: screening of serum uric acid level before physical training

We present two cases of a 12-year-old Japanese boy and a 14-year-old Japanese girl who had exercise-induced acute renal failure (ARF). They experienced general fatigue, nausea/vomiting, and vague discomfort in the abdomen after physical exercise at school. In case of the boy, abdominal pain subsided, but renal dysfunction lasted 17 days, with peak levels of creatinine 9.4 mg/dl and uric acid 11.3 mg/dl. On the other hand, as the girl had suffered from hypouricemia before, she followed a doctor’s guidance on prevention of ARF. Consequently, she was promptly diagnosed as having exercise-induced ARF associated with hypouricemia, and rapidly recovered from ARF within a week. The difference between their clinical courses suggested a possibility that previous laboratory evaluation of serum uric acid assisted in the management of exercise-induced ARF associated with hypouricemia. School-aged children, especially Japanese and Asian, may be advised to have their serum uric acid measured before starting physical training at school.     

Evaluation of sE-Selectin and sICAM-1 as Parameters for Renal Function

Introduction. In order to monitor acute renal failure, intensive care patients were examined, and routine as well as specialized parameters were compared. Materials and Methods. Thirty-three patients at the Surgical Intensive Care Unit (ICU) were examined daily over the entire period for which they stayed in the ICU. The patients were retrospectively classified as being either with or without acute renal failure. Group 1 consisted of 22 patients who resided in the ICU for 11–15 (median 14) days without ARF. Group 2 consisted of 11 patients who developed an ARF during their stay of 13–18 (median 16) days in the ICU. In addition to the routine parameters of diuresis, serum creatinine/urea, and clearance of creatinine, specialized parameters for kidney function, including the excretion rates of α1-microglobulin, N-acetyl-β-D-glucosaminidase, and total protein, were compared with the excretion rate of soluble ICAM-1 and sE-Selectin. Results. Diuresis, serum creatinine, urea, and enzyme elimination were pathological among patients with ARF. Already on the day of admission, raised elimination rates of sICAM-1 were found in the urine of patients who had developed an ARF. While high values were still shown upon discharge, levels kept falling among patients without ARF. Clearly raised values were also shown for sE-Selectin compared to patients without ARF. Conclusions. sICAM-1 and sE-Selectin as supplementary parameters indicating renal function revealed early signs of kidney damage. These parameters may play a major role in the development of novel therapeutic approaches for ARF (antibodies against ICAM-1 or sE-Selectin).     

Reversible renal vasoconstriction in a patient with acute renal failure after exercise

Acute renal failure (ARF) with severe loin pain induced by anaerobic exercise is a rare condition that is accompanied by wedge-shaped contrast enhancement seen on computerized tomographic (CT) scan without evidence of rhabdomyolysis. An 18-year-old Korean male was transferred to our hospital for evaluation of mild azotemia, that developed after anaerobic exercise. The laboratory tests revealed that the serum creatinine was 2.1 mg/dl and the serum uric acid level was 1.6 mg/dl without any elevation of the serum myoglobin or creatine phosphokinase. Under the impression of exercise-induced ARF, we tried to determine the relationship between the occurrence of clinical symptoms, renal dysfunction and the characteristic CT findings by observing those changes prospectively before and after anaerobic exercise. After obtaining a written consent, the patient underwent a strenuous period of anaerobic exercise to induce the clinical symptoms. Before exercise, he was completely asymptomatic; his serum creatinine level was 0.9 mg/dl and CT scan of the kidneys showed no abnormalities. Loin pain developed 2 hours after exercise, and the serum creatinine level increased to 1.2 mg/dl 18 hours after the exercise. CT scan 18 hours after exercise showed multiple perfusion defects, and a 24-hour delayed CT scan showed multiple areas of wedge-shaped enhancement on both kidneys. These changes were completely resolved on the follow-up CT scan obtained 13 days after exercise with the return of a normal serum creatinine level. We conclude that reversible renal vasoconstriction is probably the main pathophysiologic mechanism of acute renal failure induced by anaerobic exercise.     

Torsemide versus furosemide after continuous renal replacement therapy due to acute renal failure in cardiac surgery patients

Diuretic therapy in ARF (acute renal failure) is mainly done with loop diuretics, first of all furosemide. Torsemide has a longer duration of action and does not accumulate in renal failure. In chronic and acute renal failure, both diuretics have been effectively applied, with a more pronounced diuretic effect for torsemide. In this study, the effects of torsemide versus furosemide on renal function in cardiac surgery patients recovering from ARF after continuous renal replacement therapy (CRRT) were studied. Twenty-nine critically ill patients admitted to an intensive care unit at a university teaching hospital after cardiac surgery recovering from ARF after CRRT were included in this prospective, controlled, single-center, open-labeled, randomized clinical trial. Inclusion criteria were urine output >0.5 mL/kg/h over 6 h under CRRT. Torsemide and furosemide dosages were adjusted with the target urine output being 0.8-1.5 mL/kg/h. Hemodynamic data, urine output, volume balance, serum creatinine clearance, electrolytes, blood urea nitrogen, serum creatinine, renin, and aldosterone concentrations were measured. Fourteen patients were included in the furosemide group and 15 patients in the torsemide group. Dosages of 29 (0-160) mg torsemide and a dosage of 60 (0-240) mg furosemide were given every 6 h in each group, respectively. The dosage given at the end of the study decreased significantly in furosemide and torsemide treated patients. Urine output, 24 h balance, and serum creatinine clearance did not differ significantly between groups. Urine output decreased in both groups, mostly dose-dependent in the torsemide group. The intragroup comparison of the first time-interval after inclusion with the last time-interval showed a significant increase in serum creatinine and blood urea nitrogen in the furosemide group. Renin and aldosterone concentrations did not show significant differences. In conclusion, torsemide and furosemide were effective in increasing urine output. Torsemide might show a better dose-dependent diuretic effect in ARF patients after CRRT treatment. Serum creatinine and blood urea nitrogen elimination were less pronounced in the furosemide group.