Clinical decision support system to predict chronic kidney disease: A fuzzy expert system approach.

BACKGROUND AND OBJECTIVES: Diagnosis and early intervention of chronic kidney disease are essential to prevent loss of kidney function and a large amount of financial resources. To this end, we developed a fuzzy logic-based expert system for diagnosis and prediction of chronic kidney disease and evaluate its robustness against noisy data. METHODS: At first, we identified the diagnostic parameters and risk factors through a literature review and a survey of 18 nephrologists. Depending on the features selected, a set of fuzzy rules for the prediction of chronic kidney disease was determined by reviewing the literature, guidelines and consulting with nephrologists. Fuzzy expert system was developed using MATLAB software and Mamdani Inference System. Finally, the fuzzy expert system was evaluated using data extracted from 216 randomly selected medical records of patients with and without chronic kidney disease. We added noisy data to our dataset and compare the performance of the system on original and noisy datasets. RESULTS: We selected 16 parameters for the prediction of chronic kidney disease. The accuracy, sensitivity, and specificity of the final system were 92.13 %, 95.37 %, and 88.88 %, respectively. The area under the curve was 0.92 and the Kappa coefficient was 0.84, indicating a very high correlation between the system diagnosis and the final diagnosis recorded in the medical records. The performance of the system on noisy input variables indicated that in the worse scenario, the accuracy, sensitivity, and specificity of the system decreased only by 4.43 %, 7.48 %, and 5.41 %, respectively. CONCLUSION: Considering the desirable performance of the proposed expert system, the system can be useful in the prediction of chronic kidney disease.

Seventeen years' experience of peritoneal dialysis in Iran: first official report of the Iranian peritoneal dialysis registry.

BACKGROUND: To facilitate planning, national renal registries provide reliable and up-to-date information on numbers of patients with end-stage renal disease (ESRD), developing trends, treatment modalities, and outcomes. To that end, the present publication represents the first official report from Iranian Peritoneal Dialysis Registry. METHODS: The prevalence, demographics, and clinical characteristics of patients on peritoneal dialysis (PD) were collected from all PD centers throughout the country. RESULTS: By the end of 2009, the prevalence of ESRD was 507 per million population in Iran. The most common renal replacement modality was hemodialysis (51.2%), followed by kidney transplantation (44.7%), and then PD (4.1%). The mean age of PD patients was 46 years, and the most common causes of ESRD were diabetes (33.5%), hypertension (24.4%), and glomerulonephritis (8.2%). Overall patient mortality was 25%, with cardiac events (46%), cerebral stroke (10%), and infection (8%) being the main causes of death. The 1-, 3-, and 5-year survivals were 89%, 64%, and 49% respectively. The most common cause of dropout was peritonitis (17.6%). Staphylococcus (coagulase-negative and S. aureus) was the most prevalent causative organism in peritonitis episodes; however, in more than 50% of episodes, a sterile culture was reported. Mean baseline serum hemoglobin and albumin were 10.7 g/dL and 3.6 g/dL respectively. CONCLUSIONS: Our registry results, representing the second largest report of PD in the Middle East, is almost comparable to available regional data. We hope that, in future, we can improve our shortcomings and lessen the gap with developed countries.

Levamisole usage as an adjuvant to hepatitis B vaccine in hemodialysis patients, yes or no?

BACKGROUND: Hepatitis B virus (HBV) infection is much more common in hemodialysis patients than the general population. These patients have an impaired immune response to HBV vaccination; to that end there are certain studies that have evaluated levamisole as an immunomodulator agent improving HBV vaccination response rate in hemodialysis patients. OBJECTIVES: In the current review, we have assembled all of the results to determine whether lavamisole is of value as an adjuvant to HBV vaccination in hemodialysis patients. MATERIALS AND METHODS: Science Direct (Elsevier), ProQuest, Springer, MD Consult, BMJ Journals, Pubmed and Wiley were searched for levamisole application to HBV vaccination in hemodialysis patients. All studies revealed a seroconversion response level between levamisole plus HBV vaccine versus HBV vaccine alone. RESULTS: From 10 relevant studies, 5 studies fulfilled our inclusion criteria. Three of them suggested the significant benefit of adding levamisole to the HBV vaccine to increase augment seroprotection level in hemodialysis patients. Another study reported a decrease in seroprotection level and another study showed no significant difference caused by levamisole administration. CONCLUSIONS: Due to the limited number of studies evaluated, it is challenging to perform a definite decision about routinely administering levamisole in addition to the HBV vaccine for all hemodialysis patients. However, it does seem reasonable to recommend administration of levamisole for impaired immune response patients.

Evaluation of lipid peroxidation and erythrocyte glutathione peroxidase and superoxide dismutase in hemodialysis patients.

Oxidative stress often occurs in chronic hemodialysis (HD). The aim of the present study was to determine plasma malondialdehyde (MDA) level for lipid peroxidation product and erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities as enzymatic antioxidants. Thirty-one HD patients (aged 50.3 ± 14.9 years) who were dialyzed three times per week and 31 healthy subjects (aged 47.8 ± 13.9 years) were enrolled. The results showed lower enzymatic antioxidants activity (GPx, SOD) and higher MDA levels in comparison with control subjects. In addition, SOD and GPx activities significantly decreased and MDA increased after HD. We also found that there was a significantly negative correlation between SOD and GPx with MDA. The results suggest that elevated level of plasma MDA and reduced activities of SOD and GPx can be caused oxidative stress, which may play a critical role in HD complications.

Low prevalence of high-dose methotrexate nephropathy in patients with malignancy.

INTRODUCTION: Methotrexate is an antifolate medication frequently used in the treatment of malignant and nonmalignant diseases. The usage of high-dose methotrexate was limited to patients with osteosarcoma, Ewing sarcoma, lymphoma, and acute lymphoblastic leukemia. One of the major side effects of high-dose methotrexate is nephropathy. The aim of present study was to determine the renal side effects of high-dose methotrexate in patients with malignancies. MATERIALS AND METHODS: In a study of 102 patients with osteosarcoma (n = 72), Ewing sarcoma (n = 15), and lymphoma (n = 15), treated with high-dose methotrexate, clinical and laboratory data including kidney function tests were recorded at baseline and during follow-up visits. The mean duration of follow-up was 6 months. RESULTS: The mean age of the patients was 19.5 years (range, 5 to 80 years). The total courses of methotrexate therapy were 273 (median, 2.67 per patient). The mean creatinine level was 0.82 mg/dL. Of the 102 patients, 3 (2.9%) developed acute kidney injury with an at risk phase. Another patient (1.0%) developed acute kidney injury and its phase was injury according to the RIFLE criteria. None of the cases were failed and acute kidney injury was alleviated in all of the affected patients. CONCLUSIONS: Our data revealed a low prevalence of acute kidney injury with high-dose methotrexate therapy. In addition, these toxicities were limited to the first and second phases of the RIFLE classification, all of which resolved spontaneously.

Protective effect of high dose short term statin therapy with normal saline in prevention of contrast-induced nephropathy among iodixanol-receiving patients.

Contrast media agents are applied for various diagnostic imagines, however, contrast-induced nephropathy (CIN) limits its usage. Statins have been found to prevent CIN via various mechanisms. However, study regarding the beneficial property of simvastatin as a kind of statin is scarce. This study was aimed to evaluate the efficacy of high dose short term statin therapy against nephrotoxicity of iodixanol. 194 patients were divided equally to control and statin-treated groups. Control group (placebo) received normal satin before and after angiography and statin-treated patients received simvastatin (80 mg/day) plus normal saline before and after angiography. Simvastatin and normal saline were started 12 hours before to 12 hours after the procedure, and serum creatinine before and two consecutive days after procedure were assessed. Estimated glomerular filtration rate (eGFR) was calculated using modification of diet in renal disease (MDRD ) method. In the first 24 hours after procedure, there was no difference between two groups, however after 48 hours of treatment, a significant difference for eGFR between two groups with more values in statin treated group was observed (p=0,002). Prophylactic administration of statins along with hydration may be associated with less contrast-induced nephropathy.

Effect of vitamin C on parathyroid hormone in hemodialysis patients with mild to moderate secondary hyperparathyroidism.

INTRODUCTION: In end-stage renal disease, there is a high incidence of secondary hyperparathyroidism. It is proposed that increasing vitamin C levels by dietary supplementation results in a decrease of parathyroid hormone (PTH) in vitamin C-deficient hemodialysis patients with secondary hyperparathyroidism. The aim of this study was the evaluation of vitamin C administration for reduction of serum PTH level in hemodialysis patients. MATERIALS AND METHODS: Twenty-one hemodialysis patients with serum PTH levels less than 550 pg/mL (but more than 200 pg/mL) were administered intravenous vitamin C, 200 mg, 3 times per week for 3 months. Blood samples for measurement of PTH were obtained at the beginning of the hemodialysis session every month for three months. RESULTS: The mean level of serum biointact PTH was 333.3 ± 141.3 pg/mL (reference range, 7 pg/mL to 82 pg/mL) at baseline, and it decreased to 256.5 ± 137.2 pg/mL at 1 month (P = .03). The mean PTH level was also lower than the baseline value at 2 months (260.1 ± 123.2 pg/mL, P = .03), while it increased to 328.9 ± 176.0 pg/mL at 3 months, which was still slightly lower than the baseline level (P = .13). In 15 patients (71.4%), serum levels of PTH were lower than the baseline at months 1 to 2, while in the remaining 6 (28.6%), it was higher than the baseline value. At 3 months, 5 of the 15 patients with lower PTH levels up to the 3rd month experienced an increase in these levels again. CONCLUSIONS: Administration of intravenous vitamin C in hemodialysis patients noticeably decreased level of PTH, but its effect gradually diminished.

Epidemiology of culture-negative peritonitis in Iranian patients on continuous ambulatory peritoneal dialysis.

INTRODUCTION: Culture-negative peritonitis is a major challenge in the treatment of peritonitis in continuous ambulatory peritoneal dialysis (CAPD). This study aimed to evaluate the culture-negative peritonitis in patients from the Iranian CAPD Registry. MATERIALS AND METHODS: Data of 1472 patients from 26 CAPD centers were analysed. Peritonitis was defined as any clinical suspicion together with peritoneal leukocyte count of 100/mL and more. RESULTS: The patients had been on PD for a mean of 500 ± 402 days. There were a total of 660 episodes of peritonitis observed among 299 patients (peritonitis rate of 1 episode in 34.1 patient-months). Excluding patients with both negative and positive culture results, there were 391 episodes of peritonitis in 220 patients (174 culture-positive episodes in 97 patients and 217 culture-negative episodes in 123). The 1- to 4-year patient survival rates were 85%, 75%, 69%, and 59% for the patients with culture-positive peritonitis, and 92%, 78%, 73% and 63% for the patients with culture-negative peritonitis, respectively (P = .34). The technique survival rates were 90%, 57%, 42%, and 27% and 95%, 85%, 74%, and 40%, respectively (P = .001). On follow-up, there were higher rates of active PD patients, lower rates of PD dropouts, and higher rates of kidney transplantation in patients with culture-negative peritonitis compared to those with culture-positive peritonitis. CONCLUSIONS: In our patients, the prevalence of culture-negative peritonitis was high (55.9%). Patient survival with culture-negative peritonitis was comparable to those with culture-positive peritonitis and technique survival was higher among those with culture-negative peritonitis.

Effect of adding levamisole on seroconversion response to hepatitis B virus vaccination in hemodialysis patients: a single-center experience.

INTRODUCTION: Hepatitis B virus (HBV) infection is much more common in hemodialysis patients than the general population. Up to half of hemodialysis patients do not have adequate protective HBV antibodies after HBV vaccination. We studied the effects of adding levamisole, as an immunomodulator and adjuvant agent, on seroconversion response to HBV vaccination in hemodialysis patients. MATERIALS AND METHODS: Thirty-six hemodialysis patients were divided into 2 groups. The first group received 40 microg of HBV vaccine intramuscularly at 0, 1, and 6 months plus 100 mg of oral levamisole per day for 12 days. The second group received the same amount and method of vaccine and placebo. Serum antibody levels were measured in each group after 0, 2, and 4 months after the last dose of vaccination. RESULTS: Anti-HBV antibody level in the patients who received levamisole was lower than that in the control group. Antibody levels in the levamisole group at 0, 2, and 4 months after the last dose of vaccination were 44.4%, 77.8%, and 77.7%, respectively. In the control group, response rates at 0, 2, and 4 months were 55.6%, 72.2%, and 77.8% respectively (P = .04, P = .12, and P = .08, respectively). CONCLUSIONS: Anti-HBV antibody level was significantly lower immediately after HBV vaccination when it was accompanied by levamisole administration. However, no significant differences were observed between the two groups at 2 and 4 months. Further evaluation is recommended to assess the effect of adding levamisole on Hepatitis B surface antibody titer in hemodialysis patients.

Ifosfamide nephropathy in patients with sarcoma.

INTRODUCTION: Ifosfamide is an alkylating agent, frequently used in the treatment of sarcoma. Major side effects of ifosfamide are classified as nephropathy, neuropathy, and hematologic complications. The aim of present study was to determine the frequency and severity of ifosfamide nephropathy in patients with various types of sarcoma. MATERIALS AND METHODS: Ninety patients (52 males and 38 females) who had received ifosfamide chemotherapy for sarcoma were included in this study. Data on physical examination, laboratory studies, and estimation of glomerular filtration rate were collected. The median duration of follow-up was 6 to 12 months. Records of documented nephropathy were identified in these patients. RESULTS: The age range of patients on ifosfamide was 5 to 59 years. Thirty-four of the patients were children and 56 were adults. The most common renal side effects were proteinuria (15.5%), glycosuria (7.8%), elevation of serum creatinine (2.2%), hematuria (14.4%), and combination of proteinuria and glycosuria (5.5%). None of the patients had gross hematuria, but microscopic hematuria was present in 14.4%. CONCLUSIONS: Ifosfamide nephropathy was seen with different degrees of severity in patients with sarcoma. Monitoring of the side effects of ifosfamide should be revised in different populations.

Outcomes of fasciotomy in patients with crush-induced acute kidney injury after Bam earthquake.

INTRODUCTION. Fasciotomy may increase the morbidity and mortality in patients with crush-induced acute kidney injury (AKI), by creating an open wound, increasing the risk of bleeding, coagulopathy, and potentially fatal sepsis. This study evaluates the outcomes of fasciotomy in these patients after Bam earthquake in Iran. MATERIALS AND METHODS. We reviewed medical records of victims of Bam earthquake complicated with crush-induced AKI. Demographic, biochemical, and clinical data of patients who underwent fasciotomy were evaluated and compared with other patients with AKI. RESULTS. Fasciotomy was performed for 70 of 200 patients with crush-induced AKI (35.0%). There were no significant differences regarding sex, age, time under the rubble, and muscle enzymes level between these patients and those without fasciotomy. They did not experience higher rates of disseminated intravascular coagulopathy, sepsis, adult respiratory distress syndrome, amputation, and dialysis session. Neither did they have a longer hospitalization period or higher death rate. CONCLUSIONS. This study showed that fasciotomy did not have any deteriorating effect on morbidity and mortality of patients with crush-induced AKI after Bam earthquake.

Practical strategies to reduce morbidity and mortality of natural catastrophes: a retrospective study based on Bam earthquake experience.

BACKGROUND: Critical analysis of shortcomings of emergency medical management of earthquake casualties will provide an invaluable insight to improve outcomes for future events. Using a critical analysis methodology to evaluate the quality of emergency medical management after Bam earthquake, we suggest a practical strategic approach to decrease morbidity and mortality after such events. METHODS: We designed a questioner to register the basic demographic data and the key biologic parameters of all rescued victims arriving in hospitals. Based on that questioner a data bank was created and used for different analyses. In addition, published official reports and on the scene observations of our nephrologist colleagues were other sources of our data. RESULTS: Bam earthquake was publicly announced more than six hours after its occurrence. The earliest time when local and international rescue teams arrived at the scene was 12 hours after the disaster. Fifty-four percent of hospital inpatients had been admitted on the second or third day after the earthquake. The mean time of being under the rubble was 4.8+/-4.9 hours. The mean time between extrication and initiation of intravenous fluid infusion was 18.9 hours (min: 10 minutes, max: 96 hours). CONCLUSION: Problems encountered in the aftermath of the Bam earthquake were related to the lack of prepared action plan and data management system. Here, we present a specifically designed earthquake chart. By following the chart, rescue paramedic personnel and emergency medical teams will be able to recognize high-risk victims, in order to provide timely medical management.

Early detection of patients at high risk for acute kidney injury during disasters: development of a scoring system based on the Bam earthquake experience.

BACKGROUND: Early prophylactic hydration therapy in patients prone to acute kidney injury (AKI) can reduce its incidence in disasters. As sufficient availability of fluids might be problematic, it is important to discriminate those at risk versus not at risk for AKI. The present study uses biochemical findings from victims of the Bam earthquake to design decision rules for early detection of patients at risk for AKI. METHODS: Data were collected in hospitals admitting Bam earthquake victims. Biochemical factors on day 1 (creatinine, CPK, LDH, SGOT, uric acid, calcium, phosphorus, sodium, potassium, white blood cell count, platelet count) were introduced into multivariate models for prediction of AKI (serum creatinine >1.6 mg/dL) at a later stage. RESULTS: A rule of thumb to assess the absence of risk for AKI was developed, using ROC analysis: if on day 1, serum creatinine was <2 mg/dL, LDH was <2,000 IU and serum uric acid was <6 mg%, the risk for development of AKI was virtually nil. Using multiple regression analysis (0.45 CPK + 2.5 LDH + 2,700 K + 2,000 uric acid - 14,000)/10,000, was most predictive for serum creatinine on day 3. Dichotomizing this value at 2.0 yielded a sensitivity and specificity for prediction of AKI of 96.6% and 95.7%, respectively. CONCLUSIONS: We propose 2 decision rules to predict development of AKI in earthquake victims. These scores can easily be calculated already at an early stage of a disaster, enabling rationalization of prophylactic hydration therapy in crushed earthquake victims.

Bone mineral density in kidney transplant recipients and patients on hemodialysis: a comparison with healthy individuals.

INTRODUCTION: We measured bone mineral density (BMD) before and after transplantation to determine the frequency and severity of preoperative and postoperative osteoporosis and compare them with the BMD in healthy individuals. MATERIALS AND METHODS: We determined the BMD at the lumbar spine and femoral levels in 22 men and 18 women who were on long-term dialysis in Yazd, Iran, and a group of kidney transplant recipients including 43 men and 18 women. They were compared with each other and healthy individuals studied in a recent study in Iran. Factors potentially associated with alterations of the BMD were studied in each group. RESULTS: The frequency of osteoporosis in the vertebrae and femoral neck was higher in the kidney transplant recipients than the healthy population (21.3% versus 4.9%; P = .001; odds ratio, 5 and 9.8% versus 2.4%; P = .02; odds ratio, 5.4, respectively) but not significantly different from those in the patients on dialysis (17.9% and 17.5%, respectively). In transplantation group, multivariate analysis showed that there was a significant negative correlation between the lumbar BMD and the cumulative prednisolone dose (r = -0.36, P = .003). No correlation was found between BMD of lumbar or femoral neck and the body mass index, age, and cumulative cyclosporine level. CONCLUSIONS: Osteoporosis is more frequent in patients on dialysis and kidney transplant recipient than in general population. However, there is no difference in osteoporosis frequency between transplanted patients and those on dialysis. In the lumbar spine, a higher cumulative prednisolone dose results in decreased BMD among kidney transplant recipients.