The role of ultrasonography in the assessment of renal function in the elderly

BACKGROUND: Ageing is associated with a progressive loss of renal mass and kidney length and a decline in glomerular filtration rate (GFR). This study evaluated a possible correlation between renal function and kidney size measured by ultrasonography (US), and whether the latter helps estimate GFR in the elderly. METHODS: Twenty-five medically stable elderly patients (mean age 85 +/- 5 yrs) were examined in a geriatric ward at a university hospital. Blood samples were taken to determine serum creatinine (Cr) levels. On the same day, 51chromium ethylenediamine tetraacetic acid (51Cr-EDTA) clearance was performed as the gold standard of GFR. US measured kidney length, transverse and anteroposterior dimensions. RESULTS: Serum Cr (r=-0.67; p=0.0002), Cockcroft-Gault formula (r=0.82; p<0.0001), absolute length (r=0.51; p=0.008) and volume kidney (r=0.46; p=0.02) correlated significantly with GFR. After receiver operating curve (ROC) analysis, length was less specific than sensitive in detecting renal impairment. Adding length to the Cockcroft-Gault formula did not improve GFR estimation (p=0.44). In contrast, adding length to serum Cr levels improved GFR estimation (p=0.015). CONCLUSION: In the elderly, kidney length and volume significantly correlated with GFR. However, length has a low specificity in predicting renal impairment. Therefore, in clinical practice, serum Cr levels and calculated Cr clearance are more useful in predicting renal impairment. However, normal kidney length can help to exclude renal impairment in the elderly at risk of GFR underestimation by a calculated Cr clearance.     

Correlation between serum creatinine, creatinine clearance, the calculated creatinine clearance and the glomerular filtration rate in heart transplant patients.

Assessment of glomerular filtration rate (GFR) in heart transplant (HTx) patients is based on serum creatinine (sCr), the endogenous creatinine clearance (C(Cr)) and radionuclide GFR (rGFR); however, the latter is expensive and time consuming. We reviewed the data of 32 adult HTx patients to determine the correlation between sCr, C(Cr), the calculated C(Cr) (Calc.C(Cr); based on gender, age, weight and sCr) and rGFR in long-term (>1 year) HTx patients receiving calcineurin inhibitors. The Calc.C(Cr) was found to have the best correlation with rGFR (r(2) = 0.65), followed by C(Cr) (r(2) = 0.53) and sCr (r(2) = 0.38). The use of Calc.C(Cr) to estimate GFR may be cost-effective in assessing renal function after HTx.     

Colorectal adenocarcinoma in cirrhotic patients

BACKGROUND: Colorectal carcinoma in cirrhotic patients is different from that in patients without the liver disease. The aims of this study were to evaluate the incidence of liver metastasis, postoperative mortality, and the predictors of longterm survival. STUDY DESIGN: A retrospective analysis of patients operated on for colorectal adenocarcinoma at the Mayo Clinic, Rochester, MN between 1976 and 2001, with confirmed liver cirrhosis at the time of abdominal exploration. RESULTS: Seventy-two patients were available for analysis. They were 43% Child A, 42% Child B, and 15% Child C. The median age was 70 (range 42 to 89) years, and the mean duration of followup was 46 months. Postoperative death was 13%. The risk factors were an elevated bilirubin (p = 0.01) and prolonged prothrombin time (p = 0.009). Seven patients (10%) developed liver metastases. For the whole group 1-, 3-, and 5-year survival rates were 69%, 49%, and 35%, respectively. Child A patients had a significantly better survival rate than the combined group of Child B and C patients (p = 0.008). The risks for longterm survival were decreased albumin (p = 0.002) and prolonged prothrombin time (p < 0.001). TNM stage of the carcinoma provided no prognostic information (p = 0.51). CONCLUSIONS: Liver metastases from colorectal adenocarcinoma is infrequent (10%) in cirrhotic patients. The Child's classification, and not the TNM stage of the carcinoma, predicts the risk of postoperative death and longterm survival.     

血清胱抑素C对肝硬化病人肾功能损害的早期诊断价值研究

目的 探讨血清半胱氨酸蛋白酶抑制剂C(Cys C)检测对肝硬化病人肾功能损害早期诊断的意义.方法 测定76例肝硬化病人24 h肌酐清除率(Ccr)以及血清肌酐(SCr)和血清Cys C水平.以CCr＜80 ml/min/1.73 m2作为肾功能损害诊断标准,采用t检验、相关性分析和ROC曲线分析探讨Cys C的诊断价值.结果 在Child分级肝损害病人的肾功能评估能力比较中,Cys C能灵敏反映CCr变化,而Scr的反映能力明显低于Cys C.SCr与CCr有着显著的负相关性(CysC:r=-0.763,P＜0.001;SCr:r=-0.571,P＜0.01),而Cys C的相关系数较高.ROC曲线分析显示Cys C的曲线下面积(AUC)值明显高于SCr(0.830比0.612).结论 与SCr比较,Cys C能更准确地早期发现肝硬化病人的肾功能损害,常规监测肝硬化病人Cys C水平,对预防肝肾综合征的发生具有积极意义.     

Female Liver Transplant Recipients with the Same GFR as Male Recipients Have Lower MELD Scores—A Systematic Bias

Women have lower glomerular filtration (GFR) than men for the same serum creatinine (Cr) value, not accounted for in model for end-stage liver disease (MELD). We compare male/female Cr, GFR (using MDRD formula) and respective MELD scores in 403 Cr measurements using standard (sCr), O'Leary modified (mCr) and Compensated (cCr) Jaffe and Enzymatic (eCr) in 158 liver disease patients, mCr in 208 liver transplantation (LT) candidates, and EDTA-Cr(51)-GFR in 38 other candidates for LT; considering each female as male, a 'corrected' Cr was derived. MELD scores were calculated for measured and "corrected" Cr in females. Median Cr and GFR in females were lower than males (p < 0.05). Both MDRD and EDTA-Cr(51) GFR were lower in females than males, despite lower Cr values. In females, each MELD score was lower than the corresponding MELD-corrected Cr (p < 0.001) with > or =three-point difference in liver disease patients: 25%[sCr]; 23%[mCr]; 11%[eCr]; and 14%[cCr]. In 65% of female LT candidates, two- or three-point difference was found. Females with liver disease have lower GFR than males for the same Cr value; correcting Cr increases MELD score by two or three points in 65% of female LT candidates. MELD score adjustment in females would ensure equal LT priority by gender.     

Combined sclerotherapy and operation for the treatment of bleeding oesophageal varices.

OBJECTIVE--To identify prognostic factors in a consecutive series of patients with bleeding oesophageal varices and develop an optimum regimen of treatment. DESIGN--Retrospective review. SETTING--I Department of Surgery, University Hospital, Vienna, Austria. PATIENTS--301 consecutive patients with bleeding oesophageal varices. OUTCOME MEASURES--Median survival and survival at one year after sclerotherapy alone (n = 213), or sclerotherapy with portosystemic shunt (n = 54), Hassab's devascularisation (n = 29), or liver transplantation (n = 5). RESULTS--Prognosis was dependent on the severity of liver damage at the start of treatment. Median survival for Child's class A was 47 months, for Child's class B 54 months, and for Child's class C 2 months. The overall one year survival for patients in Child's class C was 33%, for sclerotherapy alone 28%, and for sclerotherapy and portosystemic shunt 42%, Hassab's devascularisation 50%, and liver transplantation 80%. CONCLUSION--Despite the small number of patients who underwent liver transplantation and their poor initial prognosis (Child's class C, n = 4; class B, n = 1) our results suggest that liver transplantation should be considered for the treatment of patients with end stage cirrhosis and bleeding varices.     

Laparoscopic cholecystectomy in cirrhotic patients

Since 1992, laparoscopic cholecystectomy has been the treatment of choice for symptomatic gallstones. The advantages of laparoscopic cholecystectomy for most patients have been extensively published. However, its benefits and successful use in patients with cirrhosis are less well documented. The aim of this study was to determine the efficacy and safety of laparoscopic cholecystectomy in cirrhotic patients. We did a retrospective review of the records of 26 consecutive laparoscopic cholecystectomy procedures performed on cirrhotic patients between January 1992 and September 2000. Twenty-two patients were classified as having Child's class A cirrhosis, and 4 patients were classified as having Child's class B. No patients were classified as having Child's class C cirrhosis. There were 20 men and 6 women, with a mean age of 57 years (range, 37-76). All procedures were completed laparoscopically. There was histologic confirmation of cirrhosis in all patients. The mean operative time was 126 minutes (range, 60-184). The mean estimated blood loss was 110 mL (range, 40-380). Complications occurred in 7 patients (27%). No operative mortality occurred in this study. The mean length of hospital stay was 5 days (range, 3-14). Our results and the results of others show that laparoscopic cholecystectomy in cirrhotic patients seems to be safe in selected Child-Pugh class A and B patients with compensated cirrhosis. Cholecystectomy remains a high-risk procedure in cirrhotic patients, and indications for cholecystectomy should be evaluated carefully. Controlled trials are required to confirm the safety of this procedure, and further studies are also required to evaluate the management of gallbladder disease in patients with Child-Pugh class C cirrhosis.     

Serum cystatin C as a reliable marker of changes in glomerular filtration rate in children with urinary tract malformations

PURPOSE: Cystatin C has been suggested as a simple method of estimating GFR more accurately than creatinine in children. We compared the diagnostic accuracy of cystatin C with serum creatinine and the Schwartz formula for estimating GFR in patients with UTMs. MATERIALS AND METHODS: We prospectively compared 72 patients with UTMs (20 days to 36 months old, 58 males and 14 females) with a group of 72 healthy controls (10 days to 48 months old, 53 males and 19 females). All patients underwent nuclear medicine clearance investigations with (99m)Tc DTPA. RESULTS: Serum concentration of cystatin C revealed a higher correlation with (99m)Tc DTPA (r = 0.62, p <0.001) than serum concentration of creatinine (r = 0.30, p <0.01) or Schwartz formula (r = 0.51, p <0.001). These results were more evident in patients with uropathy (19) with mild renal impairment. Agreement between methods was assessed using Bland Altman analysis. Mean differences between GFR calculated with (99m)Tc DTPA and cystatin C based GFR estimation or Schwartz formula were -2.6% +/- 46.7% and -73.4% +/- 53.6%, respectively. Diagnostic accuracy in identifying decreased GFR measured as AUC was always highest for cystatin C but hardly sufficient for the 3 variables. Cystatin C performed better in the 0 to 6-month-olds (0.70 +/- 0.08 for cystatin C, 0.58 +/- 0.07 for Schwartz estimate) and patients older than 12 months (0.82 +/- 0.09 for cystatin C, 0.65 +/- 0.11 for Schwartz estimate). CONCLUSIONS: Cystatin C proved to be a superior marker rate over serum creatinine in estimating glomerular filtration in children younger than 3 years with UTMs and mild renal impairment, thus, offering a more specific and practical measure for monitoring GFR.     

Cystatin C does not detect acute changes in glomerular filtration rate in early diabetic nephropathy

BACKGROUND: The measurement of renal functional reserve (acute change in glomerular filtration rate [GFR] after protein load) allows the detection of sub-clinical renal dysfunction and has prognostic implications in diabetes. Our aim was to test cystatin C as an index of GFR and renal functional reserve. METHODS: GFR was measured by C(Sinistrin) at baseline and after protein load in 28 diabetic patients with serum creatinine <1.2 mg/dL. The C(Sinistrin) was compared with cystatin C, serum creatinine, creatinine clearance, and Cockcroft-Gault formula. RESULTS: Baseline C(Sinistrin) ranged from 67-172 mL/min. Regression analysis showed an overall low relationship between C(Sinistrin) and the indirect markers of GFR. The highest correlation with C(Sinistrin) was obtained for cystatin C clearance (R(2) = 0.58, r = 0.76, p < 0.001), the 1/serum cystatin C (R(2) = 0.58, r = 0.76, p < 0.001), and serum cystatin C (R(2) = 0.52, r = 0.72, p < 0.001). Renal functional reserve was preserved in 6 of 28 patients. There was no significant change in cystatin C in response to protein load. CONCLUSION: Wide variation in baseline GFR emphasizes the need for the early detection of renal dysfunction. Cystatin C correlated best with C(Sinistrin) at baseline, but did not detect renal functional reserve.     

Is the corrected-creatinine model for end-stage liver disease a feasible strategy to adjust gender difference in organ allocation for liver transplantation?

BACKGROUND: The Model for End-stage Liver Disease (MELD) scoring system is used for organ allocation in liver transplantation. Female cirrhotic patients have lower glomerular filtration rates (GFR) than males for the same creatinine (Cr) level. Correcting the Cr in females for the same GFR as in males shows that females have lower MELD scores and therefore a lower priority for liver transplantation; however, there has been no outcome data that justifies this modification. METHODS: We investigated 472 cirrhotic patients, comparing the mortality rate between males and females in relation to MELD and corrected-Cr MELD. RESULTS: Compared to females, male patients had a higher MELD (14.5+/-5.5 vs. 13.8+/-5.7) and significantly higher GFR (61.7+/-21.4 vs. 54.7+/-25.6 mlLmin/1.73 m, P=0.0002) because their Cr value was higher (1.4+/-0.4 vs. 1.3+/-0.5 mg/dL, P=0.0002). The corrected-Cr MELD score in females was higher (15.7+/-6.3) compared to the MELD in their original counterpart (P<0.0001) and the males (P=0.060). Female and male patients had a similar 3-month mortality rate (6.7% vs. 6.3%) and MELD (21.9+/-8.6 vs. 21.7+/-8.9) among deceased patients. At 6 months, female patients tended to have a lower mortality (12.5% vs. 14.7%) and a lower MELD (18.9+/-7.7 vs. 19.4+/-8.5) in deceased patients. However, at 9 and 12 months, females had a consistently higher mortality (25% vs. 21.2% and 37.5% vs. 31.3%, respectively) but lower MELD scores than males by 0.3-1 point. CONCLUSIONS: Using corrected-Cr MELD, which would prioritize female patients for liver transplantation, may only be justified in predicting intermediate-term (9- and 12-month), but not short-term (3- and 6-month) mortality.     

Inguinal hernioplasty improves the quality of life in patients with cirrhosis

BACKGROUND: The optimal management of symptomatic inguinal hernia (SIH) in cirrhotics is still undefined. Both hernia and cirrhosis impair quality of life (QOL). The aim of this study was to evaluate QOL by a Short Form-36 (SF-36) questionnaire in cirrhotic patients undergoing inguinal hernioplasty. METHODS: Thirty-two cirrhotic patients undergoing inguinal hernioplasty were evaluated. They were classified according to Child's class and to the absence or presence of refractory ascites. The SF-36 questionnaire was administered the day before and 6 months after surgery. Global analyses of the 8 domains of SF-36 and of 2 comprehensive indexes of SF-36, Physical Component Summary (PCS) and Mental Component Summary (MCS), were performed. RESULTS: Lichtenstein hernioplasty for SIH originated no major complications. All 8 domains of SF-36 and MCS and PCS scores improved remarkably after hernioplasty especially in patients in Child's class C and/or with refractory ascites. CONCLUSIONS: Inguinal hernioplasty for SIH in patients with cirrhosis is a safe procedure. The improvement of QOL represents a clear cut indication for elective hernia repair.     

肝硬化合并胆石症的手术治疗

目的: 探讨肝硬化合并胆石症患者的手术风险及预后 。方法: 对我院1994~2000年间收治的42例肝硬化合并胆石症患者的临床资料进行回顾分析 。结果: 42例肝硬化合并胆石症患者中,肝功能ChildA级19例,ChildB级18例,ChildC级5例。急诊手术15例,择期手术27例。术中出血量1000ml以上13例。术后出现并发症22例,其中ChildA级6例(占31.6%),B级12例(占66.7%),C级4例(占80.0%)。治愈29例,死亡6例,术后胆道残余结石7例 。结论: Child分级适用于肝硬化患者胆道手术风险的评估。术中出血和术后肝功能衰竭是影响预后的主要因素。     

A comparison between cystatin C, plasma creatinine and the Cockcroft and Gault formula for the estimation of glomerular filtration rate.

BACKGROUND: In clinical practice, the glomerular filtration rate (GFR) is often estimated from plasma creatinine. Several studies have shown cystatin C (cys C) to be a better parameter for the diagnosis of impaired renal function. No data are available, however, on the performance of cys C in follow-up of patients, compared with creatinine. Also, comparisons of cys C with the Cockcroft and Gault (C&G) formula for estimation of GFR are few. METHODS: Plasma samples were obtained from 93 consecutive patients seen for GFR determination and from 30 patients with diabetes mellitus type 2, of whom 23 were investigated a second time after 2 years. GFR was determined with [125I]iothalamate. Plasma creatinine was determined enzymatically and the creatinine clearance calculated according to C&G. Cys C was measured with a particle-enhanced immunonephelometric method. RESULTS: GFR correlated with 1/cys C (r = 0.873) as well as with C&G (r = 0.876). The area under the curve (AUC) of the receiver operating curves (ROCs), a measure of diagnostic accuracy, for cys C (0.931) and C&G (0.938) were equal (P = 0.815) and both better than the creatinine AUC (0.848; P = 0.006). Bland and Altman analysis showed that the simple formula GFR = -4.32 + 80.35 x 1/cys C, derived from our data, gave more accurate (P < 0.0001) and more precise (P = 0.024) GFR estimates than obtained with the C&G formula. The day-to-day variation (biological +analytical) for cys C was small (3.1%, SD 2.51%) in diabetic patients. In the follow-up study in diabetic patients, cys C was the parameter which had the best correlation (r = 0.66) with changes in GFR. CONCLUSIONS: Cys C shows a high correlation with GFR. With a very simple formula, cys C gives a good estimate of GFR, more accurate and precise than C&G. Because biological variation is low, cys C gives also a good assessment of GFR changes during follow-up. Cys C is the preferred endogenous parameter for GFR.     

Surgery for cholelithiasis in cirrhotic patients

Although biliary tract surgery for cholelithiasis is performed frequently in Japan, cirrhotic patients require special consideration. Postoperative complications after biliary tract surgery were studied in 23 patients with liver cirrhosis and associated cholelithiasis, 9 of whom had no complications, 8 had minor complications, and 6 had severe complications. Concerning the relation between Child's classification and postoperative complications, no complications were seen in four Child's type A patients, but seven of ten (70%) Child's type B patients and seven of nine (78%) Child's type C patients developed complications. Two (20%) of the Child's type B patients and four (44%) of the Child's type C were severe, and three of the latter group died. Regarding the preoperative laboratory findings, significant differences were seen between the patients without complications and those with severe complications in serum bilirubin, albumin, and ICG R₁₅ values. Of the six patients with severe complications, five had choledocholithiasis, three of whom died of liver failure, while two developed biliary peritonitis caused by insufficient fistula formation after removal of the T-tube. Thus, for the treatment of choledocholithiasis in patients with severe cirrhosis, avoiding surgical invasion through the use of such techniques as endoscopic papillotomy is recommended whenever possible.     

肝硬化脾功能亢进患者肝组织中铁过载及铁调素mRNA表达的意义

目的 探讨肝硬化合并不同程度脾功能亢进(脾亢)患者肝组织中铁过载及铁调素(hepcidin)mRNA表达的意义.方法 收集肝硬化合并轻、中及重度脾亢患者肝活检标本各10例,共30例(肝硬化组),外伤性肝破裂手术标本10例(对照组),采用原子分光光度计检测肝组织铁元素含量;采用化学发光法检测血清铁蛋白的含量;采用逆转录-聚合酶链反应(RT-PCR)检测肝组织hepcidin mRNA的表达.结果 肝硬化脾亢患者按脾功能亢进程度分为轻、中及重度3组,其肝组织中铁元素含量明显递增,分别为(0.1205±0.0021)、(0.1624±0.0028)和(0.1716±0.0032)mmol/g,均明显高于正常肝组织(0.0639±0.0025)mol/g(P<0.05),表现为铁过载;肝硬化组血清铁蛋白的含量为(436.2±51.6)μg/L,显著高于对照组的(152.5±38.7) μg/L(P<0.01);肝硬化组hepcidin mRNA的表达水平为1.73±0.26,明显高于对照组的0.68±0.22(P<0.01);而且各组的hepcidin mRNA表达水平与血清铁蛋白含量之间具有显著相关性(肝硬化组r=0.735,对照组r=0.648,P<0.01).结论 肝硬化脾亢患者的肝组织中存存铁过载,并随脾亢程度加重而明显增加;hepcidinmRNA是调节铁代谢平衡并影响肝硬化进程的重要因素.     

Chronic Kidney Disease-Epidemiology Formula and Model for End-Stage Liver Disease Score in the Assessment of Renal Function in Candidates for Liver Transplantation

Assessment of renal function in patients with end-stage liver disease (ESLD) awaiting liver transplantation (OLT) is critical. Various conditions may cause renal damage in ESLD. Renal and liver functions are intertwined due to splanchnic hemodynamic relationships; renal failure rarely occurs in patients without advanced decompensated cirrhosis. The recent literature suggests that evaluation of renal function should include an assessment of liver function. The aim of this study was to evaluate different methods to estimate glomerular filtration rate (GFR) in patient among ESLD candidates for OLT over 1 year. We also correlated renal and hepatic functions. Fifty-two cirrhotic patients Model for End-Stage Liver Disease [MELD] > 10) were enrolled in the study. All patients were evaluated at baseline and every 4 months (T1-T4) thereafter for 1 year. The GFR was calculated by creatinine clearance, and estimated by Cockroft and Gault, Modified Diet Renal Disease (MDRD) 4 and 6 variable and Chronic Kidney Disease-Epidemiology (CKD-EPI) formulae. Hepatic functions were evaluated by MELD score, albumin, bilirubin, and International Normalized Ratio (INR). We observed not statistically significant increase mean value of MELD score, bilirubin, serum creatinine, and blood urea nitrogen and a reduced serum sodium. There were no significant differences among various methods to evaluate GFR at each time over 1 year. We did not observe any association between renal and hepatic function, except at T4 for MELD and GFR estimated with MDRD 4 (P = .009) and 6 (P = .008) parameters or CKD-EPI (P = .036), and MELD and sodium (P = .001). Our results showed that evaluation of renal function in cirrhosis should include an evaluation of hepatic function. In our case, MDRD and CKD-EPI seemed to be the more accurate formulae to evaluate renal function in relation to hepatic function.     

Glomerular filtration rate estimated from the uptake phase of 99mTc-DTPA renography in chronic renal failure.

BACKGROUND: The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from 99mTc-DTPA renography with that estimated from the renal clearance of 51Cr-EDTA, creatinine and urea. METHODS: Fifty patients with reduced renal function (serum creatinine between 150 and 600 micromol/l) were enrolled in the study. GFR was estimated from the uptake phase of 99mTc-DTPA renography (GFR(DTPA)). The renal clearance of 51Cr-EDTA (GFR(EDTA)) was used as the reference method. Creatinine clearance (C(Cr)), urea clearance (C(Ur)) and the mean of urea and creatinine clearance (C(Cr+Ur)/2) were also calculated from urine collected during a period of 24 h. Limits of agreement were used for method comparison. RESULTS: The limit of agreement between GFR(DTPA) and GFR(EDTA) was 2 +/- 17 ml/min. The mean difference did not deviate significantly from zero. The other clearance techniques had larger limits of agreement and a mean difference significantly different from zero. Furthermore, C(Ur) and C(Cr+Ur)/2 had systematic deviations of the differences, indicating that C(Ur) and C(Cr+Ur)/2 are poor estimates of GFR. CONCLUSION: The limit of agreement between GFR(DTPA) and GFR(EDTA) are acceptable and, therefore, GFR estimated from 99mTc-DTPA renography is acceptable for clinical use in patients with reduced renal function. Furthermore, the method is simple and less time consuming compared with renal clearance techniques.     

Rapid and accurate assessment of glomerular filtration rate in patients with renal transplants using serum cystatin C.

BACKGROUND: Assessment of renal function in patients with renal transplants is of great importance. Various studies have reported cystatin C as an easily and rapidly assessable marker that can be used for accurate information on renal function impairment. To date, no study is available to define the role of cystatin C in patients with renal transplants. METHODS: Thirty steady-state patients (50% male/50% female) with status post-kidney transplantation were studied. To assess renal function, cystatin C, creatinine clearance, serum creatinine, beta2-microglobulin (beta2M), and [125I]iothalamate clearance were determined. Correlations and non-parametric ROC curves for accuracy, using a cut-off glomerular filtration rate (GFR) of 60 ml/min, were obtained for the different markers allowing for calculations of positive predictive values (PPV), positive likelihood ratios (PLR), specificity and sensitivity, respectively. Further, to evaluate the usefulness of these markers for monitoring, intraindividual coefficients of variation (CVs) for cystatin C and creatinine measurements were compared in 85 renal transplant patients. Measurements consisted of at least six pairs of results, which were obtained at different time points during routine follow-up. RESULTS: Cystatin C correlated best with GFR (r=0.83), whereas serum creatinine (r=0.67), creatinine clearance (r=0.57) and beta2M (r=0.58) all had lower correlation coefficients. The diagnostic accuracy of cystatin C was significantly better than serum creatinine (P=0.025), but did not differ significantly from creatinine clearance (P=0.76) and beta2M (P=0.43). At a cut-off of 1.64 mg/l, cystatin C has a PPV of 93%, PLR of 6.4, specificity 89% and sensitivity 70%, respectively. For beta2M, PPV 83%, PLR 1.7, specificity 67% and sensitivity 75% was seen at a cut-off of 3.57 mg/l. Accordingly, at a cut-off of 125 micromol/l for serum creatinine, a PPV 76%, PLR 1.4, specificity 44% and sensitivity 80% was revealed. Finally, at a cut-off of 66 ml/min/1.73 m2 for creatinine clearance, the following characteristics were found: PPV 94%, PLR 7.7, specificity 89% and sensitivity 85%. The intraindividual variation of creatinine was significantly lower than that of cystatin C (P<0.001). With increasing concentrations, their ratios of CV tended towards a value of 1, demonstrating identical variability at low GFR. CONCLUSION: Together, our data show that in patients with renal transplants, cystatin C, in terms of PPV and PLR, has a similar diagnostic value as creatinine clearance. However, it is superior to serum determinations of creatinine and beta2M. The intraindividual variation of cystatin C is greater than that of creatinine. This might be due to the better ability of cystatin C to reflect temporary changes especially in mildly impaired GFR, most critical for early detection of rejection and other function impairment. Thus, cystatin C allows for rapid and accurate assessment of renal function (GFR) in renal transplants and is clearly superior to the commonly used serum creatinine.     

Determination of glomerular filtration rate per unit renal volume using computerized tomography: correlation with conventional measures of total and divided renal function

PURPOSE: Previous studies suggest that functional computerized tomography (CT) can measure glomerular filtration rate (GFR) per unit renal volume. We compared this index with conventionally determined GFR measurements. MATERIALS AND METHODS: A total of 16 men and 8 women 63.3 +/- 14.9 years old (range 31 to 88) were studied using with contrast enhanced CT. A single slice of kidney was scanned sequentially after bolus injection (0.5 to 1.0 ml. per second(-1)) of 20 ml. iopamidol (300 mg. iodine per ml.(-1)). GFR per volume of kidney was calculated using a Patlak graphical analysis, and this index was multiplied by renal volume on CT to yield global GFR (ml. per minute(-1)). Divided function was also calculated. GFR and divided renal function were calculated in all cases from radioisotope renography with 99m diethylenetetraminepentaacetic acid. In 12 subjects in whom 24-hour urine collection was possible GFR was also calculated from creatinine clearance. RESULTS: A strong correlation was observed between divided renal function, expressed with respect to the right kidney calculated from CT (52.7 +/- 14.8%, range 19.9% to 97.4%) and by radioisotope renography (51.7 +/- 14.6%, range 18.9% to 92.6%, r = 0.97, p <0.0001). A strong correlation (r = 0.92, p <0.0001) was also seen between global GFR determined by CT (80.1 +/- 43.9 ml. per minute(-1), range 38.2 to 197.9) and creatinine clearance (72.4 +/- 47.5, range 14.6 to 168.5), and was stronger than the correlation between the radioisotope and creatinine clearance method (r = 0.67, p = 0.02) in the same patients. CONCLUSION: Functional CT using nonionic contrast material can measure GFR normalized to renal volume and is an accurate alternative to conventional methods of renal function evaluation.     

Prognostic factors of cirrhotic patients in extra-hepatic surgery

BACKGROUND: The surgical approach to a cirrhotic patient is conditioned by a number of variables depending on the emergency and kind of the intervention. It is also related to the evolutionary stage of the liver pathology (evaluated following Child-Pugh score). The present study will explore the physiopathologic mechanisms which should be correlated with the preoperative risk factors responsible for the variation of morbidity and mortality of the hepatopathic patient addressed to an extrahepatic surgical intervention. METHODS: This study includes a retrospective analysis (from 1992 to 1999) of 40 patients with cirrhosis (80% HCV correlated cirrhosis, 15.5% alcoholic cirrhosis, 2.5% cryptogenic cirrhosis), who underwent such procedures as: colon resection (5), gastrectomy (4), hernioplasty (11), cholecystectomy (14), ulcorraphy (3), laparotomy (3). Patients with hepatic resection and portal shunt are excluded from this study. A pre- and postoperative evaluation of ascites, PT, APTT, albumin, bilirubin and protein value, number of leukocytes and Child-Pugh score was performed on all patients. Their follow-up was 30 days. RESULTS: The presence of tensive ascites, low albumin value, PT, APTT, together with the emergency of the operation, proved to be significant (p<0.001), in correlation with a mortality of 7.1% in Child's class A, of 23% in class B, and of 84% in class C. CONCLUSIONS: Cirrhotic patients undergoing elective or emergency surgery can incur significant preoperative risks and postoperative complications, increasing their mortality rate. An accurate preoperative predictive factor is Child's class.