微量白蛋白尿对脓毒症早期诊断及预后价值

目的 研究危重症患者微量白蛋白尿(MA)能否早期诊断脓毒症及评估其预后.方法 2013年1月至2014年12月入住本院ICU 206例危重症患者入选本研究,分别检测入ICU时尿白蛋白肌酐比值(ACR1)、乳酸(LAC1)及入ICU 6 h时ACR(ACR2)、乳酸(LAC2)等,追踪28 d病死率.比较脓毒症与非脓毒症ACR1,应用受试者工作特征(ROC)曲线测定ACR1对脓毒症诊断界值,应用Logistic回归分析脓毒症28 d病死的独立危险因素.结果 脓毒症组ACR1显著高于非脓毒症组(P＜0.01),ROC曲线分析提示ACR1诊断脓毒症界值为105 mg/g.脓毒症组28 d死亡患者ACR2显著高于生存者(P＜0.01).ACR2与LAC2是脓毒症患者28 d病死的独立危险因素(P＜0.01),两者死亡预测价值无统计学差异(P＞0.05).结论 入ICU时MA升高可能提示脓毒症.入ICU 6 h时MA与乳酸升高可能是脓毒症28 d病死的独立危险因素.     

Can spot urine protein/creatinine ratio replace 24 h urine protein in usual clinical nephrology?

BACKGROUND: This prospective study was designed to assess whether a single urine specimen, collected at the time of clinical assessment, could be used to estimate 24 h urinary protein excretion. METHODS: The spot urinary protein/creatinine ratio (P/Cr) and 24 h urine protein and creatinine excretion were determined from 103 patients attending a nephrology clinic. Using the spot urine P/Cr, a regression equation was derived, predicting 24 h protein excretion. The performance of the regression equation was tested on a new cohort of 85 patients. Within this new cohort, agreement between the predicted and the actual 24 h urinary protein excretion was assessed using the Bland-Altman technique. The ability of spot urine P/Cr and dipstick urinalysis to predict different threshold levels of protein excretion was assessed using a series of receiver operator curves. RESULTS: A logarithmic relationship exists between the spot P/Cr and 24 h protein excretion, with a correlation of 0.92, P < 0.0001. Agreement between the actual and predicted 24 h urine protein and between spot and 24 h urine P/Cr ratios was suboptimal at higher levels of protein excretion. Discriminant spot urine P/Cr values reliably predicted protein excretion thresholds of 0.3, 0.5, 1.0 and 3.0 g/day. Urinalysis was a poor test for quantitating protein excretion. CONCLUSION: Random spot urinary P/Cr predicts actual 24 h protein excretion with reasonable accuracy in patients with lower levels of protein excretion but is unreliable in patients with high protein excretion and should not be used in the clinical setting unless 24 h urine collection is unavailable.     

Overestimation of renal function in glucocorticosteroid treated patients

Summary Creatinine clearance is commonly used as a parameter for individualization of dosages of drugs primarily excreted by the kidney. Nomograms and equations have been developed for estimating creatinine clearance from serum creatinine concentration, body weight, age and sex. Glucocorticosteroids are said to cause proximal muscle wasting and therefore may be expected to cause a decrease in the creatinine production rate. The purposes of the present investigation were first to evaluate by a computed tomography the effect of long term treatment with prednisone on the mid-thigh muscle area, and second, to establish whether the presumed supposed decrease in muscle mass was associated with a decrease in the urinary creatinine excretion rate, and hence in a systematic error whenever a nomogram is used to predicte creatinine clearance in such subjects. Patients taking prednisone had smaller mid-thigh muscle areas than controls. A linear relationship between the mid-thigh muscle area and the observed urinary excretion of creatinine was found, suggesting that the muscle loss could account for the decrease in the urinary excretion rate of creatinine. The ratio of observed to predicted (by nomogram) urinary creatinine excretion was lower in patients than controls, resulting in a corresponding underprediction of creatinine clearance by nomograms in the patients taking prednisone.     

Coronary and Skeletal Muscle Enzyme Changes during a 14 km Run

ABSTRACT Increasing coronary enzyme values have previously been demonstrated after physical exercise. In the present study serum values of aspartate aminotransferase (ASAT), lactate dehydrogenase (LDH), LDH isoenzymes, creatinine kinase (CK), and the myocardialbound fraction of this enzyme (CK-MB) were measured in a random sample of healthy non-smoking, physically fit men before and immediately after a competitional 14 km run. All enzyme values increased during the run, ASAT by 7 %, LDH by 25 %, CK by 38 %, and CK-MB by 53%. Measurement of LDH isoenzymes showed special increments of the non-cardiac fractions. However, absolute increments of the cardiac fractions of the LDH isoenzymes together with other serum enzyme elevations do not exclude a cardiac source of enzyme release during and following physical exercise.     

Abnormal urinary potassium metabolism in patients with interstitial cystitis

PURPOSE: If most patients with interstitial cystitis (IC) have epithelial leakage allowing urinary K to penetrate the interstitium and provoke symptoms, urinary K should be lower in untreated patients than in healthy subjects and it should increase with successful heparinoid treatment. This study tested these hypotheses. MATERIALS AND METHODS: Na, K and creatinine (Cr) were determined in spot urine samples from new, symptomatic, untreated patients with IC meeting all National Institute of Diabetes and Digestive and Kidney Diseases clinical diagnostic criteria, returning patients with IC reporting 50% or greater symptom improvement after 4 or greater months of oral heparinoid therapy and control subjects, and in 24-hour urine samples from new untreated patients and controls. RESULTS: In spot urine specimens of 37 new patients with IC K-to-Cr ratios were significantly lower than in 18 controls (0.51 vs 0.88 mg/mg Cr, p = 0.001). A total of 50 successfully treated patients with IC had significantly higher K-to-Cr ratios than those in 37 new patients (0.66 vs 0.51 mg/mg Cr, p = 0.025). Na-to-Cr ratios in the 3 groups were not significantly different. In 24-hour urine specimens 30 new patients had lower average K (31.0 vs 46.2 mEq/l, p = 0.01) and lower K-to-Cr ratios (0.43 vs 0.52 mg K/mg Cr, p = 0.01) than in 47 controls, while Na was not significantly different. CONCLUSIONS: Our finding of lower urinary K in new, untreated patients supports the concept of abnormal epithelial permeability and K absorption in IC. Higher urinary K in successfully treated vs untreated patients may reflect decreasing urinary K absorption due to mucosal repair and a resulting decrease in epithelial permeability. K/mg Cr appears accurate for normalizing urinary K.     

The reabsorption of creatinine from the rabbit bladder

Summary Using a radioisotope technique the reabsorption of creatinine from normal, inflamed and chronically obstructed bladders of rabbits was investigated. The reabsorption of creatinine from normal bladders was minimal. Chronic obstruction lead to a rise of the reabsorption rate. The most marked reabsorption however was found with the inflamed bladders. This difference of creatinine reabsorption is statistically significant and it was detectable in the ¹⁴C-creatinine content of the blood, ¹⁴C-creatinine content of the renal pelvis urine and in the activity loss in the bladder urine. The vesical reabsorption of creatinine corresponds in principle with the urea reabsorption which was investigated earlier by the same method. The extent of reabsorption is however different and urea is reabsorbed to a substantially greater extent.     

血管紧张素转换酶抑制剂用于血清肌酐大于266μmol/L的慢性肾脏病患者的研究

目的 探讨血管紧张素转换酶抑制剂（ACEI）对血肌酐（Ser）〉266μmol／L者的肾脏是否具有保护作用及此类患者服用ACEI的安全性。方法慢性肾脏病患者168例,口服贝那普利10mg／d,剔除21例咳嗽者,余147例按Ser水平分为A组（Ser133-265μmol／L组）和B组（Ser266-442μmol／L组）,B组再分为Ⅰ组和Ⅱ组。A组和Ⅰ组患者口服贝那普利10-20mg／d,根据血压控制情况加服钙离子拮抗剂和（或）美托洛尔和（或）血管扩张剂。Ⅱ组患者不服贝那普利,服其他降压药物的情况同Ⅰ组。3组降压的靶目标为≤125／75mmHg。随访2年,以Ser水平较基线值增加1倍,或需要进入透析治疗作为主要研究终点。结果（1）平均动脉压的降幅3组间差异无统计学意义（P〉0．05）;原有高血压的患者血压达靶目标值的比率A组为59．61％,Ⅰ组为48．97％,11组为56．25％（P〉0．05）。（2）尿蛋白平均降幅A组、Ⅰ组明显高于Ⅱ组;尿蛋白基础值〉1．5g／24h者用药2年后尿蛋白降至1g／24h以下的百分率A组为55．55％,Ⅰ组为52．63％,Ⅱ组为16．66％。（3）A组、Ⅰ组、Ⅱ组2年后达主要终点事件的发生率分别为19．23％、40．90％、51．35％,左心室质量指数、左心室肥厚发生率均较基线值明显下降;3组间心血管事件发生率亦无显著差异。（5）Ⅰ组患者治疗后2个月内Ser增加超过30％的人数及咳嗽、高血钾等副作用的发生率与A组、Ⅱ组相比无明显增加。结论ACEI对Ser在266-442μmol／L的慢性肾脏病患者仍有明显的肾脏保护作用,这类患者应用ACEI后副作用的发生率无明显升高。     

Postoperative resorptive and excretory capacity of the ileal neobladder

OBJECTIVE: To assess the extent and mechanism of renal reabsorption and excretion in patients with an ileal neobladder, as mild metabolic acidosis cause by proton reabsorption is common after such surgery, and long-term pharmacological correction is often necessary. PATIENTS AND METHODS: The study comprised 30 patients (29 men and one woman) with ileal neobladders after oncological surgery; before surgery all had normal retention values. Before and after withdrawing the transurethral catheter, serum creatinine and urea were analysed and used to assess the effect of the neobladder on retention values, expressed as the percentage change from baseline (Delta creatinine and urea). RESULTS: There was a significant correlation between the Delta-creatinine and Delta-urea values (P < 0.001; r = 0.66); 15 patients (50%) showed resorption of creatinine and urea, eight (27%) excreted creatinine into the neobladder and resorbed urea from it at the same time, and three (10%) showed the reverse response, i.e. creatinine resorption and urea excretion. Interestingly, four patients (13%) excreted both creatinine and urea into the neobladder. CONCLUSIONS: We assume that there was both a resorptive and excretory function. Probably the metabolic state (resorption or secretion) of the neobladder depends on its mucus production and on the internal surface, or on diuresis. Further investigation is required to characterize these different influences.     

Renal function in patients with nephrolithiasis

PURPOSE: We describe kidney function, as measured by creatinine clearance in stone formers, and classified by type of stone formed and systemic etiologies of stone formation. MATERIALS AND METHODS: The mean of 3 pretreatment 24-hour creatinine clearance measurements in each of 1,856 stone formers and creatinine clearance in 153 normal individuals were used. Clearance was adjusted for patient sex, age and body weight using general linear modeling. RESULTS: As a group, all stone formers had decreased clearance adjusted for age, sex and body weight compared to that in normal individuals. Although clearance was particularly low in cystine and struvite stone formers, they were below normal in even common CaOx stone formers. CONCLUSIONS: As a rule, patients with kidney stones do not have normal kidney function. In clinical management all efforts must be made to minimize renal injury, balancing the risks of obstruction from stones against those of urological procedures.