An in vivo analysis of reverse ultrafiltration during high-flux and high-efficiency dialysis.

We have developed an in vivo pressure monitoring system to study the phenomenon of reverse ultrafiltration of dialysate during high-flux and high-efficiency dialysis. Under the usual operating conditions of either type of dialysis, driving pressures existed for reverse ultrafiltration of dialysate into the venous end of the blood compartment. Whether or not reverse ultrafiltration could be abolished at higher ultrafiltration rates was dialyzer-dependent, being least with high-efficiency dialysis. In addition, the degree of reverse ultrafiltration was affected by patients hematocrit, dialyzer inlet and outlet oncotic pressures, and the rate and direction of dialysate flow.     

A population-based analysis of emergent vs. elective hospital admissions for an intrathoracic stomach

Background  

Large-scale, population-based analyses of the demographics, management, and healthcare resource utilization of patients with an intrathoracic stomach are largely unknown, an issue which has become more important with the aging of the population. Our objective was to understand the magnitude of the problem and to assess clinical outcomes and hospital costs in elective and emergent admissions of patients with an intrathoracic stomach in a large population-based study.     

Acute-on-chronic kidney injury at hospital discharge is associated with long-term dialysis and mortality

Existing chronic kidney disease (CKD) is among the most potent predictors of postoperative acute kidney injury (AKI). Here we quantified this risk in a multicenter, observational study of 9425 patients who survived to hospital discharge after major surgery. CKD was defined as a baseline estimated glomerular filtration rate <45 ml/min per 1.73 m(2). AKI was stratified according to the maximum simplified RIFLE classification at hospitalization and unresolved AKI defined as a persistent increase in serum creatinine of more than half above the baseline or the need for dialysis at discharge. A Cox proportional hazard model showed that patients with AKI-on-CKD during hospitalization had significantly worse long-term survival over a median follow-up of 4.8 years (hazard ratio, 1.7) [corrected] than patients with AKI but without CKD.The incidence of long-term dialysis was 22.4 and 0.17 per 100 person-years among patients with and without existing CKD, respectively. The adjusted hazard ratio for long-term dialysis in patients with AKI-on-CKD was 19.8 compared to patients who developed AKI without existing CKD. Furthermore, AKI-on-CKD but without kidney recovery at discharge had a worse outcome (hazard ratios of 4.6 and 213, respectively) for mortality and long-term dialysis as compared to patients without CKD or AKI. Thus, in a large cohort of postoperative patients who developed AKI, those with existing CKD were at higher risk for long-term mortality and dialysis after hospital discharge than those without. These outcomes were significantly worse in those with unresolved AKI at discharge.     

Effect of high-flux dialysis on the anaemia of haemodialysis patients.

BACKGROUND: Anaemia is one of the major clinical characteristics of patients with chronic renal failure, and has a considerable effect on morbidity and mortality. Adequate dialysis is of paramount importance in correcting anaemia by removing small and medium-sized molecules, which may inhibit erythropoiesis. However, high-molecular-weight inhibitors cleared only by means of highly porous membranes have also been found in uraemic serum and it has been claimed from uncontrolled studies that high-flux dialysis could improve anaemia in haemodialysis patients. METHODS: We therefore planned this multicentre randomized controlled trial with the aim of testing whether the use of a large-pore biocompatible membrane for a fixed 12-week follow-up improves anaemia in haemodialysis patients in comparison with the use of a conventional cellulose membrane. Eighty-four (5.3%) of a total of 1576 adult haemodialysed patients attending 13 Dialysis Units fulfilled the entry criteria and were randomly assigned to the experimental treatment (42 patients) or conventional treatment (42 patients). RESULTS: Haemoglobin levels increased non-significantly from 9.5+/-0.8 to 9.8+/-1.3 g/dl (dP=0. 069) in the population as a whole, with no significant difference between the two groups (P:=0.485). Erythropoietin therapy was given to 32/39 patients (82%) in the conventional group, and 26/35 (74%) in the experimental group (P:=0.783) with subcutaneous administration to 26/32 patients in conventional and to 23/26 patients in experimental group, P:=0.495. Dialysis dose (Kt/V) remained constant in both groups (from 1.30+/-0.17 to 1.33+/-0.20 in the conventional group and from 1.28+/-0.26 to 1.26+/-0.21 in the experimental group, P:=0.242). Median pre- and post-dialysis beta(2)-microglobulin levels remained constant in the conventional group (31.9 and 34.1 mg/dl at baseline) and decreased in the experimental group (pre-dialysis values from 31.1 to 24.7 mg/dl, P:=0.004 and post-dialysis values from 24.8 to 20.8 mg/dl, P:=0.002). Median erythropoietin doses were not different at baseline (70 IU/kg/week in conventional treatment and 90 IU/kg/week in experimental treatment, P:=0.628) and remained constant during follow-up (from 70 to 69 IU/kg/week in the conventional group and from 90 to 91 IU/kg/week in the experimental group, P:=0.410). Median erythropoietin plasma levels were in the normal range and remained constant (from 12.1 to 12.9 mU/ml in the conventional group and from 13.2 to 14.0 mU/ml in the experimental group, P:=0.550). CONCLUSIONS: This study showed no difference in haemoglobin level increase between patients treated for 3 months with a high-flux biocompatible membrane in comparison with those treated with a standard membrane. When patients are highly selected, adequately dialysed, and have no iron or vitamin depletion, the effect of a high-flux membrane is much less than might be expected from the results of uncontrolled studies.     

Relatively high pulmonary and cardiovascular mortality rates in screening-detected aneurysmal patients without previous hospital admissions.

BACKGROUND: Men with abdominal aortic aneurysm (AAA) who are not hospitalised for pulmonary and cardiovascular diseases may have higher mortality due to such disorders. MATERIAL AND METHODS: Previous discharge diagnoses and causes of death were collected for 4,816 men aged 64-73 years attending mass screening for AAA. Of these, 191 (4%) had an AAA. Overall, cardiovascular- and pulmonary-disease-specific mortality was compared for men with and without AAA stratified for earlier pulmonary or cardiovascular hospitalisations by Cox's proportional hazards regression while adjusting for age. Absolute risk differences after five years were calculated by life table analysis. RESULTS: The median observation time was 63 months. 362 men died from cardiovascular causes other than AAA, and 144 died from pulmonary causes. The cardiovascular mortality was significantly higher in aneurysm patients without previous related hospitalisation (HR=4.35, 95% CI: 2.73-6.94, P<0.001) with an absolute mortality difference after 5 years of 16.3% (95% CI: 10.2-22.5%). Pulmonary-cause mortality was higher among men with AAA both with and without previous hospitalisation for pulmonary causes (HR=3.05; 95% CI: 1.19-7.83, P=0.020, and HR=3.29; 95% CI: 1.78-6.08, P<0.001, respectively). CONCLUSIONS: Men with AAA who had not been hospitalised for cardiovascular diseases have more than four times higher cardiovascular mortality. Studies of cohorts being offered relevant prophylaxis may clarify the potential benefits of general preventive actions.     

Aortic insufficiency. A multivariate analysis of incremental risk factors for operative mortality and functional results

The object of this study was to establish which of four chosen preoperative parameters, namely NYHA functional Class, cardio-thoracic ratio (CTR), left ventricular end-diastolic pressure (LVEDP) and ejection fraction (EF), might affect, singly or in combination, the operative risk in isolated, chronic aortic insufficiency (AI). To this purpose we reviewed the records of all adult patients consecutively operated upon in our Department for isolated chronic AI, from 1979 to 1985. Patients with associated cardiac disease, transvalvular aortic gradient, recent endocarditis of a malfunctioning bioprosthesis were excluded from the study, leaving 89 consecutive patients (mean age 47.2 years) for evaluation. St. Jude or Duromedics mechanical prostheses were exclusively used for aortic valve replacement (AVR). Post-operatively all patients received long term anticoagulation. Follow up period ranged from 24 to 109 months (mean 61.8 months). The method of analysis was designed as follows: a) each patient was allocated a positive (+) or a negative (-) variable for the value of each parameter, b) five patient groups were formed on the basis of the free association of parameter variables, c) single variables and their association with early and late mortality, functional results as NYHA Class were compared by statistical methods (chi 2, Student's Test, Wilcoxon Test). The results of the study show: a) only EF significantly influenced early mortality (P less than 0.05), b) late mortality was significantly influenced (P less than 0.001) by NYHA Class and CTR, c) single parameter variables (+ or -) and or their association significantly conditioned functional results.     

Open biliary tract surgery: multivariate analysis of factors affecting mortality.

BACKGROUND/AIM: The overall mortality rate in patients undergoing supraduodenal choledochotomy for benign biliary tract disease is around 3%. The aim of this study is to identify and quantify factors affecting the mortality in a group of patients undergoing open common bile duct exploration for benign biliary disease. METHODS: Patients (n = 158) who underwent common bile duct exploration during a 5-year period in a teaching hospital were retrospectively reviewed. RESULTS: Univariate and multivariate statistical analyses were performed. The former identified four statistically significant variables: age (p < 0.001), acute cholangitis on admission (p < 0. 001), heart disease (p < 0.05), and a dilated common bile duct on preoperative ultrasound scan (p < 0.05). Multivariate analysis identified three variables which independently increased operative mortality: age (p = 0.05), heart disease (p = 0.03), and cholangitis (p = 0.008). The latter was associated with the greatest operative mortality, since it increased almost eight times the risk to die after surgical intervention. CONCLUSION: We conclude that an adequate perioperative cardiovascular management may be important in order to improve surgical outcome. Appropriate antibiotic prophylaxis and subsequent treatment after routine operative bile cultures may reduce septic complications and mortality. Finally, an alternative procedure, such as endoscopic sphincterotomy, may be indicated in high-risk patients in order to drain the common bile duct preoperatively and to decrease the risk of unresponsive biliary sepsis.     

A propensity analysis of late versus early nephrologist referral and mortality on dialysis

Previous studies have analyzed the association between late versus early nephrologist referral (LR, ER) and poor clinical outcomes in patients with end-stage renal disease. We sought to determine whether these poor outcomes were causally related to LR, or whether LR was a proxy for poorer access to health care in general. An inception cohort of incident dialysis patients enrolled in the New Jersey Medicare or Medicaid programs was identified. Using a large number of demographic, clinical, and health care utilization covariates, propensity scores (PS) were then calculated to predict whether a given patient had been seen by a nephrologist at 90 d before first dialysis. Cox proportional hazards models were then built to test the association between timing of nephrologist referral and mortality during the first year of dialysis, using PS adjustment and matching to determine whether this association was confounded by other measures of reduced healthcare utilization. Neither adjustment for PS (HR = 1.31; 95% CI, 1.17 to 1.47) nor matching (HR = 1.40; 95% CI, 1.23 to 1.59) materially changed the initial 36% excess mortality in LR compared with ER patients (HR = 1.36; 95% CI, 1.22 to 1.51). Excess mortality among LR was limited to the first 3 mo of dialysis (HR = 1.75; 95% CI, 1.48 to 2.08) but not present thereafter (HR = 1.03; 95% CI, 0.84 to 1.25). Late nephrologist referral is an independent risk factor for early death on dialysis, even after controlling for other indicators of healthcare utilization. Further research is needed to identify patients at particular risk so that interventions to prevent early deaths on dialysis in LR patients can be developed and tested.     

Impact of high-flux/high-efficiency dialysis on folate and homocysteine metabolism

High-flux/high-efficiency (HF/HE) dialysis may have detrimental effects on micro-nutrients and water-soluble vitamins, such as vitamin B6, whose levels are lowered. Folate deficiency may increase cardiovascular risk through an increase in homocysteine (Hcy) serum levels. We therefore investigated the effects of dialysis with a high-flux (HF) membrane on folate and Hcy metabolism. Twelve patients without any folate supplementation, receiving dialysis with a low-flux membrane prior to the study (TO), were switched to dialysis using a HF triacetate membrane for four months (T1, T2, T3, T4) and received an oral daily folate supplementation during the two last months (T3, T4). Mean predialysis plasma folate levels fell dramatically after one month of HF dialysis (T1) and remained significantly lower than the initial level (p<0.05) at T2. Hcy concentrations were high in all patients at TO (mean 47.3 +/- 17.6 microM, normal range 5 to 15 microM). They did not change during the first two months of the study but dropped steeply after the beginning of oral folate supplementation. Folate supplementation should be used in HF/HE dialysis to avoid folate depletion. The combination of folate supplementation and HF/HE may lower Hcy levels and reduce cardiovascular morbidity and mortality in these patients.     

高通量透析对维持性血液透析患者血压的影响

高通量透析既能清除低分子毒素,也能清除部分中大分子毒素.本研究采用交叉试验设计,旨在比较高通量透析与低通量透析对维持性血液透析(血透)患者血压的影响.     

Intensive care in a hospital for Blacks. A review of 300 consecutive admissions.

Experinece with the first 300 patients in a new Intensive Care Unit for Blacks is presented. Causes of death and specific problems are considered in detail.     

SAPS 3 at dialysis commencement is predictive of hospital mortality in patients supported by extracorporeal membrane oxygenation and acute dialysis

Objective: This study examined the association between hospital mortality and five illness–severity scoring systems evaluated at different time points in the intensive care unit (ICU) as well as clinical variables as predictors in critically ill patients supported by extracorporeal membrane oxygenation (ECMO) and acute dialysis. Methods: This multicenter prospective observational study included 104 patients who received ECMO support and acute dialysis from January 2002 to December 2006. Patients’ demographic, clinical and laboratory variables were analyzed as predictors of survival. The SAPS 2, APACHE II, SOFA, MODS, and SAPS 3 scores upon ICU admission and at acute dialysis commencement were evaluated to predict the patient's hospital mortality. Results: Hospital mortality for the study group was 76% (79/104). Among the five scoring systems, only SAPS 3 score showed a significant difference between survivors and non-survivors either upon ICU admission (p = 0.038) or at dialysis commencement (p = 0.001). SAPS 3 score at dialysis commencement showed the best discrimination ability by using the area under the receiver operating characteristic curve (SOFA, 0.55; SAPS 2, 0.56; MODS, 0.58; APACHE II, 0.59; and SAPS 3, 0.73). Multiple logistic regression analysis indicated that SAPS 3 score at dialysis commencement (OR: 1.070, 95% CI: 1.016–1.216) and IABP usage before ECMO (OR: 4.181, 95% CI: 1.448–12.075) were two independent risk factors for hospital mortality. Conclusions: Among five common ICU scoring systems evaluated at different time points, SAPS 3 at dialysis commencement is the best risk adjustment systems to predict hospital mortality in critically ill patients supported by ECMO and acute dialysis. Furthermore, the SAPS 3 score at dialysis commencement and IABP usage before ECMO are two major independent predictors for hospital mortality in patients supported by ECMO and acute dialysis.     

Pediatric spinal injury: review of 174 hospital admissions.

Injury to the spinal column and spinal cord occurs relatively infrequently in the pediatric population. A review of 174 pediatric patients is presented, representing 5.4% of all patients admitted with spinal injury. Spinal cord injury was present in 45% of patients. A distinct injury profile, explained by anatomical and biomechanical features, distinguishes the young patient with an immature spine from older adolescents with a more mature, adult-like spine. The younger patients, while less likely to have spinal injury, had a higher incidence of neurological injury, in addition to a higher frequency of both spinal cord injury without radiological abnormality and upper cervical cord injury. In addition, younger patients with spinal cord injury and no radiological abnormality were more likely to have complete or severe cord injury. Prognosis was determined by the severity of spinal cord injury. Patients with complete cord injuries showed little improvement, while patients with incomplete injuries generally fared much better, with 74% showing significant improvement and 59% experiencing a complete recovery of neurological functions. There were six deaths, but none was attributed solely to spinal injury. The authors conclude that outcome is quite good after pediatric spinal cord injury that does not produce a physiologically complete cord deficit.     

Intermittent high-flux albumin dialysis with continuous venovenous hemodialysis for acute-on-chronic liver failure and acute kidney injury

Acute-on-chronic liver failure (ACLF) requiring intensive medical care and associated with acute kidney injury (AKI) has a mortality rate as high as 90% due to the lack of effective therapies. In this study, we assessed the effects of intermittent high-flux single-pass albumin dialysis (SPAD) coupled with continuous venovenous hemodialysis (CVVHD) on 28-day and 90-day survival and an array of clinical and laboratory parameters in patients with severe ACLF and renal insufficiency. Sixteen patients were studied. The diagnosis of ACLF and AKI was made in accordance with current EASL Clinical Practice Guidelines, including the recommendations of the International Club of Ascites. All patients received SPAD/CVVHD treatments as the blood purification therapy to support liver, kidneys, and other organs. Five patients were transplanted and 11 were not listed for transplantation because of active alcoholism. Data at the initiation of SPAD/CVVHD were compared with early morning data after the termination of the extracorporeal treatment phase. All patients had ACLF and renal insufficiency with 13/16 additionally fulfilling the AKI criteria. A total of 37 SPAD/CVVHD treatments were performed [2.3 ± 1.4]. The baseline MELD-Na score was 37.6 ± 6.6 and decreased to 33.4 ± 8.7 after SPAD/CVVHD (P < 0.001). In parallel, the CLIF-C ACLF grade and OF score, estimated at 28- and 90-day mortality, AKI stage, hepatic encephalopathy grade, and liver function tests were lowered (P = 0.001–0.032). The 28- and 90-day survivals were 56.2% overall and 53.8% in AKI. Survival in patients not transplanted (n = 11) was 45.4%. In patients with severe ACLF and AKI, the renal replacement therapy coupled with high-performance albumin dialysis improved estimated 28- and 90-day survival and several key clinical and laboratory parameters. It is postulated that these results may be further improved with earlier intervention and more SPAD treatments per patient. High-performance albumin dialysis improves survival and key clinical and laboratory parameters in severe ACLF and AKI.     

Disease profiles for white and black adult and geriatric patients. An analysis of 2,008 hospital medical admissions

A prospective analysis of 2,008 discharge diagnoses revealed important differences in disease incidence between black and white adult and geriatric patients treated in the Department of Medicine, Frere Hospital, East London. Among geriatric patients the major differences were the increased incidences among blacks of tuberculosis, pulmonary circulatory disorders and cardiomyopathy, as opposed to ischaemic heart disease, cerebrovascular disorders and chronic obstructive pulmonary disease among whites. Among blacks hypertension was less common than had been expected and occurred predominantly in females. Tuberculosis affected 14% of blacks but only 1.6% of whites. It was also the commonest cause of medical deaths and responsible for 31% of deaths of black patients. Analysis of age patterns showed that 68% of whites and 31% of blacks were over 60 years old; 18% of whites and 3% of blacks were over 80 years old. These figures indicate the need to extend hospital facilities for geriatric patients, and for more comprehensive training in geriatric medicine for doctors and nurses.