Beating-heart valve surgery in patients with renal failure requiring hemodialysis

BACKGROUND AND AIM OF THE STUDY: The safety and efficacy of beating-heart valve surgery as a myocardial protection strategy was evaluated in patients with renal failure requiring hemodialysis. METHODS: This was a retrospective review of nine patients (four males, five females; mean age 46.7 years; mean duration of hemodialysis 47 +/- 49 months) who underwent beating-heart valve surgery at the present authors' institution between April 2000 and September 2002. RESULTS: The mean cardiopulmonary bypass time was 77.2 +/- 8 min. Perioperatively, two patients died (one from sepsis; one from complication of anticoagulation). There were no deaths in the follow up since discharge, with average follow up 18.3 months (range: 9-27 months). Other complications included reintubation for <24 h (one case), AV graft thrombosis (one patient) and stroke (one patient, as mentioned above). There were no new cardiac (including arrhythmia and low cardiac output syndrome) or metabolic complications (including hyperkalemia and fluid overload). CONCLUSION: This is the first report of beating-heart valve surgery using simultaneous antegrade and retrograde perfusion with normothermic blood. Despite being small in size, the study demonstrated the safety of this approach in a high-risk population with renal failure requiring hemodialysis. The results suggested a low incidence of complications, and short ICU and hospital stays.     

Treatment of malarial acute renal failure by hemodialysis

We studied 112 patients with malarial acute renal failure (ARF) during the period 1991-1997 at Bangkok Hospital for Tropical Diseases (Mahidol University, Bangkok, Thailand). Hemodialysis was performed in 101 (90.2%) of these patients. The mean number of times the patients were hemodialyzed was 6.5 (range = 1-27). Ninety-three (83.0%) patients were oliguric and the remainder were nonoliguric. Patients who had oliguric renal failure required more hemodialyses and had more complications than the nonoliguric patients. The oliguric patients had an eight-fold higher risk of requiring six or more hemodialyses (95% confidence interval = 1.2-53.9, P = 0.0008). The overall mortality rate was 10.7% (12 of 112). Eleven of the patients who died were jaundiced and eight of them had cerebral malaria with a Glasgow Coma Score < or = 8. We conclude that hemodialysis is a useful treatment for oliguric and nonoliguric ARF from severe malaria, particularly when initiated early in the course of the illness.     

Selected electrocardiographic changes during acute renal failure and hemodialysis

Selected electrocardiographic changes are described in 13 patients with acute renal failure, 12 of whom required hemodialysis with the Kolff Twin-Coil Artificial Kidney.

Arrhythmias, particularly paroxysmal atrial tachycardia with A-V block, were observed in digitalized patients during and after hemodialysis. The dangers associated with the use of digitalis and the prevention and therapy of its toxicity are discussed.

Arrhythmias, especially atrial fibrillation, are observed during hemodialysis. These are probably due to hemodynamic and not chemical factors. A fatal arrhythmia occurred in 1 patient in the presence of normal serum concentrations of potassium, sodium and magnesium and without morphologic explanation.

Electrocardiographic evidence of A-V and intraventricular conduction disturbances due to severe hyperkalemia and reverting to normal within minutes of onset of hemodialysis, is demonstrated.

Electrocardiographic patterns similar to those observed in myocardial injury and infarction have been described in patients with acute renal insufficiency. These changes were reversible in 2 of the 3 patients presented.

Electrocardiographic patterns of myocardial injury observed in patients with acute renal insufficiency due to carbon tetrachloride poisoning are illustrated.     

Risk factors influencing survival in acute renal failure treated by hemodialysis

A retrospective analysis of 58 patients with acute renal failure treated by hemodialysis between 1980 and 1984 was carried out to study mortality and the risk factors that might adversely influence survival. Twenty-six factors, suggested by published data to be relevant to the short-term prognosis of such patients, were evaluated by univariate analysis. Survivors were found to be significantly younger, they were less frequently malnourished or jaundiced, and fewer required inotropic drugs (due to hypotension) or ventilator support after the first week of their illness. Sepsis, heart failure, central nervous system depression, and a greater number of the above complications were characteristic in the nonsurvivors. Multivariate analysis suggests that the probability of survival could be estimated by taking into account three of these factors: age, central nervous system depression, and hypotension. Further studies would be appropriate to test the predictive value of such a probability equation.     

The influence of age and respiratory failure on the outcome of complicated acute renal failure

Acute Renal Failure (ARF) is common in the Intensive Care Unit with elderly patients providing an increasing proportion of cases. We have reviewed 106 cases of ARF requiring renal replacement therapy between 1 January 1989 and 31 December 1991 to investigate the significance of age as a determinant of survival. The overall mortality of the group was 64%. No significant difference was found between the mean age of survivors (51±21 years, n=38) and the 68 patients who died (58±18 years). Twenty eight of the 106 patients were aged 70 years or older and 16 (57%) of these died. However, the mortality of all patients with ARF requiring mechanical ventilation survival was 72% compared to 26% in patients not requiring ventilation, p<0.01. Similarly, 78% (n=14) of the patients aged 70 years or older requiring renal replacement and ventilation died. We conclude that whereas age is not a useful determinant of survival from ARF, co-incident respiratory failure significantly reduces survival. These findings may have important implications for the provision of intensive care to the elderly.     

两种评价急性肾衰竭患者预后及肾脏转归积分模型的比较

目的　比较急性生理和平素健康评估Ⅱ (APACHEⅡ )与急性肾小管坏死 个体严重程度指数 (ATN ISI)两种积分模型对急性肾衰竭 (ARF)患者的预后和肾脏转归的预示效果。方法　回顾性分析了近 1 0年的 42 2例ARF患者资料 ,比较两种积分模型对患者病死率及肾脏转归的预测效果 ,并采用两种积分评定方式对ARF发生 30、45、60d后的肾脏转归进行了判别分析。结果　随着两种模型积分值的增加 ,患者的病死率升高 ,当ATN ISI积分≥ 0 85、APACHEⅡ积分≥ 35时病死率为 1 0 0 % ;APACHEⅡ和ATN ISI模型的ROC曲线下的面积分别为 0 81 7± 0 0 2 1和 0 880± 0 0 1 8,表明两种模型对ARF患者病死率的判别均有意义。对肾脏转归的判别 ,ATN ISI在各评定时间的判别符合率均高于APACHEⅡ ;ATN ISI积分≥ 0 75时 ,均需依赖透析治疗 ;<0 75但≥ 0 58时 ,肾功能未恢复正常 ;肾功能完全恢复者积分值均在 0 58以内。APACHEⅡ积分≥ 2 6时 ,均需依赖透析治疗 ;<2 6时 ,肾功能完全恢复和肾功能不全病人之间无明显积分界限 ;但≤ 2 2时 ,上述二者所占比例分别为 80 4%和1 9 6 %。结论　两种积分模型对ARF患者的病死率及肾脏转归均有较好的预示效果 ,但ATN ISI积分模型对肾脏转归的预示价值更优于APACHEⅡ。     

Immune abnormalities in renal failure and hemodialysis

Considerable work needs to be done in order to understand the immunosuppressive effect of 'uremia' and the lymphocyte changes induced by hemodialysis. For example, the lymphocyte population dynamics can be further defined using monoclonal antibodies specific for lymphocyte subgroups. In vitro assays are available for lymphokine detection (i.e. IL-1, IL-2 which are important for T cell function) and may be correlated with both the clinical state and overall immunobiological status of hemodialyzed patients. The possibility of specifically delineating the extent of the immune system dysfunction in renal failure patients (on or off dialysis) is at hand. With this knowledge it will be possible to manipulate their management so as to minimize function alterations.     

Busulfan clearance in renal failure and hemodialysis

The impact of hemodialysis on the clearance of busulfan was determined in a patient with chronic renal failure undergoing autologous peripheral stem cell transplantation for non-Hodgkin's lymphoma. The extraction ratio for busulfan across the dialyzer was 0.530 +/- 0.026 at a blood flow of 400 ml/min, which corresponds to a hemodialysis clearance of 2.23 +/- 0.11 ml/min/kg body weight. Apparent oral clearance of busulfan without hemodialysis was 3.38 +/- 0.56 ml/min/kg. Thus, a 4 h hemodialysis session enhanced the apparent oral clearance of busulfan by 65%. We conclude that hemodialysis effectively removes busulfan from circulating blood, but a standard hemodialysis period (ie, 4 h) does not significantly alter busulfan exposure. Bone Marrow Transplantation(2000) 25, 201-203.     

Correlates of urea kinetic modeling during hemodialysis in patients with acute renal failure

The current guidelines on dialysis adequacy in acute renal failure (ARF) are loosely defined and have been extrapolated from patients with end-stage renal disease. The objectives of this study were (1) to compare three methods of urea kinetic modeling measurement in patients with ARF receiving intermittent hemodialysis, (2) to compare prescribed to delivered dose of dialysis, and (3) to explore the factors that are associated with dialysis delivery. 'Single-pool' urea kinetic modeling was assessed by the Ureakin) software and the second-generation equation which uses a logarithmic estimate of spKt/V. 'Equilibrated' Kt/V (eKt/V) was calculated using the rate adjustment equation. The prescribed dose was derived using the manufacturer's specifications of the dialyzer clearance, prescribed time, actual delivered blood and dialysate flow, and estimates of volume of urea distribution. A total of 78 consecutive spKt/V measurements were obtained in 24 patients. The mean urea reduction ratio was 51 +/- 1%. The delivered spKt/V was significantly lower than that prescribed (0.87 +/- 0.03 or 0.83 +/- 0.03 vs. 1.28 +/- 0.05; p = 0.0001). The equilibrated Kt/V was markedly lower than the delivered spKt/V (0.73 +/- 0.03 vs. 0.83 +/- 0.03; p = 0.0001). Univariate analyses demonstrated that female gender, low body mass index, low predialysis weight, use of cellulose acetate dialyzers, and increased prescribed time were associated with increased odds of prescribed spKt/V > or =1.2. Similarly, old age, increased delivered time, and high cytokine production were associated with increased odds of delivered spKt/V > or =1.2. In summary, while the impact of delivered intermittent hemodialysis on the survival of patients with ARF remains to be determined, these results indicate that dialysis delivery is suboptimal in ARF, and empiric dosing should strongly consider factors related to lean body mass, including age and gender.     

Long-term outcome for children with acute renal failure following cardiac surgery

Acute renal failure requiring dialysis occurred in 34 children (2.9%) following cardiac surgery over a five year period. 17 children (50%) recovered renal function with 11 (32%) long-term survivors. The long-term outcome for the survivors, in terms of renal function, was studied from 1 to 5 years after their episodes of acute renal failure. Three children had significant abnormalities of renal function despite normal urinalysis. Detailed assessment of renal function is advocated for children who survive acute renal failure following cardiac surgery.     

End-stage renal failure patients requiring renal replacement therapy in the intensive care unit: incidence,clinical features,and outcome

AIMS: To study incidence, clinical features, and outcome of critically ill patients with end-stage renal failure (ESRF) requiring renal replacement therapy (RRT) in the intensive care unit (ICU) and to test the validity of severity scoring systems for these patients. METHODS: Data for ESRF patients treated with RRT were collected from 81 Australian adult ICUs providing RRT. They were compared with matched controls with acute renal failure. RESULTS: Thirty-eight ESRF patients received RRT in the ICU over 3 months. The mean APACHE II score was 21.8 (predicted mortality: 37%) and the SAPS II score 44.7 (predicted mortality: 37%). The hospital mortality was 34%. Receiver operating characteristic curves showed good discrimination ability for hospital mortality for these two scores (AUC: 0.81 for APACHE II and 0.84 for SAPS II). Using admission diagnosis and SAPS II scores, 32 ESRF patients treated with continuous RRT (CRRT) were matched to 32 acute renal failure patients also treated with CRRT. ICU mortality (22 vs. 38%) and hospital mortality (38 vs. 38%) were comparable between the two groups. CONCLUSIONS: ESRF patients requiring RRT in the ICU were relatively frequent. Severity scores could be used to predict the hospital outcome for these patients. Their mortality, when treated with CRRT, was similar to that of diagnosis- and severity-score-matched patients with acute renal failure.     

Risk factors and outcome of hospital-acquired acute renal failure. Clinical epidemiologic study

In order to evaluate potential risk factors for the development of hospital-acquired acute renal failure, a case-control study was performed, comparing patients with hospital-acquired acute renal failure with control subjects matched on age, sex, hospital, service of admission, and baseline renal function. The same patients were then reanalyzed utilizing a cohort study design to investigate outcomes from this syndrome. The following elevated odds ratios (95 percent confidence interval) were found while simultaneously adjusting for possible confounding variables using logistic regression: volume depletion, 9.4 (2.1 to 42.8); aminoglycoside use, 5.6 (1.3 to 23.7); congestive heart failure 9.0 (2.1 to 38.9); radiocontrast exposure, 4.9 (1.2 to 19.7); and septic shock, approached infinity, p less than 0.0001. The effect of volume depletion was markedly accentuated in those with diabetes (odds ratio = 1.9) (p less than 0.05). The risk from aminoglycoside use markedly increased with increasing age (p less than 0.002). Finally, the development of hospital-acquired acute renal failure was associated with a marked increase in the risk of dying--the relative risk (95 percent confidence interval) was 6.2 (2.6 to 14.9)--and a marked increase in length of stay, from a median of 13 days in control subjects to a median of 23 days in case subjects (p = 0.005). In conclusion, hospital-acquired acute renal failure is a serious illness. Attempts to prevent it should focus on proved risk factors.     

Continuous arteriovenous hemodialysis and continuous venovenous hemofiltration in burn patients with acute renal failure

Acute renal failure (ARF) is a very common condition that may occur in patients with major burn injuries. The majority of burn patients with ARF have a high mortality rate, ranging from 73% to 100%. There are several ways to treat ARF in burn patients, including peritoneal dialysis (PD), intermittent hemodialysis, and continuous renal replacement therapy (CRRT). CRRT is generally used in patients in whom intermittent hemodialysis has failed to control hypovolemia, as well as in patients who cannot tolerate intermittent hemodialysis. Additionally, PD is not suitable for patients with burns within the abdominal area. For these reasons, most patients with unstable hemodynamic conditions receive CRRT. In this study (conducted in our burn unit between 1997 and 2004), six burn patients received CRRT: three received continuous arteriovenous hemodialysis (CAVHD) and the other three received continuous venovenous hemofiltration (CVVH). The patients were all males, with a mean age of 49.8 years (range, 27-80 years), and a mean burnt surface area of 65.1% (range, 30-95%). Four patients died due to multiple organ failure, and two patients recovered from severe ARF. CRRT has been proven safe and useful for burn patients with ARF. According to this study, we conclude that CVVH is an appropriate tool for treating ARF, with a lower incidence of vascular complications than CAVHD.     

Oxidative stress in chronic renal failure and hemodialysis

Evidence has accumulated that oxidative stress resulting from the increased generation of oxidants (reactive oxygen species and chlorinated oxidants) by activated phagocytes at the contact of dialysis membranes and dialysate endotoxins and from the uremia-related profound deficiency in antioxidants (glutathion system mainly) plays a prominent role in the pathogenesis of the accelerated atherosclerosis process which accounts for almost one half of deaths in dialysis patients. However more recent studies of large cohorts of uremic patients have shown that oxidative stress is already present at an early stage of chronic renal failure, increases with the progression of uremia and that phagocytic cells are elective targets of uremic toxins. Our recent studies aimed at better characterizing oxidative stress in dialysis patients have led to describe the presence in the plasma of uremic patients of AOPP (Advanced Oxidation Protein Products) which proved to be potential uremic toxins and mediators of inflammation. A better knowledge of the respective contribution of bioincompatibility and uremic toxins at the origin of phagocyte activation will allow to develop therapeutic strategies aimed at reducing the incidence of oxidative stress related complications and with AOPP as a gauge of their efficacy.