Peritoneal dialysis as a therapeutic solution in elderly patients with cardiorenal syndrome and heart failure: A case-series report.

BACKGROUND: The aim of this work was to evaluate the impact of peritoneal dialysis (PD) on venous congestion, right ventricular function, pulmonary artery systolic pressure (PASP), and clinical functional status in elderly patients with cardiorenal syndrome (CRS) and chronic heart failure (HF). METHODS: A case series of 21 (17 males, age 70 ± 11 years) consecutive patients with HF along with diuretic resistance and right ventricular dysfunction (median renal failure duration 60 months, range 13-287 months, mean ejection fraction 36 ± 11%) having been engaged in PD; 76% of the patients were under automated peritoneal dialysis (APD), whereas the rest were under continuous ambulatory PD (CAPD). Patients' PASP and central venous pressure (CVP) - through compression sonography - and body weight were evaluated before initiating the PD program and at 6 and 12 months. RESULTS: During the follow-up period, the mortality rate was 8 deaths out of 21 patients (38%) A significant reduction by 29.9% in PASP levels (p = 0.013) and by 42% in CVP levels (p < 0.001), and in right ventricular function assessed by tricuspid annulus tissue Doppler velocity (p = 0.04) was observed, whereas patients' weight increased by 3.7% (p = 0.001). New York Heart Association class improved in 12 patients, whereas in the remaining patients, it remained constant (p = 0.046). In 8 patients, complications were reported (mainly presence of Staphylococcus aureus). In conclusion, PD seems to confer a substantial benefit in clinical status, which is in line with improvement in venous congestion and right ventricular systolic pressure among elderly patients with HF along with CRS.

Noninvasive assessment of haemodynamics in resistant hypertension: the role of the renal resistive index.

OBJECTIVE: The association of resistant hypertension (RHTN) with renal haemodynamics is unclear. Our aim was to evaluate differences in haemodynamic characteristics of patients with RHTN compared with patients with controlled hypertension (HTN) at the level of the heart, kidney and aorta. METHODS: We studied 50 patients with RHTN confirmed by ambulatory blood pressure monitoring and 50 controlled hypertensive patients matched for age and sex. All participants underwent renal Doppler ultrasound to determine the renal resistive index (RRI), a complete echocardiographic study including measurements of diastolic function and evaluation of augmentation index. RESULTS: Hypertensive patients with RHTN compared with those without RHTN had a significantly decreased E/A ratio (by 0.12, P = 0.043), an increased E/e' ratio (by 3.1, P < 0.001), increased albumin-to-creatinine ratio levels (by 49 mg/g, P = 0.023) and a significantly higher RRI (by 0.078, P < 0.001) but similar augmentation index values (P = 0.79). Logistic regression revealed that presence of RHTN was the strongest predictor of an RRI more than 0.7 after controlling for other haemodynamic variables including blood pressure levels. Receiver-operator characteristic analysis revealed an area under the curve for prediction of RHTN by the RRI alone of 80.3% (95% confidence interval: 0.72-0.89, P < 0.001). An RRI cut-point of 0.648 has a sensitivity of 78% and a specificity of 72% for prediction of RHTN. CONCLUSION: In a well treated hypertensive population, patients with RHTN show more pronounced renal and cardiac haemodynamic dysfunction compared with patients with controlled HTN. A greater RRI seems to be associated with RHTN and may help identify such patients.

Preclinical cardiorenal interrelationships in essential hypertension.

A diseased heart causes numerous adverse effects on kidney function, and vice versa renal disease can significantly impair cardiac function. Beyond these heart-kidney interrelationships at the clinical level, a reciprocal association has been suggested to exist even in the early stages of those organs' dysfunction. The aim of the present review is to provide evidence of the presence of a preclinical cardiorenal syndrome in the particular setting of essential hypertension, focusing on the subsequent hypertensive sequelae on heart and kidneys. In particular, a plethora of studies have demonstrated not only the predictive role of kidney damage, as expressed by either decreased glomerular filtration or increased urine albumin excretion, for adverse left ventricular functional and structural adaptations but also preclinical heart disease, i.e. left ventricular hypertrophy that is associated with deterioration of renal function. Notably, these reciprocal interactions seem to exist even at the level of microcirculation, since both coronary flow reserve and renal hemodynamics are strongly related with clinical and preclinical renal and cardiac damage, respectively. In this preclinical setting, common pathophysiological denominators, including the increased hemodynamic load, sympathetic and renin-angiotensin system overactivity, increased subclinical inflammatory reaction, and endothelial dysfunction, account not only for the reported associations between overt cardiac and renal damage but also for the parallel changes that occur in coronary and renal microcirculation.

Comparative prognostic role of nighttime blood pressure and nondipping profile on renal outcomes.

Different studies have addressed the predictive role of nighttime hemodynamics on cardiovascular and renal outcomes, although nocturnal blood pressure (BP) phenotypes (i.e. nondipping pattern and absolute nocturnal BP) have been found to be predictive of worse health outcomes. Furthermore, differences in both examined populations - ranging from healthy and younger subjects to those with overt cardiovascular disease - and study design (i.e. cross-sectional or longitudinal) make the interpretation of the suggested correlations difficult. Focusing on the kidney, we reviewed the literature addressing the impact of nocturnal BP phenotypes on renal outcomes in different populations by further dividing our search by study design. The evidence so far qualifies absolute nocturnal BP as a better predictor or determinant of kidney dysfunction as compared with the nondipping status. The magnitude of nocturnal hemodynamic load imposed at the glomerular level might be of higher prognostic value as compared with the integration of the pathophysiological mechanisms associated with impaired nocturnal BP variability. These findings underline the importance of nocturnal BP phenotypes, retrieved by ambulatory BP measurements, on age-dependent progressive kidney function decline and question whether, to what extent and in whom the reduced nocturnal BP or reverse nondipping BP profile to a normal pattern will be of benefit.

Association of obstructive sleep apnea with urinary albumin excretion in essential hypertension: a cross-sectional study.

BACKGROUND: Microalbuminuria reflects a state of widespread vascular dysfunction, whereas obstructive sleep apnea (OSA) further promotes atherosclerotic damage in hypertension. STUDY DESIGN: Cross-sectional. SETTING & PARTICIPANTS: In an outpatient hypertensive unit, 62 untreated hypertensive patients (aged 48 +/- 7 years; office blood pressure [BP], 151 +/- 8/97 +/- 7 mm Hg) with OSA and 70 hypertensive patients without OSA (apnea hypopnea index [AHI] < or = 5) matched for age, sex, smoking status, body mass index, and 24-hour pulse pressure were studied. PREDICTOR VARIABLE: Hypertension and OSA compared with hypertension without OSA. OSA defined as AHI greater than 5, documented by polysomnography. OUTCOME VARIABLE: Albuminuria assessed by urinary albumin-creatinine ratio (ACR). MEASUREMENTS: Participants underwent polysomnography, ambulatory BP monitoring, echocardiography, routine metabolic profile assessment, and glomerular filtration rate estimation, whereas ACR was measured from 2 nonconsecutive morning spot urine samples. RESULTS: Hypertensive patients with OSA compared with those without OSA showed increased 24-hour diastolic BP (87 +/- 7 versus 85 +/- 7 mm Hg; P = 0.03) and nighttime pulse pressure (50 +/- 10 versus 45 +/- 10 mm Hg; P = 0.008), but did not differ regarding metabolic profile and estimated glomerular filtration rate. Albuminuria was greater by 57% in patients with OSA compared with those without OSA: log(10)ACR, 1.1 +/- 0.2 versus 0.7 +/- 0.4 mg/g; P < 0.001). In the entire study population, log10(ACR) correlated with log10(AHI) (r = 0.35; P < 0.001), minimum oxygen saturation during sleep (r = -0.33; P < 0.001), 24-hour pulse pressure (r = 0.38; P < 0.001), and nighttime pulse pressure (r = 0.21; P =0 .01). In a multivariable linear regression model, independent predictors of ACR were AHI (beta = 0.36; P < 0.001) and 24-hour pulse pressure (beta = 0.25; P = 0.01). LIMITATIONS: Cross-sectional study. CONCLUSIONS: Albuminuria increases within the normal range in hypertensive individuals with OSA compared with those without OSA proportionally to OSA severity independently of confounders. The association of upper-airway dysfunction with albuminuria and pulsatile hemodynamic load may provide an explanatory mechanism for the OSA-related risk in hypertension.

Pulse high-volume hemofiltration in critically ill patients: a new approach for patients with septic shock.

Mortality rates in septic shock remain unacceptably high despite advances in our understanding of the syndrome and its treatment. Humoral factors are increasingly recognized to participate in the pathogenesis of septic shock, giving a biological rationale to therapies that might remove varied and potentially dangerous humoral mediators. While plasma water exchange in the form of hemofiltration can remove circulating cytokines in septic patients, the procedure, as routinely performed, does not have a substantial impact on their plasma levels. More intensive plasma water exchange, as high-volume hemofiltration (HVHF)can reduce levels of these mediators and potentially improve clinical outcomes. However, there are concerns about the feasibility and costs of HVHF as a continuous modality--very high volumes are difficult to maintain over 24 hours and solute kinetics are not optimized by this regimen. We propose pulse HVHF (PHVHF)-HVHF of 85 ml/kg/hr for 6-8 hours followed by continuous venovenous hemofiltration (CVVH) of 35 ml/kg/hr for 16-18 hours-as a new method to combine the advantages of HVHFimprove solute kinetics, and minimize logistic problems. We treated 15 critically ill patients with severe sepsis and septic shock using daily PHVHF in order to evaluate the feasibility of the technique, its effects on hemodynamics, and the impact of the treatment on pathologic apoptosis in sepsis. Hemodynamic improvements were obtained after 6 hours of PHVHF and were maintained subsequently by standard CVVHas demonstrated by the reduction in norepinephrine dose. PHVHFbut not CVVHsignificantly reduces apoptotic plasma activity within 1 hour and the pattern was maintained in the following hours. PHVHF appears to be a feasible modality that may provide the same or greater benefits as HVHFwhile reducing the workload and cost.

Practice patterns in the management of acute renal failure in the critically ill patient: an international survey.

BACKGROUND: Several controversies have developed over acute renal failure (ARF) definition and treatment: which approach to patient care is most desirable and which form of renal replacement therapy (RRT) should be applied is an everyday matter of debate. There is also disagreement on clinical practice for RRT including the best timing to start, vascular access, anti-coagulation, membranes, equipment and finally, if continuous or intermittent techniques should be preferred. In this lack of harmony, the epidemiology of ARF has recently displayed an outbreak of cases in the intensive care units and nephrologists and intensivists are now called to work together in the case of such a syndrome. SUBJECTS AND METHODS: We report on the responses of 560 contributors, mostly coming from Europe, to a questionnaire submitted during the third International Course on Critical Care Nephrology held in Vicenza, Italy in June 2004. The questionnaire was divided into several sections concerning demographic and medical information, definition of ARF, practice of RRT, current opinions about clinical advantages and problems related to different RRTs and modalities, and beliefs on alternative indications to extracorporeal treatments. RESULTS: More then 200 different definitions of ARF and about 90 RRT start criteria were reported. Oliguria and RIFLE (an acronym classifying ARF in different levels of severity: Risk of renal dysfunction; Injury to the kidney; Failure of kidney function; Loss of kidney function; End-stage kidney disease.) were the most frequent criteria used to define ARF. In 10% of centres all forms of renal replacement techniques are available, and in 70% of cases two or more different techniques are available: absolute analysis of different techniques showed that continuous renal replacement therapies are utilized by 511 specialists (91%), intermittent haemodialysis by 387 (69%) and sustained low efficiency dialysis by 136 (24%). Treatment prescription showed significant differences among specialists, 60% of intensivists being uncertain on RRT dose prescription compared to 40% of nephrologists (P = 0.002). The most frequently selected dosage was '35 ml/kg/h' for urea (25%) and creatinine targets (26%), and '2-3 l/h' for the septic dose (25%). Of the participants, 90% said that they used RRT for non-renal indications, 60% although responders admitted the lack of scientific evidence as a limiting factor to its use. CONCLUSIONS: New classifications such as RIFLE criteria might improve well-known uncertainty about ARF definition. Different RRT techniques are available in most centres, but a general lack of treatment dose standardization is noted by our survey. Non-renal indications to RRT still need to find a definitive role in routine practice.