Hemodialysis vascular access flow measurements by the novel DMed NephroFlow® device: A comparative study with Transonic®

INTRODUCTION

The current Spanish Clinical Guidelines on Vascular Access for Hemodialysis support the need for surveillance and monitoring of vascular access (VA) to avoid complications. Ultrasound dilution (UD) methods are accepted for the evaluation of VA flow and Transonic® has established the gold standard method for the measurement. The DMed NephroFlow (NIPRO®) device, based on UD method has recently been incorporated. We report a comparative study between the classic Transonic® versus the new NephroFlow® device.

MATERIAL AND METHODS

For two consecutive months, measurements of VA flow using both referred systems were performed in patients with a native arteriovenous fistula (AVF) or a graft (AVG) on hemodialysis (HD) in our unit. Both studies were undertaken according to the usual recommendations: VA flow of 250 ml/min, ultrafiltration rate without modifications, both needles in the same vein, and always in the first hour of the HD session.

RESULTS

Forty-five patients were included: 17 women and 28 men, mean age of 67 ± 12 years. Thirty patients were diabetic. The baseline meantime on HD was 51 ± 39 months (range: 3-163). Type of VA was: 17 patients radio-cephalic AVF, 17 brachiocephalic AVF, 7 brachiobasilic AVF, and 3 with a graft. The mean flow estimated by the Transonic® was 1222 ± 805 ml/min and the estimated flow by the NephroFlow® device was 1252 ± 975 ml/min. Good reliability between Transonic® and NephroFlow® was observed, with a reliability index of Cronbach's Alpha of 0.927 and an Intraclass Correlation Index of 0.928.

CONCLUSIONS

The NephroFlow® device seems comparable with the accepted gold standard UD method for estimating VA flow. More studies must be performed to verify these results. However, they should be considered for the surveillance and monitoring of VA flow, in agreement with the Spanish Guidelines.

Establishment of buttonhole technique as a puncture alternative for arteriovenous fístulas. experience of a centre over 3years

INTRODUCTION

The buttonhole (BH) puncture technique for arteriovenous fistulas is an alternative to the classical staggered puncture.

PURPOSE

We present 3years' results incorporating the BH puncture technique for arteriovenous fistulas in our dialysis unit.

MATERIAL AND METHODS

Twenty-two patients were started on BH technique, 15 men and 7 women (mean age: 62 years; SD: 12), with time spent on dialysis when starting the BH technique of 34 months (SD: 34, median: 27, range: 3-136). Seven patients received acenocoumarol and 9 antiplatelet agents. The vascular access median time at the beginning of the technique was 27 months (range: 3-252).

RESULTS

Between 5 and 8 consecutive dialysis sessions were necessary to achieve a proper tunnel puncture. No patient suffered major complications. The average time on BH technique until December 2015 was 12 months (SD: 10, median: 9, range: 1-45). By the end of the study, 5patients were performing self-puncture. Haemostasis times post-dialysis were reduced from 18.6min (SD: 8, prior to the BH technique), to 12.2minutes (SD: 3 after BH) (P=.0005).

CONCLUSIONS

The BH technique is an alternative puncture technique for dialysis patients. Self-puncture and reduction in hemostasis time are potential beneficial aspects. A greater diffusion of this technique in the hemodialysis units would allow it to be better applied. A highly motivated nursing staff is key and a necessary condition for its implementation.

Serratia marcescens bacteraemia outbreak in haemodialysis patients with tunnelled catheters due to colonisation of antiseptic solution. Experience at 4 hospitals

INTRODUCTION

The application of antiseptic solution for handling tunnelled catheters is recommended in patients undergoing haemodialysis. These routine antiseptic procedures in handling catheters are crucial to avoid complications. We report an outbreak of Serratia marcescens (S. marcescens) bacteraemia in numerous haemodialysis units of the Community of Madrid.

MATERIAL AND METHODS

The first cases of bacteraemia due to S. marcescens were isolated in December 2014. The Preventive Medicine Services were informed of the detection of an atypical pathogen in several patients, suspecting a probable nosocomial outbreak. Information from 4 centres with similar S. marcescens bacteraemia was analysed.

RESULTS

Twenty-one cases of bacteraemia related to S. marcescens were identified. The mean age of affected patients was 72±10 years. The mean time on haemodialysis of affected patients was 33±13 months (range: 3-83 months), the median time of tunnelled catheter was 22±13 months. In 11 cases the clinical picture was similar, with hypotension and general malaise during the haemodialysis session. Fever was present in a further 7 cases. In 3 cases the presentation was asymptomatic and was detected by blood cultures. All patients had tunnelled catheters (12 patients with catheter in the right jugular vein, 5 in the left jugular, 2 in the right femoral artery and 2 in the left subclavian artery). Gentamicin intravenous doses (1mg/kg) with catheter lock solution with ciprofloxacin post-dialysis were administered for 3 weeks in 6 patients. In 12 patients the treatment was ceftazidime (2g IV) plus catheter lock solution with the same antibiotic, for 2 weeks. Four patients received oral ciprofloxacin for 2 weeks, in one case together with IV vancomycin. The patients were asymptomatic and without new episodes 48hours after the treatment. No major complications were observed. The teams informed the health authorities of the situation, which then reported the presence of batches of antiseptic (chlorhexidine 0.05 and 2%) colonised by S. marcescens. Given the routine application of this antiseptic in handling catheters at these units, this was considered the source of contagion and new cases were not observed after the removal of the batches.

CONCLUSIONS

The presence of bacteraemia due to unconventional germs should alert us to a potential outbreak. The application of a solution contaminated by S. marcescens in haemodialysis catheters was the source of bacteraemia. The intravenous antibiotic treatment and the catheter lock solution allowed an excellent survival of patients and catheters.

[Relapsing nephrotic syndrome in a diabetic patient with minimal change]

Although nondiabetic nephropathies are common among type 2 diabetic patients, very few cases of minimal change nephrotic syndrome have been reported in diabetic patients. We describe a type 2 diabetic patient that rapidly developed a nephrotic syndrome accompanied by a mild worsening of renal function. Proteinuria was negative one year before and no signs of diabetic retinopathy were found. Renal biopsy established the diagnosis of minimal change disease. Steroid treatment induced a complete remission of nephrotic syndrome and recovery of normal renal function. However, massive proteinuria relapsed two years later. A second cycle of steroids was followed by a disappearance of proteinuria, but a third bout of nephrotic syndrome was observed 6 months later. An 8-weeks cycle of steroids plus chlorambucil induced a complete and persistent remission. Throughout a five-year follow up, no relapse of the nephrotic syndrome was observed and microalbuminuria is negative.

[Membranoproliferative glomerulonephritis associated with autoimmune thyroiditis]

Several cases of glomerular disease have been associated to thyroid diseases. The most frequent lesion described is membranous glomerulopathy, presented as a nephrotic syndrome. Here we report a 67-year-old man who developed a nephrotic syndrome accompanied by rapid derangement of renal function shortly after the onset of a primary hypothyroidism due to autoimmune thyroiditis. High titers of circulating anti-thyroglobulin and anti-microsomal thyroid antigen antibodies were detected. Serum levels of C3 and C4 fractions of complement were markedly decreased. Renal biopsy showed a membranoproliferative glomerulonephritis with severe mesangial proliferation, a type of glomerular involvement non-described previously in the literature, in relation with thyroid diseases. Four boluses of intravenous steroids were administered, followed by oral prednisone for three months. A dramatic recovery of renal function, together with normalization of urinary sediment, proteinuria decrease and normalization of serum complement were observed. Three years later, the patient suffered from a similar event, with a positive response to steroids again. One year later, the patient had a new recurrence and was treated with mycophenolate mofetil , improving his clinical situation.

Obesity favors surgical and infectious complications after renal transplantation

The prevalence of obesity is increasing in the renal transplant population. There are controversial data with respect to posttransplant outcome. We performed a study comparing the incidence of surgical and infectious complications among 40 obese patients (body mass index [BMI] pretransplant > or =30 kg/m2) versus a matched nonobese control group (BMI <30 kg/m2) transplanted at our center between June 1989 and March 2001.

RESULTS

There were no differences in patient demographic variables (mean age, gender, cause of renal failure, or percentage of diabetes or hepatitis C virus infection). Donor age, HLA mismatching, sensitization, cold ischemia time, and immunosuppressive regimen were similar in both groups. The mean pretransplant BMI in obese and nonobese patients was 34.1+/-4.0 versus 23.00+/-2.73 kg/m2 (P<.01). The obese group showed a higher incidence of delayed graft function (30% versus 5%, P<.05) and wound infections (12.5%) posttransplant with similar incidences of wound dehiscence, perigraft collections, and graft function at the end of follow up.

[Immunoallergic interstitial nephritis vs. cholesterol atheroembolism. Differentiating characteristics]

The commonest clinical presentation of both immunoalergic interstitial nephritis (IIN) and atheroembolic renal disease (ATD) is an acute renal failure accompanied by skin lesions and eosinophilia. As a consequence, differential diagnosis between both entities is often very difficult. We have performed a comparative retrospective study of those patients diagnosed as having IIN or ATD in our Hospital in the period 1980-2000. A total of 42 patients have been diagnosed of IIN and 16 of ATD. Demographic data, as well as clinical and laboratory parameters and outcomes of every studied patient were analysed. We found a significantly higher prevalence of male sex (100% vs 57%, p < 0.01), previous history of hypertension (100% vs 55%, p < 0.01), chronic renal insufficiency (56% vs 17%, p < 0.01), ischemic heart disease (56% vs 14%, p < 0.001), peripheral ischemic disease, endovascular procedures (87% vs 7%, p < 0.001) and anticoagulant treatments (25% vs 5%, p < 0.001) among patients with ATD as compared with IIN, respectively. On the contrary, previous infections (45% vs 12%, p < 0.01) and exposure to new drugs (100% vs 40%, p < 0.001) were significantly more frequent among IIN patients in compare with ATD. ATD patients showed skin lesions consisting of livedo reticularis and digital infarcts (63% vs 31%, p < 0.05) accompanied by blood pressure increase (100% vs 24%, p < 0.001), whereas IIN patients showed fever (41% vs 19%, p < 0.05) and cutaneous rash as significant clinical manifestations, respectively. The number of ATD patients with proteinuria > 1 g/24 h was significantly higher, but no differences between both groups in the prevalence of urinary sediment abnormalities were observed. The prevalence of absolute eosinophilia was high in both groups (88% among ATD patients, 64% among IIN patients; pNS). Prognosis of both entities was clearly different: Almost all patients with ATD died (69%) or evolved to end-stage renal failure, whereas most patients with IIN showed a recovery of renal function after withdrawal of responsible drugs and steroid treatment. In summary, the analysis of clinical and laboratory data allows an initial differential diagnosis in patients suspected as having IIN or ATD.

Significance of high C-reactive protein levels in pre-dialysis patients

BACKGROUND

An elevated serum C-reactive protein (CRP) has been shown to be strongly predictive of morbidity and mortality in dialysis patients. However, the significance of high CRP levels in the pre-dialysis period has not been studied extensively. The aim of our study was to analyse the evolution of our pre-dialysis population according to their basal levels of CRP.

METHODS

A cohort of 66 pre-dialysis patients was followed for 1 year, after initial determination of serum CRP. The evolution of blood pressure (BP) control, CRP levels, nutritional data (body mass index, serum albumin, prealbumin, transferrin, cholesterol), proteinuria, calcium-phosphorus product, bicarbonate, haemoglobin (Hb), the weekly dose of erythropoietin (Epo)/kg body weight, and the Hb/Epo dose ratio were measured and compared between patients with high (>6 mg/l) or low (<6 mg/l) CRP levels at baseline. The decline in renal function, hospitalization, and death also were measured and compared between the two groups.

RESULTS

At baseline, 23 patients (35%) showed high (>6 mg/l) CRP levels. CRP was higher in patients with a previous history of cardiovascular disease (P<0.01), as well as in patients in whom ischaemic nephropathy or nephrosclerosis was the cause of end-stage renal disease (P<0.01). There were no differences between diabetic and non-diabetic patients. During the study period, patients with higher CRP levels at baseline maintained higher levels (P<0.001). During this period, these patients showed lower (P<0.05) albumin concentration, higher bicarbonate levels, lower Hb concentration, and lower Hb/Epo ratio and needed higher Epo doses. There were no differences in systolic BP, the degree of proteinuria, and the decline in renal function between groups; diastolic BP was lower in patients with high CRP levels. Hospitalization was higher (P<0.005) in this group. Only one patient died.

CONCLUSIONS

The prevalence of inflammation is high in pre-dialysis patients. High serum CRP levels predict a constant inflammatory state on follow-up. As occurs in dialysis patients, pre-dialysis inflammation predicts lower serum albumin concentration, poorer response to Epo, and a higher hospitalization rate. The decline in renal function does not seem to be related to the inflammatory state. Mortality was not affected on short-term follow-up.

[The "quality of life" concept in medical students and postgraduate residents in a university hospital]

We investigated the quality of life's concept and its uses by both residents and interns as well as last year medical students in the University Hospital in Caracas (HUC). A random sample by strata, without replacement of 123 persons, completed a self administered questionnaire which included a set of closed questions and one of open questions related to the quality of life's concept. The mean age was 29 years for both sexes (3.55 standard deviation or SD). There was not a statistically significant difference between males and females. More than 50% read about quality of life in either newspapers, journals and fiction literature. There was no difference among the groups (p = 0.25). Only 68% had heard in a different sort of academical institution the term "quality of life" such as in the school of medicine, highschool or in some discussion groups with no differences among the groups (p = 0.15). However, there was no agreement as from whom and where they learned about quality of life (p < 0.001). Although everybody considered that the quality of life was an important element in medical actions such as diagnostic or therapeutics, its importance was reduced for diagnosis compared to treatment (p < 0.0001). All the elements that were considered as part of the concept were also considered as important, regardless of the group and was statistically significant (p < 0.05). The open question analysis showed that the non-medical definitions represent 85.15% of the group, 50% out of them included terms of potentiality or condition. Among the elements included in the definition was the social in 27.65%, psychological in 23.53% and, the economical in 12.35% of the questionnaires. The great majority of the "quality of life" definitions did not include a clearly defined subject and in many cases it was exclusively related to ill persons. Finally, there is an informal and not well oriented form of learning about "quality of life" in residents, interns and last year medical students with a lack of a good applicability in the medical practice. Therefore, there is a need for a formal training on quality of life along the medical studies and its uses in the medical practice in general and with special emphasis on diagnosis and therapeutics.