Risk Factors for Potential Drug-Drug Interactions in Patients on Chronic Peritoneal Dialysis.

INTRODUCTION: The prevalence of potential drug-drug interactions (pDDIs) is becoming a major safety concern, as it has been previously linked to a significant number of adverse drug events and could have serious consequences for patients, including death. This is especially relevant for patients with chronic renal failure, as they are particularly vulnerable to drug-drug interactions. The aim of this study was to evaluate the prevalence and associated factors of pDDIs in patients receiving chronic peritoneal dialysis. METHODS: An observational, cross-sectional study was conducted on consecutive peritoneal dialysis patients attending four tertiary care hospitals for regular monthly examination. The primary outcome was the number of pDDIs identified using Lexicomp. Potential predictors were determined using multiple linear regression. RESULTS: Total number of patients included in the study was 140. The results showed that pDDIs were highly prevalent, especially in patients who use antiarrhythmics (p = 0.001), have diabetes mellitus (p = 0.001), recently started peritoneal dialysis (p = 0.003), or have higher number of prescribed drugs (p < 0.001). Number of prescribed drugs (p < 0.001) remained a significant predictor of high-risk pDDIs in addition to the female gender (p = 0.043). CONCLUSION: Clinicians should be particularly cautious when prescribing multiple medications to high-risk patients, such as peritoneal dialysis patients, to mitigate the risk of drug-drug interactions and associated adverse health outcomes.

Factors Associated with Potentially Inappropriate Prescribing in Patients on Peritoneal Dialysis.

INTRODUCTION: Inappropriate prescribing is common in patients with end-stage kidney disease, especially in those over 65 years of age. Our study aimed to reveal potentially inappropriate drug prescribing in patients on peritoneal dialysis (PD) and explore factors associated with this phenomenon. METHODS: The research was designed as an observational, cross-sectional study on a convenient sample of 145 consecutive patients with PD who attended the four tertiary-care hospitals in Serbia. The main outcome was the extent of inappropriate prescribing, as assessed by the medication appropriateness index, and potential predictors were tested by multiple linear regression. RESULTS: Inappropriate prescribing was a widespread phenomenon among patients on PD. The main factors that promote inappropriate prescribing in this subgroup of patients on kidney replacement therapy are comorbidities (p = 0.000), increased body weight (p = 0.022), a number of prescribed drugs (p = 0.000), and arterial hypertension on examination (p = 0.030). On the other hand, drinking alcohol and higher systolic blood pressure were associated with a lower inappropriate prescribing. CONCLUSION: In order to prevent the occurrence of inappropriate prescribing and its severe health or economic consequences, clinicians should pay special attention when prescribing new drugs to high-risk patients.

Cardiovascular risk assessment and coronary artery calcification burden in asymptomatic patients in the initial years of hemodialysis.

The specific tool for cardiovascular risk assessment in hemodialysis population has not yet been proposed, despite high prevalence of cardiovascular morbidity, and mortality in clinically asymptomatic patients. Coronary artery calcium score (CACS), as a reliable predictor of future cardiovascular events, might be a valuable approach. We sought to evaluate coronary artery calcification burden and its association with clinical and laboratory parameters in asymptomatic patients who recently initiated hemodialysis. The cross-sectional study included 60 asymptomatic patients receiving chronic hemodialysis for no longer than 48 months. CACS was assessed by cardiac computed tomography. Intima-media thickness (IMT) of both common carotid and femoral arteries were measured using ultrasonography. The mean total CACS was 160.50 (443). Patients' age correlated significantly with CACS (σ = 0.367; P = 0.004), carotid (σ = 0.375; P = 0.004) and femoral IMT (σ = 0.323; P = 0.013). Patients with CACS = 0 were significantly younger than patients with CACS >400: 52.4 ± 7.91 vs. 63.88 ± 8.37 years old, respectively (P = 0.034). In patients receiving dialysis for longer than 24 months CACS, femoral and carotid IMT were higher than in those dialyzed for less than 24 months; however, none has reached significance. There was a significant positive correlation between CACS and right (σ = 0.312; P = 0.018) and left (σ = 0.521; P < 0.001) femoral IMT, while not with carotid. CACS showed significant negative correlation with the serum iron (σ = -0.351; P = 0.007). Calcification burden varies significantly in asymptomatic patients in early years of dialysis. It correlates with patients' age and tends to increase with dialysis vintage. Femoral IMT might be useful for cardiovascular risk stratification in asymptomatic patients who recently initiated hemodialysis.

The role of Doppler ultrasonography in vascular access surveillance-controversies continue.

Chronic hemodialysis therapy required regular entry into the patient's blood stream with adequate flow. The use of arteriovenous fistulas and grafts is linked with lower morbidity and mortality than the use of catheters. However, these types of accesses are frequently affected by stenoses, which decrease the flow and lead to both inadequate dialysis and access thrombosis. The idea of duplex Doppler ultrasound surveillance is based on the presumption that in-time diagnosis of an asymptomatic significant stenosis and its treatment prolongs access patency. Details of performed trials are conflicting, and current guidelines do not support ultrasound surveillance. This review article summarizes the trials performed and focuses on the reasons of conflicting results. We stress the need of precise standardized criteria of significant access stenosis and the weakness of the metaanalyses performed.

Role of Doppler ultrasonography in the evaluation of hemodialysis arteriovenous access maturation and influencing factors.

The goal of vascular access creation is to achieve a functioning arteriovenous fistula (AVF) or arteriovenous graft (AVG). An autologous fistula has been shown to be superior to AVG or to central venous catheters (CVCs) with lowest rate of re-intervention, but vessel obstruction or immaturity accounts for 20 % to 54% of cases with primary failure of AVF. This review is focused on the factors influencing maturation; indication and timing of preoperative mapping/creation of vascular access; ultrasound parameters for creation AVF/AVG; early postoperative complications following creation of a vascular access; ultrasound determinants of fistula maturation and endovascular intervention in vascular access with maturation failure. However, vascular accesses that fail to develop, have a high incidence of correctable abnormalities, and these need to be promptly recognized by ultrasonography and managed effectively if a high success rate is to be expected. We review approaches to promoting fistula maturation and duplex ultrasonography (DUS) of evaluating vascular access maturation.

Quality assessment of vascular access procedures for hemodialysis: A position paper of the Vascular Access Society based on the analysis of existing guidelines.

Quality assessment in vascular access procedures for hemodialysis is not clearly defined. The aim of this article is to compare various guidelines regarding recommendation on quality control in angioaccess surgery. The overall population of end-stage renal disease patients and patients in need for hemodialysis treatment is growing every year. Chronic intermittent hemodialysis is still the main therapy. The formation of a functional angioaccess is the cornerstone in the management of those patients. Native (autologous) arteriovenous fistula is the best vascular access available. A relatively high percentage of primary failure and fistula abandonment increases the need for quality control in this field of surgery. There are very few recommendations of quality assessment on creation of a vascular access for hemodialysis in the searched guidelines. Some guidelines recommend the proportion of native arteriovenous fistula in incident and prevalent patients as well as the maximum tolerable percentage of central venous catheters and complications. According to some guidelines, surgeon's experience and expertise have a considerable influence on outcomes. There are no specific recommendations regarding surgeon's specialty, grade, level of skills, and experience. In conclusion, there is a weak recommendation in the guidelines on quality control in vascular access surgery. Quality assessment criteria should be defined in this field of surgery. According to these criteria, patients and nephrologists could choose the best vascular access center or surgeon. Centers with best results should be referral centers, and centers with poorer results should implement quality improvement programs.

Optimal timing for vascular access creation.

Many guidelines recommend that end-stage renal disease (ESRD) patients should have a permanent vascular access, preferably an autologous arteriovenous fistula (AVF), at the start of renal replacement therapy. Nevertheless, a large proportion of patients still start hemodialysis with a central venous catheter (CVC). On the other hand, there are increasing numbers of patients in whom an AVF has been created, but who never actually end up on dialysis, as well as a substantial number of patients in whom creation of a vascular access has been attempted unsuccessfully.To improve this situation, timely exploration to assess suitability for and creation of preemptive AVF should be promoted. Decision to construct an AVF should depend on the likelihood and rate of progression to ESRD. For this goal, some reliable prediction models are available. Also, the likelihood that such an attempt will result in a successful outcome should be taken into account, but suitable validated models to accurately make such estimates are lacking. Next to patient-specific factors, some local conditions such as easy access to a vascular surgeon should also be incorporated in the decision-making process between the nephrology team and the patient.

Vascular access registry of Serbia: a 4-year experience.

PURPOSE: Adequate and functional long-term vascular access (VA) is pivotal for the efficient hemodialysis (HD). It has been shown that the most reliable VA is autogenous arteriovenous fistulas (AVFs) as compared with arteriovenous grafts (AVGs) and vascular catheters (VCs). The vascular access register (VAR) has been established since 2010, and the 4-year trend of VA in Serbia is presented in this paper. METHODS: All HD centers in Serbia provided their data by fulfilling the questionnaire that included prevalent and incident HD patients on December 31, 2010-1013. RESULTS: AVF is the most frequent prevalent VA (89.5-93.1 %) and also the most frequent newly created VA (87-89 %) during the observational period. The number of preemptive AVF is increasing, but it is still low (7.8 % in 2010 and 14.6 % in 2013). The percentage of incident AVG is constant (~3.4 %) as well as the number of permanent VC (8.2 % in 2010 and 7.8 % in 2013). The number of incident patients who started HD with AVF is decreasing (from 37 to 27 %), and the number of urgent start with VC is on the increase (from 63 to 73 %). In almost all relevant dialysis centers, vascular access is created by surgeons. Temporal VCs are placed by anesthesiologists (all centers), nephrologists (up to 25 % of centers) and vascular surgeons (up to 20 %). VCs are located mainly in jugular vein, but the number of femoral catheters remains high (up to 69 %). CONCLUSION: Although we have favorable data, the VAR is of a great importance and ensures continuous quality improvement.

[High rate of native arteriovenous fistulas: how to reach this goal?].

The types of vascular accesses for hemodialysis (HD) include the native arteriovenous fistula (AVF), arteriovenous graft (AVG) and central venous catheter (CVC). Adequately matured native AVF is the best choice for HD patients and a high percentage of its presence is the goal of every nephrologist and vascular surgeon. This paper analyses the number and type of vascular accesses for HD performed over a 10-year period at the Clinical Center of Serbia, and presents the factors of importance for the creation of such a high number of successful native AVF (over 80%). Such a result is, inter alia, the consequence of the appointment of the Vascular Access Coordinator, whose task was to improve the quality of care of blood vessels in the predialysis period as well as of functional vascular accesses, and to promote the cooperation among different specialists within the field. Vascular access is the "lifeline"for HD patients. Thus, its successful planning, creation and monitoring of vascular access is a continuous process that requires the collaboration and cooperation of the patient, nephrologist, vascular surgeon, radiologist and medical personnel.

Morphologic and functional vessels characteristics assessed by ultrasonography for prediction of radiocephalic fistula maturation.

PURPOSE: Although native radiocephalic arteriovenous fistula (RCAVF) is the best vascular access for hemodialysis (HD), a major obstacle to increase its use is high frequency of fistulas that fail to mature. The aim of this study was to investigate and define cut-off values of morphologic and functional vessel parameters influencing successful RCAVF maturation using ultrasound. METHODS: A prospective, observational study was performed on 122 patients (66 men) who underwent primary RCAVF creation. Internal diameters of cephalic vein (CVd) and radial artery (ARd), venous distensibility (VD), resistance index (RI) and endothelial function by flow mediated dilatation (FMD) were determined by ultrasound examination before AVF placement. AVF maturation was observed by measuring blood flow (Qa) and CVd 0, 14 and 28 days after creation. Depending on the time when AVFs attained maturity (Qa ≥500 mL/min, CVd ≥5 mm), patients were divided into three groups: (i) successful maturation (after four weeks), (ii) prolonged maturation (within eight weeks) and (iii) failure to mature. RESULTS: Only 11% of patients failed to achieve a mature RCAVF. Successful AVF maturation occurred in 53% of patients and prolonged maturation in 36% of patients. ROC analysis defined the limits ​​of variables relevant for RCAVF success (CVd >1.8 mm, ARd >1.6 mm, VD >0.4 mm). Female sex was associated with prolonged maturation (OR 0.35, 95% CI=0.17-0.72; P=0.005) having a significantly smaller ARd (1.83 vs. 2.01 mm, P=0.01) but better FMD (2981.5 vs. 2689.5, P=0.02) compared to men. CONCLUSIONS: ARd ≤1.6 mm, CVd ≤1.8 mm and VD ≤0.4 mm are exact cut-off points, which best predict nonmaturation of RCAVF. Women need extended time for adequately matured AVF.

Health-related quality of life, treatment efficacy, and hemodialysis patient outcome.

The aim of the study was to examine the influence of improved treatment of hemodialysis (HD) patients on their health-related quality of life (HrQoL) and to assess the predictive value of HrQoL dimensions on patient outcome. The prospective cohort study involved 102 HD patients, and their clinical and laboratory parameters and HD adequacy indices were followed from 2001 to 2007. HrQoL was measured using KDQOL-SF Version 1.3 in 2001, 2004, and 2007. During a six-year period, quality of HD and anemia treatment improved and resulted in significant increase of mean Kt/V (1.2-1.56) and hemoglobin levels (86.5-115.6 g/L). All four HrQoL dimensions (i.e., physical, mental health, kidney disease target issues, and patient satisfaction) remained unchanged, but significant improvement in several HrQoL physical health domains and the effects of kidney disease domain was found. Mortality rate decreased from 18.6% to 7.14% per year. Age was associated positively, but kidney disease target issue score negatively, with patient death. Improved HD adequacy and anemia treatment in HD patients were followed with maintenance of all four HrQoL dimensions unchanged over six years. Moreover, an improvement in several physical health domains and the effects of kidney disease domain was found. Age and kidney disease target issue appeared as significant predictors of patients' death.