Long-term Hemodialysis Patients Research Articles

Pulmonary hypertension among patients undergoing hemodialysis.

Introduction: The epidemiology of pulmonary hypertension (PHT) among long-term hemodialysis patients has been described in relatively small studies in Iran. Objectives: The purpose of this study was to evaluate the prevalence of PHT and its relationship among end-stage renal disease (ESRD) patients undergoing long-term hemodialysis (HD). Patients and Methods: In a cross-sectional study, patients with ESRD treated with HD for at least 3 months in the Imam hospital enrolled for the study. PHT was defined as an estimated systolic pulmonary artery pressure (PAP) equal to or higher than 25 mm Hg using echocardiograms performed by cardiologist. Results: A total of 69 HD patients were included in the investigation. The mean of age of our patients was 52.6±15.3 years. The mean duration of HD was 39±36 months. The mean ejection fraction was 45±7%. The prevalence of PHT was 62.3%. These patients were more likely to have lower ejection fraction. The PHT was more common among female HD patients. We did not find any association between PHT and cause of ESRD, duration of HD, anemia and serum calcium, phosphor and parathyroid hormone levels. Conclusion: Our findings show that PHT is a common problem among ESRD patients undergoing maintenance HD and it is strongly associated with heart failure. It is necessary to screen this disorder among these patients.

Associations between Soluble Receptor for Advanced Glycation End Products (sRAGE) and S100A12 (EN-RAGE) with Mortality in Long-term Hemodialysis Patients.

Hemodialysis (HD) patients experience vascular calcification, ultimately leading to high mortality rates. Previously, we reported associations between soluble receptor for advanced glycation end products (sRAGEs) and extracellular newly identified RAGE-binding protein S100A12 (EN-RAGE) and vascular calcification. Here, we extended our observations, investigating whether these biomarkers may be useful for predicting cardiovascular morbidity and mortality in these subjects. Thus, we evaluated the relationship between sRAGE and S100A12 and mortality in long-term HD patients. This was a prospective observational cohort study in 199 HD patients from an extended analysis of our previous study. Plasma sRAGE, S100A12, comorbidities, and other traditional risk factors were investigated. The cumulative incidences for death using Cox proportional hazards regression were evaluated in multivariable analyses. The observation period was 44 months. During the observation period, 27 (13.6%) patients died. Univariate analysis demonstrated that S100A12 was correlated with diabetes (P = 0.040) and high-sensitivity C-reactive protein (hsCRP) (P = 0.006). In multivariable analyses, plasma sRAGE (hazard ratio [HR] = 1.155; 95% confidence interval [CI] = 0.612–2.183; P = 0.656) and S100A12 (HR = 0.960; 95% CI = 0.566–1.630; P = 0.881) were not associated with mortality in HD patients, although traditional predictors of mortality, including age, history of cardiovascular diseases (CVDs), and serum levels of albumin and hsCRP were related to mortality. Powerful predictors of mortality were age, CVD, and albumin levels. Plasma sRAGE and S100A12 may be weak surrogate markers for predicting all-cause mortality in patients undergoing HD, although S100A12 was partly related to diabetes and inflammation.

Determinant Effects of Average Fasting Plasma Glucose on Mortality in Diabetic End-Stage Renal Disease Patients on Maintenance Hemodialysis

IntroductionDiabetic kidney disease is an increasingly frequent cause of end-stage renal disease. However, mixed results were shown between glycated hemoglobin and mortality.MethodsWe used the average fasting plasma glucose (FPG) levels to predict mortality rates in long-term hemodialysis patients. We enrolled 46,332 hemodialysis patients with diabetes mellitus, who were registered in the Taiwan Renal Registry Data System between January 2005 and December 2012. The patients were stratified based on the quartiles of average FPG levels measured for the first (1-year FPG) and third years (3-year FPG) of hemodialysis. Survival analysis was conducted via multivariable Cox regression.ResultsAfter the first year of hemodialysis, the mean FPG levels were 103.5 ± 14.5, 144.7 ± 11.5, 189.6 ± 15.2, and 280.8 ± 1.2 mg/dl for the first, second, third, and fourth quartile, respectively. The Kaplan-Meier curve showed an incremental reduction in the survival as FPG levels increased (P < 0.0001). In the Cox regression model, the adjusted hazard ratios were 1.15 (95% CI: 1.10–1.20), 1.30 (95% CI: 1.25–1.36), and 1.45 (95% CI: 1.39–1.51) for the pairwise comparisons between the first quartile and the second, third, and fourth quartile, respectively. Similar trends were observed by 3-year FPG. Patients whose FPG levels increased had a 22% increased risk (95% CI: 1.16–1.29) for all-cause mortality compared with patients whose FPG levels decreased.DiscussionOur results suggest that the average FPG levels are useful predictors of all-cause mortality in dialysis patients. In addition, an increasing trend in average FPG levels indicates poor survival.

Predialysis hypotension is not a predictor for mortality in long-term hemodialysis patients: insight from a single-center observational study.

IntroductionPredialysis hypotension has been noted to be a predictor of mortality in hemodialysis (HD) patients. Previous studies evaluating the impact of predialysis hypotension on the mortality of HD patients did not exclude patients with diabetes mellitus (DM) or cardiovascular disease.MethodsEight hundred and sixty-six patients on maintenance HD were recruited. Clinical parameters were recorded and subjected to the analysis of predictors of predialysis hypotension and mortality.ResultsMultivariate logistic regression analyses indicated that DM (odds ratio [OR]: 0.439, P=0.002), hypertension history (OR: 0.634, P=0.022), Kt/V Daugirdas (OR: 2.545, P=0.001), anuria (OR: 2.313, P=0.002), serum phosphate (OR: 0.833, P=0.010), and serum triglyceride (OR: 1.002, P=0.012) were associated with predialysis hypotension. Multivariate Cox regression analysis showed that age (P<0.001), male sex (P=0.029), anuria (P=0.004), and DM (P=0.011) were associated with higher probability of 24- and 36-month mortality. Predialysis hypotension was not associated with higher probability of 12-, 24-, and 36-month mortality.ConclusionPredialysis hypotension is not a predictor of 12-, 24-, and 36-month survival in patients without DM and with higher dialysis adequacy.

Aseptic loosening of uncemented femoral components in long-term hemodialysis patients: a systematic review of the literature

Background: The purpose of this study was to determine if reliable cementless fixation in hip arthroplasty can be achieved in patients on long-term hemodialysis. Methods: A systematic review was conducted with an emphasis on aseptic loosening of femoral components in total hip arthroplasty and hemiarthroplasty. Studies were analyzed using the Methodological Index for Nonrandomized Studies (MINORS) instrument and the Center for Evidence-Based Medicine’s Levels of Evidence Scale. Six lower-quality cases series were included. Results: Rates of radiographic evidence of loosening and revision caused by aseptic loosening ranged from 0% to 100%. Data pooling could not be performed because of heterogeneity of the studies included. Conclusions: It appears that patients with end-stage renal disease have bone stock suitable for cementless fixation. However, the varying outcomes reported in the literature reflect that the factors leading to early loosening of femoral components in dialyzed patients still remain unclear.

Comparison of Intradialytic Parenteral Nutrition with Glucose or Amino Acid Mixtures in Maintenance Hemodialysis Patients.

Many long-term maintenance hemodialysis patients have symptoms of protein-energy wasting caused by malnutrition. Each session of hemodialysis removes about 10 to 12 g of amino acids and 200 to 480 kcal of energy. Patients receiving hemodialysis for chronic kidney disease may be undernourished for energy, protein consumption, or both. Non-diabetic hemodialysis patients were randomized to three treatment groups: oral supplementation, oral supplementation plus high-concentration glucose solution (250 mL containing 50% glucose) and these two interventions plus 8.5% amino acids solution. The post-treatment energy status of the glucose group was significantly higher than its baseline level, whereas the control group’s status was significantly lower. The glucose group had significantly higher concentrations of asparagine, glutamine, glycine, alanine, and lysine after treatment. All treatment groups had significantly increased hemoglobin levels but significantly decreased transferrin levels after treatment compared to baseline. After treatment, the amino acid group had significantly higher albumin level compared to the glucose group (p = 0.001) and significantly higher prealbumin level compared to the control group (p = 0.017). In conclusion, long-term intervention with high-concentration glucose solution at each hemodialysis session is a simple and cheap method that replenished energy stores lost during hemodialysis of non-diabetic patients.

Diffuse Pulmonary Ossification Developing in Patients with End-stage Renal Disease

Diffuse pulmonary ossification (DPO) is a rare condition characterized by chronic metaplastic ossification of the lung parenchyma. DPO is associated with various underlying pulmonary, cardiac, and systemic diseases. However, to our knowledge, DPO has rarely been described in patients with end-stage renal disease undergoing hemodialysis. We describe two cases of DPO diagnosed in long-term hemodialysis patients. Awareness of this rare disorder is required for a better differential diagnosis of cases presenting with bilateral diffuse micronodular lesions, including calcific opacities. (Korean J Med 2016;90:346-350)

Molecular pathogenesis of human amyloidosis: Lessons from β2 -microglobulin-related amyloidosis.

Amyloidosis refers to a group of diseases with amyloid fibrils deposited in various organs and is classified into more than 30 diseases in humans based on the kind of amyloid protein. In order to elucidate the molecular pathogenesis of human amyloidosis, we studied the molecular mechanism of amyloid fibril formation in vitro. We first developed a novel fluorometric method to determine amyloid fibrils in vitro based on the unique characteristics of thioflavin T. We next proposed a nucleation-dependent polymerization model to explain the general mechanism of amyloid fibril formation in vitro. Based on this model, we characterized the biological molecular interactions that promote or inhibit amyloid fibril formation in vitro and developed models of pathological molecular environment for inducing human β2-microglobulin-related amyloidosis in long-term hemodialysis patients. We also proposed a novel and attractive cytotoxic mechanism of β2-microglobulin amyloid fibrils, that is, the disruption of endosomal/lysosomal membranes by endocytosed amyloid fibrils. These findings may be useful to elucidate the molecular pathogenesis of other kinds of human amyloidosis.

Chronic pain in hemodialysis patients: Role of bone mineral metabolism

BackgroundPain is one of the most common complaints in clinical practice because it is a symptom for a myriad of physical and mental problems. The high prevalence of pain in the chronic kidney disease (CKD) population is particularly concerning because pain has been shown to adversely affect quality of life. The aim of this study was to evaluate the prevalence and possible causes of chronic pain in patients with end stage renal disease on long-term hemodialysis (HD). MethodsWe prospectively enrolled 100 patients who were undergoing maintenance HD for at least 6months or more. Pain was evaluated using the Brief Pain Inventory (BPI). Data collected on each participant included age, gender, body mass index (BMI), time on dialysis and biochemical findings. ResultsThe average age was 42.06years ranged from 22 to 58years; the average duration on dialysis was 4.97years. 52 patients were males and 48 were females. Although 52% of patients experienced chronic pain, only 25% described the pain as severe, 28% described pain as moderate while 52% of patients described as mild. Musculoskeletal pain was the most frequent form of chronic pain reported by patients who were on HD (54%). Malnutrition and high CRP were highly statistically associated with chronic pain (p<0.001). High statistical significant correlation was found between lower calcium, lower 25(OH) D3 levels, higher parathyroid hormone (PTH) levels and experienced chronic pain (p<0.001). ConclusionChronic pain is highly experienced in long-term hemodialysis patients. Malnutrition, high CRP and disturbed bone mineral metabolism are highly correlated with the incident of this pain.

Different impact of hemodialysis vintage on cause-specific mortality in long-term hemodialysis patients.

Although dialysis vintage is associated with increased mortality risk in patients receiving hemodialysis (HD), the association of dialysis vintage with cause-specific mortality is unclear. We conducted a nationwide registry-based retrospective cohort study of 216 246 patients receiving maintenance HD for > 1 year at the end of 2009. The associations of dialysis vintage categories (1 -< 2, 2 -< 5, 5 -< 10, 10 -< 15, 15 -< 20, 20 -< 25, 25 -< 30 and ≥ 30 years) with 1-year all-cause and cause-specific mortality, including cardiovascular diseases (CVDs) and infection-related mortality, were examined using logistic regression models. During the 1-year study period, 18 614 deaths occurred from all causes, including 7263 and 3504 deaths from CVD and infection-related causes. From multivariate analysis, the dialysis vintage was incrementally associated with a higher risk for all-cause mortality, with worse outcome observed in the ≥ 30 years category {odds ratio [OR] = 2.43 (95% confidence interval (CI) 2.13-2.77}. A similar association was apparent between the dialysis vintage and infection-related mortality, with a higher risk than that of all-cause mortality in each vintage category [≥ 30 years, OR = 3.55 (95% CI 2.72-4.66)], while the dialysis vintage was associated with only a modest increase in risk of CVD mortality [≥ 30 years, OR = 1.64 (95% CI 1.30-2.08)]. Dialysis vintage has a different impact on cause-specific mortality, with a higher risk for infection-related mortality than CVD mortality. This impact is most pronounced in long-term HD survivors, to whom much attention should be devoted to prevent infectious complications.

Treating hypertension in hemodialysis improves symptoms seemingly unrelated to volume excess.

Among hemodialysis patients, probing dry weight is an effective strategy for improving control of hypertension. Whether controlling hypertension improves or worsens symptoms among such patients remains unclear. The purpose of the study was to develop a tool to evaluate symptoms and examine the relationship of the change in these symptoms with blood pressure (BP) control. Among patients participating in the Hemodialysis Patients Treated with Atenolol or Lisinopril (HDPAL) randomized controlled trial, a confirmatory factor analysis (CFA) was performed to establish the relationship between symptoms and organ systems. Next, the change in symptom scores pertaining to organ systems was analyzed using a mixed model. Finally, the independent effect of lowering home BP on change in symptoms was evaluated. Among 133 participants where symptoms were available at baseline, CFA revealed four level 1 domains: gastrointestinal symptoms, dialysis-related symptoms, cardiovascular symptoms and general symptoms. All except dialysis-related symptoms were ascribed to uremia (level 2 domain). Uremic symptoms improved over 6 months and then increased. Dialysis-related symptoms (fatigue, cramps and orthostatic dizziness) did not worsen despite lowering home BP. Probing dry weight was independently associated with an improvement in cardiovascular symptoms such as shortness of breath. Reducing BP through the use of a strategy that includes volume control and medication improves symptoms seemingly unrelated to volume excess. In long-term hemodialysis patients, treating hypertension using home BP measurements may improve well-being.

Multicenter Evaluation of Current Knowledge of Hepatitis C Screening Recommendations Among Trainee Physicians

Introduction: Hepatitis C (HCV) is a significant burden within the United States, with the Center for Disease Control and Prevention (CDC) estimating 3.2 million individuals chronically infected. Newer therapies for HCV have brought hope for a significant percentage of these patients with rates of cure over 90% among approved regimens. In 2012, the CDC set forth guidelines for screening for HCV. We sought to identify understanding of CDC recommendations amongst primary care residents in the United States. Methods: A web-based survey was used to gauge understanding of current CDC screening recommendations. The survey included basic demographic data such as gender, residency in internal medicine or family medicine, and current level of training. The survey was sent to all primary care residents within the Henry Ford Health System and to Internal Medicine residency program directors throughout the United States through the ACGME list-server with request to be distributed to their residents. Results: 186 responses were received. 58.8 were male and 98.2% were internal medicine residents. Level of training was evenly split, with 34.6% PGY1, 33.3% PGY2, and 30.9% PGY3. 59.8% of respondents have received formal education regarding screening guidelines in their residency program. 69.5% of respondents stated they screened every patient born from 1945-65 at least once for HCV. Amongst the groups currently recommended for screening, 95.7% of residents recognized the role for screening in history of injected drug use, 70.6% in long-term hemodialysis patients, 92% in patients with HIV, and 95.7% in healthcare workers after sharps exposure or mucosal exposure to HCV-positive blood. There was a broad spread of understanding of current cure rates for HCV, with 13.9% of respondents believing the cure rate was 90%. Limited provider time was the most significant obstacle to screening patients born between 1945 and 1965 for HCV (68.7%). Conclusion: Our findings indicate good understanding of current CDC recommendations for HCV screening. There is room for improvement in follow-through with actual screening. There is poor understanding of the efficacy of current available therapies for HCV. This may reflect a lack of formal education in regards to HCV screening and treatment. Our study is limited by low response rate, especially among family medicine residents.

Endocytosed β2-Microglobulin Amyloid Fibrils Induce Necrosis and Apoptosis of Rabbit Synovial Fibroblasts by Disrupting Endosomal/Lysosomal Membranes: A Novel Mechanism on the Cytotoxicity of Amyloid Fibrils

Dialysis-related amyloidosis is a major complication in long-term hemodialysis patients. In dialysis-related amyloidosis, β2-microglobulin (β2-m) amyloid fibrils deposit in the osteoarticular tissue, leading to carpal tunnel syndrome and destructive arthropathy with cystic bone lesions, but the mechanism by which these amyloid fibrils destruct bone and joint tissue is not fully understood. In this study, we assessed the cytotoxic effect of β2-m amyloid fibrils on the cultured rabbit synovial fibroblasts. Under light microscopy, the cells treated with amyloid fibrils exhibited both necrotic and apoptotic changes, while the cells treated with β2-m monomers and vehicle buffer exhibited no morphological changes. As compared to β2-m monomers and vehicle buffer, β2-m amyloid fibrils significantly reduced cellular viability as measured by the lactate dehydrogenase release assay and the 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay and significantly increased the percentage of apoptotic cells as measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. β2-m amyloid fibrils added to the medium adhered to cell surfaces, but did not disrupt artificial plasma membranes as measured by the liposome dye release assay. Interestingly, when the cells were incubated with amyloid fibrils for several hours, many endosomes/lysosomes filled with amyloid fibrils were observed under confocal laser microscopy and electron microscopy, Moreover, some endosomal/lysosomal membranes were disrupted by intravesicular fibrils, leading to the leakage of the fibrils into the cytosol and adjacent to mitochondria. Inhibition of actin-dependent endocytosis by cytochalasin D attenuated the toxicity of amyloid fibrils. These results suggest that endocytosed β2-m amyloid fibrils induce necrosis and apoptosis by disrupting endosomal/lysosomal membranes, and this novel mechanism on the cytotoxicity of amyloid fibrils is described.

Epicardial adipose tissue in long-term hemodialysis patients: its association with vascular calcification and long-term development.

Epicardial adipose tissue (EAT) is associated with coronary artery disease (CAD) in the general population. EAT is suggested to promote CAD by paracrine mechanisms and local inflammation. We evaluated whether in chronic hemodialysis (HD) patients EAT associates with CAD, how the amount of EAT develops over time, and if EAT independently predicts the mortality risk. Post-hoc analysis of a prospective study in 59 chronic HD patients who underwent non-enhanced multi-slice computed tomography (MSCT) at baseline. Thirty-seven patients underwent another MSCT after 24 ± 5 months. We measured EAT volume (cm³) and Agatston calcification scores of coronary arteries (CAC) and aortic valves (AVC). All-cause mortality was assessed after a follow-up of 88 months (IQR 52-105). Baseline EAT was 128.2 ± 60.8 cm³ and significantly higher than in a control group of non-renal patients (94 ± 46 cm³; p < 0.05). Median Agatston score for CAC was 329 (IQR 23-1181) and for AVC was 0 (IQR 0-25.3) in HD patients. We observed significant positive correlations between baseline EAT and age (r = 0.386; p = 0.003), BMI (r = 0.314; p = 0.016), CAC (r = 0.278; p = 0.03), and AVC (r = 0.282; p = 0.03). In multivariate analysis, age, BMI and AVC remained as significant predictors of EAT (p < 0.01). Calcification scores significantly increased over 2 years; in contrast EAT change was not significant (+11 %, IQR -10 to 24 %; p = 0.066). The limited patient number in the present study precludes analysis of the EAT impact upon survival. EAT correlated significantly with cardiovascular calcification in long-term HD patients. Mean EAT did not significantly change over 2 years.

Predialysis and Postdialysis pH and Bicarbonate and Risk of All-Cause and Cardiovascular Mortality in Long-term Hemodialysis Patients

To date, very few studies have been carried out on the associations of pre- and postdialysis acid-base parameters with mortality in hemodialysis patients. An observational study including cross-sectional and 1-year analyses. Data from the renal registry of the Japanese Society of Dialysis Therapy (2008-2009), including 15,132 dialysis patients 16 years or older. Predialysis pH<7.30, 7.30 to 7.34 (reference), 7.35 to 7.39, or≥7.40 (1,550, 4,802, 6,023, and 2,757 patients, respectively); predialysis bicarbonate level< 18.0, 18.0 to 21.9 (reference), 22.0 to 25.9, or≥26.0 mEq/L (2,724, 7,851, 4,023, and 534 patients, respectively); postdialysis pH<7.40, 7.40 to 7.44, 7.45 to 7.49 (reference), or≥7.50 (2,114, 5,331, 4,975, and 2,712 patients, respectively); and postdialysis bicarbonate level< 24.0, 24.0 to 25.9, 26.0 to 27.9 (reference), or≥28.0 mEq/L (5,087, 4,330, 3,451, and 2,264 patients, respectively). All-cause and cardiovascular (CV) mortality during the 1-year follow-up. HRs were estimated using unadjusted models and models adjusted for age, sex, dialysis vintage, history of CV disease, diabetes, weight gain ratio, body mass index, calcium-phosphorus product, serum albumin level, serum total cholesterol level, blood hemoglobin level, single-pool Kt/V, and normalized protein catabolic rate. Of 15,132 patients, during follow-up, 1,042 died of all causes, including 408 CV deaths. In the adjusted analysis for all-cause mortality, HRs compared to the reference group were significantly higher in patients with predialysis pH≥7.40 (HR, 1.36; 95% CI, 1.13-1.65) and postdialysis pH<7.40 (HR, 1.22; 95% CI, 1.00-1.49). Predialysis pH≥7.40 was also associated with higher risk of CV mortality (HR, 1.34; 95% CI, 1.01-1.79). No association of pre- or postdialysis bicarbonate level with all-cause and CV mortality was observed. Single measurements of acid-base parameters, short duration of follow-up, small number of CV deaths. Predialysis pH≥7.40 was associated with significantly elevated risk of all-cause and CV mortality. However, pre- and postdialysis bicarbonate levels were not associated with all-cause and CV mortality. Predialysis pH may be the most appropriate reference for accurate correction of metabolic acidosis in dialysis patients.

Effectiveness of new push/pull hemodiafiltration for arthralgia in long-term hemodialysis patients.

Effectiveness of new push/pull hemodiafiltration for arthralgia in long-term hemodialysis patients.

Circulating Wnt/β-catenin signalling inhibitors and uraemic vascular calcifications.

The process of vascular calcification has been associated with the canonical Wnt/β-catenin signalling pathway in cell cultures and animal studies. The relationship between circulating Wnt/β-catenin inhibitors and vascular calcification in dialysis patients is unknown. The aim of this study was to investigate the associations between serum dickkopf-1 (Dkk-1) and sclerostin, two circulating inhibitors of the Wnt/β-catenin signalling pathway, and the severity of aortic calcification (AoC) and cardiovascular outcomes in dialysis patients. This was a prospective observational cohort study. One hundred and twenty-five patients on maintenance haemodialysis participated in the study. Serum levels of Dkk-1 and sclerostin were measured. AoC scores were calculated from plain films of both posterior-anterior and lateral views. The patients were followed up for 2 years or until death or withdrawal. The circulating sclerostin level was inversely associated with the severity of AoC (P = 0.035) and indicators of the bone turnover rate including serum alkaline phosphatase (ALP) (r = -0.235, P = 0.008) and intact parathyroid hormone (r = -0.523, P < 0.001). Furthermore, Cox regression analysis indicated that the patients with high circulating sclerostin levels were less likely to experience future cardiovascular events [1 pmol/L sclerostin increase, hazard ratio 0.982 (95% CI, 0.967-0.996), P = 0.015] after adjusting for a propensity score. In contrast, serum Dkk-1 was not associated with AoC and clinical outcomes. In long-term haemodialysis patients, circulating sclerostin but not Dkk-1 is inversely associated with AoCs and future cardiovascular events. Our findings suggest that sclerostin, as a bone-related protein, might act as a communicator between uraemic bone and vasculature.

Unilateral pedicle stress fracture in a long-term hemodialysis patient with isthmic spondylolisthesis.

Most unilateral pedicle stress fractures occur on the contralateral side of patients with unilateral spondylolysis. However, there are few reports of unilateral pedicle stress fractures in patients with bilateral spondylolysis and spondylolisthesis. We report a unique case of unilateral pedicle stress fracture in a long-term hemodialysis patient with isthmic spondylolisthesis. A 65-year-old man who had undergone hemodialysis presented with lower back pain that had persisted for several years. The patient experienced severe right lower extremity pain with no history of trauma. Computed tomography revealed unilateral pedicle fracture with bilateral L5 spondylolysis and spondylolisthesis with progression of scoliosis. The patient underwent Gill laminectomy of L5 with pedicle screw fixation at L4-S1 and interbody fusion at L5-S1. The patient's leg pain ceased immediately, and he began walking without leg pain. In our present patient, development of scoliosis caused by destructive spondyloarthropathy may have contributed to a unilateral pedicle fracture.

Absent internal jugular vein: Another case for ultrasound guided vascular access.

Sir, We describe a case of absence of right internal jugular vein (IJV), which is a rare form of anatomical variation of the IJV. A 65-year-old male patient was admitted to the intensive care unit (ICU) with the complaints of fever and hypotension. The ICU resident placed a central venous catheter (CVC) in left IJV as he was unable to visualize the right IJV on ultrasound. On the 10th ICU day, the CVC insertion site was found to be inflamed, and it was decided to resite the catheter on the right side. The right side of the neck was examined carefully, and no evidence of scarring suggesting previous surgery or cannulation was seen. The ICU consultant scanned the right side of the neck carefully using a portable ultrasound (US) machine (IMAGIC Agile, Kontron Medical, WA, USA) with a linear, high frequency transducer (7.5–12 MHz). Care was taken to apply minimal pressure on the probe to prevent collapse of the IJV. Imaging showed a single pulsatile vessel, which was non compressible suggestive of the carotid artery with no evidence of the IJV [Figure 1]. Doppler confirmed the characteristic pulsatile blood flow in the carotid artery. The 2D US imaging on the left side showed normal anatomy with good size IJV [Figure 2]. Subsequently, the CVC was placed in the right axillary vein under real-time US guidance in a single attempt. Figure 1 Ultrasound image of the right side of the neck showing absence of internal jugular vein. CA: Carotid artery Figure 2 Ultrasound image of the left side of the neck showing normal anatomy. CA: Carotid artery; IJV: Internal jugular vein Landmark guided central venous cannulation is based on the premise of normal anatomy of the vein and its adjoining structures. In a study on long-term hemodialysis patients, the incidence of significant US findings such as total occlusion, nonocclusive thrombus and stenosis was seen to be as high as 35%.[1] Agenesis or hypoplasia of the central veins though rare is another probable cause of failed cannulation in patients where US guidance is not used. In our patient, the possible absence of the vein can be explained by IJV agenesis, which represents a form of truncular venous malformation due to a developmental arrest during the later stages of embryonic development, which could lead to either aplasia or hypoplasia of the vein.[2] Denys and Uretsky studied 200 patients undergoing IJV cannulation under US guidance and found that in 2.5% of the patients, the IJV was not visualized.[3] Absence of the right sided IJV has also been reported in a 12-year-old boy during US evaluation prior to attempted cannulation.[4] In another report, IJV agenesis was discovered during neck dissection. Patients who require removal of IJV due to disease infiltration may have potentially life-threatening complication of cerebral edema if the other IJV is aplastic.[5] In developing countries, landmark based technique is commonly practiced as an US machine may not be available in all centers. Central venous cannulation using the landmark technique in a patient with absent IJV may be associated with a higher incidence of complications such as arterial puncture and pneumothorax.[6] Therefore, repeated attempts to cannulate the IJV should be avoided in patients keeping in mind the possibility of anatomical variations of IJV. This case reiterates the use of US guided vascular access to prevent complications, which can arise due to the absence of a vein or other venous anomalies. In addition, it has been shown that US-guided CVC placement technique is easy to learn even by novices and any previous CVC and/or US experience allows a better technique and shorter total time to placement.[7] It would be a good general practice to use US for both assessment of anatomy prior to venipuncture and real-time visualization during insertion of CVC to increase the success rate and prevent complications.

Vitamin D Binding Protein Is Not Involved in Vitamin D Deficiency in Patients with Chronic Kidney Disease.

Objective. This study was designed to evaluate vitamin D status with separate determination of 25-OH D2 and 25-OH D3 and its relationship to vitamin D binding protein (VDBP) in patients with chronic kidney disease (CKD) and long-term haemodialysis patients (HD). Methods. 45 CKD patients, 103 HD patients, and 25 controls (C) were included. Plasma vitamin D concentrations were determined using chromatography and VDBP in serum and urine in CKD using enzyme immunoassay. Results. Plasma vitamin D levels were lower in CKD (30.16 ± 16.74 ng/mL) and HD (18.85 ± 15.85 ng/mL) versus C (48.72 ± 18.35 ng/mL), P < 0.0001. 25-OH D3 was the dominant form of vitamin D. Serum VDBP was higher in CKD (273.2 ± 93.8 ug/mL) versus C (222 ± 87.6 ug/mL) and HD (213.8 ± 70.9 ug/mL), P = 0.0003. Vitamin D/VDBP ratio was the highest in C and the lowest in HD; however, there was no correlation between vitamin D and VDBP. Urinary concentration of VDBP in CKD (0.25 ± 0.13 ug/mL) correlated with proteinuria (r = 0.43, P = 0.003). Conclusions. Plasma levels of vitamin D are decreased in CKD patients and especially in HD patients. 25-OH D3 was the major form of vitamin D. Despite urinary losses of VDBP, CKD patients had higher serum VDBP concentrations, indicating compensatory enhanced production. Vitamin D binding protein is not involved in vitamin D deficiency.