Lancisi's sign and central venous catheter tip position: a case report.

INTRODUCTION: Valvular disease and pulmonary hypertension are common conditions in haemodialysis patients. In presence of tricuspid regurgitation, an increased retrograde blood flow into the right atrium during ventricle systole results in a typical modification of the normal venous waveform, creating a giant c-v wave. This condition clinically appears as a venous palpable pulsation within the internal jugular vein, also known as Lancisi's sign. CASE REPORT: An 83-year-old woman underwent haemodialysis for 9 years. After arteriovenous fistula thrombosis, a right internal jugular vein non-tunnelled central venous catheter (CVC) was placed. About one month later, the patient was referred to our facility for the placement of a tunnelled CVC. Neck examination revealed an elevated jugular venous pulse, the Lancisi's sign. Surprisingly, chest x-ray posteroanterior view showed the non-tunnelled catheter tip in correspondence with the right ventricle. She underwent surgery for temporary to tunnelled CVC conversion using the same venous insertion site (Bellcath®10Fr-length 25 cm to Mahurkar®13.5Fr-length 19 cm). In the postoperative period, we observed a significant reduction of the jugular venous pulse. DISCUSSION: The inappropriate placement of a 25-cm temporary CVC in the right internal jugular vein worsened the tricuspid valve regurgitation, which became evident by the Lancisi's sign. Removal of the temporary CVC from the right ventricle resulted in improved right cardiac function. Safe approaches recommended by guidelines for the CVC insertion technique and for checking the tip position should be applied in order to avoid complications.

Clinical use of computational modeling for surgical planning of arteriovenous fistula for hemodialysis.

BACKGROUND: Autogenous arteriovenous fistula (AVF) is the best vascular access (VA) for hemodialysis, but its creation is still a critical procedure. Physical examination, vascular mapping and doppler ultrasound (DUS) evaluation are recommended for AVF planning, but they can not provide direct indication on AVF outcome. We recently developed and validated in a clinical trial a patient-specific computational model to predict pre-operatively the blood flow volume (BFV) in AVF for different surgical configuration on the basis of demographic, clinical and DUS data. In the present investigation we tested power of prediction and usability of the computational model in routine clinical setting. METHODS: We developed a web-based system (AVF.SIM) that integrates the computational model in a single procedure, including data collection and transfer, simulation management and data storage. A usability test on observational data was designed to compare predicted vs. measured BFV and evaluate the acceptance of the system in the clinical setting. Six Italian nephrology units were involved in the evaluation for a 6-month period that included all incident dialysis patients with indication for AVF surgery. RESULTS: Out of the 74 patients, complete data from 60 patients were included in the final dataset. Predicted brachial BFV at 40 days after surgery showed a good correlation with measured values (in average 787 ± 306 vs. 751 ± 267 mL/min, R = 0.81, p < 0.001). For distal AVFs the mean difference (±SD) between predicted vs. measured BFV was -2.0 ± 20.9%, with 50% of predicted values in the range of 86-121% of measured BFV. Feedbacks provided by clinicians indicate that AVF.SIM is easy to use and well accepted in clinical routine, with limited additional workload. CONCLUSIONS: Clinical use of computational modeling for AVF surgical planning can help the surgeon to select the best surgical strategy, reducing AVF early failures and complications. This approach allows individualization of VA care, with the aim to reduce the costs associated with VA dysfunction, and to improve AVF clinical outcome.

The impact of haemodialysis arteriovenous fistula on haemodynamic parameters of the cardiovascular system.

BACKGROUND: Satisfactory vascular access flow (Qa) of an arteriovenous fistula (AVF) is necessary for haemodialysis (HD) adequacy. The aim of the present study was to further our understanding of haemodynamic modifications of the cardiovascular system of HD patients associated with an AVF. The main objective was to calculate using real data in what way an AVF influences the load of the left ventricle (LLV). METHODS: All HD patients treated in our dialysis unit and bearing an AVF were enrolled into the present observational cross-sectional study. Fifty-six patients bore a lower arm AVF and 30 an upper arm AVF. Qa and cardiac output (CO) were measured by means of the ultrasound dilution Transonic Hemodialysis Monitor HD02. Mean arterial pressure (MAP) was calculated; total peripheral vascular resistance (TPVR) was calculated as MAP/CO; resistance of AVF (AR) and systemic vascular resistance (SVR) are connected in parallel and were respectively calculated as AR = MAP/Qa and SVR = MAP/(CO - Qa). LLV was calculated on the principle of a simple physical model: LLV (watt) = TPVR·CO(2). The latter was computationally divided into the part spent to run Qa through the AVF (LLVAVF) and that part ensuring the flow (CO - Qa) through the vascular system. The data from the 86 AVFs were analysed by categorizing them into lower and upper arm AVFs. RESULTS: Mean Qa, CO, MAP, TPVR, LLV and LLVAVF of the 86 AVFs were, respectively, 1.3 (0.6 SD) L/min, 6.3 (1.3) L/min, 92.7 (13.9) mmHg, 14.9 (3.9) mmHg·min/L, 1.3 (0.6) watt and 19.7 (3.1)% of LLV. A statistically significant increase of Qa, CO, LLV and LLVAVF and a statistically significant decrease of TPVR, AR and SVR of upper arm AVFs compared with lower arm AVFs was shown. A third-order polynomial regression model best fitted the relationship between Qa and LLV for the entire cohort (R (2) = 0.546; P < 0.0001) and for both lower (R (2) = 0.181; P < 0.01) and upper arm AVFs (R (2) = 0.663; P < 0.0001). LLVAVF calculated as % of LLV rose with increasing Qa according to a quadratic polynomial regression model, but only in lower arm AVFs. On the contrary, no statistically significant relationship was found between the two parameters in upper arm AVFs, even if mean LLVAVF was statistically significantly higher in upper arm AVFs (P < 0.0001). CONCLUSIONS: Our observational cross-sectional study describes statistically significant haemodynamic modifications of the CV system associated to an AVF. Moreover, a quadratic polynomial regression model best fits the relationship between LLVAVF and Qa, but only in lower arm AVFs.

Impact of hyperhydration on the mortality risk in critically ill patients admitted in intensive care units: comparison between bioelectrical impedance vector analysis and cumulative fluid balance recording.

BACKGROUND: Studies have demonstrated a positive correlation between fluid overload (FO) and adverse outcomes in critically ill patients. The present study aims at defining the impact of hyperhydration on the Intensive Care Unit (ICU) mortality risk, comparing Bioelectrical Impedance Vector Analysis (BIVA) assessment with cumulative fluid balance (CFB) recording. METHODS: We performed a prospective, dual-centre, clinician-blinded, observational study of consecutive patients admitted to ICU with an expected length of ICU stay of at least 72 hours. During observational period (72-120 hours), CFB was recorded and cumulative FO was calculated. At the admission and daily during the observational period, BIVA was performed. We considered FO between 5% and 9.99% as moderate and a FO ≥ 10% as severe. According to BIVA hydration scale of lean body mass, patients were classified as normohydrated (>72.7%-74.3%), mild (>71%-72.7%), moderate (>69%-71%) and severe (≤ 69%) dehydrated and mild (>74.3%-81%), moderate (>81%-87%) and severe (>87%) hyperhydrated. Two multivariate logistic regression models were performed: the ICU mortality was the response variable, while the predictor variables were hyperhydration, measured by BIVA (BIVA model), and FO (FO model). A p-value <0.05 was considered to indicate statistical significance. RESULTS: One hundred and twenty-five patients were enrolled (mean age 64.8 ± 16.0 years, 65.6% male). Five hundred and fifteen BIVA measurements were performed. The mean CFB recorded at the end of the observational period was 2.7 ± 4.1 L, while the maximum hydration of lean body mass estimated by BIVA was 83.67 ± 6.39%. Severe hyperhydration measured by BIVA was the only variable found to be significantly associated with ICU mortality (OR 22.91; 95% CI 2.38-220.07; p < 0.01). CONCLUSIONS: The hydration status measured by BIVA seems to predict mortality risk in ICU patients better than the conventional method of fluid balance recording. Moreover, it appears to be safe, easy to use and adequate for bedside evaluation. Randomized clinical trials with an adequate sample size are needed to validate the diagnostic properties of BIVA in the goal-directed fluid management of critically ill patients in ICU.

[An unusual cause of ureteral obstruction in kidney transplant]. / Una causa non usuale di ostruzione ureterale nel trapianto renale.

Inguinal herniation of the ureter in a kidney transplantation is a rare cause of late distal ureteral obstruction. Herniation is usually secondary to the implant of a long redundant ureter and to its course on the spermatic cord. This clinical condition can worsen graft function in the presence of ipsilateral hydroureteronephrosis. In this review, we describe the case of an asymptomatic 51-year-old man with a history of right iliac renal allotransplantation 12 years before. Kidney ultrasound showed moderate hydroureteronephrosis and ureteral kneeling at the upper third of the inguinal canal. The patient presented a mild increase in serum creatinine; physical examination revealed an ipsilateral inguinal hernia. A CT scan of the abdomen with no contrast medium confirmed middle-distal ureteral kneeling engaging in the sac of the right inguinal hernia. The patient underwent surgical hernia repair with no complications and his renal function recovered completely.

Vitamin D status and cholecalciferol supplementation in chronic kidney disease patients: an Italian cohort report.

This study investigated the factors associated with hypovitaminosis D, in a cohort of 405 prevalent patients with chronic kidney disease (CKD) stages 2-4, living in Italy and followed-up in tertiary care. The effect of cholecalciferol 10,000 IU once-a-week for 12 months was evaluated in a subgroup of 100 consecutive patients with hypovitaminosis D. Vitamin D deficiency was observed in 269 patients (66.4%) whereas vitamin D insufficiency was found in 67 patients (16.5%). In diabetic patients, 25-hydroxyvitamin D deficiency was detected in 80% of cases. In patients older than 65 years, the prevalence of hypovitaminosis D was 89%. In the univariate analysis, 25-hydroxyvitamin D was negatively related to age, parathyroid hormone (PTH), proteinuria, and Charlson index, while a positive relationship has emerged with hemoglobin level. On multiple regression analysis, only age and PTH levels were independently associated with 25-hydroxyvitamin D levels. No relationship emerged between vitamin D deficiency and renal function. Serum levels of 25-hydroxyvitamin D or prevalence of hypovitaminosis D did not differ between patients on a free-choice diet and on a renal diet, including low-protein, low-phosphorus regimens. Twelve-month oral cholecalciferol administration increased 25-hydroxyvitamin D and reduced PTH serum levels. In summary, hypovitaminosis D is very prevalent in CKD patients (83%) in Italy, and it is similar to other locations. PTH serum levels and age, but not renal function, are the major correlates of hypovitaminosis D. Implementation of renal diets is not associated with higher risk of vitamin D depletion. Oral cholecalciferol administration increased 25-hydroxyvitamin D and mildly reduced PTH serum levels. Oral cholecalciferol supplementation should be recommended as a regular practice in CKD patients, also when serum 25-hydroxyvitamin D determination is not available or feasible.

[An unusual cause of acute pyelonephritis: the retrocaval ureter]. / Una causa non usuale di pielonefrite acuta: l'uretere retrocavale.

Retrocaval ureter is a rare congenital malformation in which the proximal right ureter courses toward the midline on the posterior aspect of the inferior vena cava before emerging medial and anterior to this structure and then descending into the pelvis. This anatomical anomaly may be asymptomatic or manifest clinically, usually starting from the fourth decade of life, with flank pain, pyelonephritis, gross hematuria or other rarer signs. We describe the case of a young woman being hospitalized because of acute pyelonephritis; she had previously complained of flank pain associated with episodes of high fever. Computed tomography of the abdomen identified the malformation. The patient underwent surgical correction by laparoscopy and, at one year of follow-up, did not show any further clinical problem.

Nutrition and physical activity in CKD patients.

Chronic kidney disease (CKD) patients are at risk for protein-energy wasting, abnormal body composition and impaired physical capacity. These complications lead to increased risk of hospitalization, morbidity and mortality.In CKD patient as well as in healthy people, there is a close association between nutrition and physical activity. Namely, inadequate nutrient (energy) intake impairs physical performance thus favoring a sedentary lifestyle: this further contributes to loss of muscle strength and mass, which limit the quality of life and rehabilitation of CKD patients. In CKD as well as in end-stage-renal-disease patients, regular physical activity coupled with adequate energy and protein intake counteracts protein-energy wasting and related comorbidity and mortality. In summary, exercise training can positively influence nutritional status and the perception of well-being of CKD patients and may facilitate the anabolic effects of nutritional interventions.