RESUMO
We present a short review of discrete-time quantum walks (DTQW) as a potentially useful and rich formalism to model human decision-making. We present a pedagogical introduction of the underlying formalism and main structural properties. We suggest that DTQW are particularly suitable for combining the two strands of literature on evidence accumulator models and on the quantum formalism of cognition. Due to the additional spin degree of freedom, models based on DTQW allow for a natural modeling of model choice and confidence rating in separate bases. Levels of introspection and self-assessment during choice deliberations can be modeled by the introduction of a probability for measurement of either position and/or spin of the DTQW, where each measurement act leads to a partial decoherence (corresponding to a step towards rationalization) of the deliberation process. We show how quantum walks predict observed probabilistic misperception like S-shaped subjective probability and conjunction fallacy. Our framework emphasizes the close relationship between response times and type of preferences and of responses. In particular, decision theories based on DTQW do not need to invoke two systems ("fast" and "slow") as in dual process theories. Within our DTQW framework, the two fast and slow systems are replaced by a single system, but with two types of self-assessment or introspection. The "thinking fast" regime is obtained with no or little self-assessment, while the "thinking slow" regime corresponds to a strong rate of self-assessment. We predict a trade-off between speed and accuracy, as empirically reported.
Assuntos
Tomada de Decisões , Teoria Quântica , Cognição/fisiologia , Tomada de Decisões/fisiologia , Teoria da Decisão , Humanos , Tempo de ReaçãoRESUMO
In non-dialysis-dependent chronic kidney disease (NDD-CKD), erythropoiesis-stimulating agents (ESAs) and iron supplementation are essential for anemia management. Ferric carboxymaltose (FCM) is a relatively novel intravenous iron formulation used in different clinical settings, although scarce data exist in NDD-CKD patients. Primary objective of this study was to retrospectively evaluate the efficacy of FCM compared with oral ferrous sulfate for the treatment of iron-deficiency anemia in a cohort of NDD-CKD patients, considering also the treatment costs. This was a monocentric, retrospective observational study reviewing 349 NDD-CKD patients attending an outpatient clinic between June 2013 and December 2016. Patients were treated by either FCM intravenous infusion or oral ferrous sulfate. We collected serum values of hemoglobin, ferritin and transferrin saturation (TSAT) and ESAs doses at 12 and 18 months. The costs related to both treatments were also analysed. 239 patients were treated with FCM intravenous infusion and 110 patients with oral ferrous sulfate. The two groups were not statistically different for age, BMI and eGFR values. At 18 months, hemoglobin, serum ferritin and TSAT values increased significantly from baseline in the FCM group, compared with the ferrous sulfate group. ESAs dose and rate of infusion decreased only in the FCM group. At 18 months, the treatment costs, analysed per week, was higher in the ferrous sulfate group, compared with the FCM group, and this was mostly due to a reduction in ESAs prescription in the FCM group. Routine intravenous FCM treatment in an outpatient clinic of NDD-CKD patients results in better correction of iron-deficiency anemia when compared to ferrous sulfate. In addition to this, treating NDD-CKD patients with FCM leads to a significant reduction of the treatment costs by reducing ESAs use.
Assuntos
Anemia/tratamento farmacológico , Anemia/economia , Custos e Análise de Custo , Compostos Férricos/uso terapêutico , Compostos Ferrosos/uso terapêutico , Maltose/análogos & derivados , Insuficiência Renal Crônica/complicações , Idoso , Anemia/sangue , Anemia/complicações , Darbepoetina alfa/uso terapêutico , Compostos Férricos/efeitos adversos , Compostos Ferrosos/efeitos adversos , Testes Hematológicos , Hemoglobinas/análise , Humanos , Ferro/sangue , Maltose/efeitos adversos , Maltose/uso terapêutico , Insuficiência Renal Crônica/sangue , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Studies addressing the anti-inflammatory properties of citrate dialysate enrolled patients in both hemodialysis (HD) and hemodiafiltration (HDF), the latter not adjusted for adequate convective exchange. This is a potential source of confounding in that HDF itself has anti-inflammatory effects regardless of the buffer, and optimal clinical outcomes are related to the amount of convection. METHODS: To distinguish the merits of the buffer from those of convection, we performed a 6-month, prospective, randomized, crossover AB-BA study. Comparisons were made during the 3-month study period of on-line HDF with standard dialysate containing three mmol of acetic acid (OL-HDFst) and the 3-month of OL-HDF with dialysate containing one mmol of citric acid (OL-HDFcit). Primary outcome measure of the study was interleukin-6 (IL-6). Klotho, high sensitivity C-reactive protein (hsCRP), fetuin and routine biochemical parameters were also analyzed. RESULTS: We analyzed 47 patients (mean age 64 years, range 27-84 years) enrolled in 10 participating Nephrology Units. Convective volumes were around 25 L/session with 90 percent of sessions > 20 L and ß2-microglobulin reduction rate 76% in both HDFs. Baseline median IL-6 values in OL-HDFst were 5.6 pg/ml (25:75 interquartile range IQR 2.9:10.6) and in OL-HDFcit 6.6 pg/ml (IQR 3.4:11.4 pg/ml). The difference was not statistically significant (p 0.88). IL-6 values were lower during OL-HDFcit than during OL-HDFst, both when analyzed as the median difference of overall IL-6 values (p 0.02) and as the median of pairwise differences between the baseline and the 3-month time points (p 0.03). The overall hsCRP values too, were lower during OL-HDFcit than during OL-HDFst (p 0.01). Klotho levels showed a time effect (p 0.02) and the increase was significant only during OL-HDFcit (p 0.01). CONCLUSIONS: Citrate buffer modulated IL-6, hsCRP and Klotho levels during high volume OL-HDF. These results are not attributable to differences in the dialysis technology that was applied and may suggest a potential biological effect of citrate on CKD-associated inflammatory state. ClinicalTrials.gov identifier NCT02863016.
Assuntos
Hemodiafiltração , Interleucina-6 , Adulto , Idoso , Idoso de 80 Anos ou mais , Ácido Cítrico , Hemodiafiltração/efeitos adversos , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Diálise RenalRESUMO
Humans are notoriously bad at understanding probabilities, exhibiting a host of biases and distortions that are context dependent. This has serious consequences on how we assess risks and make decisions. Several theories have been developed to replace the normative rational expectation theory at the foundation of economics. These approaches essentially assume that (subjective) probabilities weight multiplicatively the utilities of the alternatives offered to the decision maker, although evidence suggest that probability weights and utilities are often not separable in the mind of the decision maker. In this context, we introduce a simple and efficient framework on how to describe the inherently probabilistic human decision-making process, based on a representation of the deliberation activity leading to a choice through stochastic processes, the simplest of which is a random walk. Our model leads naturally to the hypothesis that probabilities and utilities are entangled dual characteristics of the real human decision making process. It predicts the famous fourfold pattern of risk preferences. Through the analysis of choice probabilities, it is possible to identify two previously postulated features of prospect theory: the inverse S-shaped subjective probability as a function of the objective probability and risk-seeking behavior in the loss domain. It also predicts observed violations of stochastic dominance, while it does not when the dominance is "evident". Extending the model to account for human finite deliberation time and the effect of time pressure on choice, it provides other sound predictions: inverse relation between choice probability and response time, preference reversal with time pressure, and an inverse double-S-shaped probability weighting function. Our theory, which offers many more predictions for future tests, has strong implications for psychology, economics and artificial intelligence.
Assuntos
Técnicas de Apoio para a Decisão , Processos Estocásticos , Comportamento de Escolha , Cognição , Tomada de Decisões , Humanos , Probabilidade , Assunção de RiscosRESUMO
Anomalous origin of a coronary artery from the opposite aortic sinus of Valsalva can present in various ways, ranging from a benign and incidental finding to sudden cardiac death. The variant with an intraseptal subpulmonary course (sometimes referred to as intraconal), is widely perceived to carry a low risk of ischemia and has been considered to be a benign variant, not requiring surgical treatment. In one of our recent patients, however, nuclear scintigraphy highlighted a myocardial perfusion deficit in the territory supplied by the allegedly benign anomalous coronary artery, prompting the need for a more aggressive surgical approach.
Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Circulação Coronária/fisiologia , Anomalias dos Vasos Coronários/cirurgia , Vasos Coronários/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Criança , Anomalias dos Vasos Coronários/diagnóstico , Vasos Coronários/cirurgia , Ecocardiografia , Humanos , Masculino , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND:: Estimated glomerular filtration rate (eGFR) is a predictor of outcome among patients with non-ST-elevation acute coronary syndrome (NSTE-ACS), but which estimation formula provides the best long-term risk stratification in this setting is still unclear. We compared the prognostic performance of four creatinine-based formulas for the prediction of 10-year outcome in a NSTE-ACS population treated by percutaneous coronary intervention. METHODS:: In 222 NSTE-ACS patients submitted to percutaneous coronary intervention, eGFR was calculated using four formulas: Cockcroft-Gault, re-expressed modification of diet in renal disease (MDRD), chronic kidney disease epidemiology collaboration (CKD-Epi), and Mayo-quadratic. Predefined endpoints were all-cause death and a composite of cardiovascular death, non-fatal reinfarction, clinically driven repeat revascularisation, and heart failure hospitalisation. RESULTS:: The different eGFR values showed poor agreement, with prevalences of renal dysfunction ranging from 14% to 35%. Over a median follow-up of 10.2 years, eGFR calculated by the CKD-Epi and Mayo-quadratic formulas independently predicted outcome, with an increase in the risk of death and events by up to 17% and 11%, respectively, for each decrement of 10 ml/min/1.73 m2. The Cockcroft-Gault and MDRD equations showed a borderline association with mortality and did not predict events. When compared in terms of goodness of fit, discrimination and calibration, the Mayo-quadratic outperformed the other formulas for the prediction of death and the CKD-Epi showed the best performance for the prediction of events (net reclassification improvement values 0.33-0.35). CONCLUSIONS:: eGFR is an independent predictor of long-term outcome in patients with NSTE-ACS treated by percutaneous coronary intervention. The Mayo-quadratic and CKD-Epi equations might be superior to classic eGFR formulas for risk stratification in these patients.
Assuntos
Síndrome Coronariana Aguda/cirurgia , Creatinina/sangue , Previsões , Taxa de Filtração Glomerular/fisiologia , Intervenção Coronária Percutânea , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/complicações , Síndrome Coronariana Aguda/complicações , Síndrome Coronariana Aguda/mortalidade , Idoso , Eletrocardiografia , Feminino , Seguimentos , Humanos , Itália/epidemiologia , Rim/fisiopatologia , Masculino , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida/tendênciasRESUMO
BACKGROUND: Aim of this study was to evaluate the early and mid-term outcomes of drug-coated balloons (DCBs) in hemodialysis patients with recurrent stenosis of arteriovenous fistula and previously treated with plain balloon angioplasty (PBA). METHODS: Between July 2013 and June 2016 38 hemodialysis patients with recurrent stenosis of arteriovenous fistula underwent endovascular treatment with a DCB at our center. All patients were previously treated at the target lesion with a PBA. The intervals in months between the standard PBA and the procedure with DCB (time PBA-DCB) and between the procedure with DCB and the restenosis at the target lesion (time DCB-restenosis) were evaluated and compared with T-test. Estimated outcomes at 2 years in terms of patient survival, primary patency, primary assisted patency, secondary patency, and freedom from target lesion restenosis were assessed with Kaplan-Meier curves. RESULTS: Intraprocedural technical success was obtained in 97.4% of the cases. During the follow-up (mean duration 14.3 months, range 2-33) 19 patients (50%) developed a restenotic lesion at the target lesion with an estimated 2-year freedom from target lesion restenosis of 32.8%. Mean time PBA-DCB was 6.4 months, and the mean time DCB-restenosis was 7.9 months with a statistically significant difference at T-test (P<0.001). Estimated 2-year rates of primary patency, primary assisted patency, and secondary patency were 40.8%, 73.1%, and 82.5%, respectively. CONCLUSIONS: In our experience DCBs were safe and effective in the treatment of recurrent stenosis in patients with failing arteriovenous fistula. The time to restenosis at the target lesion was longer respect to that necessary to have a recurrent restenosis after PBA.
Assuntos
Angioplastia com Balão/métodos , Fístula Arteriovenosa/terapia , Artéria Femoral/fisiopatologia , Artéria Poplítea/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Angioplastia com Balão/efeitos adversos , Constrição Patológica/terapia , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva , Diálise Renal/efeitos adversos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular , Adulto JovemRESUMO
BACKGROUND: Benefits and risks of angiotensin converting enzyme inhibitors (ACE-I) in advanced chronic kidney disease (CKD) are controversial. We tested the role of ACE-I in slowing the progression of renal damage in a real-world elderly population with CKD stage 5. METHODS: We evaluated all patients consecutively referred to our CKD stage 5 outpatient clinic from January 2002 to December 2013. Chronicity was defined as two consecutive estimated glomerular filtration rate (eGFR) measurements below 15 ml/min/1.73 m2. We retrieved parameters of interest at baseline and assessed eGFR reduction rate during follow-up. We estimated GFR by the 4-variable Modification of Diet in Renal Disease (MDRD) formula. RESULTS: Mean age of the 342 subjects analyzed was 72 years and eGFR 10 ml/min/1.73 m2. In the 188 patients on ACE-I at baseline, the subsequent annual rate of eGFR reduction was less than a third of that found in the 154 patients off ACE-I. Across phosphate quartiles, baseline eGFR significantly decreased while its annual reduction rate significantly increased. Of the original cohort, 60 patients (17 %) died, 201 (59 %) started dialysis and 81 (24 %) were still in conservative treatment at the end of the study. Multivariate analysis identified age, phosphate, proteinuria, baseline eGFR and its rate of progression as independent risk factors directly or inversely predictive of progression to dialysis. ACE-I use significantly reduced by 31 % the risk of dialysis. CONCLUSIONS: Our study shows that proteinuria independently predicts further renal damage progression even in end-stage renal disease patients not yet in dialysis. In our cohort of elderly patients with very advanced CKD, ACE-I was effective in slowing down further renal damage progression.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Falência Renal Crônica/tratamento farmacológico , Rim/efeitos dos fármacos , Proteinúria/tratamento farmacológico , Insuficiência Renal Crônica/tratamento farmacológico , Sistema Renina-Angiotensina/efeitos dos fármacos , Idoso , Assistência Ambulatorial , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Progressão da Doença , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Itália , Rim/enzimologia , Rim/fisiopatologia , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/enzimologia , Falência Renal Crônica/fisiopatologia , Masculino , Análise Multivariada , Fosfatos/sangue , Modelos de Riscos Proporcionais , Proteinúria/diagnóstico , Proteinúria/enzimologia , Proteinúria/fisiopatologia , Diálise Renal , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/enzimologia , Insuficiência Renal Crônica/fisiopatologia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
The Senning procedure is an operative technique for atrial inversion in congenital heart anomalies. We sought to evaluate our contemporary outcomes employing this technique. A retrospective analysis of all patients who underwent the Senning procedure at our institution was performed. Hospital records were reviewed, and follow-up data were obtained to evaluate outcomes. Overall, a total of 19 patients underwent a Senning procedure between August 2005 and July 2014. Median age at repair was 594 days (range: 5 days to 15 years). Of those, 7 patients underwent a combined Senning-Rastelli operation and 10 patients underwent a double switch operation (arterial switch or atrial switch). Primary diagnosis was congenitally corrected transposition of the great arteries (cc-TGA) in 17 patients. Associated lesions included ventricular septal defect (n = 10), pulmonary stenosis or atresia (n = 7), and Ebstein׳s anomaly of the tricuspid valve (n = 4). There was an operative death (5%). In all, 2 patients required superior vena cava baffle revision in the operating room. No new pulmonary venous or systemic venous baffle obstruction was observed during follow-up. A total of 5 (26%) patients developed heart block requiring pacemaker implantation. Actuarial survival was 81% at 5 years with a median follow-up of 38 months. The 2 patients in the cc-TGA group were subsequently transplanted. Surviving patients (n = 15) are all well at the last clinical follow-up, most with normal biventricular function. In conclusion, the Senning procedure offers excellent outcomes with regard to systemic and pulmonary venous baffle patency. Results in patients with cc-TGA, however, are affected by significant early mortality after Senning-Rastelli and incidence of left ventricular dysfunction after double switch; which should be considered during patient selection and surgical planning.
Assuntos
Transposição das Grandes Artérias , Transposição dos Grandes Vasos/cirurgia , Adolescente , Transposição das Grandes Artérias/efeitos adversos , Transposição das Grandes Artérias/mortalidade , Estimulação Cardíaca Artificial , Criança , Pré-Escolar , Transposição das Grandes Artérias Corrigida Congenitamente , Intervalo Livre de Doença , Feminino , Bloqueio Cardíaco/diagnóstico , Bloqueio Cardíaco/etiologia , Bloqueio Cardíaco/terapia , Transplante de Coração , Humanos , Lactente , Recém-Nascido , Estimativa de Kaplan-Meier , Masculino , Marca-Passo Artificial , Seleção de Pacientes , Reoperação , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Texas , Fatores de Tempo , Transposição dos Grandes Vasos/diagnóstico , Transposição dos Grandes Vasos/mortalidade , Transposição dos Grandes Vasos/fisiopatologia , Resultado do Tratamento , Grau de Desobstrução Vascular , Disfunção Ventricular Esquerda/etiologiaRESUMO
The HeartWare HVAD has been used as a bridge to cardiac transplantation in the pediatric population. We describe outcomes following HeartWare HVAD implantation at a single center. A retrospective chart review was performed of all HeartWare HVAD implants performed at our institution between May 2013 and March 2015. Eight children between the ages of 9 and 17 years underwent HVAD implantation as a bridge to transplant (N = 7 cardiomyopathy, N = 1 complex single ventricle). There was one operative death in the complex single ventricle patient. Seven patients (87%) were successfully bridged to transplant. Median time of support was 24.5 days (range, 6-91 days). All transplanted patients are alive and well at a median follow-up of 448 days. Our results demonstrated that mechanical support with HeartWare HVAD is feasible in patients of varying sizes (from older children to adolescents).
Assuntos
Insuficiência Cardíaca/terapia , Transplante de Coração , Coração Auxiliar , Função Ventricular Esquerda , Adolescente , Fatores Etários , Criança , Estudos de Viabilidade , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Desenho de Prótese , Recuperação de Função Fisiológica , Estudos Retrospectivos , Texas , Fatores de Tempo , Resultado do TratamentoRESUMO
Durable mechanical support in situations of physiologic single ventricle has been met with little success so far, particularly in small children. We created an animal model to investigate whether pulsatile or continuous flow would be superior. Three 1 month old sheep (10-16 kg) were instrumented. Via sternotomy and with cardiopulmonary bypass, a large ventricular septal defect and atrial septal defect were created. The left ventricle was cannulated using a Berlin Heart inflow cannula. This was connected sequentially to a continuous flow device (Thoratec HeartMate X, Pleasanton, CA) and to a pulsatile device (Berlin Heart Excor, The Woodlands, TX). Outflow was via a Y-graft to both aorta and pulmonary artery, striving for equal flow to both. Atrial filling pressures were controlled with volume infusions over a wide range. Under comparable loading conditions, significantly higher maximum flow was obtained by HeartMate X than by Excor (4.95 ± 1.27 L/min [range, 3.84-6.34 L/min] for HeartMate X vs. 1.80 ± 0.85 L/min [range, 1.01-2.7 L/min] for Excor; p < 0.05). Judging from this limited animal study, in single ventricle scenarios, continuous flow devices may achieve higher pump flows than pulsatile devices when provided with similar filling pressures. Their clinical use should be investigated. More extensive experimental studies are needed.
Assuntos
Cardiopatias Congênitas/complicações , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/cirurgia , Coração Auxiliar , Fluxo Pulsátil/fisiologia , Animais , Modelos Animais de Doenças , Projetos Piloto , Carneiro DomésticoRESUMO
Telemetric physiological monitoring systems (TPMS) have enabled accurate continuous measurement of animal blood pressures and flows. However, few studies describe approaches for use of TPMS in the great vessels or inside the heart. We describe our initial experiences using two types of TPMSs. Twelve lambs (20-37 kg) underwent sternotomy. Two lambs were not instrumented and were killed at 14 days to confirm normal sternal wound healing (sham group, n = 2). Ten lambs underwent placement of either standard indwelling pressure-monitoring catheter and perivascular-flow-probe (CFP group, n = 3) or TPMS implantation (TPMS group, n = 7). The TPMS used were EG1-V3S2T-M2 (EG1, n = 5; Transonic Endogear Inc.) and Physio Tel Digital L21 (PTD, n = 2; Data Sciences Inc.). Two deaths because of respiratory problems occurred in TPMS group, attributed to lung compression by the implanted device. In TPMS group, more consistent trends of blood pressures and flows were recorded, and management of animals was easier and less labor-intensive. Comparing the two TPMSs, the initiation and renewal costs for each case was $28 K vs. $20 K and $1,700 vs. $0, (PTD versus EG1, respectively). In conclusion, TPMS implantation was feasible via median sternotomy in lambs. Telemetric physiological monitoring systems significantly improve reliability of hemodynamic monitoring in chronic survival animal study. EG1 was less costly than PTD.
Assuntos
Modelos Animais de Doenças , Hemodinâmica/fisiologia , Monitorização Fisiológica/métodos , Telemetria/métodos , Animais , Ovinos , EsternotomiaRESUMO
As currently performed, on line hemodiafiltration reduces, but does not normalize, the micro-inflammation of uremic patients. Recent technological advances make it possible to further reduce the inflammation connected to the dialysis treatment. Short bacterial DNA fragments are pro-inflammatory and can be detected in the dialysis fluids. However, their determination is not currently within normal controls of the quality of the dialysate. The scenario may change once the analysis of these fragments yields reliable, inexpensive, quick and easy to evaluate the results. At variance with standard bicarbonate dialysate, Citrate dialysate induces far less inflammation both for the well-known anti-inflammatory effect of such buffer and also because it is completely acetate free, e.g. a definitely pro-inflammatory buffer. However, the extensive use of citrate dialysate in chronic dialysis is prevented because of concerns about its potential calcium lowering effect. In our view, high convective exchange on line hemodiafiltration performed with dialysate, whose sterility and a-pirogenicity is guaranteed by increasingly sophisticated controls and with citrate buffer whose safety is certified, can serve as the gold standard of dialysis treatments in future.
Assuntos
Hemodiafiltração , Inflamação/prevenção & controle , Ácido Cítrico , Soluções para Diálise , Humanos , Inflamação/etiologia , Uremia/complicaçõesAssuntos
Cardiopatias Congênitas/cirurgia , Anuloplastia da Valva Mitral , Valva Mitral/anormalidades , Valva Mitral/cirurgia , Pericárdio/transplante , Adolescente , Ecocardiografia Doppler , Ecocardiografia Transesofagiana , Feminino , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/diagnóstico , Humanos , Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/etiologia , Insuficiência da Valva Mitral/cirurgia , Resultado do TratamentoRESUMO
BACKGROUND: In haemodialysis (HD) patients, anaemia is associated with reduced survival. Despite treatment with erythropoiesis-stimulating agents (ESAs), a large number of patients with chronic kidney disease show resistance to this therapy and require much higher than usual doses of ESAs in order to maintain the recommended haemoglobin (Hb) target, and recent studies suggest that hepcidin (HEP) may mediate the ESA resistance index (ERI). High-volume online haemodiafiltration (HV-OL-HDF) has been shown to improve anaemia and to reduce the need for ESAs in HD patients; this effect is associated with a reduced inflammatory state in these patients. The aim of the REDERT study (role of haemodiafiltration on ERI) was to investigate the effect of different dialysis techniques on ERI and HEP levels in chronic dialysis patients. METHODS: A single cross-over, randomized, multicentre study (A-B or B-A) was designed. Forty stable HD patients from seven different dialysis units (male 65%, mean age 67.6 ± 14.7 years and mean dialytic age 48 ± 10 months) were enrolled. Patients were randomized to the standard bicarbonate dialysis (BHD) with low-flux polysulfone (PS) membrane group or to the HV-OL-HDF group with high-flux PS membranes and exchange volume of >20 L/session. After 6 months, patients were shifted to the other dialytic group for a further 6 months. Clinical data, Hb, ESA doses and iron metabolism were recorded every month. HEP, beta2-microglobulin (b2MG) and C-reactive protein (CRP) were determined every 3 months, and ERI was calculated monthly as the weekly ESA dose per kilogram of body weight divided by Hb level. Data were analysed using paired-samples t-test, Wilcoxon signed-rank test and Spearman's correlation coefficient. RESULTS: Dialysis efficiency for small molecules assessed as Kt/V was significantly increased in HV-OL-HDF from 1.47 ± 0.24 to 1.49 ± 0.16; P < 0.01. A significant reduction of b2MG was obtained in HV-OL-HDF from month 3 whereas CRP values were not significantly changed during the study period either in BHD or HV-OL-HDF.ERI was significantly reduced in HV-OL-HDF at month 3 and 6 (from 9.1 ± 6.4 UI/weekly/Kg/Hb to 6.7 ± 5.3 UI/weekly/Kg/Hb; P < 0.05) due to a higher ESA consumption in BHD in spite of similar Hb levels. HEP levels were reduced in HV-OL-HDF with respect to BHD after 3 and 6 months. Iron consumption was not significantly different during BHD or HV-OL-HDF treatment as well as transferrin, ferritin and TSAT levels. A significant positive linear correlation between HEP and ERI (r(2) = 0.258, P < 0.001) was observed. CONCLUSIONS: In a uraemic patient population with low-grade inflammation treated with HV-OL-HDF, we observed a significant reduction of ERI values as well as HEP levels. The positive correlation between these two parameters supports a role for HEP in the development of ERI in the dialytic population. Moreover, the lower b2MG and the higher Kt/V achieved in HV-OL-HDF confirms the better depurative effect of this technique in comparison with BHD with respect to middle molecules and small-molecular-weight molecules.
Assuntos
Anemia/tratamento farmacológico , Bicarbonatos/uso terapêutico , Resistência a Medicamentos , Hematínicos/farmacologia , Hemodiafiltração/métodos , Soluções para Hemodiálise/uso terapêutico , Idoso , Proteína C-Reativa/metabolismo , Estudos Cross-Over , Eritropoese/efeitos dos fármacos , Feminino , Hemoglobinas/metabolismo , Hepcidinas/metabolismo , Humanos , Inflamação/tratamento farmacológico , Ferro/metabolismo , Masculino , Sistemas On-Line , Estudos Prospectivos , Uremia/tratamento farmacológicoRESUMO
OBJECTIVE: Fetal cardiac surgery is a potential innovative treatment for certain congenital heart defects that have significant mortality and morbidity in utero or after birth, but it has been limited by placental dysfunction after fetal cardiac bypass. We have used the TinyPump device for fetal cardiac bypass in sheep fetuses at 90 to 110 days gestation. METHODS: Ten mixed-breed pregnant ewes were used over a period of 6 months, and 10 fetuses were placed on bypass for 30 minutes. Five fetuses with a mean gestational age of 104 ± 4.5 days and mean weight of 1.4 ± 0.4 kg were placed on bypass using the TinyPump device, and 5 fetuses with a mean gestational age of 119 ± 4.5 days and mean weight of 3.4 ± 0.4 kg were placed on bypass using the roller head pump. The fetuses were monitored for up to 3 hours after bypass or until earlier demise. RESULTS: Progressive respiratory and metabolic acidosis developed in all fetuses. The TinyPump group had a lower gestational age and weight compared with the roller head pump group. However, the rate of postbypass deterioration in the TinyPump group, as measured with blood gases, was noted to be significantly slower compared with the roller head pump group. CONCLUSIONS: We demonstrate the feasibility of the TinyPump device for fetal cardiac bypass in a fetal sheep model. The TinyPump group showed improved results compared with the roller head group despite more immature fetuses. The TinyPump device seems to be a promising device for future studies of fetal cardiac bypass in immature fetal sheep and in primates.
Assuntos
Ponte Cardiopulmonar/instrumentação , Coração Fetal/cirurgia , Coração Auxiliar , Animais , Feminino , Gravidez , Resultado da Gravidez , OvinosRESUMO
We report the case of a woman with a history of chronic alcohol abuse who was hospitalized with diarrhea, severe hypokalemia refractory to potassium infusion, nausea, vomiting, abdominal pain, alternations of high blood pressure with phases of hypotension, irritability and increased urinary 5-hydroxyindoleacetic acid and cortisol. Although carcinoid syndrome was hypothesized, abdominal computed tomography and colonoscopy showed non-specific inflammatory bowel disease with severe colic wall thickening, and multiple colic biopsies confirmed non-specific inflammation with no evidence of carcinoid cells. During the following days diarrhea slowly decreased and the patient's condition progressively improved. One year after stopping alcohol consumption, the patient was asymptomatic and serum potassium was normal. Chronic alcohol exposure is known to have several deleterious effects on the intestinal mucosa and can favor and sustain local inflammation. Chronic alcohol intake may also be associated with high blood pressure, behavior disorders, abnormalities in blood pressure regulation with episodes of hypotension during hospitalization due to impaired baroreflex sensitivity in the context of an alcohol withdrawal syndrome, increased urinary 5-hydroxyindoleacetic acid as a result of malabsorption syndrome, and increased urinary cortisol as a result of hypothalamic-pituitary-adrenal axis dysregulation. These considerations, together with the regression of symptoms and normalization of potassium levels after stopping alcohol consumption, suggest the intriguing possibility of a alcohol-related acute inflammatory bowel disease mimicking carcinoid syndrome.