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Hemodialysis (HD) is a life-sustaining therapy as well as an intermittent and repetitive stress condition for the patient. In ridding the blood of unwanted substances and excess fluid from the blood, the extracorporeal procedure simultaneously induces persistent physiological changes that adversely affect several organs. Dialysis patients experience this systemic stress condition usually thrice weekly and sometimes more frequently depending on the treatment schedule. Dialysis-induced systemic stress results from multifactorial components that include treatment schedule (i.e. modality, treatment time), hemodynamic management (i.e. ultrafiltration, weight loss), intensity of solute fluxes, osmotic and electrolytic shifts and interaction of blood with components of the extracorporeal circuit. Intradialytic morbidity (i.e. hypovolemia, intradialytic hypotension, hypoxia) is the clinical expression of this systemic stress that may act as a disease modifier, resulting in multiorgan injury and long-term morbidity. Thus, while lifesaving, HD exposes the patient to several systemic stressors, both hemodynamic and non-hemodynamic in origin. In addition, a combination of cardiocirculatory stress, greatly conditioned by the switch from hypervolemia to hypovolemia, hypoxemia and electrolyte changes may create pro-arrhythmogenic conditions. Moreover, contact of blood with components of the extracorporeal circuit directly activate circulating cells (i.e. macrophages-monocytes or platelets) and protein systems (i.e. coagulation, complement, contact phase kallikrein-kinin system), leading to induction of pro-inflammatory cytokines and resulting in chronic low-grade inflammation, further contributing to poor outcomes. The multifactorial, repetitive HD-induced stress that globally reduces tissue perfusion and oxygenation could have deleterious long-term consequences on the functionality of vital organs such as heart, brain, liver and kidney. In this article, we summarize the multisystemic pathophysiological consequences of the main circulatory stress factors. Strategies to mitigate their effects to provide more cardioprotective and personalized dialytic therapies are proposed to reduce the systemic burden of HD.
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BACKGROUND AND AIMS: Intradialytic hypertension, in patients on maintenance hemodialysis, is associated with increased morbidity and mortality. As there is no data available from India, this study was aimed to determine the prevalence and outcome of intradialytic hypertension (IDH) in a tertiary care dialysis centre in India. METHODS: This was a prospective analytical study of 120 patients on hemodialysis. At screening phase, all patients were subjected to fluid optimization and adjustment in the antihypertensive medicines for appropriate control of blood pressure (BP). BP measurements during hemodialysis were recorded. The prevalence of IDH was noted. IDH was defined as increase in systolic BP of >10 mmHg from pre to post hemodialysis or after 2nd hour of dialysis when significant ultrafiltration had occurred, on 3 consecutive sessions. Factors associated with IDH were evaluated and compared with cohort without IDH. The outcome of these patients in terms of morbidity and mortality over a follow-up period of 12 months were recorded. RESULTS: The prevalence of IDH was 21.9%. The baseline demographic parameters of patients in both the groups (with and without IDH) including age, sex, dialysis access, duration of dialysis, and comorbidities were similar. Laboratory parameters were similar except serum potassium and serum phosphorus, which were lower in patients with IDH. Out of all the variables studied, only low serum phosphorus was associated independently with IDH. During follow-up, at 6 months, 19/71 (26%) non-IDH and 12/20 (60%) IDH patients (P = 0.006) and at 12 month, 30/71 (42%) non-IDH patients and 12/20 (60%) IDH patients required admission (P = 0.05). Mortality at 6 months was similar, 5/71 (7%) in non-IDH and 4/20 (20%) in IDH (P = 0.10) patients, but was higher at 12 months, 11/71 (15.5%) in non-IDH and 8/20 (40%) in IDH (P = 0.028). CONCLUSION: Incidence of intradialytic hypertension is high (21.9%) with increased morbidity in terms of hospitalization and increased mortality over a period of one year.
RESUMEN
RATIONALE & OBJECTIVE: Patients with kidney failure treated with maintenance dialysis experience a high rate of mortality, in part due to sudden cardiac death caused by arrhythmias. The prevalence of arrhythmias, including the subset that are clinically significant, is not well known. This study sought to estimate the prevalence of arrhythmias, characterize the pattern of arrhythmic events in relation to dialysis treatments, and identify associated clinical characteristics. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: 152 patients with kidney failure treated with maintenance dialysis in Denmark. EXPOSURES: Dialysis treatment; clinical characteristics; cardiac output and preload defined using echocardiography. OUTCOMES: Prevalence and pattern of arrhythmias on 48-hour Holter monitoring; odds ratios for arrhythmias. ANALYTICAL APPROACH: Descriptive analysis of the prevalence of arrhythmias. Pattern of arrhythmias described using a repeated-measures negative binomial regression model. Associations between clinical characteristics and echocardiographic findings with arrhythmias were assessed using logistic regression. RESULTS: Among the 152 patients studied, 83.6% were treated with in-center dialysis; 10.5%, with home hemodialysis; and 5.9%, with peritoneal dialysis. Premature atrial and ventricular complexes were seen in nearly all patients and 41% had paroxysmal supraventricular tachycardia. Clinically significant arrhythmias included persistent atrial fibrillation observed among 8.6% of patients, paroxysmal atrial fibrillation among 3.9%, nonsustained ventricular tachycardia among 19.7%, bradycardia among 4.6%, advanced second-degree atrioventricular block among 1.3%, and third-degree atrioventricular block among 2.6%. Premature ventricular complexes were more common on dialysis days, while tachyarrhythmias were more often observed during dialysis and in the immediate postdialytic period. Older age (OR per 10 years older, 1.53; 95% CI, 1.15-2.03; P=0.003), elevated preload (OR, 4.02; 95% CI, 1.05-15.35; P=0.04), and lower cardiac output (OR per 1L/min greater, 0.66; 95% CI, 0.44-1.00; P=0.05) were independently associated with clinically significant arrhythmias. LIMITATIONS: Arrhythmia monitoring limited to 48 hours; small sample size; heterogeneous nature of the population, risk for residual confounding. CONCLUSIONS: Arrhythmias, including clinically significant abnormal rhythms, were common. Tachyarrhythmias were more frequent during dialysis and the immediate postdialytic period. The relevance of these findings to clinical outcomes requires additional study.
Asunto(s)
Arritmias Cardíacas/etiología , Fallo Renal Crónico/terapia , Diálisis Renal/efectos adversos , Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/fisiopatología , Estudios Transversales , Dinamarca/epidemiología , Electrocardiografía Ambulatoria , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/mortalidad , Masculino , Persona de Mediana Edad , Prevalencia , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia/tendenciasRESUMEN
BACKGROUND: It is the object of debate whether a low or high dialysate sodium concentration (DNa(+)) should be advocated in chronic haemodialysis patients. In this paper, we aimed at evaluating benefits and harms of different DNa(+) prescriptions through a systematic review of the available literature. METHODS: MEDLINE and CENTRAL databases were searched for studies comparing low or high DNa(+) prescriptions. Outcomes of interest were mortality, blood pressure (BP), interdialytic weight gain (IDWG), plasma sodium, hospitalizations, use of anti-hypertensive agents and intradialytic complications. RESULTS: Twenty-three studies (76 635 subjects) were reviewed. There was high heterogeneity in the number of patients analysed, overall study quality, duration of follow-up, DNa(+) and even in the definition of 'high' or 'low' DNa(+). The only three studies looking at mortality were observational. The risk of death was related to the plasma-DNa(+) gradient, but was also shown to be confounded by indication from the dialysate sodium prescription itself. BP was not markedly affected by high or low DNa(+). Patients treated with higher DNa(+) had overall higher IDWG when compared with those with lower DNa(+). Three studies reported a significant increase in intra-dialytic hypotensive episodes in patients receiving low DNa(+). Data on hospitalizations and use of anti-hypertensive agents were sparse and inconclusive. CONCLUSIONS: There is currently no definite evidence proving the superiority of a low or high uniform DNa(+) on hard or surrogate endpoints in maintenance haemodialysis patients. Future trials adequately powered to evaluate the impact of different DNa(+) on mortality or other patient-centred outcomes are needed.