Additional intermittent peritoneal dialysis in difficult-to-treat hemodialysis patients with severe heart disease

Abstract

Usually, patients treated by peritoneal dialysis are switched to full-time hemodialysis due to technique failure. Sometimes, hemodialysis can be added to peritoneal dialysis to improve dialysis delivery. It can be difficult to use hemodialysis on patients with significant heart disease (valvular disease or ischemic cardiomyopathy) and severe heart failure due to common immediate complications and intradialytic hypotension that may worsen cardiac function, thus closing the vicious cycle of cardiac dysfunction and ischemia. This can result in poor dialysis delivery along with volume overload despite regular hemodialysis sessions. Here, we describe a case series of difficult-to-treat hemodialysis patients (7 males aged 51–73) with significant cardiac comorbidities and heart failure in whom additional intermittent peritoneal dialysis was reintroduced on top of regular hemodialysis. They all were initially treated by peritoneal dialysis (median duration of peritoneal dialysis treatment was 16 months, range 2–44) and then switched to full-time hemodialysis due to insufficient ultrafiltration or reasons unrelated to ultrafiltration, but thereafter, they faced significant hemodialysis-related complications and volume overload despite regular weekly sessions. Peritoneal dialysis (one manual exchange) was reintroduced (2–4 months after switching to full-time HD) on 3 hemodialysis-free days, and patients were followed up. After 12 months, better volume management (regression of pleural effusion, a reduction in water body mass composition (median of 1 vs. 2.4 L), reduced serum NT-proBNP values (median of 13,030 vs. 45,384 pg/ml)), better cardiac functional status, and a reduction in the frequency and number of dialytic complications were achieved. Moreover, during the 12-month follow-up, such bimodal treatment resulted in improved health-related quality of life as assessed by the WHOQoL-BREF questionnaire (median of 74 vs 55). The addition of peritoneal dialysis in difficult-to-treat hemodialysis patients may result in benefits despite additional costs and burdens for patients.

Introduction

Kidney failure (KF), defined by a permanent decline in glomerular filtration rate of less than 15 ml/min/1.73m², requires renal replacement therapy (RRT), i.e. kidney transplantation or dialysis, or sometimes supportive care when RRT is not an option[1]. Maintenance dialysis is a blood purification method which aims to remove metabolic waste, water excess and rebalance electrolytes thus mimicking exocrine kidney function. For patients with chronic KF requiring maintenance dialysis, there are two options, hemodialysis (HD) and peritoneal dialysis (PD), both of which can be applied at the same time (bimodal dialysis treatment). In HD, extracorporal circulation is used to remove water and solutes from blood, and remains the most common form of RRT, counting for more than 80% of patients receiving RRT in near all countries, followed by PD and kidney transplantation[2]. Standard HD can be performed in a dialysis clinic (in-centre HD) or at home (home HD). In-centre HD typically occurs 3 times weekly for 4 hours per treatment. In some centers shorter or longer overnight HD treatments can be provided and in developed countries home-HD became important modality of individualized HD treatment[1]. In PD, peritoneal membrane is used for the water and solute exchange after instillation of dialysis solution in the abdomen. This can be performed manually, typically with 4-6 manual exchanges daily (CAPD, continuous ambulatory PD), or via machine-automated exchanges (APD, automated PD) which is often performed at night[3]. Although PD is more cost-effective than in-center HD, it is still used less frequent than HD, only in approximately 11% of patients receiving dialysis (3). In long-term PD patients, loss of residual renal function and deterioration of peritoneal membrane function may cause toxin accumulation and ultrafiltration (UF) insufficiency, with volume overload leading to technique failure and switch to HD[4][5]. This conversion can be direct from PD to HD or, sometimes, combination of PD and HD (bridge therapy) is used for some time (e.g. two HD sessions per month or one weekly session) before switching to full-time HD. Such bimodal regimen seems to be not redundant, but a rational and cost-effective modality of RRT with comparable admission and mortality rate as in patients directly switched to HD[6]. Several studies showed that bimodal dialysis therapy could increase dialysis adequacy, decrease fluid overload and improve health-related quality of life (HRQoL) in patients requiring dialysis[7][8].

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Patients receiving maintenance dialysis as RRT have high mortality rate with a 5-year survival of less than 50% in some countries[1]. Cardiovascular diseases are the major cause of morbidity and mortality in dialysis patients and the primary leading cause of death in both HD and PD patients, accounting for around 50% of deaths in dialysis patients[1][9]. In incident patients with KF, the prevalence of heart failure (HF) is around 30% and atherosclerotic coronary artery disease (CAD) around 18%. Even in dialysis patients without significant cardiovascular risk, a risk of cardiovascular events including admission due to HF increases significantly after dialysis initiation[9]. Before reaching KF, HF and chronic kidney disease (CKD) frequently co-exist and probably bidirectional causality is present with one system dysfunction predating the other[10]. Mechanisms involved in myocardial decline during dialysis include atherosclerosis, aldosterone-induced cardiac fibrosis, left-ventricular hypertrophy, vascular stiffening and medial vascular calcifications upon bone-mineral disorder in KF[10]. In circumstances of the cardiac disease and HF in dialysis patients, volume overload can be frequent and more severe, and its management more difficult. This may be particularly seen in patients without residual kidney function receiving HD where diuretics have no any effect. During the conventional three-times weekly in-center HD, aggressive UF is often needed in response to interdialytic weight gain, thereby placing stress on the heart and peripheral vasculature. Such stress is aggravated in patients with co-existing HF whose hemodynamic is already vulnerable, thus episodes of hypotension may occur[9]. Even in HD patients without known heart disease, episodes of myocardial stunning due to hemodynamic changes during the HD treatment may occur, leading to higher morbidity and mortality and development of HF[11]. Taken all together, volume management in HD patients with HF and other heart conditions can be challenging. On the other hand, adjustment of blood volume, predominately by removal of excess salt and water by UF, is necessary for cardiac function optimization[10]. Due to much lower UF rate, PD is not associated with such hemodynamic changes like HD, neurohumoral activation is less intense and myocardial stunning is absent[12]. PD, usually prescribed as intermittent treatment (IPD) can be used for severe and drug-resistant HF treatment in patients with cardiorenal syndrome, even before reaching KF[10][13]. While there is plenty of data on additional HD treatment in PD patients encountering technique failure (bimodal PD and HD treatment), there is little data on the additional use of PD in patients switched to full-time HD in order to improve volume status management.

Here, we describe a series of the patients switched from PD to full-time HD, in whom significant HF was present and volume overload was treated by reintroduction of intermittent PD (aIPD) on the top of conventional three-times weekly HD.

Methods

Patients included in this retrospective case series were treated and followed up at Division of Dialysis, General Hospital Zadar, Croatia. All included patients were switched directly from PD

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