Serafim N Nanas

• MD, PhD, Em. Prof of Critical Care
• Professor (Full) at National and Kapodistrian University of Athens

Chronic heart failure (CHF) is a complex clinical syndrome leading to exercise intolerance due to muscular fatigue and dyspnea. Hemodynamics fail to explain the reduced exercise capacity, while a significant skeletal muscular pathology seems to constitute the main underlying mechanism for exercise intolerance in CHF patients. There have been propos...

Background: Tissue oxygen saturation (StO₂) measured by near-infrared spectroscopy (NIRS) has been used to provide information on local tissue oxygenation in different clinical settings. This study aims to determine the effect of weaning from mechanical ventilation on thenar muscle StO₂. Methods: In consecutive critically ill mechanically ventil...

Patients in the intensive care unit (ICU) are often exposed to prolonged immobilization, thus they lose their functional ability. Therefore, it is crucial to assess patients’ functional ability during their stay in and upon their discharge from the ICU. Several scales have been used so far for the assessment of functional ability, impairment and/or...

The metabolic support of the critically ill patient is a relatively new target of active research and little is as yet known about the effects of critical illness on metabolism. The nonthyroidal illness syndrome, also known as the low T3 syndrome or euthyroid sick syndrome, describes a condition characterized by abnormal thyroid function tests enco...

Until recently, the sonographic visualization of pulmonary and pleural diseases was considered a poorly accessible method, due to the inability of sound to penetrate air-filled lung. Despite its limitations, lung ultrasonography is becoming an important diagnostic tool in a growing number of pathological situations such as pneumonia, atelectasis, i...

Background: Critically ill patients treated in intensive care units (ICU) are characterized by a qualitative and quantitative change in the composition of their intestinal microflora, leading to a reduction in commensal flora and an overgrowth of potentially pathogenic bacteria, which increase susceptibility to nosocomial infections and compromise...

Background: The use of immersive Virtual Reality (VR) in stroke rehabilitation appears to be promising for the improvement of motor and cognitive functions. Methods: The purpose of this pilot study was to investigate the suitability, usability and safety of VR applications that combine motor and cognitive training. Patients suffering from stroke in...

Background/Objectives: The aim of this study was to investigate the feasibility and safety of neuromuscular electrical stimulation (NMES) in patients on extracorporeal membrane oxygenation (ECMO) and thoroughly assess any potential adverse events. Methods: We conducted a prospective observational study assessing safety and feasibility, including 16...

Introduction Chronic heart failure (CHF) has been characterized with microcirculation and endothelial abnormalities, as well as impaired function of the respiratory system. Exercise training programs have been an important component of CHF rehabilitation. Inspiratory muscle training (IMT), a supplementary form of exercise, induces beneficial effect...

Introduction Patients with chronic heart failure (CHF) have an increased risk of presenting symptoms of stress and depression compared to the general population. For this reason, mental health components have been integrated into exercise rehabilitation programs. The effectiveness of behavioral interventions has not been evaluated in this clinical...

Introduction Patients with chronic heart failure (CHF) have been presented with microcirculation alterations and vascular endothelial dysfunction. Exercise training programs, including inspiratory muscle training (IMT) as an alternative/additional means of exercise, have been shown to improve the functional status of these patients. However, there...

Background: Pulmonary hypertension (PH) is a serious progressive disorder of the modern world, characterized by endothelial dysfunction and impaired vasoreactivity. Patients with PH usually present exercise intolerance from the very early stages and reduced exercise capacity. Exercise training has been shown to have beneficial effects in patients...

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation. The purpose of this systematic review is to evaluate the effectiveness of exercise training on functional capacity and quality of life (QoL) in patients with RA. We performed a search in four databases, selecting clinical trials that included community or outp...

Background/Objectives: The aim of this study was to investigate feasibility and safety of neuromuscular electrical stimulation (NMES) in patients on extracorporeal membrane oxygenation (ECMO) and assess thoroughly any potential adverse events. Methods: We conducted a safety and feasibility study including 16 ICU patients on ECMO support who were ad...

Endothelial dysfunction and inflammation are common pathophysiological characteristics of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are recognized as useful markers of vascular damage and endothelial repair. The aim of this study was to investigate the effects of a cardiac rehabilitation program on EPCs and inflammatory profi...

Aim: The aim of the present study was to investigate whether a high-frequency (HF) neuromuscular electrical stimulation (NMES) protocol could result in a smaller loss of muscle mass than a moderate-frequency (MF) protocol in ICU patients. Methods and materials: In this randomized pilot control trial, patients of the two intervention groups followed...

Background: Patients with hematological malignancies who undergo hematopoietic stem cell transplantation (HSCT) face complex challenges and need appropriate information to help them cope with the physical and psychological demands of their treatment and experience greater health related quality of life (HRQoL). This study investigated the impact of...

Background: Current European heart failure (HF) Guidelines suggests the use of risk score: among them, the Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score has demonstrated to be one of the most accurate. However, the risk scores are still poorly implemented in clinical practice, also due to lack of strong eviden...

Background: Patients admitted to intensive care unit (ICU) after cardiac surgery develop acute kidney injury (AKI) immediately post-operation. We hypothesized that AKI occurs mainly due to perioperative risk factors and may affect outcome. Aim: To assess peri-operative risk factors for AKI post cardiac surgery and its relationship with clinical...

Background Millions of people face critical illnesses and need to be hospitalized in an Intensive Care Unit (ICU) annually worldwide. Despite the fact that survival rates of these patients have increased, they develop various cognitive, psychological and functional impairments. This study aims to investigate the significance of the recovery interve...

Background: Type 2 diabetes mellitus (T2DM) is a chronic metabolic syndrome characterized by insulin resistance and hyperglycemia that may lead to endothelial dysfunction, reduced functional capacity and exercise intolerance. Regular aerobic exercise has been promoted as the most beneficial non-pharmacological treatment of cardiovascular diseases....

Background: Patients with chronic heart failure (CHF) present microcirculation alterations and vascular endothelial dysfunction. Exercise training programs have been shown to improve the functional status of these patients, however less is known yet about the acute systemic effect of exercise on peripheral muscle microcirculation. The aim of the pr...

Background: The provision of information to patients is one of the most important factors of supportive cancer care. We conducted a systematic review to detect information-giving interventions and their impact on quality of life, psychological distress and satisfaction of hematopoietic stem cell transplant (HSCT) patients. Methods: Randomized contr...

Background: Swallowing is an important function for life sustenance but our understanding of its neural organization in the human cortex is not yet fully explored. Electroencephalography is a functional neuroimaging modality that already has and could further contribute to that direction. In this review, we have sought to gather and present finding...

Background Peripheral myopathy consists a hallmark of heart failure (HF) and has been associated with poor prognosis. Inflammation has been suggested to dominate this pathology, while exercise training is typically associated with the induction of anti-inflammatory mechanisms. However, the current knowledge regarding the involvement of inflammation...

Background: Transcranial Photobiomodulation (t-PBM) is a current, innovative method that is used in the therapy of many neurological and psychological diseases. Its mechanisms of action have been investigated and the most well described ways of action are its effects on mitochondrial function and on heat/light-activated ion channels on neurons memb...

Background Aerobic exercise, either continuous or high intensity interval training (HIIT), induces important benefits in chronic heart failure (CHF) patients. Resistance training has been also shown to be beneficial in CHF. However, data regarding combined aerobic exercise and muscle strength training is still limited. The aim of this study was to...

We aimed to assess the lipopolysaccharide (LPS), or heat shock (HS) induction, and glutamine-modulating effects on heat shock protein-90α (HSP90α) and cytokines in an ex vivo model using peripheral blood mononuclear cells (PBMCs). The PBMCs of patients with septic shock, trauma-related systemic inflammatory response syndrome (SIRS), and healthy sub...

Aims Endothelial progenitor cells(EPCs) play a vital role in protecting endothelial dysfunction and cardiovascular disease (CVD). Physical exercise stimulates the mobilization of EPCs, and along with vascular endothelial growth factor, (VEGF) promotes EPC differentiation and contributes to vasculogenesis. The meta-analysis examines the exercise-ind...

Background Over the past few years, technological innovations have been increasingly employed to augment the rehabilitation of stroke patients. Virtual reality (VR) has gained attention through its ability to deliver a customized training session and to increase patients’ engagement. Virtual reality rehabilitation programs allow the patient to perf...

Stroke is the leading cause of disability and one of the leading causes of death1. Usual rehabilitation methods are consisted by physical, occupational and speech-language therapy. Virtual Reality (VR) is a new technology increasingly used in rehabilitation that is expected to enhance neuroplasticity in stoke recovery. Even though there is limite...

Background: Patients with heart failure (HF) have impaired function of respiratory system and frequently experience dyspnea. Inspiratory muscle training (IMT) offers an alternative way of exercise with a lot of benefits for HF patients. Aim: The aim of this review was to summarize and to reveal the effects of IMT in HF patients. Methods: Electronic...

Heart failure (HF) is a major public health issue worldwide with increased prevalence and a high number of hospitalizations. Patients with chronic HF and either reduced ejection fraction (HFrEF) or mildly reduced ejection fraction (HFmrEF) present vascular endothelial dysfunction and significantly decreased circulating levels of endothelial progeni...

Background: Acute kidney injury (AKI) is associated with markedly increased morbidity and mortality in critically ill patients and often necessitates the use of continuous renal replacement therapy (CRRT). The aim of the present study was to compare the predictive performance of urine neutrophil gelatinase (uNGAL), plasma cystatin C (pCysC), serum...

Background: Virtual Reality (VR) is a new technology used more and more in clinical trial. Aim: The aim of this study is to investigate the effects of immersive VR as a rehabilitation approach of cognitive functions. Method and Material: A systematic literature review was conducted in the electronic databases of PubMed, Cochrane, OTseeker and PsycI...

Purpose: The purpose of this study was to investigate the effect of a cardiac rehabilitation program on the acute response on endothelial progenitor cells and circulating endothelial cells after maximal exercise in patients with chronic heart failure of different severity. Methods: Forty-four chronic heart failure patients were enrolled in a 36-...

Background Active cycle breathing technique (ACBT), which includes cycle of breathing control, thoracic expansion exercises and forced expiratory technique (FET), appears to have beneficial effects in patients with a variety of respiratory diseases. This systematic review provides an update on the new related studies, expanding the evidence base th...

Background and objectives Chronic obstructive pulmonary disease (COPD) dyspnea intensity is strongly correlated with respiratory drive, when assessed in relation to EMGdi activity expressed as a percentage of maximum (EMGdi%max). There is growing evidence that respiratory drive can be improved by exercise. The present systematic review investigates...

Aim: The present study investigates the effect of Strength Training addition in a High Intensity Interval Training (HIIT) program, on the inflammatory profile of chronic heart failure (CHF) patients. Materials and Methods: Forty-six CHF patients were randomized into the two different exercise rehabilitation groups. A patient group (control) perform...

Background: The benefits derived from supervised aerobic exercise in people living with human immunofeficiency virus– HIV (PLWH) have not yet been clearly identified. Objective: To evaluate the impact of supervised aerobic exercise on immunological, cardiorespiratory, pulmonary, hemodynamic and mental parameters of PLWH. Methods: A systematic rev...

Oxidative stress is considered pivotal in the pathophysiology of sepsis. Oxidants modulate heat shock proteins (Hsp), interleukins (IL), and cell death pathways, including apoptosis. This multicenter prospective observational study was designed to ascertain whether an oxidant/antioxidant imbalance is an independent sepsis discriminator and mortalit...

The aim of this qualitative systematic review is to summarize and analyze the different modalities of exercise training and its potential effects in patients on extracorporeal membrane oxygenation (ECMO) support. ECMO is an outbreaking, life-saving technology of the last decades which is being used as a gold standard treatment in patients with seve...

The purpose of this study was to compare the acute cardiorespiratory responses and time spent above different %VO2peak intensities between three “iso-work” protocols: (a) a high intensity interval training protocol (HIIT), (b) a higher intensity continuous protocol (CON70) and (c) a lower intensity continuous protocol (CON50) in patients with chron...

Heart transplantation remains the gold standard in the treatment of end-stage heart failure (HF). Heart transplantation patients present lower exercise capacity due to cardiovascular and musculoskeletal alterations leading thus to poor quality of life and reduction in the ability of daily self-service. Impaired vascular function and diastolic dysfu...

Background: Early mobilization of the Intensive Care Unit (ICU) patients improves muscle strength and functional capacity. It has been demonstrated that prevents Intensive Care Unit Acquired Weakness (ICUAW) and accelerates ICU discharge. However, data on mobilization early after cardiac surgery are inadequate. This study aimed to record early mobi...

Background: Chronic heart failure (CHF) is a complex syndrome characterized by a progressive reduction of the left ventricular (LV) contractility, low exercise tolerance, and increased mortality and morbidity. Diastolic dysfunction (DD) of the LV, is a keystone in the pathophysiology of CHF and plays a major role in the progression of most cardiac...

Peripheral myopathy consists of a hallmark of heart failure (HF). Exercise enhanced skeletal muscle angiogenesis, and thus, it can be further beneficial towards the HF-induced myopathy. However, there is limited evidence regarding the exercise type that elicits optimum angiogenic responses of skeletal muscle in HF patients. This study aimed to (a)...

Background: There is a growning evidence that CBT (Cognitive Behavioral Therapy) improves mental health of patients with chronic illnesses but its effectiveness is not well established in patients with heart diseases. The present systematic review was conducted to evaluate the effects of CBT in heart failure (HF) and coronary heart disease (CHD) pa...

Introduction Acute exercise and exercise training may confer epigenetic modifications in healthy subjects. Epigenetic effects after exercise have been showed in patients with cardiovascular disease. The aim of this systematic review was to summarize the evidence from available clinical trials that study epigenetic adaptations after exercise in pati...

Funding Acknowledgements Type of funding sources: None. PURPOSE The aim of the present study is to evaluate the impact of a cardiac rehabilitation program on the diastolic dysfunction, the ejection fraction (EF) of left ventricular and the volume index of the left atrium comparing 2 groups: those with restricted EF (<40%) and those with intermedia...

Background: The management of Heart Failure (HF) is the cornerstone for the appropriate therapy and the knowledge obtained concerning the disease is known to affect self-care behaviours. Aim: The aim was to test the association between self-care management, knowledge, self-efficacy for medication and quality of life in chronic HF patients.Material...

Background Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are also impaired. The purpose of the study was to assess the effect of a cardiac rehabilitation (CR) program on the increase of EPCs at rest and on the acute response after maximal exercise in...

Sepsis is a dysregulated host response to infection related to devastating outcomes. Recently, interest has been shifted towards apoptotic and antiapoptotic pathobiology. Apoptosis is executed through the activation of caspases regulated by a number of antiapoptotic proteins, such as survivin. The survivin and caspases’ responses to sepsis have not...

Background: Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Patients with CHF are characterized by impaired vasodilation and inflammation of the vascular endothelium. They also have low levels of endothelial progenitor cells (EPCs). EPCs are bone marrow derived cells involved in endothel...

Aims Despite published guidelines emphasizing the importance of education in the management of heart failure (HF), the most effective method of education remains unknown. The aim of this study was to test the efficacy of constructivist teaching method (CTM) on the patients with HF. Methods and results This is a single-centre, randomized controlled...

Background Chronic heart failure (CHF) remains a leading cause of morbidity and mortality and it is characterized by vascular endothelial dysfunction. During the last decades, endothelial progenitor cells (EPCs) are being used as an index of the endothelium restoration potential, therefore reflecting the vascular endothelial function. Exercise trai...

Background Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are being used as an index of vascular endothelial function. Cardiac rehabilitation (CR) programs have been shown to stimulate the mobilization of EPCs in CHF patients. However, the effect of di...

Regular exercise affects the vascular system, endothelial function,¹ and facilitates microcirculation² in patients with chronic heart failure (CHF). It promotes mobilization of endothelial progenitor cells (EPCs) into circulation which repair dysfunctional or injured endothelium and contribute to angiogenesis.³ Furthermore, haematopoietic progenito...

Background: Patients undergoing cardiac surgery particularly those with comorbidities and frailty, experience frequently higher rates of post-operative morbidity, mortality and prolonged hospital length of stay. Muscle mass wasting seems to play important role in prolonged mechanical ventilation (MV) and consequently in intensive care unit (ICU) a...

Rationale & Objective The usefulness of measures of neutrophil gelatinase-associated lipocalin in urine or plasma (u/pNGAL) obtained on clinical laboratory platforms for predicting acute kidney injury (AKI) and severe AKI requiring kidney dialysis (AKI-D) has not been fully evaluated. We sought to quantitatively summarize published data to evaluate...

Chronic total occlusion (CTO) recanalization and its effects on left ventricular function and patient outcomes has intrigued the interventional community over the last several years. Now that there is plenty of knowledge and experience on "how to treat" the lesion, another scientific effort should focus on "when to treat" the lesion. Physiologic as...

Introduction: Acute kidney injury is a severe complication occurring in critically ill patients treated in the intensive care units, which has a significant impact on morbidity and mortality in these patients. Moreover, despite technological and pharmaceutical advances during the last decades, acute kidney injury is still associated with markedly i...

Purpose: ICU acquired Weakness (ICUaW) is a common complication of critical illness. The aim of our study was the assessment of quality of life (QoL) and functional ability of patients with ICUaW, 6 months post hospital discharge. Material and methods: Eight hundred seventy eight consecutive patients who had been discharged from the ICU were evalua...

Introduction Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Exercise has been shown to stimulate the mobilization of endothelial progenitor cells (EPC) in healthy populations. EPC contribute to the regeneration of the inflammatory endothelium and promote neovascularization. Purpose The...

Objective: Acute effects of passive smoking on microcirculation have not been sufficiently studied. The aim of the present study was to detect microcirculatory alterations in healthy non-smokers after passive exposure to cigarette smoke, utilizing the Near Infrared Spectroscopy method combined with the vascular occlusion technique. Methods: Sixt...

Purpose: Mechanically ventilated patients with left ventricular (LV) dysfunction are at risk of weaning failure. We hypothesized that optimization of cardiovascular function might facilitate the weaning process. Therefore, we investigated the efficacy of levosimendan in difficult-to-wean patients with impaired LV performance. Materials and method...

Background: Heterotopic ossification is a musculoskeletal complication in patients in intensive care unit which expects to impair their mobility and quality of life after discharge. The aim of the study was to examine the incidence and the risk factors of heterotopic ossification in critically ill patients. Methods: One hundred-ninety seven consecu...

Background: Survival following critical illness has been associated with physical disability and reduced quality of life especially in patients that have ICU acquired weakness (ICUaW). The detrimental effects of ICUaW rise the need for examining the therapeutic approaches as rehabilitation strategies for ICUaW have not been extensively studied. Pur...

Background: Heterotopic ossification is a musculoskeletal complication in patients in intensive care unit which expects to impair their mobility and quality of life after discharge. The aim of the study was to examine the incidence and the risk factors of heterotopic ossifi-cation in critically ill patients. Methods: One hundred-ninety seven consec...

Background: Patients with heart failure (HF) suffer from ventilatory abnormalities that are related to poor prognosis.Aim: The aim of the study was to investigate the respiratory drive in HF patients early after left ventricular assist device (LVAD) implantation. Methods: We enrolled eight HF patients after LVAD (HeartMate II) implantation and 8 pa...

Background: Heterotopic ossification is a musculoskeletal complication in patients in intensive care unit which expects to impair their mobility and quality of life after discharge. The aim of the study was to examine the incidence and the risk factors of heterotopic ossification in critically ill patients. Methods: One hundred-ninety seven consecu...

Background: Patient education is an important intervention for the management of heart failure; however, in practice patient education varies considerably. The purpose is to systematically review educational interventions that have been implemented for heart failure patients and assess their effectiveness.Method and Material: Randomized controlled...

Background: Muscle mass loss has been a contributing factor to intensive care unit acquired weakness (ICUAW), a common complication in critically ill patients. Although research evidence supports neuromuscular electrical stimulation (NMES) as a means of early mobilization, there are not any data on the effects of different protocols on muscle mass...

Background: Muscle mass loss has been a contributing factor to intensive care unit acquired weakness (ICUAW), a common complication in critically ill patients. Although research evidence supports neuromuscular electrical stimulation (NMES) as a means of early mobilization, there are not any data on the effects of different protocols on muscle mass...

Introduction: Acute kidney injury (AKI) is a very common complication of critically ill patients in ICU. It is associated with significantly increased morbidity and mortality. Renal replacement is a treatment with a lot of complications.Aim: The aim of the present study was to observe the incidence of AKI, the need for treatment with continuous ren...

Objective: Virtual Reality (VR) is an advanced technology recently used in clinical trials. Although there is data in relation to the therapeutic aspect of VR in the motor rehabilitation, there is lack of evidence regarding the neuropsychological rehabilitation. The aim of this review is to investigate the effectiveness of VR as a rehabilitation ap...

Introduction: Survival following critical illness has been associated with physical disability and reduced quality of life. The field of recovery has become the focus for clinicians and researchers. Yet, few studies have examined specific interventions to improve the recovery of survivors of critical illness. Aim: The aim of this randomized control...

Over the last 15 years there have been significant increases in intensive care unit (ICU) admissions and in the number of patients treated in the ICU. This has led to an increase in the number of patients surviving and being discharged from the ICU. Although many survivors of critical illness return to their prior ICU state regarding their cognitio...

The pathophysiology of chronic heart failure (CHF) involves peripheral myopathy (PM), and skeletal muscle atrophy plays an important role in the muscle dysfunction and limited exercise capacity of patients with CHF. PM appears to be the determining factor of a variety of their symptoms, including dyspnea, severe muscle fatigue and decreased aerobic...