Chronic heart failure is associated with a bad prognosis with considerably shortened survival and repeated hospitalisations. Patients suffering from heart failure also have symptoms that can affect their food intake, for example, tiredness when strained, breathing difficulties and gastrointestinal symptoms like nausea, loss of appetite and ascites. Pharmacological therapy can lead to a loss of appetite, which will make the intake of food inadequate to fill the required energy and nutritional needs. The nurse's interest in and knowledge of diet issues can improve these patients' nutritional status. The aim of this literature review was to describe the nurse's interventions regarding malnutrition in patients suffering from chronic heart failure. The literature search gave 13 articles, which were analysed, and sentences whose content was related to the aim were identified. Three areas of content appeared; drug treatment and consequences, gastrointestinal effects, and information and education. The results show that the nutritional status of these patients can be significantly improved by means of simple nursing interventions. Future research should focus on controlled experimental studies to evaluate differences in body weight, body mass index and quality of life between patients suffering from chronic heart failure, who are taking part in a fully enriched nutrition intervention, and patients suffering from chronic heart failure, who are eating their normal diet.
Heart failure is defined as the pathophysiological state in which an abnormality of the cardiac function is responsible for the failure of the heart to pump blood at a rate adequate to meet the metabolic requirements of the tissues . Chronic heart failure is associated with a bad prognosis with considerably shortened survival, repeated hospitalisations and thereby considerable costs to society [2,3]. Non-compliance with diet or drug treatment is the most common cause of readmission . It is therefore important to allocate more financial and knowledge-related resources to the care of these patients . At chronic heart failure, the disturbed function of the heart has led to an activation of various compensation mechanisms, which all strive to maintain the circulation of the blood at a normal level. These mechanisms are often the cause of the symptoms, the most common being increased fluids in the body, leading to oedema and dyspnoea . Patients suffering from chronic heart failure also have symptoms that can affect their food intake, for example tiredness when strained, breathing difficulties and gastrointestinal symptoms like nausea, loss of appetite, early feeling of satisfaction and ascites . From a health perspective, nutrition is of great importance for patients with chronic heart failure, an area in which nurses can exert a great influence. Despite this, it is a relatively unexplored area. Several studies have shown a relation between length of hospital stay and nutritional status, with a prolonged stay occurring in the case of malnutrition [8–12]. Several factors like diet routine, choice of food, the hospital environment and the disease can give rise to malnutrition. Pharmacological therapy can lead to loss of appetite which will make the intake of food inadequate to fill the required energy and nutritional needs. The nurse's interest in and knowledge of diet issues can improve these patients’ nutritional status . It has been shown that up to 50% of patients suffering from chronic heart failure are to some degree malnourished. Cardiac cachexia is a serious complication of chronic heart failure, long known but little investigated . No specific diagnostic criteria have been established but can be defined on the basis of the presence of a documented non-intentional and non-oedematous weight loss of more than 7.5% of the pre-morbid normal weight, occurring over a time period of more than 6 months [14,15]. The pathophysiological alterations leading to cardiac cachexia remain unclear but humoral neuroendocrine and immunologic abnormalities are linked, independently of established heart failure severity markers, to the presence of body wasting. Cachectic patients suffering from chronic heart failure are weaker and fatigue earlier, which is due to both impaired muscle quality and reduced skeletal muscle mass . The muscle strength deteriorates , which affects the activity level and mobilisation [8,15,17]. Likewise, the muscles in the heart and lungs are weakened, which has a negative effect on the breathing and cardiac function [18,19]. For adults suffering from malnutrition, who had lost 40% of their original weight, a biopsy of the heart muscle showed that they had also lost 35% of the weight of the heart . The presence of cardiac cachexia is an independent predictor of mortality, and the wasting process in patients with chronic heart failure is a risk factor for poor prognosis [14–16]. Myocardial atrophy and decreased heart function can be observed already after a fast of 10 days . For optimal support of an adequate nutritional intake by the patient suffering from chronic heart failure, the nursing interventions have to be built on knowledge of eating habits and problems related to nutrition as well as utilisation of the individual's own resources. Nursing care is necessary when patients lack the capability to take care of themselves and their own needs in their unique life situation. Through the nurse's knowledge and commitment, a fruitful relation can be created built on respect and understanding of the individual . The aim of this literature review was to describe the nurses’ interventions regarding malnutrition in patients suffering from chronic heart failure.
1.1. The review process
The review process started by searches in the computerised sources MEDLINE and CINAHL. As the researchers work as nurses in a medical ward where patients with heart disease are cared for, the literature included in the search should contain information regarding the importance of the diet to these patients as well as the nurse's role in their nursing care. The search words used were ‘cardiac cachexia’, ‘congestive heart failure’, ‘dietary recommendations’, ‘malnutrition’, ‘nursing care’, ‘nursing interventions’ and ‘nutrition disorders’ used alone or in combination. The systematic search gave 11 original articles. Then the names of the authors from the reference lists in these articles were used for a continued search, which gave another two articles. The inclusion criteria were that the articles were written in English, Swedish, Danish or Norwegian and were published between 1983 and 1998. All articles were analysed by content and categorised. In all 13 articles, five quantitative and eight qualitative studies met the criteria (see Fig. 1). Eight of the articles were American and five were European.
2.1. Drug treatment and consequences
Drugs usually affect the food intake, which in turn has a negative effect on the patient's nutritional status. Malnutrition can appear as a side-effect of the drugs used. Minor degrees of digitalis intoxication may cause anorexia, nausea and diarrhoea. Drugs can destroy or alter the taste and reduce the appetite, which poses a risk of creating drug-induced anorexia [20,23–25]. One class of drug causing this are the angiotensin-converting enzyme inhibitors . Furthermore, drugs are a common cause of change in taste. Optimal medication with a well-adjusted dosage is of great importance for treating the actual disease as well as for reducing the side-effects of taking tablets, which can often give gastrointestinal symptoms [24,25].
2.2. Gastrointestinal effects
One problem for patients suffering from heart failure is oedema in the stomach and intestines, which can lead to hypomotility in the gastrointestinal tract. This hypomotility can lead to loss of appetite and constipation . The function of the gastrointestinal tract is also affected by old age, resulting in slower digestion and slower emptying of the stomach . By eating a diet that promotes intestine motility [20,26] and using laxatives when needed, hypomotility can be reduced . Patients suffering from heart failure have an increased need for nutrition and should eat a diet high in fat and carbohydrates [20,28]. Beyond the normal diet, patients suffering from heart failure often need additional nutrition, such as nutritional drinks with a higher calorie level. Small regular meals or continuous nutrient supply is preferable, as it decreases the need for oxygen in the heart muscle . Patients with heart failure suffer from hypermetabolism as well as an increased loss of nutrition through the forced diuresis . The nutritional need is higher the more severe the heart failure is . To stimulate the appetite in patients suffering from chronic heart failure it is important that the food is appetising . The importance of good oral health has also been pointed out . Salt restrictions vary with regard to daily intake from 1.6 to 4.0 g for mild to moderate heart failure [23,26,30]. With a deterioration of the heart failure, the recommendation is 0.8–1.6 g salt/day [20,31]. Elderly patients rate taste and flavour as the most important for their choice of which food to eat , and they find it hard to accept a diet poor in salt [23,27]. The quality of life is affected negatively if the food is tasteless. Therefore, alternative ways of flavouring the food, for example using herbs and other spices, should be suggested to them. One simple measure to keep the consumption of salt down is to remove the salt cellar from the dining room table .
2.3. Information and education
In order to make patients suffering from chronic heart failure feel safe and secure in their life situation it is important that they have knowledge of their situation and feel that they are in control of it. To increase their understanding of the total situation in general and the importance of the diet in particular, information is of crucial importance [26,31–33]. A tool used to meet the specific nutritional needs of the individual and to promote a good nutritional status is to create an individualised nutritional plan . Many patients suffering from chronic heart failure are too tired to eat [23,24]. However by, for example, sitting down while cooking and/or resting an hour before the meal, it is possible to have more strength for eating . The nurse should view the individual suffering from chronic heart failure from a holistic perspective . She also has an important role in educating patients, their families and colleagues in the subject [25,30,32,34]. By making the information easy to understand with respect to limitations and restrictions, patient compliance can be improved . The restriction in fluids is controversial, but 1.5–2.0 l/day is still the standard recommendation [20,26,31].
3.1. General limitations
In this literature review about nurses’ interventions regarding malnutrition in patients suffering from chronic heart failure, few scientific articles could be identified (see Fig. 1). The lack of knowledge in this area clearly indicates that more research is needed in order to develop nursing care regarding nutrition, nursing interventions and chronic heart failure.
3.2. Nursing care issues
3.2.1. Drug treatment and consequences
Two of the most common drugs used in connection with heart failure, digitalis and ACE-inhibitor, can have various effects on the sense of taste and cause nausea, diarrhoea, vomiting and anorexia [15,24,35]. Human growth hormone improves myocardial energy metabolism and clinical status in patients with chronic heart failure and could be a benefit for patients with severe heart failure and cardiac cachexia . The findings merit further investigation . Furthermore, there is a distinct connection between dryness of the mouth and the amount of drugs taken . The nurse has to minimise the risk of malnutrition caused by the drugs, and it is important that the nurse teaches these patients to take their medicine at a time when their eating is affected the least by it. Furosemide and beta-blockers in combination will increase dryness of the mouth, a problem that tends to be more troublesome around lunchtime . Another important task for the nurse is, when possible, to minimise the risk of malnutrition due to lack of compliance. This task includes increasing patients’ compliance, which, in turn, embraces both the intake of medicines and understanding their effects and side-effects. Only approximately 50% of all patients with chronic heart failure follow their drug prescriptions . The nurse can support them by creating habits surrounding the intake of medication. Patients suffering from chronic heart failure need to know why they take their medicine and what will happen if they do not follow the prescription, such as increased tiredness and shortness of breath. Deterioration of their disease, due to lack of compliance, will make them unable to eat, leading to an insufficient energy intake. Lack of compliance increases mortality and the need for hospital care . Nausea is common in patients with heart failure due to effects on the gastrointestinal system, and antiemetics should be used more frequently than today to avoid this.
3.2.2. Gastrointestinal effects
Gastrointestinal oedema, enlarged liver and ascites can suppress the feeling of hunger. As knowledge of the problem with constipation is available, it is important to help patients suffering from chronic heart failure to prevent constipation by, for example, following a diet that promotes digestion [20,26] or informing the patient of intestine stimulating products such as prunes. When the nurse observes that the patient does not finish the meal, she should find out the reason for this. The explanation can be a continuous feeling of being full or a lack of strength to take the food into the mouth, chew and swallow it, in which case feeding-assistance can be required. The most common cause of dry mouth is the drugs used but the disease itself can also create changes in the mouth, affecting the taste and causing malnutrition . Oral hygiene as well as assisting the patients to maintain their oral hygiene is important if they are unable to maintain this by themselves. The connection between food intake and dental status is bi-directional. Just as poor health status affects food choices, so does inadequate nutrition affect the oral health . One way of overcoming this problem is to stimulate saliva by, for example, brushing the teeth more often, rinsing the mouth on a regular basis, using saliva-stimulating tablets and chewing sugar-free gums. Chewing sugar-free gums and/or using saliva-stimulating tablets can also stimulate the appetite. Chewing-gum can create a feeling of hunger and, by reducing the dryness of the mouth, the condition of the mouth is improved and the food will taste better. The nurse can also make use of the expert help of a dental hygienist . The nurse plays a key role as a co-ordinator between the patient and his or her family as well as between the patient and various health professionals, such as dental hygienists, physiotherapists and dieticians. It is important to create an individual care plan and, by conducting an admittance conversation that includes anamnesis and health status , to create good opportunities for optimal care. It is important to adapt the nutritional intake to the individual. This can be done if the nurse learns how to calculate the need of energy for different individuals suffering from heart failure and to use this knowledge routinely. Furthermore, strategies to minimise anorexia are necessary. It is difficult to foresee whether the lack of appetite will lead to anorexia or vice versa. Lack of nutrition will shorten life expectancy  and decrease the quality of life while a sufficient intake of nutrition will improve the quality of life . By offering patients suffering from chronic heart failure energy-enriched food of their choice, both appetite and energy intake can be stimulated. If the amount of salt is restricted, the food tends to become tasteless. This makes it necessary to be creative when planning meals and to use herbs and various spices to replace the salt [27,30]. If a patient cannot come to terms with a restricted salt diet and this results in a low nutritional intake, the nurse will have to take a more liberal view towards the restriction. A low nutritional intake due to a salt restriction can deteriorate the nutritional status of the patient and cause hypoalbuminaemia, anaemia and reduced immunity. This may change the already bad prognosis for the worse . Already at the hospital, a taste and calorie-enriched diet, specially designed for patients suffering from chronic heart failure can be served, thereby helping these patients to realise that a diet with less salt can be tasteful. Even minor, and for the untrained eye insignificant, nursing interventions can be of great importance to these patients . For example, their room should be well aired, which is especially important when sharing with others and when used for all situations, due to the different smells that may occur.
3.2.3. Information and education
All chronic diseases require that the patients, as well as their family members, share the responsibility for managing the disease. This makes it necessary that they are well informed and that there is a system in place for maintaining the patients’ knowledge and their feeling of responsibility for their self-care. Here, the nurse plays an important role by teaching and supporting patients with chronic heart failure in order to enable them to handle their medicines and to exercise self-care. Besides those directly affected by chronic heart failure, the rest of the family is also affected . The family should be given the same information as the patient. Social support, both from family members and health care professionals, increases compliance . If patients and their family members become experts in those areas of the disease that they can influence and learn to understand, this may diminish the feelings of vulnerability, helplessness, stress and anxiety often experienced by the patient suffering from chronic heart failure [27,43]. The care of patients suffering from chronic heart failure has two primary goals; to increase the duration and quality of life . These goals can compete with each other, and therefore nurses need to take a special approach regarding diet and diet-related information . Confidence and trust in the health care professionals increase compliance . If restrictions, for example with regard to fluid- and/or salt intake, are made relevant and comprehensible to these patients, it will make it easier for them to live as they have been taught . It is important to teach patients individually, in addition to standard guidelines, how to handle and recognise symptoms. It is also important to determine how to tailor therapy to each patient's situation . The goal of the information provided is that it should be suited to the individual and be given in such a way that the patient is willing and able to accept it . A study conducted in Canada shows that nurses and patients differed with regard to which information they considered essential [33,46]. The patients rated medicine, risk factors, anatomy and physiology as the three most important areas to be informed about, while the nurses rated medicine, diet and risk factors as the most essential. In the study, patients gave information about diet the lowest rating out of seven categories, which indicates that patients suffering from chronic heart failure may have some difficulty in understanding the importance of the diet for their quality of life. Therefore, the provision of information primarily includes answering the patient's questions but should also cover those areas that the nurse judges to be important. Studies have shown that, when education given by nurses contained information about diet as well as prescribed medicines and symptoms when the patient's condition was deteriorating, the readmittance rate was reduced .
In this literature review, with the aim to describe nurses’ interventions regarding malnutrition in patients suffering from chronic heart failure, three areas of content appeared; drug treatment and consequences, gastrointestinal effects, and information and education. The malnutrition that the majority of these patients suffer from is mainly due to loss of appetite, malabsorption and hypermetabolism. This study shows that the nurse can help these patients with their choice of food as well as when to take the medicine and when to eat. She can also create a favourable and pleasant environment and increase these patients’ knowledge of their life situation, thereby improving their quality of life. It is important that the nurse is attentive and responsive and has the intuition to meet the expressed and unexpressed needs of the patient. Nurses can in a direct way influence the chronic heart failure patient's understanding of the importance of nutrition by specific nursing interventions, aimed at supporting an adequate nutritional balance. It is important to the patients suffering from chronic heart failure that the nurse can co-operate with other healthcare professionals, such as dieticians, dental hygienists and physiotherapists. Due to the relatively short period of time that the patients suffering from chronic heart failure reside in hospital and the large number of nurses involved in their care, a consequence can be difficulties to meet their needs regarding malnutrition. Continuous contact with a heart failure nurse can create a better understanding of the reasons behind a specific diet and its effects as well as stimulate the patients’ own interest in their disease. Nurses working with patients suffering from chronic heart failure need adequate education regarding the pathophysiology of heart failure as well as regarding information techniques to be able to care for these patients’ diet in the best possible way. A research implication could be to undertake controlled experimental studies to evaluate differences in body weight, body mass index and quality of life between patients suffering from chronic heart failure, who are taking part in a fully enriched nutrition intervention, and patients suffering from chronic heart failure, who are eating their normal diet.