Sleep disturbances — A significant problem for cardiovascular nurses in practice and/or research?

1. Background 

Sleep, a state in which humans spend almost one third of their life, is a basic human need [1]. All functions of sleep are not yet fully understood, but sleep appears to restore energy, promote learning and consolidation of memory and is important for the human immune function [2]. Most of us have also experienced how it feels when our sleep has been bad; and as a consequence we feel excessive daytime sleepiness and/or fatigue; are less able to perform daily tasks as we are used to; become irritable and may feel of depressed. Hence, sleep is a central aspect for human physical and psychological well-being. During the last decade several studies using objective sleep recordings have found sleep disturbances to be common among patients with different cardiovascular diseases such as hypertension, angina, myocardial infarction, heart failure, stroke and atrial fibrillation [3]. A recent study including 700 patients with heart failure reported a prevalence of 76% suffering from sleep disordered breathing [4]. Looking at data based on self reports, around 50% of patients with heart failure, report that their sleep is bad [4]. These patients may complain that they have problems to initiate sleep, maintain sleep, or do not feel fresh after a night's sleep. Patients who express that they have a poor sleep are probably very common in clinical practice. Reasons for sleep related problems are multiple and complex, but some probable causes are related to side effects of drugs; nocturia (diuretics?); nocturnal dyspnoea; worries and anxiousness because of the disease [2]. Other causes of sleep related complaints are sleep related breathing disorders.

2. Practice 

In nursing care, sleep is advocated as a basic caring aspect. Despite this, the association between cardiovascular diseases and sleep disturbances, as well as their impact on the life situation is not always recognized by nurses. In clinical practice nurses may feel unsure on how to identify and handle patients complaining of a poor sleep or to promote interventions aimed to improve patients sleep. This might be the underlying reason that sleep disturbances have not achieved a lot of attention within cardiovascular nursing. A quick search on the PubMed with the key words, ‘sleep disorders’, ‘cardiovascular disease’ and ‘nursing’ retrieved only 15–20 studies with a nursing perspective. Some sleep disturbances such as sleep related breathing disorders, can be difficult to detect. In a recent study we found that sleep related breathing disorders were highly prevalent in an elderly community population with and without impaired systolic function, but the associations to self reports of poor sleep or daytime sleepiness were weak [5]. This weak association could depend on the measurements used in the study. There are several options regarding objective and self-assessment tools, but the development and validation of more sensitive instruments that could be used by nurses in clinical practice to detect sleep problems and sleep related breathing disorders are therefore of great importance. Patients who complain of tiredness may suffer from sleep related breathing disorders without being aware of it. Without knowledge of clinical signs and without knowing how to detect sleep related breathing disorders, many patients with cardiovascular diseases may not get adequate help with their sleeping problems. To improve the management of patients with cardiovascular diseases, nurses need to pay more attention to sleeping problems. Nurses therefore need knowledge to assess and treat sleeping problems, based on evidence based literature.

3. Research 

The majority of the sleep research in patients with cardiovascular diseases has been performed by physicians within sleep medicine, pulmonary medicine and cardiology; and only a few studies are performed by cardiovascular nurses. Hence, many questions associated to sleep disturbances still remain to be examined, both from a general, but especially from a cardiovascular nursing perspective. Development of tools as to recognize sleep related breathing disorders in clinical practice, as mentioned before, is of great importance. Depression is common among patients with cardiovascular diseases and often associated to sleeping problems [6]. Other questions that suggestively could be focused in future nursing research are; should depression be suspected in patients who complain of poor sleep? Is depression associated to sleep related breathing disorders? Does treatment of sleep disturbances and/or sleep related breathing disorders also treat depression? Implementing sleep research into the discipline of cardiovascular nursing is therefore of great importance. We may have to learn and accept new concepts and acronyms, such as obstructive sleep apnoea (OSA); central sleep apnoea with Cheyne Stokes respiration (CSA/CSR); apnoea–hypopnoea index (AHI); excessive daytime sleepiness (EDS), difficulties initiating sleep (DIS) and many more. We also have to understand that studies designed to objectively register sleep or sleep apnoea are complex and expensive to perform. The size of such sleep studies can therefore not be compared to what we are used within cardiovascular research, for example the studies might be smaller [1], [2].

To conclude, in clinical practices complaints of sleeping problems are common, but many nurses may have lack of knowledge on how to recognize and manage such complaints. The majority of research about sleeping problems in patients with cardiovascular diseases is, however, performed by healthcare personnel from other disciplines and professions. So dear colleagues, it is now time to wake up and start to plan for studies focusing questions of interest for cardiovascular nursing. Our patients in clinical practice need it.