Discussion
The current study examined the onset, features, and progression of delirium in hospice patients as described by their caregivers. Given their special role, caregivers are often witness to the subtle signs and symptoms that precede delirious episodes. Caregiver observations were analyzed using grounded theory methodology, which revealed six categories of clinical changes leading to the diagnosis of delirium: physically declining, cognitively/psychologically declining, withdrawing, end-of-life awareness, deteriorating sleep pattern, and suffering. Although the categories identified within this study have previously been associated with either delirium or the end-of-life process, there is an absence of data exploring the progression of signs and symptoms leading to the diagnosis of delirium.
Prior studies have established a connection between illness progression and delirium. Morita et al surveyed bereaved family members whose loved ones developed delirium. Family members associated factors such as pain, medications, and physical discomfort with the emergence and progression of delirium. Caregivers interviewed in this study also noted pain and generalized decline in the timeframe leading up to delirium. Physical weakness, to the point of falling down, was described in multiple interviews. This finding has not been previously explored in relationship to delirium and may warrant further consideration, as it is not clear whether falls may serve as an indicator of potential emergence of delirium and related symptoms such as agitation, or may be due to progression of illness. Cognitive decline, behavioral changes, and withdrawal have also been correlated with the pathogenesis of the delirious state. Duppils and Wikblad noted several behavioral and psychological changes, such as anxiety, experienced in postoperative, elderly patients who subsequently developed delirium. Bush and Bruera, in their exploration of delirium, noted lack of focus and inattention, as well as other cognitive changes including altered perceptions. The cognitive decline and withdrawal revealed by caregivers in the current study add to these findings and suggest that subtle and nonspecific signs and symptoms that characterize the progression of delirium may be clinically significant.
Alterations in the sleep/wake cycle have long been associated with delirium. The delirious state is known to include symptoms of daytime somnolence and reversal of the sleep/wake cycle as well as sleep interrupted by agitation and restlessness. It remains uncertain whether a disrupted sleep cycle is a cause or consequence of delirium. A recent prospective, longitudinal study of 105 hospice patients found that poor sleep quality precedes delirium onset, adding support to a causal relationship between sleep disturbance and delirium. Others have proposed a link between severe rapid eye movement deficiency and the development of delirium in neurodegenerative disease as well as in intensive care unit patients. The current findings describe a prodromal pattern of poor sleep quality progressing to fragmentation of the sleep/wake cycle, agitation, and cognitive disturbances. Although an orderly progression is suggested, the time period of sleep disturbance described in this study varied. However, recognition of the core deficit of sleep dysfunction may help alert clinicians and other members of the interdisciplinary team caring for the patient to the early signs of delirium or predelirious states.
The overarching theme reported by caregivers of delirious patients in this study was suffering. Clinicians share an understanding that delirium involves sufferable states, including pain, which are challenging to define. In the current study, participants stated both indirectly and directly that they also experienced suffering as they witnessed the loss of personhood, which characterizes delirium. Suffering was also associated with each of the other categories of delirium-associated changes as well. There is an element of suffering associated with physical and cognitive decline, as well as patient withdrawal from loved ones, activities, and interests. Given complications such as nocturnal agitation and sleeplessness, it is not surprising that the interviews conducted in this study suggested that deteriorating sleep plays a key role in contributing to overall suffering for both patients and their caregivers. Previous research has also shown that caregivers may score even higher than their delirious loved ones on measures of distress leading to challenges in coping with consequences of delirium.
Processing impending death is intrinsic to end-of-life closure and acceptance. However, this process also contributes to the spiritual and psychological suffering experienced by dying patients and their loved ones. Participants in this study consistently reported distressing comments made by their loved ones, which were categorized in this study as "end-of-life awareness." It is unclear to what extent the degree of distress associated with end-of-life awareness in this study was affected by developing delirium. The overall prevalence of suffering in the current study leads to questions regarding the relationship between confusional states and the psychological processing inherent to the dying process. Is it possible, for example, that the process of dying is associated with psychological discomfort that may also lower the threshold for delirium? Do states of severe psychological suffering contribute to the development of cognitive disorganization? Further research is needed to explore the association between end-of-life awareness, associated psychogenic distress, and the development of delirium.
Implications for Practice and Future Research
The current study highlights the importance of caregivers as witnesses to the signs and symptoms associated with the progression of delirium. Although delirium is common and distressing for end-of-life patients, the pathogenesis of delirium is poorly understood, and there is a clear need for caregiver education. Interviews of families whose loved ones experienced delirium at the end of life have demonstrated a desire for improved delirium screening and management. Others have reported that families can assist in the prevention of delirium given their bedside presence and advocacy. The current study suggests the existence of a set of signs and symptoms that may precede delirium and that may progress in a more or less predictable fashion to full-blown delirium. Findings from this research study are important for clinical practice, education, and research. An understanding of this progression may help lead to improved screening methods to identify delirium in its early, more easily treated stages, resulting in greater quality of life and a decrease in suffering for patients and their caregivers. A greater awareness of the prodromal symptoms of delirium may also help other members of the hospice interdisciplinary team, such as chaplains, social workers, aides, therapists, and even volunteers, identify patients at risk for development of delirium so that the patient's nurse and physician can intervene to provide education and intervention at earlier stages.
Limitations of this study include the retrospective nature of the interviews, which may have affected participants' ability to recall the episodes reported in the interviews. The emotional content of the interviews may also have colored recollections of the severity of symptoms and relative prominence of events. Given the nature of delirium, which by definition causes confusion, the actual person experiencing delirium is not a reliable source of information, and thus data had to be collected from the next best source, the caregivers. This may have resulted in a degree of bias due to second-person assessment of the delirium experience as lived by the patient. Limitations inherent to the use of grounded theory analysis include the potential for researcher-induced bias in the categorization of data and the qualitative nature of the results, but the rigorous methods used in this study, including purposive sampling, bracketing, member checking, and researcher triangulation, help increase the degree of credibility, transferability, dependability, and confirmability of the findings. In addition, there may be some confound between delineating what may be due to prodrome of delirium and what is related to general disease-related decline. Despite these limitations, the results of this study provide a starting point for future studies of the signs and symptoms of the prodrome to delirium and may help lead to earlier identification of and screening for delirium.