First ripples in a tidal wave?

Abstract

The importance of delirium as a component of cognitive impairment is well known to the readers of this journal, but little is known of the true incidence in the community. Accurate diagnosis of delirium used to require specialist input, but two years ago, in this journal, Richardson et al. (2017) demonstrated the reliability and specificity of a “combined arousal and attention testing procedure” for detecting delirium superimposed on dementia in hospital inpatients, where the patient is physically present. The paper by Luijendijk et al. (2019) in this journal takes this process two steps further with a questionnaire for caregivers. Two steps because, firstly, it has been validated for delivery over the telephone, and secondly, the input from usual caregivers provides a valuable additional perspective on what has changed about a patient. The work of Richardson and Luijendijk is important, but also challenging to the whole sector. In their introduction, Luijendijk et al. document the very high estimates of the number of undetected delirium cases that may be in the community, noting that it may be missed in 40–60% of hospitalized patients and nursing home residents (de Lange et al., 2013; Siddiqi et al., 2006). They note that for screening and detection, the sensitivity of the tool is more important than its specificity. Importantly, these new procedures are quick to administer and Luijendijk’s questionnaire does not even require the patient to be present. They noted that this tool reduced the time from referral to the patient being seen by a specialist service from 31 to 11 days. The tools also have the potential to be taught to a wide range of practitioners who are involved in the care of the elderly and used in more settings than acute hospital admission or primary care teams. If this were to happen, more cases of delirium will be identified in a wide range of healthcare and social care settings, not all of which will have expertise in the management of frail cognitively impaired elderly patients. So with these tools, delirium has a much higher chance of being effectively detected, but what happens then? Finding the condition does not identify the cause, but it does present a duty to refer or further investigate. To safely and effectively investigate and thenmanage all these newly identified cases will require guidelines and infrastructure that will require establishment, training, and resourcing. Thanks to medical advances, people are living for longer, but often heavily based upon ongoing use of medication, and increasingly of multiple medications (World Health Organization, 2015). Delirium may be a consequence of a recent change in health such as the development of an infection. However, the gradual accumulation of a medication, or multiple medications, is more insidious. The majority of dosage forms are designed to treat a 70-kg man with normal renal and hepatic functions. Many reliable reference sources will describe drug–drug interactions (Preston, 2019), but with so many patients taking multiple medications, it is far less clear what happens when five or more drugs are taken together, most commonly at the same time, in an older patient with declining cardiac, renal, and hepatic function and over an extended period of time. In clinical practice, in many occasions, when one health professional or a carer raises suspicion with medical staff that a patient’s confusion may be due to a certain medication, a frequent response has been; “but it cannot be that, they have been taking it for years.” Our personal clinical experience over many years demonstrates that it certainly can be. Medication accumulation is another hidden challenge (Alagiakrishnan and Wiens, 2004). Biochemical changes are a common cause of delirium and may easily be precipitated by diuretics. For most heart failure patients, current management includes a diuretic, an angiotensin converting enzyme inhibitor (or angiotensin receptor blocker) with or without an aldosterone antagonist. Additionally, patients are frequently told to avoid consuming salt and regulate their fluids intake. As diuretics excrete sodium and the water goes with the sodium, plus the inhibition of aldosterone release and antagonism of its action, we find one easy explanation for the growing interest in hyponatremia as a frequently missed condition. This “depletional” form of hyponatremia occurs at serum sodium levels much closer to what is regarded as “normal,” frequently identified with levels around 130–135mmol/l, which is very different from the “dilutional” form seen with the syndrome of inappropriate antidiuretic hormone secretion produced by medications such as the selective serotonin reuptake inhibitors where levels of 118–125mmol/l are common (Saepudin et al., 2015; 2016). International Psychogeriatrics (2021), 33:1, 3–5 © International Psychogeriatric Association 2021