Delirium – the silent killer.
What is it, and how to prevent it?
As a young Masters of Health Psychology student working in a hospital, I learnt many things, but one that stands out is the curious case of delirium. Even if someone is not familiar with delirium, it is likely that they have seen the signs, might even noticed that something is not right, but were unsure what is unfolding before them.
Firstly, what is delirium? According to the Diagnostic and Statistical Manual of Mental Disorder (DSM-5-TR) it is a state of acute confusion, characterised by:
- A disturbance in attention and awareness
- Rapid development, fluctuating in severity during the course of the day
- Disturbance in cognition (e.g. disorientation, memory deficit, perception), and
- The disturbance is a direct physiological consequence of another medical condition such as substance intoxication or withdrawal, or exposure to toxins
The DSM-5-TR categories delirium into the following sub-types:
- Substance intoxication delirium
- Substance withdrawal delirium
- Medication-induced delirium
- Delirium due to another medical condition
Substances that may cause delirium upon intoxication or withdrawal include alcohol, cannabis, opioids, hallucinogens, anxiolytics, sedatives, hypnotics, amphetamines, and cocaine (DSM-5-TR).
Delirium can manifest through a variety of vastly different symptoms, and can range from lasting a few hours to weeks or months. Thus, it is important to distinguish between different presentations:
- Hyperactive: Accompanied by mood lability, agitation, refusal to cooperate with medical care
- Hypoactive: Accompanied by sluggishness, lethargy, stupor
- Mixed level of activity: Attention is disturbed, level of activity fluctuates rapidly
It is relatively easy to spot the hyperactive presentation, since that is the most disruptive to those around the person with delirium. They may display aggressive behaviour, agitation, and reduced ability to sleep, thus they are prone to be active during the night.
However, what makes delirium a curious case is the hypoactive presentation. Delirium is characterised by rapid onset, thus there are many among the elderly who are one day walking around, keeping themselves busy, and the next day, they prefer to stay in bed. It does not appear a big deal first, but after sometime of quiet inactivity the person can drastically deteriorate and without sufficient medical intervention, they may never recover.
Delirium is the most common psychiatric syndrome in hospitals, especially in intensive care and postoperative units (Thom et al. 2019), and it is associated with the following risk factors:
- On average, it extends hospital stays by 5-10 days
- Often remains undetected or mistaken for another condition, such as depression
- Expected loose one daily living activity per delirious episode
- Increases the risk of institutionalization
- Increases the risk of dementia
- Doubles the risk of death
Therefore, detection and early intervention is crucial to reduce the above listed risk factors. Unfortunately, lack of knowledge and a negative attitude towards screening are among the reasons why doctors and nurses may not proactively screen for delirium. Wells (2012) found that only 3% of nurse participants considered routine delirium screening important in Intensive Care Units (ICU). In my own research study, I found that only 21% of doctors and nurses participating agreed to have a good knowledge of the diagnostic criteria for delirium, compared to their knowledge of pneumonia 95%, coronary syndromes 90% or acute pancreatitis 77%.
Prevention is considered the most effective approach to reduce mortality due to delirium (Thom et al. 2019). The Yale Delirium Prevention Trial identified the following non-pharmacological protocol that is highly adaptable to various settings and found to reduce the incidence of delirium in a hospital setting:
- Focus on orientation of the individual
- Early mobilisation
- Medication reconciliation
- Preservation of sleep-wake cycle
- Sensory impairment
In addition, certain nutritional deficiencies can increase the vulnerability to delirium. For example, Thiamine (vitamin B1) deficiency has been found to be associated with delirium (Thom et al. 2019). Vitamin B1 deficiency can occur for a number of reasons, such as extensive alcohol intake, anorexia nervosa, gastric bypass, or colon cancer to mention just a few (Olsen et al. 2010). In such cases, Thiamine supplementation is encouraged under medical guidance (Osiezagha et al. 2013).
Author: Vivian Jarrett
Co-Author: Katalin Mezei,BA (Hons) Psych & Crim, G. Dip Psych, MSc Health Psych
Katalin Mezei is a Provisional Psychologist now based in Brisbane, having completed my undergraduate and Master’s training in the United Kingdom. My aim is to help people identify my clients’ core values and help them live according to them.
To make an appointment with Katalin please call Vision Psychology Brisbane on (07) 3088 5422 or M1 Psychology Loganholme on (07) 3067 9129
Farrell KR, Ganzini L: Misdiagnosing delirium as depression in medically ill elderly patients. Arch Intern Med 1995; 155:2459– 2464
Olsen RQ, Regis JT: Delirious deficiency. Lancet 2010; 376:1362
Osiezagha K, Ali S, Freeman C, et al: Thiamine deficiency and delirium. Innov Clin Neurosci 2013; 10:26–32
Thom, RP, Levy-Carrick, NC, Bui, M, Silbersweig, D. (2019) American Journal of Psychiatry 176:10
Wells, L. (2012) Why don’t intensice care nurses perform routine delirium assessment? Australian Critical Care 167.