Diagnosing delirium
Delirium is an acute confusional state characterised by fluctuating mental status, inattention, and either disorganized thinking or altered level of consciousness. (See Table 1.)
Hippocrates described delirium as a fatal sign and described even then agitated and lethargic variants.
It’s all delirium
In the UK there have been any number of synonyms in use for delirium in critical care including ICU psychosis, ICU syndrome, acute confusional state, acute brain failure, septic encephalopathy, acute brain dysfunction as well as the exotic sounding sun downing. These are all delirium. It has been thought to be of little consequence, far from true.
There is hypoactive and hyperactive delirium
Delirium is a clinical syndrome and a bedside diagnosis. An acute change in mental status usually temporary it is always triggered by something be it a new infection, drug induced etc. The number one feature is an inability to maintain attention. Patients who can pay attention - squeezing on the right letters in a short sequence - are not delirious. The delirious patient is unable to organise their thoughts - figure out the answers to simple questions. There is an altered level of consciousness, most commonly drowsiness.
Hypoactive delirium, a lethargic patient who cannot pay attention or organise thought is much more common than hyperactive delirium and associated with worse outcomes. Hypoactive delirium is not depression, lack of motivation or a benign residual drug effect it is delirium. To detect hypoactive delirium you need to screen for it.
Many patients will fluctuate not only in and out of delirium but in between hyperactive and hypoactive delirium.
Screen for delirium
There are 2 validated screening tools to detect delirium in critically ill patients, the CAM-ICU (see below), which is a confusion assessment method for Intensive Care, and the ICDSC (opens in new window) Intensive Care Delirium Screening Checklist.
To monitor your patient’s brain you will need to screen for delirium, no equipment is needed and it can take less than 2 minutes. We’ve prepared a short video demonstration of the CAM-ICU assessment method, which you can watch on YouTube, or play the embedded video below:
CAM-ICU Delirium Assessement Method
CAM-ICU
Altered mental status
Has the patient shown any sign of being other than completely “themselves”?
Inattention
Ask the patient to squeeze your hand. They will need to be responsive to verbal stimulation and keep their eyes open.
Ask the patient to correctly identify the letter ‘A’ in 10 letter sequence by squeezing only when they hear the letter ‘A’. Suggested Sequence:
“SAVE A HAART”
They are allowed 2 mistakes - squeezing on a non-A, not squeezing on a A. More than 2 mistakes (however many it does not matter) is inattention.
If they pass the inattention test they are not delirious, the test is now complete.
More than 2 mistakes proceed to look for disorganized thinking or decreased level of consciousness.
Disorganized thinking &/or Reduced level of consciousness
5 elements - 4 simple yes/no questions, one simple command.
Use Set A or Set B
Set A:
Will a stone float on water?
Are there fish in the sea?
Does 1 pound weigh more than 2?
Do you use a hammer to hit a nail?
Set B:
Will a leaf float on water?
Are there elephants in the sea?
Does 2 pounds weigh more than 1?
Do you use a saw to hit a nail?
Ask the patient to “raise 2 fingers with one hand” and then to “do the same with the other hand” (do not instruct the patient to “raise 2 fingers” a second time, but instead instruct them to “do the same with the other hand”) .
They are allowed one mistake - one question wrong or unable to do the command. Two mistakes means disorganized thinking. The patient is CAM-ICU positive.
Come again?
Inattention plus altered conscious level equals delirium.
Inattention plus disorganized thinking equals delirium.
Inattention plus altered conscious level plus disorganized thinking equals delirium.
Resources for implementation:
Stones do float on water- pumice- as I have witnessed in Iceland. So if I was asked that question I would not know how to answer with yes or no.
“Will a brick float on water” might be a better question.
Iceland - volcanoes, northern lights and floating stones! Yes I have actually heard this answer from a patient who was being asked the questions for research but in fact did not have inattention i.e. brain normal. You don’t need to do the questions if a patient is not inattentive. Generally if they are thinking clearly enough to point out that some stones do float it is unlikely they are delirious.
I am working as PG (MD.Critical care medicine)at QPGMC,PIMS,Islamabad,Pakistan, want to conduct a survy among DRs and Nurses,working in critical areas to know their attitudes towards diagnosing and treating Delirium, kindly help me devicing a Questionair to be circulated among Drs of all levels working in Pakistan Institute of Medical Sciences, can u help, i will appreciate that, I have special intrest in Delirium, which is being un recognised……saim
I spent a week in ICU 14 years ago with status asthmaticus. I remember being intubated THEN paralysed THEN sedated. Confused and amnesic to say the least!! I was aggressively confused for the first 24hrs post-extubation then terrified-confused back on the ward for another five days until discharge. I then suffered flashbacks, memory problems with a touch of dysphasia, nightmares and insomnia…for over two years until a kindly practice nurse got me referred to a psychologist, who diagnosed PTSD. The critical care staff reaction to my distress? Injected haloperidol (it made me worse)and a great deal of amusement.I’ve now worked in Critical Care for over ten years, and I’ve tried to explain all this to my colleagues….with varied results. I shall continue to spread the word…..I remember being so frightened whilst sedated and paralysed, that I wanted to give up.
Re. 3
Regarding surveys there are a few examples published, there is an article on medscape http://www.medscape.com/viewarticle/583535 with some useful references. The UK Intensive Care Foundation with funding from the Alzheimer’s Society did a scenario based survey with a couple of attitude questions published in April 2010 Quarterly Journal of medicine. The Netherlands had a postal survey published: Neth J Med. 2009 Jul-Aug;67(7):296-300. Finally ref Crit Care Med. 2009 Mar;37(3):825-32 for a large USA survey.
Good luck!
Dear Frances
Thank you for writing in. Patients and relatives experiences are very powerful in getting the message across to clinicians about how important delirium is and why we have to do something about it now. I wonder if you are aware of the website ICU steps http://www.icusteps.com/ for ex-ICU patients. One of the trustees recently gave an interview for Radio 4 on her experiences. I hope you have started to see a change for the better in ICU practice of managing delirium.
I find this all very interesting, and agree that recognising ITU delirium is important. However, how do we recognise this in a patient who cannot squeeze hands, or who cannot raise hands, e.g., high leison spinal patients, those with ITU neuropathy, or who are just too weak to move their arms? I have nursed patients with Guillain-Barre Syndrome and encephalitis, and therefore have seen patients who can perhaps only just move their eyebrows a tad. Is it possible to screen for ICU delirium in such patients? Or do we just have to wait and let the patient suffer? I welcome your thoughts!
Dear Peena.
A valid way of looking for inattention is to use a series of pictures. You show the patient 5 simple drawings and then show those 5 mixed up with another 5 and ask them to indicate which ones they were shown first (eyebrow communication?). The instructions and pictures are free to download from http://www.icudelirium.org in the CAM-ICU assessment tools. On that website there are also a list of frequently asked questions which are very useful as well.
Thanks Valerie
very interesting topic indeed.I am a critical care nurse undertaking my ICU course with a huge interest in ICU delirium. I am currently doing my assignment on subject topic, got to say this condition is under diagnosed and nurses’ attitude towards cognitive impairment in the ICU ought to change.
my dad is in an ICU unit after undergoing a bowel resection after an accident where his bowel was perforated and he got septicemia post op he was mechanicaly ventilated for five days reduced gradually over the next two days.
he was previously an 84 yr old who was lucid computer literate,drove and managed the day to day running of his house and elderly wife,
From a relatives point of view and the little I know of ICU Delirium I am shocked and suprised that we were not pre-warned of this condition, and advised how we might aid my Dads recovery so reducing further implications from this condiion.
It is only in the last few years that the significance and impact of delirium has been appreciated in ICU. Frankly there are still a few influential sceptics. I have, in fact, produced an information sheet for the relatives and carers of our ICU patients which informs them about delirium. It does sound like your father would inevitably get delirium given his septicaemia from perforated bowel. I hope he makes a good recovery.
I wondered if anyone else has a concern over the RASS scoring part of the testing. I have a bit of a theory that it isn’t recorded frequently enough to satisfy feature 1 and also sometimes a patient who may be drowsy (-1) is scored as 0 (Alert & calm) and therefore the patient is thought to be negative without proceeding. My second observation is: do you think some patients pass the test who are still delirious as I tested one man recently who was negative but before I had left the bedspace asked how he was getting home. Thank you
Feature 1 is altered mental status so essentially a patient who is not themselves or has behaved oddly in the previous 12-24 hours, asking inappropriate questions would qualify. There is a screening tool which asks a relative “is this what XX is usually like?”. That would answer feature 1. RASS can be used but if 0 would not mean feature 1 is negative.
The CAM-ICU is not as sensitive at diagnosing delirium in non-intubated patients - patients not on ventilators who are able to talk. (It is very specific so a CAM-ICU +ve patient will have delirium.) Alternatives include the ICDSC - see under screen for delirium above - or the 4AT has impressed me, if you are looking for a quick screening tool http://www.the4AT.com/home.
There are a number of other screening tools used in general medical settings which usually would take 10-15 minutes or are observations recorded over a shift (which is essentially how the ICDSC works). Frankly even in expert hands the diagnosis of hypoactive delirium can be challenging.
My father has been in ICU in 3 different hospitals for just under a month following an op for aortic dissection, subsequent complications e.g. pneumonia, and now icu delirium. I am beginning to lose hope for a good outcome despite reassurances by medical staff.
The impact of delirium on relatives and friends cannot be underestimated not the least of which is concern that it will not recover. The facts are a percentage of patients are left with persistent delirium but that is only considered after there are no signs of recovery despite treating the cause(s) at 3 months. I understand your concern and he may be left with some problems concentrating but as/if he recovers from the complications and gets stronger I would expect a very good chance his delirium will clear over time.
My 67 year old wife was admitted to ICU on 14 December 2011 and had a resection of the small bowel on Boxing Day and discharged to a surgical ward on 9 January 2012. She was noticed to be confused and somewhat agitated when revived from sedation but I was assured that ‘it’ would resolve on the ward. She became increasingly confused and agitated over the following weeks falling out of bed several times in late February. She remained in hospital while various diagnostic test were conducted. On 31 March she was diagnosed as being delirious and discharged in mid May to complete a long course of antibiotics at home. She did not improve and is back in hospital where further tests have proved fruitless and is about to be discharged once again.
Is there a ‘pathway’ for patients such as my wife? She is quite lucid at times while at others she is loud and verging on violent. Any advice would be very much appreciated since I am extremely reluctant to resign her to a nursing home.
Thank you Mr Henderson - I will respond shortly. Valerie
Hello Valerie,
We have recently introduced the CAM-ICU into our Oncology specific ICU but have had a few patient’s recently who have been both hyper and hypo-activly delirious (pulling out lines to seeing ants on their bed sheets) but have passed the ‘SAVEAHAART’ inattention test. None of them were ventilated but on either non-invastive ventilation, septic or on haemofiltration. Because of this we have really lost the staff’s trust in the CAM-ICU to a point where they are no longer testing. Have you experienced this problem before? If so, are their ways to improve the test or other test to be done?
Hi Molly. While the CAM-ICU is reliable in ventilated patients it is proving not as sensitive in non-ventilated patients. On an acute medical ward you will fail to diagnose delirium in about 80% of patients with obvious signs of delirium you describe. (In fact if they clearly have hypo or hyperactive delirium there is no need to screen, they can be documented as having delirium.)
To look for delirium I often ask the patients to tell me the months of the year backwards, if they refuse or cannot manage up to 7 in a row correctly then I assume they have some brain dysfunction i.e. delirium. Then I go on to look for a reversible cause to manage and check again the next day.
The Nu-DESC is one that I would like to introduce on our non-ventilated patients and the trauma wards. Or the delirium observation screening score (DOS)? Both involve recognising the symptoms of delirium over a shift as you describe and adding up the number at the end.
It sounds like you are doing an excellent job in getting the staff to at least consider the patients brain function along with the lungs and kidneys.