In our June 23, 2009 Patient Safety Tip of the Week More on Delirium in the ICU we noted that delirium, if appropriately looked for, occurs in over 60% of ICU patients at some time during their ICU stay. Some studies say the incidence may be as high as 80%. And the occurrence of delirium increases morbidity and mortality, time on ventilator, ICU and total hospital length of stay, and costs. We provided multiple lessons learned in that column, particularly regarding the relationship between delirium and sedation practices in the ICU.
The American Association of Critical-Care Nurses (AACN) has recently published an evidence-based Practice Alert on Delirium Assessment and Management (AACN 2011). Its recommendations include:
· Daily assessment of ICU patients for delirium, using a validated tool like the CAM-ICU (Confusion Assessment Method for the ICU) or the ICDSC (Intensive Care Delirium Screening Checklist).
· Create strategies to decrease delirium risk factors, including early exercise.
· Be cautious with benzodiazepines, giving only when needed.
· Consider whether to adopt a core bundle like the ABCDE bundle.
While weve discussed most of these in our previous columns on delirium, there are some relatively new emphases here that are valuable. First is the emphasis on early exercise, starting with passive ROM exercises within the first 3 days in the ICU and having a progressive mobility program. This recommendation is based on several studies showing that progressive mobility in critically ill patients improves not only physical function but also improves cognitive function as well (reducing delirium duration by 2 days).
They also recommend use of the THINK mnemonic to identify potential causes of the delirium:
T Toxic situations
· CHF, shock, dehydration
· Delirogenic meds (tight titration of sedatives)
· New organ failure (eg. liver, kidney)
H - Hypoxemia
I Infection/sepsis (nosocomial), Immobilization
N Nonpharmacologic interventions (Are these being neglected?)
· Hearing aids, glasses, sleep protocols, music, noise control, ambulation
K K+ or electrolyte problems
They provide a good discussion on avoiding benzodiazepines and a good discussion on the paucity of data supporting use of any of the antipsychotic drugs.
Lastly, they suggest putting these recommendations all together through use of the ABCDE bundle (Awakening and Breathing, Careful sedation choice, Delirium monitoring, and Early progressive mobility and exercise). See our December 2010 Whats New in the Patient Safety World column The ABCDE Bundle for details.
We like these recommendations, particularly their use of THINK and ABCDE mnemonics to help with the assessment and management of delirium.
Note also that a new tool to predict delirium in ICU patients has been developed and validated (van den Boogaard 2012) in several Dutch hospitals. The PRE-DELIRIC tool uses 10 risk factors that can readily be obtained within 24 hours of admission to the ICU (age, APACHE-II score, admission group, coma, infection, metabolic acidosis, use of sedatives and morphine, urea concentration, and urgent admission). The tool was considerably better at predicting delirium than were the individual predictions of nurses and physicians. Note, however, that the tool does not include presence of dementia or alcohol misuse (mainly because the incidence in their population was too low to include for statistical reasons). The authors point out that any patient having either of those two risk factors should be considered at high risk for delirium regardless of the PRE-DELIRIC score. The authors suggest that the value of the predictive tool is to allow staff to implement preventive measures in the highest risk patients but spare lower risk patients from those interventions. Wed argue those preventive measures make sense in all ICU patients. The biggest difference between our thinking and that of the Dutch authors is that they appear to consider drug prophylaxis (haloperidol) to prevent delirium, a concept we dont buy into at this time because of a scant evidence base. The non-pharmacologic preventive measures are pretty risk-free and probably good for most ICU patients anyway.
Nevertheless, we like the idea of using a simple risk prediction tool that does not take a lot of time and effort. We would hope that future studies would look at whether implementation of preventive measures based upon risk stratification actually reduces the incidence or duration of ICU delirium. The PRE-DELIRIC tool is downloadable from the authors in both English and Dutch versions in multiple formats (pdf, html, Excel).
Some of our prior columns on delirium assessment and management:
· October 21, 2008 Preventing Delirium
· October 14, 2009 Managing Delirium
· February 10, 2009 Sedation in the ICU: The Dexmedetomidine Study
· March 31, 2009 Screening Patients for Risk of Delirium
· June 23, 2009 More on Delirium in the ICU
· January 26, 2010 Preventing Postoperative Delirium
· August 31, 2010
· September 2011 Modified HELP Helps Outcomes in Elderly Undergoing Abdominal Surgery)
· December 2010 The ABCDE Bundle
AACN (American Association of Critical-Care Nurses). Practice Alert. Delirium Assessment and Management. November 2011
van den Boogaard M, Piockkers P, Slooter AJC, et al. Development and validation of PRE-DELIRIC (PREdiction of DELIRium in ICu patients) delirium prediction model for intensive care patients: observational multicentre study. BMJ 2012; 344: e420 Published 9 February 2012
downloadable versions of the PRE-DELIRIC model/tool