Andrew Stephen, MD
Definition
A disturbance of attention, focus or awareness to one’s environment that occurs over a short period of time and is disparate from the patient’s baseline level of function.
Active delirium-because of the presence of agitation it is often detected by critical care providers
Negative delirium-denoted by lethargy and quiet inattentiveness, is often not detected and is often the dominant form of delirium in the elderly.
Why is delirium important to understand and diagnose?
Delirium is associated with increased mortality, need for mechanical ventilation, increased ICU length of stay, and longterm cognitive dysfunction.
Issues with the GCS:
As we work at a hospital with a large number of trauma patient and many cases of traumatic brain injury(TBI) we tend to use GCS frequently as it is reproducible and fairly objective. However it gets applied too widely and we often present patients’ GCS in the SICU and for non-neurologically injured patients in the TICU. GCS however is not adequate to assess higher level cortical function. A classic example is a SICU patient with hepatic encephalopathy or an elderly patient with a recent bout of sepsis with GCS of 14 that has significantly altered cognition and orientation. This patient has delirium and may have inability to protect their airway, participate in care, and has a much higher risk of in hospital mortality.
Please see this page for a brief discussion of the advantages and disadvantages of using the GCS as a measure of consciousness:
Other tools for delirium assessment
The Confusion Assessment Method(CAM-ICU) and the Intensive Care Delirium Screening Checklist(ICDSC) are highly validated techniques for delirium assessment in ventilated and non-ventilated patients. CAM-ICU was shown to have a sensitivity of 80.5% and specificity of 95.9% in a recent systematic review: (The confusion assessment method for the intensive care unit (CAM-ICU) and intensive care delirium screening checklist (ICDSC) for the diagnosis of delirium: a systematic review and meta-analysis of clinical studies. Gusmao-Flores D, Salluh JI, Chalhub RÁ, Quarantini LC. Crit Care. 2012 Jul 3;16(4):R115.)
CAM-ICU components:
- Acute onset of mental status changes or fluctuating course
- Inattention
- Disorganized thinking
- Altered level of consciousness
The following 6 minute video provides a succinct review of how to use the CAM-ICU method:
Treatment of delirium
The first goal is to determine the etiology. Most cases in SICU patients are multifactorial-sepsis, medication changes, pain, electrolyte derangements, alteration of the day/night cycle, the ICU environment. Then we try to mitigate each of these conditions if they are present. Prevention is also important-avoid benzodiazepines and use opioids judiciously. Family involvement to maintain orientation is helpful as is continued mobilization, physical therapy. The most effective management tools for delirium are supportive, even holistic, and non-pharmacologic.
There are few effective pharmacologic treatments for delirium. “Efficacy or safety of antipsychotic medication for treating delirium has not been extensively investigated by evidence-based randomized controlled clinical trials in critically ill patients”.
Options include:
- Haloperidol at doses of 2-10 mg IV that can be repeated (risks-dystonic reaction, akathisia, QTc prolongation, NMS)
- Atypical 2nd generation antipsychotics such as olanzapine, quetiapine, ziprasidone, risperidone (less extrapyramidal symptoms than with haloperidol)
Studies are mixed as to whether atypicals are safer and more effective than haloperidol.
Consider the following recent review for discussion of alpha-2 agonists, issues with physical restraints: (Delirium in the Intensive Care Unit.Arumugam S, El-Menyar A, Al-Hassani A, Strandvik G, Asim M, Mekkodithal A, Mudali I, Al-Thani H. J Emerg Trauma Shock. 2017 Jan-Mar;10(1):37-46.)