Delirium on the ICU

Delirium on the ICU

A 67 year old with signficant cardiovascular comorbidities presented with a fractured neck of femur after a fall. She had a hemiarthroplasty performed under GA with fascia iliaca blocks, and went to HDU postoperatively. She became acutely confused during the first postoperative night with hallucinations and paranoia. She was CAM-ICU positive and was given haloperidol to control her agitation.

What is the optimum management of delirium on the ICU?

Tahir Ali

Delirium in critically ill patients is common accounting for 60% to 80% of ventilated patients.(1) It accounts for prolonged Intensive Care Unit (ICU) and hospital stays (2) which could increase incidences of hospital acquired infections with obvious financial implications. The intensive care society (ICS) therefore advocates daily assessment of patients on ICU for evidence of delirium along with recommendations on its prevention and management.

Delirium is defined as an acute disturbance of consciousness and change in cognition.(3) It is a syndrome with a range of presentations broadly classified into
hypoactive, hyperactive and mixed delirium. The incidences of the various subtypes based on an observational study of 614 critically ill patients demonstrated the mixed form as the commonest (54.9%). Hypoactive occurred in 43.5% and hyperactive was rare, occurring in only 1.6% of all cases.

Various risk factors predispose patients to the development of delirium, especially on ICU, where polypharmacy and the presence of severe resistant infection frequently co-exist. It is therefore imperative that organic causes, such as sepsis, electrolyte abnormalities and cerebrovascular accident, are promptly diagnosed to allow appropriate management.

The gold standard for diagnosis of delirium utilises the DSM-IV criteria. However this requires a specialist psychiatrist and various pre-requisites which cannot always be achieved on ICU. As a result various screening tools have been published and verified including the cognitive test for delirium, the intensive care delirium screening checklist (ICDSC),(4) and the confusion assessment method for ICU (CAM-ICU) (5).

A multi-system, multi-modal approach to management is necessary, both
pharmacological and non-pharmacological. Treating underlying disorders and
normalisation of physiology is paramount. Prevention is superior to treatment and
therefore every attempt must be taken to perform daily sedation holds, maintain and correct sleep-wake cycle, and orientation using clocks, hearing and visual aids. The current mainstay pharmacological treatment includes Haloperidol 2.5mg, which can be doubled every 20-30 minutes as required. The alternative drug is Olanzapine 5mg orally.

Benzodiazepines must be avoided as they have been demonstrated to be an
independent risk factor in the daily development of delirium (6) as well as worsening symptoms of delirium (7) despite their short term sedative effects.


References
1. Ely EW, Inouye SK, Bernanrd GR et al. Delirium in mechanically ventilated
patients: validity and reliability of the confusion assessment method for the
intensive care unit (CAM-ICU). J Am Med Assoc 2001; 286:2703– 10
2. McCusker, J., Cole, M. G., Dendukuri, N. and Belzile, E. (2003), Does
Delirium Increase Hospital Stay?. Journal of the American Geriatrics Society,
51: 1539–1546.
3. American Psychiatric Association. Diagnostic and Statistical Manual of Mental
Disorders, 4th Edn (DSM-IV). Washington, DC: APA, 1994.
4. Bergeron N, Dubois MJ, Dumont M et al. Intensive care delirium screening
checklist: evaluation of a new screening tool. Intensive Care Med 2001; 27:
859–64
5. Ely EW, Margolin R, Francis J et al. Validation of the confusion assessment
method for the intensive care unit (CAM-ICU). Crit Care Med 2001; 29: 1370–
9.
6. Pandharipande P et al. Lorazepam is an independent risk factor for
transitioning to delirium in intensive care unit patients. Anesthesiology. 2006
Jan; 104(1):21-6.
7. Breitbart W, Marotta R, Platt MM et al. A double blind trial of haloperidol,
chlorpromazine and lorazepam in the treatment of delirium in hospitalized
AIDS patients. Am J Psychiatr 1996; 153: 231–7

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