Clearing up the confusion: minimizing postoperative delirium

Lionel Lim, MD, MPH, FACP, FACPM

Postoperative delirium is an under-diagnosed yet common geriatric syndrome that manifests as an acute confusional state, typically within 48 to 72 hours after surgery.  Occurrence of postoperative delirium is variable (15-25% in elective surgery) and its incidence is highest in hip and coronary artery bypass surgeries (>50%).¹  Delirium in elderly patients is associated with increased mortality, hospital length of stay, institutionalization, and dementia.^{2, 3}  Furthermore, functional and cognitive impairment from delirium may persist for months after discharge from hospital.¹  Risk factors for delirium are older age, neurocognitive impairment, multiple comorbidities, functional and sensory impairments, male gender and alcoholism.¹  Patients should be screened for risk factors or cognitive impairment at baseline so that appropriate delirium-preventing interventions can be implemented. 

It is also important to educate the patient and family regarding the etiology, treatment and prognosis of delirium.  Informing family that delirium is not permanent and may take weeks to months to eventually resolve may help to reduce anxiety or frustration.  Having the support and continued presence of family members or caregivers can also help patients during their recovery by providing frequent orientation, reassurance, and avoiding the need to institute unfamiliar “sitters” or physical restraint use during episodes of confusion.  Providers should pay close attention for delirium occurrence in previously affected or high-risk patients by using a validated screening tool like the Confusion Assessment Method (CAM).⁴  Appropriate steps should be taken to avoid the precipitants mentioned above and to correct and treat any underlying infective or metabolic derangements.  

Patients at high risk of post-operative delirium should be followed closely by an interdisciplinary team that is knowledgeable in the prevention, detection and management of delirium.  This team should include a geriatrician or internist working in a setting with established protocols in place to reduce the risk of postoperative delirium.⁵  These protocols would include adequate postoperative pain management, early mobilization, close monitoring of fluid status to avoid dehydration, adequate cognitive stimulation to maintain orientation, maintenance of diurnal rhythm through nonpharmacologic sleep protocols, bowel regimens to avoid constipation, minimizing the use of bladder or vascular catheters, and avoiding deliriogenic medications (benzodiazepines or sedatives and highly anticholinergic medications, e.g. diphenhydramine).  Implementation of the Hospital Elder Life Program (HELP) which targets some of the above risk factors and includes a nonpharmacologic sleep protocol in hospitalized older adults has been shown to reduce the risk of delirium by over a third.⁶  Although haloperidol for postoperative delirium prophylaxis may be a promising agent for use in high risk patients, larger trials are needed before their routine use can be justified in higher-risk patients.^7-9

References

1.            Marcantonio ER. In the clinic. Delirium. Ann Intern Med. Jun 7 2011;154(11):ITC6-1 to 6-16.

2.            Inouye SK. Delirium in older persons. N Engl J Med. Mar 16 2006;354(11):1157-1165.

3.            Witlox J, Eurelings LS, de Jonghe JF, Kalisvaart KJ, Eikelenboom P, van Gool WA. Delirium in elderly patients and the risk of postdischarge mortality, institutionalization, and dementia: a meta-analysis. Jama. Jul 28 2010;304(4):443-451.

4.            Inouye SK, van Dyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI. Clarifying confusion: the confusion assessment method. A new method for detection of delirium. Ann Intern Med. Dec 15 1990;113(12):941-948.

5.            Marcantonio ER, Flacker JM, Wright RJ, Resnick NM. Reducing delirium after hip fracture: a randomized trial. J Am Geriatr Soc. May 2001;49(5):516-522.

6.            Inouye SK, Bogardus ST, Jr., Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med. Mar 4 1999;340(9):669-676.

7.            Girard TD, Pandharipande PP, Carson SS, et al. Feasibility, efficacy, and safety of antipsychotics for intensive care unit delirium: the MIND randomized, placebo-controlled trial. Crit Care Med. Feb 2010;38(2):428-437.

8.            Kalisvaart KJ, de Jonghe JF, Bogaards MJ, et al. Haloperidol prophylaxis for elderly hip-surgery patients at risk for delirium: a randomized placebo-controlled study. J Am Geriatr Soc. Oct 2005;53(10):1658-1666.

9.            Wang W, Li HL, Wang DX, et al. Haloperidol prophylaxis decreases delirium incidence in elderly patients after noncardiac surgery: a randomized controlled trial*. Crit Care Med. Mar 2012;40(3):731-739.