Postoperative Delirium in the older patient Topic review

Postoperative Delirium in the older patient. Topic review 26/5/48 Suthinee Ithimakin, MD

Postoperative delirium Acute disorder of cognition and attention after operation n Anytime in perioperative period n Most commonly occurs during postsurgical period n Underdiagnosed 78% n 40% routinely screen for delirium n

Postoperative delirium Associated with n Poor cognitive and functional recovery n Longer hospital stay n Greater hospital costs n Risk factor for institutionalization and morbidity n Reduced risk by early identification, assessment and treatment

Incidence/ prevalence ¼ of adult older than 65 year experience delirium during hospitalization n Wide range estimate of postoperative delirium pending on type of operation n Delirium is likely to increase in future n

Pathogenesis CNS changes with age n Loss of nerve cells n Decreased in cerebral blood flow n Changes in neurotransmitter system n Decreased acetylcholinesterase activity n Carbonic anhydrase activity n Muscarinic receptor n Serotonin receptors n

Pathogenesis Abnormal levels of endorphins, serotonin, neuropeptides in CSF n EEG : slowing of dominant posterior alpha rhythm and abnormal slow wave activity n

Cause of CNS dysfunction after surgery

Risk factors

Risk factors Older age Cognitive impairment Functional impairment Decreased postoperative hemoglobin Markedly abnormal sodium, potassium and glucose Alcohol abuse Noncardiac thoracic operation History of delirium Preoperative used of narcotic Preoperative used of benzodiazepine Low postoperative oxygen saturation History of cardiovascular disease Untreated pain

Drug associated with delirium n Drugs with anticholinergic activity n n n Tricyclic antidepressants Cimetidine Corticosteroids Digoxin Diphenhydramine Belladonna Dipyridamole Theophylline Promethazine Amantadine Oxybutyrin

Drugs associated with delirium n Analgesics Narcotics (especially meperidine) n NSAIDs n Benzodiazepines n Antiparkinsonian agents n

Diagnosis Modified from Diagnostic and Statistical Manual of Mental Disorder, 4 TH ed

features depression delirium dementia

Clinical features Change of consciousness and recognition n Cognitive abnormalities n Disorientation n Language difficulty n Impairment of learning and memory n Fluctuating course

Clinical features n Emotional disturbances Anxiety n Fear n Anger n Irritability n Depression n

Clinical features 4 different types Hypoactive delirium n Hyperactive delirium n Mixed delirium n Delirium without psychomotor change n

History Description of patient’s behavior n Earlier episode of delirium n Evidence of cognitive impairment n Information to rule out alcohol or drug withdrawal n

Physical examination Vital signs n Oxygen saturation n Sign of trauma or infection n State of hydration n New neurological signs n

Confusion assessment method Item 1 and 2 and 3 or 4 Sensitivity 94 -100% Specificity 90 -95%

Diagnostic tests To identify potentially correctable factors n CBC, electrolytes, creatinine, glucose, and urinalysis n Neuroimaging may be used selectively n

Prevention Tarketing modifiable risk factors prevent some case of delirium* n Standardized protocols of known risk factors for delirium Sleep deprivation n Reduction in delirium episodes (15% 9. 9%) Immobility n No effect on delirium severity and rate of Dehydration Visual impairment recurrence n Cognitive impairment Hearing impairment *N Engl J Med 1999; 340: 669 -676

Prevention Patients with fracture neck of femur Outcome : Postoperative delirium ? ? Pre and postoperative geriatric assessments, n Oxygen therapy n Early operation n Prevention treatment of perioperative BP fall n Treatment of postoperative complication n J Am Geriatr Soc 1991; 39: 655 -62

Prevention Interventions Decreased postoperative delirium from 61% to 48% J Am Geriatr Soc 1991; 39: 655 -62

Prevention n Identify and reduce risk factors can decrease postoperative delirium in elderly n Preoperative educate the patients

Management Treat contributing illness n Providing supportive measures n Symptom control n Identify causes and treat Safe environment Appropiate stimulation Nutrition Reserve for agitated or disruptive individuals

Supportive measures

Medication for symptom control n Antipsychotics Haloperidol or newer antipsychotic agent ? ? n Goal is to control disruptive symptoms and avoid obtundation n Taper in 3 -5 days n n Benzodiazepine Paradoxical agitation n Treat withdrawal from alcohol of sedative drugs n

Prevention and treatment of postoperative delirium

Outcome Sequels of delirium can persist for 6 months n Risk for future cognitive decline n Associated with increase mortality (10 -65%( n Longer hospital stay and higher nursing home placement n

Outcomes of delirium n Relationship between delirium and dementia in 3 years with 203 patients age ≥ 65 in medical services Incidence of dementia 5. 6% per year in patient without delirium 18. 1% per year in delirium group Age aging 1999; 28: 551 -556

Outcomes of delirium 78 patients with femoral neck fractures Postoperative delirium 69% Without Postoperative delirium 5 years 20% Dementia J Am Geriatr Soc 2003; 51: 1002 -1006

Conclusion Risk of postoperative delirium can be reduced with careful attention to risk factors n Intervention to target problems n Systemic approach to diagnostic workup n Early identification, assessment and management n