Confusion about Confusion: What the orthopedic surgeon needs to know about delirium Edward R. Marcantonio, M.D., S.M. Orthopedic Surgery Grand Rounds University of Massachusetts Medical School November 12, 2008
Delirium • What is it? • How do you diagnose it? • Why is it important? • What causes it? • What is the appropriate workup? • Can it be prevented? • How do you manage the delirious patient?
Delirium What is it?
Delirium: early descriptions • Celsus, 1st Century • “Sick people, sometimes in a febrile paroxysm, lose their judgment and talk incoherently… when the violence of the fit is abated, the judgment presently returns… • Aurelius, 2nd Century • “mental derangement may result…from the drinking of a drug…”
Acute confusional state Acute mental status change Altered mental status Organic brain syndrome Toxic/metabolic encephalopathy Dysergastic reaction Subacute befuddlement Synonyms: Peer-reviewed literature
Agitated Confused Combative Crazy Lethargic Out of it Out to lunch Poor historian Seeing things Sleepy Uncooperative Wild man Synonyms: on the wards
Take home point: Recognizing and naming delirium is the first step in its appropriate management.
Delirium How do you diagnose it?
DSM Definition • First described in DSM-III, 1980 • Changes every few years • DSM-IV: • disturbance of consciousness with inattention • develops over a short time and fluctuates • change in cognition not explained by dementia • Etiology: General Medical vs. Drug
Confusion Assessment Method (CAM) • Feature 1: Acute change in mental status with a fluctuating course • Feature 2: Inattention • Feature 3: Disorganized thinking • Feature 4: Altered level of consciousness • Diagnosis of Delirium: requires presence of Features 1 and 2 and either 3 or 4.
Testing Attention • One of the most basic, but neglected areas of the mental status exam • Affects all other areas of cognition • Formal methods: • MMSE: Serial 7’s, WORLD backwards • Digit Span: 5 forwards, 4 backwards • Days of Week, Months of Year backwards • Informal methods: • LOC: Are the lights on? • Attention: Is anybody home?
Psychomotor variants • Hyperactive (“Wild man”): 25% • most often recognized • risk: oversedation, restraints • Hypoactive (“Out of it”): 50% • risk: failure to recognize • sometimes confused with depression • Mixed delirium: hypo alt with hyper
Acute onset Inattention Sometimes abnl LOC Fluctuating: minutes to hours Reversible Gradual onset Memory disturbance Normal LOC Fluctuating: none or days to weeks Irreversible Delirium vs. Dementia Common: Delirium superimposed on Dementia
Take home point When in doubt, diagnose delirium!
Delirium Why is it important?
Common Orthopedic patients aged 70 and older • 15-20% incidence after THR, TKR • 25% incidence after laminectomy • 50% incidence after hip fracture
Morbid • Hospital complications: RR=2-5 • Hospital death: RR=2-20! • Increased nursing home placement RR=3
Postop delirium: complications OutcomeDeliriumNo Delirium Major Complications 15% 2%* Before delirium 5% After delirium 10% Death 4% 0.2%* *p<.001, unadjusted and adjusted Marcantonio, et. al. JAMA. 1994, 271: 134-139
Costly • Acute hospitalization: • increased LOS: 2-5 days • increased inpatient costs • common reason for “falling off” pathways • Long term: • increased short and long term NH placement • incremental cost per pt over next year: > $60K
Delirium What causes it? I. Basic pathophysiology
Cholinergic failure hypothesis • Acetylcholine: impt in cognitive processes • Delirium: • “caused” by anticholinergic poisoning • reversed by pro-cholinergic drugs • assoc. with “anticholinergic burden” • Pilot RCT of donepezil in hip fx pts • Cholinergic agonist used for dementia • Can it prevent/treat delirium?
Inflammation and Delirium • Delirium: inflammatory states • Infections, cancer • Delirium: common in cytokine treatment • Inflammation: • Breakdown of BBB • Adversely impacts cholinergic transmission • Several studies show assoc. between delirium and inflammatory biomarkers in medical and surgical patients de Rooij et. al., J Psychosom Med, 2007
Neuronal Injury Markers • Measure neuronal damage in serum • Examples: • Neuron specific enolase • S100 Beta • Neuronal tau protein • Delirium associated with release of neuronal injury markers
Delirium and Neuron Injury Markers Serum Tau Protein Serum S-100β Ramlawi et. al., Ann Surg, 2006
Summary: Pathophysiology • Multiple pathophysiologies: • Cholinergic failure • Inflammation • Different mechanisms may pertain in different clinical situations • Some cases of delirium may cause direct neuronal injury
Delirium What causes it? II. Epidemiological Model
Predisposing factors: advanced age pre-existing dementia other CNS diseases functional impairment multiple comorbidities multiple medications imp. vision/hearing Precipitating factors: new psychoactive med acute medical problem exacerbation of chronic medical problem surgery pain ?environmental change Risk Factors for Delirium
Implications of Model • More baseline vulnerability, less acute precipitants needed • Acute precipitants rarely in the CNS • “Law of Parsimony” rarely applies: • effective treatment requires evaluation and correction of all reversible factors
Preoperative Prediction Rule Risk Factor: Points Age 70 or older 1 Cognitive impairment 1 Severe physical impairment 1 Alcohol Abuse 1 Markedly abnl serum chemistries 1 Aortic aneurysm surgery 2 Non-cardiac thoracic surgery 1
Performance of the Clinical Prediction Rule: Validation Set RiskPointsIncidence of Delirium Low 0 2% Medium 1, 2 11% High 3 or more 50% Area under the ROC curve=0.79 Marcantonio, et. al. JAMA. 1994, 271: 134-139
Postop (Precipitating) Factors for Delirium • Low postoperative hematocrit (<30%) • Meperidine (highly anticholinergic) • Benzodiazepines • high dose, long acting • Pain at Rest
Delirium What is appropriate workup?
Workup • History: • time course of mental status changes • association with other “events” • Physical examination: • Vital signs: HR, BP, temp, oxygen sat. • General medical: cardiac, pulmonary • Neuro: new focal signs
Medication Review • Include OTCs, PRNs, alcohol • Recent changes, additions, discontinuations • Biggest offenders: • sedative-hypnotics (esp. long, ultra short acting) • opioid analgesics (esp. meperidine: RR=2.5) • anti-cholinergic drugs (anti-histamines, TCAs, esp. tertiary amines, misc. others)
Laboratory testing • CBC (hct, wbc), electrolytes, glucose • Infectious workup: U/A, CXR, etc. • Selected additional testing: • drug levels, toxic screen, ABG, EKG • ?role for CT/LP/EEG: • new focal sxs, high suspicion, no other dx
Common reversible factors • DRUGS • E lectrolyte imbalance (dehydration) • L ack of drugs (withdrawal, uncontr. pain) • I nfection • R educed sensory input (vision, hearing) • I ntracranial (CVA, subdural, etc.--rare) • U rinary retention/fecal impaction • M yocardial/Pulmonary
Correct all reversible factors Don’t stop at one!
Delirium Can it be prevented?
Delirium and Hip Fracture Hip Fracture: >300,000 annually in U.S. • Paradigm for acute functional decline in hospitalized elderly • Hip is easily fixed, but less than 50% recover to pre-fracture status • Delirium: affects 50% of hipfx pts • Indpt risk factor for poor functional recovery, even after adjusting for dementia
Geriatrics consultation: proactive: preop, or within 24 hrs postop daily visits: targeted recommendations structured protocol 10 modules adequate CNS oxygen fluid/electrolyte pain management psychoactive meds bowel/bladder nutrition mobilization postop complications environment management delirium Intervention
Geriatrics consultation • 61% pts seen preop, all 24 hrs postop • 10+4 recs, 77% adherence (32%-100%) • Recs made in >2/3 pts (%adh): • transfuse to hematocrit > 30% (79%) • d/c urinary catheter by POD 2 (89%) • d/c or adjust psychoactive meds (83%) • RTC acetaminophen for pain (72%)
Impact of Geriatrics Consultation Marcantonio et. al. JAGS. 2001; 49: 516-522
Implications • Delirium is not inevitable: • It is preventable using a proactive, multifactorial approach • Evolution: Geriatrics-Orthopedics Co-management service • Hip fracture • High risk elective patients
How do you manage the delirious patient? Do’s and Don’ts