confusion about confusion: what the orthopedic surgeon needs to know about delirium
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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? - PowerPoint PPT PresentationTRANSCRIPT
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 SchoolNovember 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…”
Synonyms: Peer-reviewed literature
• Acute confusional state• Acute mental status change• Altered mental status• Organic brain syndrome• Toxic/metabolic
encephalopathy
• Dysergastic reaction
• Subacute befuddlement
Synonyms: on the wards
• Agitated• Confused• Combative• Crazy• Lethargic• Out of it
• Out to lunch• Poor historian• Seeing things• Sleepy• Uncooperative• Wild man
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
Delirium vs. Dementia
• Acute onset• Inattention• Sometimes abnl LOC• Fluctuating: minutes
to hours• Reversible
• Gradual onset• Memory disturbance• Normal LOC• Fluctuating: none or
days to weeks• Irreversible
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
Delirium: Central in a Cascade of Adverse Events
Postop delirium: complications
*p<.001, unadjusted and adjusted
Marcantonio, et. al. JAMA. 1994, 271: 134-139
Outcome Delirium No DeliriumMajor Complications 15% 2%*
Before delirium 5% After delirium 10%
Death 4% 0.2%*
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
Delirium and Inflammatory Markers
Inflammatory Marker
Delirium
(N=13)
No Delirium
(N=30)
P Value
C-reactive Protein
6 hrs postop
38 ± 11 17 ± 4 0.04
Interleukin-1β
6 hrs postop
2.4 ± 0.3 1.2 ± 0.2 0.002
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
Risk Factors for Delirium
• 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
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
Area under the ROC curve=0.79
Marcantonio, et. al. JAMA. 1994, 271: 134-139
Risk Points Incidence of DeliriumLow 0 2%
Medium 1, 2 11%
High 3 or more 50%
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
Intervention• 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
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
Outcome Geri Consult
Usual Care
P value
Delirium 32% 50% .04
Severe delirium 12% 29% .02
Days delirium per episode
2.9 days 3.1 days .72
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
Agitated Behavior
Drug Treatment of Agitation• What / Who are we treating?
– Reduce agitation but prolong cognitive symptoms
• Only 4 RCTs (largest N=73):– Neuroleptics preferable to benzodiazepines
in most cases (excpt: PD, DLBD, ETOH)– Low dose high potency neuroleptics (e.g.,
starting at haloperidol 0.25-1 mg) – Newer “atypical” agents: no better than
haloperidol
Lacasse et. al., Ann Pharm, 2006
Immobility
Malnutrition
Bowel and Bladder Dysfunction
Shift focus of care
Support
Not control
Summary
• Delirium: call it by its name
• Diagnosis: Confusion Assessment Method
• Important: Common, Morbid, Costly
• Multiple pathophysiologies: no magic bullet
• Assess and treat all correctable factors
• Prevent delirium using a proactive approach
• Support and rehabilitate the delirious patient