# Delirium: Diagnosis and Management on Medical and Surgical Services
## Definition and Epidemiology
Acute, fluctuating disturbance in attention and awareness, with additional cognitive disturbance (memory, orientation, language, visuospatial, perception) Most common psychiatric diagnosis in general hospital settings. Prevalence: 10-30% of hospitalized medical patients; up to 50-80% in ICU patients. Post-surgical delirium: 15-25% after major surgery; up to 50% after hip fracture or cardiac surgery. Associated with increased mortality (up to 2-3x), longer hospital stays, increased institutionalization, and accelerated cognitive decline. Often unrecognized: up to 60-70% of cases missed by medical/surgical teams (hypoactive delirium especially)
## DSM-5-TR Diagnostic Criteria
A. Disturbance in attention and awareness (reduced ability to direct, focus, sustain, and shift attention) B. Develops over hours to days; represents a change from baseline; fluctuates in severity during the day. C. Additional cognitive disturbance (memory deficit, disorientation, language, visuospatial, or perception) D. Not better explained by a pre-existing neurocognitive disorder or coma. E. Evidence from history, exam, or labs that the disturbance is a direct consequence of a medical condition, substance, toxin exposure, or multiple etiologies.
## Subtypes
| Subtype | Prevalence | Presentation | Detection Rate | Prognosis | Common Misdiagnosis |
|---------|-----------|--------------|----------------|-----------|-------------------|
| Hyperactive | ~25% | Agitation, restlessness, hallucinations, pulling at lines | High | Better (earlier detection) | Psychosis, mania |
| Hypoactive | ~50% | Lethargy, withdrawal, psychomotor slowing | Low (~30% missed) | Worse | Depression, fatigue, dementia |
| Mixed | ~25% | Alternates between hyperactive and hypoactive | Moderate | Intermediate | Varies |
**Hyperactive:** agitation, restlessness, hypervigilance, hallucinations, pulling at lines -- the "classic" delirium that gets attention. **Hypoactive:** lethargy, decreased responsiveness, withdrawal, psychomotor slowing -- more common than hyperactive but frequently missed (mistaken for depression or fatigue) **Mixed:** alternates between hyperactive and hypoactive features. Hypoactive delirium has WORSE outcomes than hyperactive (less likely to be diagnosed and treated promptly)
## Screening and Assessment
### Confusion Assessment Method (CAM)
Most widely used delirium screening instrument. **Four features:**. Acute onset and fluctuating course. Inattention. Disorganized thinking. Altered level of consciousness. Diagnosis requires features 1 + 2 + EITHER 3 or 4. Sensitivity ~94%, specificity ~89% when administered by trained raters. **CAM-ICU:** adapted for intubated/non-verbal patients; uses visual attention tasks.
### Other Assessment Tools
**3D-CAM:** brief structured version (~3 minutes) **bCAM:** brief screening for ED settings. **DRS-R-98 (Delirium Rating Scale):** severity measurement tool. **Nursing Delirium Screening Scale (Nu-DESC):** nurse-administered observation scale.
### Bedside Cognitive Testing
Attention testing is the cardinal feature to assess: Months of the year backwards. Serial 7s (subtract 7 from 100 repeatedly) Digit span (forward and backward) Spelling WORLD backwards. Orientation (person, place, time, situation) Clock drawing (visuospatial function)
## Etiologic Workup
### Mnemonic: "I WATCH DEATH"
**I**nfection (UTI, pneumonia, sepsis, meningitis) **W**ithdrawal (alcohol, benzodiazepines, opioids) **A**cute metabolic (electrolyte disturbances, hepatic/renal failure, DKA) **T**rauma (head injury, burns, surgery) **C**NS pathology (stroke, seizure, tumor, subdural hematoma) **H**ypoxia (hypoxemia, cardiac failure, pulmonary embolism, anemia) **D**eficiencies (thiamine, B12) **E**ndocrinopathies (thyroid, adrenal, glucose) **A**cute vascular (MI, stroke, shock) **T**oxins/drugs (medications, illicit substances, anticholinergics) **H**eavy metals (lead, mercury -- rare)
### Medication Review -- Critical Step
Anticholinergics: diphenhydramine, oxybutynin, atropine, scopolamine, TCAs. Benzodiazepines and sedative-hypnotics. Opioids (especially meperidine) Fluoroquinolones. Corticosteroids. H2 blockers (cimetidine, ranitidine) Anti-Parkinsonian agents (dopamine agonists, amantadine) NSAIDs in elderly.
### Standard Workup
CBC, BMP (electrolytes, glucose, BUN/Cr), LFTs, calcium, magnesium, phosphate. Urinalysis and culture. Blood cultures (if febrile) Chest X-ray. Arterial blood gas or pulse oximetry. ECG. Thyroid function (TSH) Drug levels (digoxin, lithium, etc.) if applicable. Additional as indicated: CT head, LP, EEG, ammonia, B12, cortisol, HIV, RPR.
## Non-Pharmacologic Prevention and Management
### HELP (Hospital Elder Life Program)
The most well-validated delirium prevention program. Multi-component intervention targeting modifiable risk factors. Components: **Orientation:** frequent reorientation, clocks, calendars, familiar objects. **Cognitive stimulation:** engaging activities, cognitive exercises. **Sleep protocol:** noise reduction, eye masks, earplugs, avoid nighttime medications and vitals. **Mobility:** early mobilization, physical therapy. **Vision/hearing:** ensure glasses and hearing aids are available. **Hydration:** avoid dehydration; monitor fluid balance. Reduces delirium incidence by ~40% (Inouye et al., 1999) Cost-effective and evidence-based.
### ABCDEF Bundle (ICU)
**A**ssess, prevent, manage pain. **B**oth spontaneous awakening and breathing trials. **C**hoice of analgesics and sedatives (avoid benzodiazepines) **D**elirium monitoring and management. **E**arly mobility. **F**amily engagement.
## Pharmacologic Management
### Antipsychotics for Hyperactive Delirium
**Haloperidol:** most studied; typical starting dose 0.5-2 mg PO/IM/IV; redose q30-60 min PRN. Advantages: available IV, minimal hemodynamic effects, no respiratory depression. Risks: QTc prolongation (monitor ECG), EPS, NMS, lowers seizure threshold. **Atypical antipsychotics:** quetiapine (12.5-50 mg), olanzapine (2.5-5 mg), risperidone (0.25-1 mg) May be preferred in patients at risk for EPS (Parkinson disease, DLB -- but see warning below) Limited IV formulations. **Critical exception: Lewy body dementia** -- antipsychotics can cause severe, life-threatening sensitivity reactions (rigidity, obtundation, NMS-like syndrome); use extreme caution or avoid entirely.
### The Pharmacologic Prophylaxis Debate
Multiple RCTs have examined prophylactic antipsychotics (haloperidol, olanzapine) for delirium prevention in surgical patients. Results: inconsistent; most large, high-quality trials show NO benefit of pharmacologic prophylaxis (HECTOR trial, REDUCE trial) Current consensus: non-pharmacologic prevention (HELP, ABCDEF) is the standard; pharmacologic prophylaxis is NOT routinely recommended. Dexmedetomidine may reduce delirium in ICU patients (vs. benzodiazepine sedation) -- emerging evidence.
### Medications to AVOID in Delirium
Benzodiazepines (worsen confusion and delirium EXCEPT in alcohol/benzodiazepine withdrawal and sedative-hypnotic withdrawal) Anticholinergics (frequently causative) Physical restraints (increase agitation, injury, and mortality; use as last resort with time-limited orders)
A flowchart for delirium assessment and management on a medical service. Start with "Acute change in mental status." Screen with CAM (four features). If CAM positive: confirm delirium diagnosis, then pursue etiologic workup (labs, imaging, medication review using I WATCH DEATH mnemonic). Simultaneously implement non-pharmacologic interventions (HELP protocol). If hyperactive with safety risk: low-dose antipsychotic (haloperidol or quetiapine). If hypoactive: focus on treating underlying cause; do NOT sedate. Warning box: avoid benzodiazepines except for withdrawal. Color-coded algorithm.
A comparison diagram of hyperactive versus hypoactive delirium subtypes. Two columns. For each: clinical presentation, frequency (hypoactive more common), likelihood of being recognized (hypoactive often missed), prognosis (hypoactive worse), common misdiagnoses (depression for hypoactive, psychosis for hyperactive), and management approach. Include the mixed subtype as a third category. Highlight that hypoactive delirium has worse outcomes because it is diagnosed later. Clinical education format.
An infographic on the HELP (Hospital Elder Life Program) delirium prevention bundle. Show six intervention domains in a circular arrangement: orientation protocols, cognitive stimulation, sleep hygiene, early mobilization, vision/hearing optimization, and hydration management. For each, list specific interventions. Include the key statistic: reduces delirium incidence by ~40%. Show that this is evidence-based, cost-effective, and should be standard of care for all hospitalized older adults. Clinical implementation guide format.
## Clinical Pearls
Hypoactive delirium is MORE common than hyperactive delirium and has WORSE outcomes -- screen proactively with CAM; do not wait for agitation to suspect delirium. Every medication should be considered as a potential cause of delirium until proven otherwise -- perform a thorough medication review with special attention to anticholinergics, benzodiazepines, and opioids. Benzodiazepines CAUSE delirium in most contexts and should be avoided EXCEPT in alcohol/benzodiazepine withdrawal, where they are the treatment. Non-pharmacologic prevention (HELP program) reduces delirium by ~40% and is more effective than any medication -- implement for all at-risk hospitalized patients. Pharmacologic prophylaxis with antipsychotics does NOT reliably prevent delirium -- non-pharmacologic approaches are the standard. In patients with known or suspected Lewy body dementia, antipsychotics can cause severe neuroleptic sensitivity -- use with extreme caution or avoid entirely. Delirium is a medical emergency, not a psychiatric nuisance -- it indicates serious underlying pathology, increases mortality, and accelerates cognitive decline; treat the cause, not just the symptoms.
## References
- Inouye SK, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. *N Engl J Med*. 1999;340(9):669-676.
- Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. *Lancet*. 2014;383(9920):911-922.
- Ely EW, et al. Evaluation of delirium in critically ill patients: validation of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). *Crit Care Med*. 2001;29(7):1370-1379.
- Girard TD, et al. Haloperidol and ziprasidone for treatment of delirium in critical illness. *N Engl J Med*. 2018;379(26):2506-2516.
- van den Boogaard M, et al. Effect of haloperidol on survival among critically ill adults at high risk for delirium: the REDUCE randomized clinical trial. *JAMA*. 2018;319(7):680-690.