Psychiatry · Year 3 · from Psychiatry

Case 1: Delirium in a Post-Surgical Patient

Consultation Request

"Please evaluate for confusion and agitation. 68 y/o male POD 2 from CABG, now pulling at lines and trying to get out of bed."

Patient Demographics

  • Age: 68 years old
  • Sex: Male
  • Occupation: Retired teacher
  • Current Location: Cardiac ICU

History of Present Illness (from chart review and nursing)

The patient is a 68-year-old man who underwent three-vessel coronary artery bypass grafting 2 days ago after presenting with unstable angina. The surgery was technically successful without complications. He was extubated on POD 1 and was initially oriented and following commands appropriately.

This morning, nursing noted he became acutely confused, did not recognize his wife, and believed he was in a "prison." He attempted to pull out his central line and Foley catheter, requiring soft restraints. He has been intermittently somnolent and agitated throughout the day. His wife states "this is not him at all - he was sharp as a tack before surgery."

Chart Review

Medical History:

  • Coronary artery disease
  • Type 2 diabetes
  • Hypertension
  • Mild chronic kidney disease (baseline Cr 1.4)
  • Hearing loss (uses hearing aids - not currently in)

Current Medications:

  • Morphine PCA for pain
  • Metoprolol
  • Aspirin
  • Atorvastatin
  • Insulin sliding scale
  • Famotidine
  • Diphenhydramine 50 mg PRN for sleep (received x2 last night)

Recent Labs:

  • Na: 129 mEq/L (low)
  • K: 3.2 mEq/L (low)
  • BUN: 38, Cr: 2.0 (elevated from baseline)
  • Glucose: 186 mg/dL
  • WBC: 11.2
  • Hgb: 9.8

Recent Studies:

  • Chest X-ray: Post-surgical changes, no infiltrate
  • ECG: Normal sinus rhythm, post-surgical changes

Psychiatric Consultation Examination

Appearance: Elderly man in ICU bed, disheveled, IV lines, Foley, soft restraints on wrists

Behavior: Alternates between picking at lines and somnolent periods; startles easily; looking around room apprehensively

Speech: Intermittently mumbling, sometimes loud, disorganized

Mood: Unable to assess reliably

Affect: Fearful, irritable when staff approach

Thought Process: Disorganized, tangential, difficult to follow

Thought Content:

  • Paranoid beliefs ("the guards are coming")
  • Disoriented to place ("I'm in jail") and time (thinks it's 1995)
  • Cannot assess for suicidal ideation given disorganization

Perceptions: Appears to have visual hallucinations - pointing at things not present, talking to empty corner of room

Cognition:

  • Attention: Severely impaired - cannot spell WORLD, loses track mid-sentence
  • Orientation: Person only (knows name but not age accurately)
  • CAM: POSITIVE (all 4 features present)

Confusion Assessment Method (CAM)

Feature 1 - Acute Onset and Fluctuating Course: YES

  • Wife confirms acute change from baseline
  • Nursing notes fluctuation throughout day

Feature 2 - Inattention: YES

  • Cannot maintain focus on conversation
  • Unable to complete simple attention tasks

Feature 3 - Disorganized Thinking: YES

  • Incoherent speech
  • Illogical thought content

Feature 4 - Altered Level of Consciousness: YES

  • Fluctuates between hyperalert/agitated and lethargic

CAM Diagnosis: DELIRIUM

Identified Contributing Factors

Using I WATCH DEATH mnemonic:

  • Infection: Low probability (no fever, no infiltrate, UA negative)
  • Withdrawal: No alcohol or benzodiazepine use history
  • Acute metabolic: Hyponatremia (129), hypokalemia (3.2), acute kidney injury
  • Trauma: Recent major surgery
  • CNS pathology: Low probability (no focal neuro findings)
  • Hypoxia: Sats adequate, no respiratory issues
  • Deficiencies: Not assessed
  • Endocrine: Glucose mildly elevated but not severe
  • Acute vascular: Post-cardiac surgery increases risk
  • Toxins/drugs: Morphine (opioid), Diphenhydramine (anticholinergic)
  • Heavy metals: No

Primary Contributors Identified:

  1. Post-operative state (cardiac surgery = highest risk surgery for delirium)
  2. Medications: Opioid (morphine PCA), Anticholinergic (diphenhydramine)
  3. Electrolyte abnormalities: Hyponatremia, hypokalemia
  4. Acute kidney injury (may prolong medication effects)
  5. Sensory deprivation (hearing aids not in)
  6. Sleep deprivation (ICU environment)
  7. Pain (undertreated vs. overtreated?)

Recommendations to Primary Team

1. Treat Underlying Causes:

Medications:

  • Discontinue diphenhydramine (anticholinergic - major contributor)
  • Reduce opioid burden: Consider transitioning from morphine PCA to scheduled acetaminophen + low-dose PRN opioid
  • Avoid benzodiazepines for sleep

Electrolytes:

  • Correct hyponatremia (slowly to avoid osmotic demyelination)
  • Replete potassium

Kidney Injury:

  • Nephrology input for AKI management
  • Review all renally cleared medications

2. Non-Pharmacological Interventions:

Reorientation:

  • Hearing aids placed and functional
  • Clock and calendar at bedside
  • Glasses if used
  • Frequent verbal reorientation by all staff and family
  • Family photos in room

Sleep-Wake Cycle:

  • Minimize nighttime interruptions
  • Cluster care activities
  • Lights off at night, blinds open during day
  • No caffeine after noon

Mobilization:

  • Early mobilization as cardiothoracic surgery allows
  • Out of bed to chair starting today if cleared

Environment:

  • Minimize restraints (worsen agitation and delirium)
  • Consistent nursing staff
  • Family presence encouraged (especially during evening)

3. Symptomatic Management (if non-pharm insufficient):

For agitation interfering with care/safety:

  • Haloperidol 0.5-1 mg IV/IM PRN (low dose given age, cardiac surgery)
  • Maximum 3 mg/24 hours
  • Monitor QTc (baseline 445 ms)
  • Reassess need daily - goal is to discontinue ASAP

4. Monitoring:

  • CAM assessment every shift
  • Daily medication review
  • Reassess mental status with each electrolyte improvement

5. Prognosis Discussion with Family:

  • Delirium is common after cardiac surgery (25-50%)
  • Usually resolves in days to weeks
  • Full recovery expected if underlying causes treated
  • May have prolonged cognitive recovery period

Follow-up Consultation Note (Day 4)

  • Diphenhydramine discontinued
  • Morphine PCA stopped, now on acetaminophen + tramadol PRN
  • Sodium corrected to 134, potassium 4.0
  • Hearing aids in place
  • Family present 12 hours/day
  • Sleeping better with sleep hygiene measures
  • Haloperidol used x2 total, not in past 36 hours
  • Mental status: Significantly improved, oriented x2 (person, place), attention improved
  • CAM: Borderline positive (Feature 1 and 2 only)
  • Expect continued improvement over next several days

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