Overview
Definition:
Postoperative delirium (POD) is an acute, fluctuating disturbance of consciousness characterized by inattention, disorganized thinking, and altered level of consciousness, occurring in the perioperative period.
Epidemiology:
Incidence varies widely based on patient population and surgical procedure, ranging from 10% in younger patients undergoing minor surgery to over 50% in elderly patients undergoing major elective or emergency surgery
Higher rates seen in cardiac, orthopedic, and abdominal surgeries.
Clinical Significance:
POD is associated with prolonged hospital stay, increased morbidity and mortality, higher rates of institutionalization, and long-term cognitive decline
Early recognition and management are crucial to mitigate these adverse outcomes.
Risk Factors
Patient Factors:
Advanced age (>65 years)
Pre-existing cognitive impairment or dementia
Delirium in the past
Low socioeconomic status
Poor baseline functional status
Comorbidities (e.g., hypertension, diabetes, heart failure, renal impairment)
Sensory deficits (hearing, vision)
Alcohol or substance abuse.
Surgical Factors:
Emergency surgery
Major surgery
Prolonged operative time
Intraoperative blood loss
Use of general anesthesia (vs
regional)
Specific anesthetic agents.
Postoperative Factors:
Pain
Sleep deprivation
Immobility
Fluid and electrolyte imbalances
Hypoxia
Hypoglycemia
Infection
Polypharmacy
Urinary catheterization
Physical restraints
Intensive care unit (ICU) environment.
Clinical Presentation
Symptoms:
Acute onset of fluctuating mental status
Inattention and distractibility
Disorganized thinking or speech
Altered level of consciousness (hyperactive, hypoactive, or mixed)
Hallucinations (visual, auditory)
Delusions
Agitation or withdrawal
Disorientation (time, place, person)
Sleep-wake cycle disturbances.
Signs:
Inability to focus or maintain attention
Random, incoherent speech
Fluctuating vital signs (tachycardia, hypertension, or hypotension)
Evidence of distress or anxiety
Psychomotor agitation or retardation
May appear drowsy or stuporous.
Diagnostic Criteria:
Based on DSM-5 criteria for delirium: 1
Disturbance of attention and awareness
2
Acute onset and fluctuating course
3
Disturbance in cognition (memory deficit, disorientation, language, visual-spatial ability, perception)
4
Not better explained by another neurocognitive disorder
5
Not due to substance intoxication/withdrawal or another medical condition
The Confusion Assessment Method (CAM) is a widely used screening tool.
Prevention Strategies
Preoperative Optimization:
Identify and address risk factors
Optimize comorbidities
Cognitive assessment
Patient and family education about POD
Medication review to discontinue high-risk drugs.
Intraoperative Measures:
Minimize anesthetic agents
Maintain hemodynamic stability
Ensure adequate oxygenation and ventilation
Minimize blood loss
Use of intraoperative monitoring
Consider regional anesthesia where appropriate.
Postoperative Care Bundle:
Early mobilization
Early removal of catheters
Pain management without over-sedation
Sensory aids (glasses, hearing aids)
Sleep hygiene measures
Hydration and nutrition
Prevention of infection
Avoidance of physical restraints
Regular reorientation and reassurance
Use of low-risk medications.
Management
Initial Assessment:
Rapid assessment of airway, breathing, and circulation
Assess for reversible causes of delirium (e.g., hypoxia, hypoglycemia, electrolyte disturbances, infection, drug toxicity, withdrawal)
Rule out other acute neurological events (stroke, seizure).
Addressing Precipitants:
Treat underlying causes aggressively
Manage pain effectively with multimodal analgesia
Optimize fluid and electrolyte balance
Treat infections promptly
Correct hypoxia
Manage hypoglycemia
Discontinue or adjust offending medications.
Pharmacological Management:
Antipsychotics (e.g., haloperidol, olanzapine, quetiapine) are generally reserved for severe agitation or psychosis that poses a risk to the patient or staff
Use the lowest effective dose for the shortest duration
Avoid benzodiazepines in most cases, as they can worsen delirium (except in alcohol or benzodiazepine withdrawal).
Non Pharmacological Management:
Environmental modifications: quiet room, good lighting, familiar objects
Frequent reorientation and reassurance by staff
Family involvement and support
Promote sleep-wake cycles
Encourage early ambulation and physical therapy
Sensory stimulation
Avoid excessive noise and stimulation
Gradual reduction of monitoring equipment.
Complications
Associated Morbidity:
Increased risk of falls
Poor wound healing
Prolonged mechanical ventilation
Higher rates of deep vein thrombosis (DVT) and pulmonary embolism (PE)
Urinary tract infections (UTIs)
Pneumonia
Pressure ulcers
Longer length of stay
Higher readmission rates.
Long Term Sequelae:
Persistent cognitive impairment
Increased risk of developing dementia
Functional decline and loss of independence
Increased mortality
Negative impact on quality of life.
Prevention Strategies:
Adherence to comprehensive delirium prevention protocols
Multidisciplinary team approach involving physicians, nurses, therapists, and pharmacists
Patient and family education
Continuous quality improvement initiatives.
Key Points
Exam Focus:
Recognize POD as a common and serious complication
Know the risk factors (patient, surgical, postoperative)
Understand the diagnostic criteria (CAM)
Prioritize prevention strategies with the "ABCDE" bundle or similar protocols
Manage underlying causes first
judicious use of antipsychotics for agitation only.
Clinical Pearls:
The hypoactive subtype of delirium is often missed but carries a poor prognosis
Treat pain aggressively but monitor for over-sedation
Non-pharmacological measures are the cornerstone of management
Early mobilization is key
Consider delirium as a sign of underlying physiological distress.
Common Mistakes:
Attributing all confusion in elderly patients to dementia without considering acute causes
Over-reliance on antipsychotics without addressing underlying precipitants
Underestimating the importance of non-pharmacological interventions
Failure to implement comprehensive prevention protocols.