What strategies can be used to decrease post-operative delirium in an elderly patient undergoing general anesthesia?

Strategies to Decrease Postoperative Delirium in Elderly Patients Undergoing General Anesthesia

Implement multicomponent nonpharmacologic interventions as first-line prevention, use processed EEG monitoring to avoid deep anesthesia, optimize pain control with nonopioid analgesics, and consider regional anesthesia when feasible—these evidence-based strategies can reduce postoperative delirium incidence by up to 40%. 1

Intraoperative Anesthetic Management

Depth of Anesthesia Monitoring

• Use processed EEG monitors (such as BIS) during general anesthesia to maintain lighter anesthetic depth and avoid excessive sedation, as deeper anesthesia levels are associated with increased delirium rates. 2, 3
• Target BIS values that prevent awareness while avoiding unnecessarily deep anesthesia, particularly in patients aged 75 years and older. 2
• Deeper levels of sedation with propofol have been associated with increased rates of postoperative delirium in hip fracture patients. 2

Anesthetic Agent Selection

• Consider total intravenous anesthesia (TIVA) over volatile anesthetics in elderly patients, especially those 75 years and older, as volatile anesthetics increase delirium risk 1.8-fold compared to TIVA. 4
• In patients 87 years or older, volatile anesthetics increase delirium risk 6.2-fold compared to intravenous techniques. 4
• The risk increases further (3.0-fold) with unplanned surgery when volatile anesthetics are used. 4

Regional Anesthesia Consideration

• Regional anesthesia should be considered when feasible for lower extremity orthopedic operations, as it reduces postoperative delirium incidence compared to general anesthesia. 2
• Regional nerve blocks (such as fascia iliaca blocks for hip surgery) can reduce delirium incidence while providing superior postoperative pain control. 5
• However, the evidence shows no significant difference in delirium incidence between general and regional anesthesia in some studies of hip surgery patients. 6

Multicomponent Nonpharmacologic Interventions

Core Prevention Strategies

• Implement the following evidence-based interventions starting preoperatively and continuing through the postoperative period: 1, 5

  • Frequent reorientation to time, place, and person using calm tones and simple commands
  • Early mobilization to prevent complications of bed rest
  • Ensuring adequate hydration and nutrition
  • Promoting normal sleep-wake cycles by reducing nighttime disruptions and noise
  • Ensuring sensory aids (glasses, hearing aids) are available and functional immediately postoperatively

• High-quality perioperative care with multicomponent interventions can reduce delirium incidence by up to 40%. 5, 3

Pain Management Optimization

Nonopioid-First Approach

• Start acetaminophen (paracetamol) immediately as first-line therapy for postoperative pain, as inadequate pain control increases delirium risk 9-fold. 2, 5
• Use multimodal analgesia combining acetaminophen, NSAIDs (celecoxib, ibuprofen), and gabapentin to minimize opioid requirements. 2
• One prospective study of 220 older patients using standardized multimodal analgesia (paracetamol, gabapentin, tramadol, celecoxib, ibuprofen) found zero cases of postoperative delirium. 2

Opioid Minimization

• Titrate opioids to the minimal effective dose when necessary, as excessive opioid use may contribute to delirium. 5
• However, undertreating pain directly causes delirium, so adequate analgesia must be ensured. 5

Ketamine Considerations

• Do not use prophylactic ketamine to prevent postoperative delirium, as the large PODCAST trial found no benefit and increased hallucinations and nightmares. 2
• In 672 patients over 60 years undergoing major surgery, neither low-dose (0.5mg/kg) nor high-dose (1.0mg/kg) ketamine reduced delirium incidence compared to placebo (19.45% vs 19.82%, p=0.92). 2
• Ketamine groups experienced significantly more hallucinations (20-28% vs 18%, p=0.01) and nightmares (12-15% vs 8%, p=0.03). 2

Medications to Avoid

High-Risk Medications

• Avoid benzodiazepines, anticholinergics, meperidine, and sedative-hypnotics perioperatively, as these medications precipitate delirium. 1, 5
• Benzodiazepines should not be used as first-line treatment for postoperative agitation, as they increase delirium incidence and duration. 1
• Anticholinergic medications (diphenhydramine, oxybutynin, cyclobenzaprine) worsen agitation and cognitive function. 5

Prophylactic Medications NOT Recommended

• Do not prescribe cholinesterase inhibitors to prevent postoperative delirium, as they provide no benefit. 1
• Gabapentin alone (despite reducing opioid consumption) did not reduce delirium incidence in one trial (24% vs 20.8%, p=0.30). 2

Postoperative Monitoring and Management

Delirium Screening

• Use validated screening tools (4AT or Confusion Assessment Method) twice daily until postoperative day 5 or discharge. 5
• Recovery room delirium strongly predicts ongoing postoperative delirium and requires immediate intervention. 5

Management of Established Delirium

• Perform thorough medical evaluation to identify and treat underlying causes (infection, hypoxia, urinary retention, constipation, dehydration, metabolic disturbances) as the first step. 1
• Continue multicomponent nonpharmacologic interventions as primary treatment. 1
• For severely agitated patients posing risk of harm, antipsychotics may be considered at the lowest effective dose for the shortest duration. 1

Common Pitfalls to Avoid

• Never use physical restraints, as they exacerbate delirium and worsen outcomes. 5
• Do not continue antipsychotics beyond the acute period if they were started for severe agitation. 5
• Avoid repeating neuroimaging unless new focal neurological findings develop. 5
• Do not undertreat pain in cognitively impaired patients—use observational pain scales (PAINAD, BPS) for assessment. 5