Can total knee replacement be performed without general anesthesia in patients with severe respiratory or cardiac disease, or those who are elderly or have significant comorbidities, such as diabetes or obesity?

Can Total Knee Replacement Be Done Without General Anesthesia?

Yes, total knee replacement can and should be performed without general anesthesia in most patients, including those with severe respiratory or cardiac disease, elderly patients, and those with significant comorbidities—neuraxial (spinal or epidural) anesthesia is the preferred technique and is associated with superior outcomes.

Primary Recommendation: Neuraxial Anesthesia is Preferred

The International Consensus on Anaesthesia-Related Outcomes After Surgery (ICAROS) group strongly recommends neuraxial anesthesia over general anesthesia for knee arthroplasty, based on multiple positive postoperative outcome benefits 1. This recommendation is supported by evidence showing:

• Reduced mortality in hip arthroplasty (OR: 0.83) 1
• Lower pulmonary complications (OR: 0.69) 1
• Decreased acute renal failure (OR: 0.73) 1
• Reduced deep venous thrombosis (OR: 0.77) 1
• Lower infection rates (OR: 0.80) 1
• Decreased blood transfusion requirements (OR: 0.84) 1

Specific Anesthetic Options Without General Anesthesia

Option 1: Spinal Anesthesia (Preferred)

Spinal anesthesia with local anesthetic plus morphine is recommended as a primary technique 1. Key considerations:

• Use lower doses of intrathecal bupivacaine (<10 mg) in elderly patients to reduce hypotension 1
• Add intrathecal fentanyl rather than morphine or diamorphine to minimize respiratory and cognitive depression 1
• Consider hyperbaric bupivacaine with lateral positioning (fractured side down) to reduce hypotension 1
• Provide supplemental oxygen during spinal anesthesia 1

Option 2: Epidural Anesthesia

While effective, epidural anesthesia may limit early mobilization and is less commonly used 1. Combined spinal-epidural provides excellent postoperative analgesia but shares this limitation 1.

Option 3: Regional Anesthesia with Femoral Nerve Block

General anesthesia combined with femoral nerve block can be used, but this still involves general anesthesia 1. For truly avoiding general anesthesia, neuraxial techniques are superior.

Evidence Supporting Neuraxial Over General Anesthesia

Large-Scale Registry Data

Analysis of 779,491 patients from the National Joint Registry showed regional anesthesia reduced 2:

• Length of stay by 0.47 days (p<0.001) 2
• Readmissions (OR: 0.91) 2
• Any complication (OR: 0.90) 2
• Urinary tract infections (OR: 0.87) 2
• Surgical site infections (OR: 0.84) 2

National Surgical Quality Improvement Program Data

In 14,052 primary TKA cases, spinal anesthesia demonstrated 3:

• Lower superficial wound infections (0.68% vs 0.92%, p=0.0003) 3
• Reduced blood transfusions (5.02% vs 6.07%, p=0.0086) 3
• Shorter operative time (96 vs 100 minutes, p<0.0001) 3
• Shorter hospital stay (3.45 vs 3.77 days, p<0.0001) 3
• Overall complication reduction (OR: 1.129 for general anesthesia) 3

The benefit was greatest in patients with multiple comorbidities (11.63% vs 15.28% complication rate, p=0.0152) 3.

Special Populations Where Neuraxial Anesthesia is Particularly Beneficial

Elderly Patients

The American Geriatrics Society recommends regional anesthesia to reduce postoperative delirium in older adults 1. Regional anesthesia was beneficial in reducing delirium incidence in knee replacement patients 1.

Patients with Cardiac Disease

Regional anesthesia is preferred for patients with cardiac disease undergoing orthopedic surgery 4, 5. The American Society of Anesthesiologists suggests regional anesthesia reduces sympathetic hyperactivity and may improve outcomes in patients with cardiac autonomic neuropathy 5.

Patients with Respiratory Disease

Neuraxial anesthesia avoids airway manipulation and mechanical ventilation, reducing pulmonary complications (OR: 0.69) 1.

Diabetic Patients

Regional anesthesia is preferred in diabetic patients as it reduces sympathetic hyperactivity, improves outcomes in those with cardiac autonomic neuropathy, and allows better postoperative pain control and early mobilization 5.

When Sedation is Needed with Neuraxial Anesthesia

Sedation may be provided cautiously during spinal anesthesia 1:

• Midazolam and propofol are commonly used 1
• Use lower doses in very elderly patients 1
• Ketamine may counteract hypotension but can cause postoperative confusion 1
• Patients with cognitive dysfunction may not tolerate regional anesthesia without heavy sedation, which negates benefits 1

Critical Caveats and Contraindications

Absolute Contraindications to Neuraxial Anesthesia

• Patient refusal 1
• Coagulopathy or therapeutic anticoagulation 1
• Infection at injection site 1
• Severe hypovolemia 1

Relative Contraindications

• Severe cognitive dysfunction requiring heavy sedation 1
• Severe spinal deformity 1
• Prior spinal surgery at intended level 1

Important Safety Considerations

Antithrombotic prophylaxis or therapy must be used with extreme caution in patients undergoing spinal puncture or epidural catheter placement 1. Complications of regional anesthesia (nerve injury, hematoma, intravascular injection, neurotoxicity, cardiac toxicity) are uncommon 1.

Postoperative Pain Management Algorithm

After neuraxial anesthesia, supplement with 1:

1. Paracetamol (acetaminophen) 1
2. Conventional NSAIDs or COX-2-selective inhibitors 1
3. Intravenous strong opioids for breakthrough high-intensity pain 1
4. Weak opioids for moderate- to low-intensity pain 1
5. Cooling and compression techniques 1

Optimize postoperative pain control, preferably with nonopioid medications, to prevent delirium 1.

Revision TKA Considerations

For revision TKA, regional anesthesia remains superior to general anesthesia 6, 7:

• Decreased unplanned readmission (OR: 1.43 for general) 6
• Reduced nonhome discharge (OR: 1.60 for general) 6
• Lower transfusion rates (OR: 1.63 for general) 6
• Decreased deep surgical site infection (OR: 1.43 for general) 6
• Shorter length of stay (OR: 1.22 for general) 6

Bottom Line for Clinical Practice

Neuraxial anesthesia should be considered the reference standard for patients undergoing total knee replacement 2. The Scottish Intercollegiate Guidelines Network states: "Spinal/epidural anaesthesia should be considered for all patients undergoing hip fracture repair, unless contraindicated" 1, and this principle extends to elective knee arthroplasty 1. The choice between spinal and general anesthesia is less important than how sympathetically the technique is administered 1, but when no contraindications exist, neuraxial anesthesia is preferred 1.