Authors: Shah D et al.
Cureus, June 11, 2026.
Summary
This case report describes the successful use of four ultrasound-guided peripheral nerve blocks as the sole anesthetic for staged bilateral above-knee amputations in a 79-year-old man with severe cardiopulmonary and multisystem disease.
The patient had chronic limb-threatening ischemia and an exceptionally high-risk medical profile, including:
• Ejection fraction of 25%
• Severe aortic stenosis not suitable for transcatheter valve replacement
• Severe pulmonary hypertension
• Coronary artery disease with previous bypass surgery
• Atrial fibrillation
• Chronic obstructive pulmonary disease requiring home oxygen
• End-stage renal disease on hemodialysis
• Cirrhosis with refractory ascites
• Chronic hypotension requiring midodrine
• Immune thrombocytopenic purpura with platelet counts around 60,000-69,000/µL
• Type 2 diabetes
General anesthesia was considered prohibitively risky because of the patient’s severe cardiac and pulmonary disease. Neuraxial anesthesia was also considered unsuitable because of thrombocytopenia, severe aortic stenosis, and the risk of profound hypotension from sympathetic blockade.
For the left above-knee amputation, the anesthesia team performed ultrasound-guided blocks of four nerves:
• Sciatic nerve
• Femoral nerve
• Obturator nerve
• Lateral femoral cutaneous nerve
The blocks were performed with 0.5% ropivacaine. Complete sensory and motor blockade was confirmed after approximately 45 minutes. The patient received only 2 mg of intravenous midazolam for anxiolysis.
The operation was completed without general anesthesia, neuraxial anesthesia, intraoperative opioids, respiratory complications, or anesthetic-related hemodynamic deterioration. The patient’s blood pressure remained low but consistent with his baseline. Only 100 mL of crystalloid was administered.
His postoperative pain score was 0. The blocks were repeated on postoperative day 1 to help manage pain and possible phantom limb symptoms, further limiting opioid requirements.
Three weeks later, the same four-nerve technique was used for the right above-knee amputation. The patient was already severely hypotensive following removal of 6 L of ascitic fluid the previous day, but the limb ischemia required urgent treatment.
The second operation was again performed using the four peripheral nerve blocks with 0.5% ropivacaine and only 1 mg of midazolam. No intraoperative opioids were given, and the approximately 40-minute operation was completed successfully.
The patient later deteriorated because of progressive multiorgan failure, severe biventricular cardiac failure, persistent hypotension, and inability to continue dialysis. He died on postoperative day 6 after transitioning to comfort-focused care. The authors concluded that neither the anesthetic technique nor the surgery caused his deterioration.
The report emphasizes the importance of blocking the obturator nerve. This nerve supplies sensation to the medial thigh and motor innervation to the adductor muscles. Omitting it may result in pain, involuntary leg movement, and the need for systemic anesthetic supplementation.
What You Should Know
A complete four-nerve peripheral block can provide surgical anesthesia for an above-knee amputation without general or neuraxial anesthesia.
The required nerves are the sciatic, femoral, obturator, and lateral femoral cutaneous nerves.
Peripheral nerve blocks may be particularly valuable in patients with severe cardiac disease, pulmonary disease, coagulopathy, anticoagulation, or profound baseline hypotension.
The obturator nerve should not be omitted because its sensory and motor distribution involves the surgical field.
Ropivacaine was selected partly because it has a more favorable cardiac safety profile than bupivacaine.
Both amputations were completed without anesthetic-related hemodynamic collapse, respiratory complications, or intraoperative opioid administration.
Single-injection blocks eventually wear off. Perineural catheters may provide more prolonged postoperative analgesia in similar patients.
The patient’s later death was attributed to advanced multiorgan and cardiopulmonary failure rather than an anesthetic or surgical complication.
This was a single case report, so it cannot establish that peripheral nerve blocks are superior to general or neuraxial anesthesia for all amputations.
The findings support considering the four-nerve technique early in the planning process for exceptionally high-risk patients rather than reserving it only as a last resort.
Thank you to Cureus for allowing us to summarize this article.