Does using bupivacaine during hip replacement lower the risk of postoperative cognitive dysfunction?
Postoperative cognitive dysfunction (POCD) is a decline in memory, concentration, and mental clarity that can occur after surgery, especially in older adults. For hip replacement, doctors have been looking for ways to lower this risk. One approach is using a nerve block with the local anesthetic bupivacaine before surgery. A 2026 study specifically tested whether a bupivacaine-based pericapsular nerve group (PENG) block could reduce POCD after total hip arthroplasty. The answer appears to be yes: the block significantly lowered the chance of POCD at 7 days after surgery.
What the research says
A 2026 prospective, randomized, double-blind study looked at 84 older patients undergoing total hip replacement under spinal anesthesia 9. Half received a PENG block with 20 mL of 0.25% bupivacaine before surgery, and the other half received a sham (fake) block 9. The study measured cognitive function using a telephone version of the Mini-Mental State Examination (T-MMSE) before surgery and again at 7, 30, and 90 days after 9.
At 7 days after surgery, the incidence of POCD was significantly lower in the bupivacaine group: 14.6% compared to 37.2% in the control group 9. This means the block reduced the relative risk of POCD by about 60% at that time point. The study also found that patients who received the bupivacaine block had lower pain scores and used less opioid medication in the first 24 hours after surgery 9. Better pain control and less opioid use may contribute to preserving cognitive function.
Other sources confirm that bupivacaine is a well-studied local anesthetic for pain relief after surgery, but they do not directly address POCD. For example, a meta-analysis of liposomal bupivacaine in brachial plexus blocks found it reduced pain scores at 24 hours 3, and another meta-analysis showed liposomal bupivacaine in TAP blocks modestly reduced opioid use and pain scores 5. However, these studies focused on pain outcomes, not cognitive function. The 2026 hip replacement study is the only source that directly links bupivacaine to lower POCD risk 9.
Broader research on POCD highlights that neuroinflammation and oxidative stress are key mechanisms 48. The bupivacaine block may help by reducing the surgical stress response and opioid requirements, which could in turn limit inflammation in the brain. However, the exact reason for the cognitive benefit is not yet fully understood.
What to ask your doctor
- Would a PENG block with bupivacaine be appropriate for my hip replacement surgery?
- What are the potential risks or side effects of a PENG block compared to standard pain management?
- How does this block affect my recovery time and ability to start moving after surgery?
- If I have other health conditions, could a bupivacaine nerve block still be safe for me?
- Are there other anesthetic options that might also help protect cognitive function after surgery?
This question is drawn from common patient questions about Anesthesiology & Pain Medicine and answered using cited medical research. We do not provide individualized advice.