From the Guidelines
A peripheral nerve (PN) block catheter is a highly effective method for managing postoperative pain after knee surgery, with the most recent evidence suggesting its benefits in reducing opioid consumption and improving patient outcomes. The catheter is typically placed near the femoral nerve or as an adductor canal block by an anesthesiologist before or during surgery. Common medications used include ropivacaine (0.2%) or bupivacaine (0.125-0.25%), which are continuously infused at rates of 6-10 mL/hour for 2-3 days postoperatively 1.
Key Considerations
- The catheter connects to a small pump that can be programmed for continuous infusion with optional patient-controlled bolus doses (typically 5 mL every 30-60 minutes as needed).
- This approach works by temporarily blocking sodium channels in nerve membranes, preventing pain signal transmission to the brain.
- PN blocks provide superior pain control compared to opioids alone, reduce overall opioid consumption, allow earlier mobilization, and minimize side effects like nausea and respiratory depression.
- Patients should monitor the insertion site for signs of infection, ensure the pump is functioning properly, and understand that some muscle weakness may occur, particularly with femoral nerve blocks.
Recent Guidelines and Recommendations
The most recent guidelines from 2019 suggest that while perinervous catheters can be beneficial for postoperative pain management, their use should be carefully considered due to potential risks such as catheter mobilization and the impact on rehabilitation and early recovery after knee prosthetic surgery 1.
Clinical Decision Making
In clinical practice, the decision to use a PN block catheter should be based on individual patient needs and risk factors, with careful consideration of the potential benefits and risks. The evidence from the 2019 revision of expert panel's guidelines on postoperative pain management 1 should guide clinical decision-making, prioritizing the use of PN block catheters in patients who are likely to benefit from reduced opioid consumption and improved pain control.
From the FDA Drug Label
Indication: For use as a peripheral nerve block to provide regional postoperative analgesia following onychectomy in cats.
The FDA drug label does not answer the question.
From the Research
Mechanism of Peripheral Nerve Block Catheter
A peripheral nerve (PN) block catheter works by continuously delivering local anesthetic to the peripheral nerves, providing prolonged postoperative pain relief for patients undergoing knee surgery 2, 3. The catheter is typically inserted near the nerve under ultrasound guidance, and a continuous infusion of local anesthetic, such as ropivacaine, is administered through the catheter.
Types of Peripheral Nerve Blocks
There are different types of peripheral nerve blocks that can be used for postoperative pain control in knee surgery, including:
- Femoral nerve block: This block targets the femoral nerve, which provides sensation to the front of the thigh and knee 3, 4.
- Sciatic nerve block: This block targets the sciatic nerve, which provides sensation to the back of the thigh and knee 2, 4.
- Lumbar plexus block: This block targets the lumbar plexus, a group of nerves that provide sensation to the lower back and legs 2.
Efficacy of Peripheral Nerve Block Catheters
Studies have shown that peripheral nerve block catheters are effective in reducing postoperative pain and opioid consumption in patients undergoing knee surgery 3, 5, 4, 6. For example, a study found that patients who received a continuous femoral nerve block had lower pain scores and opioid consumption compared to those who received a periarticular injection with ropivacaine or liposomal bupivacaine 4.
Advantages of Peripheral Nerve Block Catheters
The advantages of peripheral nerve block catheters include:
- Reduced postoperative pain and opioid consumption 3, 5, 4, 6
- Improved patient satisfaction 6
- Reduced length of hospital stay 5
- Minimized risk of local anesthetic complications 2
Comparison with Other Pain Management Techniques
Peripheral nerve block catheters have been compared to other pain management techniques, such as periarticular injections and patient-controlled analgesia, and have been found to be effective in reducing postoperative pain and opioid consumption 3, 4. However, the choice of pain management technique ultimately depends on the individual patient's needs and medical history.