The Case for Continuous Nerve Blocks

Pain Management

By: Nadia Hernandez

Published: 11/6/2020

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New technology and advancing techniques could make extended pain relief the norm in same-day surgery.


The use of continuous nerve blocks to manage post-op pain provides many benefits. Patients require fewer opioids, which lowers their risk of opioid misuse and eliminates prolonged PACU stays caused by opioid-related side effects such as nausea, vomiting, urinary retention and sedation. They leave your facility sooner and feeling good, which increases their overall level of satisfaction with the care you provided and pleases surgeons who appreciate answering fewer calls from distressed patients in pain.

My anesthesia group performs 10 times as many blocks at the Texas Medical Center's trauma center than we did when I became director of regional anesthesia five years ago. Our anesthesia group also works at the ambulatory surgery center across the street, and we just began a study there to compare the cost of using blocks as a primary anesthetic in place of general anesthesia. We think the study will show what we already suspect: Regional anesthesia is significantly less expensive — and just as safe.

To manage post-op pain, our team administers single-shot blocks with the option of extending the analgesia with a catheter attached to a pain pump or a local injection of extended-release bupivacaine — a long-acting, non-opioid medication. Single-shot blocks with bupivacaine and some sort of additive such as dexamethasone or clonidine provide adequate analgesia for 24 hours after the surgery, with the pain quickly tapering off after that. After the first post-op day, patients transition to whatever medication surgeons decide is necessary — acetaminophen, ibuprofen or celecoxib, for example — and an opioid to control break-through pain as needed.

Total joint replacement patients are ideal candidates for prolonged block durations because significant post-op pain can last for many days. In fact, single-shot blocks for these cases are actually counter-productive because the patient will feel great for 24 hours, then experience "rebound analgesia," during which they go into a pain crisis. Catheter placements are appropriate for outpatient total joints, as is the use of bupivacaine.

A nerve block is an effective alternative to general anesthesia for hand surgeries. Instead of injecting a dilute formulation of bupivacaine or ropivacaine in pre-op, the anesthesia provider doubles the concentration to eliminate feeling and movement in the arm. Light sedation can be administered to improve patient comfort.

Rapid evolution

ON POINT Ultrasound guidance has increased the number of available nerve blocks, which can serve as the primary anesthetic for procedures — not just a tool to reduce post-op pain — and could be less expensive to administer than general anesthesia.

There are several factors that are allowing anesthesia providers to deliver more effective and longer-lasting blocks that keep patients comfortable for days after discharge.

  • New options. The number of blocks available to perform have grown dramatically in recent years. Only 15 or 20 years ago, an anesthesia provider's choices were limited to femoral, interscalene, tap, supraclavicular and infraclavicular blocks. Since then, ultrasound-guided regional anesthesia has opened the door to a variety of possibilities. A distal femoral triangle block, for example, is very similar to a femoral block, but targets branches of the femoral nerve to provide better pain relief after knee surgery.

There are now numerous blocks that are more targeted to single nerves throughout the body. Truncal blocks have particularly exploded in popularity. Epidurals and tap blocks are approximately 15 additional blocks that control abdominal pain.

A patient who had a thoracic epidural placed 15 years ago could not have been sent home the day of surgery because they had to be monitored for hypotension or hematomas. Anesthesia providers can now place a fascial plane block and safely discharge patients after surgery. The anesthetic used with the fascial plane block isn't as strong as an epidural, but it provides more than adequate analgesia for many procedures.

  • Advanced pain pumps. Catheter-placed pain pumps are our best option for prolonged analgesia for patients who have undergone outpatient surgery. Elastomeric pumps deliver consistent, moderate amounts of analgesia, while electronic pumps can provide more targeted and controlled pain control. Some electronic pumps allow the provider to administer pre-programmed intermittent boluses, while others allow for patient-controlled boluses. These allow the medicine to fill into the incision space as needed instead of continuously running the anesthetic at a higher volume. Many electronic pumps feature integrated sensors to detect interruptions in medication delivery and alarms to alert the patient of malfunctions.

Limitations with continuous nerve blocks include the volume in the pain pump's reservoir. If you give a patient 400ccs of local and send them home with a pump that dispenses at 10ccs per hour, patients receive 40 hours of pain relief before the catheter must be removed. Newer pumps allow you to refill the reservoir, but the literature surrounding how long it's safe to leave peripheral nerve or fascial plane catheters in place is scant. How long continuous blocks stay in is based on anesthesiologists' comfort level and institutional culture.

  • Better imaging. Handheld ultrasound devices don't replace larger ultrasound machines, but are well suited for bread-and-butter blocks, as well as for serving as a backup to your main unit. Some handheld devices feature pixel electronics and require different probes for different functions. Cost can be a limiting factor, as the machine runs about $60,000 and each probe costs roughly $15,000. Most blocks, however, can be performed with a single linear probe. Other handheld devices use semi-conductor technology instead of pixel electronics, work very well and are a game-changer because of their cost — only $2,000. The image isn't quite as good as more expensive models, but is adequate for many applications. Some models come with needle-identification technology that can help new practitioners safely place a block or help with placement in a patient with a large body habitus.

Untapped potential

One reason nerve blocks aren't used as often as they should be is many experienced anesthesia providers were trained to use nerve stimulation blocks and don't see the advantage of using ultrasound. Lack of training in regional anesthesia will result in inconsistent outcomes —and surgeons don't like inconsistencies. Some anesthesia providers think they can perform nerve blocks without additional training or after taking the equivalent of a weekend course, which isn't the case.

The first step toward incorporating or increasing the use of nerve blocks in your facility is to hire a provider with experience in administering regional anesthesia with the intention of teaching the rest of the anesthesia team how to do it. Investing in someone who performs successful blocks all the time is the best way to safely transition to performing more blocks and achieve more consistent results.

If you plan on sending patients home with continuous nerve blocks in place, assign a group of nurses to provide a 24/7 phone presence. Someone needs to answer the phone if a patient is having a complication such as infection or bleeding, the pump has failed or if there's kinking, leaking, or clogging. Catheters can also migrate, or a part of them could remain inside the patient if the tubing rips or tears.

I also suggest incorporating Enhanced Recovery After Surgery (ERAS) protocols into the care plan of every procedure you perform, and making blocks part of those protocols. Work with your surgeons' groups to get them onboard with the use of regional anesthesia. Discuss which anesthetics will be given and the best blocks for their particular patient populations. These protocols will be instrumental in increasing your use of nerve blocks because they eliminate having to sell surgeons and patients on the idea — you simply implement the protocols that everyone has agreed to follow.

Increasing your facility's use of regional anesthesia will help patients go home quickly, safely and in less pain — that's always a positive first step on their road to recovery. OSM

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