Count on Continuous Nerve Blocks

The effects of single-shot nerve blocks and oral analgesics wear off soon after patients arrive home, leaving them in a significant amount of discomfort. Continuous nerve blocks (CNBs) and infusion pumps can extend your pain management efforts beyond your walls, keeping patients comfortable during the first few days of recovery.

Patients who take opioids to manage chronic pain disorders are ideal candidates for CNBs because the effects of opioids are blunted in these individuals, according to Roman Margulis, MD, an assistant site director at Montefiore Health’s Joint Replacement Center in the Bronx, N.Y. “CNBs also work well for patients with respiratory issues, and other worrisome comorbidities such as high BMIs and pulmonary issues — indications the patient won’t tolerate opioids well,” he says.

Continuous catheter designs have progressed over the years, making them more appropriate to send home with patients. While some physicians once had concerns about using the systems due to potential kinking, leaking, clogging or pump failure, the delivery systems today are made of more resilient materials that are not as prone to those issues as they were in the past.

• Better pumps. Elastomeric pumps are simple devices that are easy for patients to use. Some models feature patient-controlled medication boluses for managing breakthrough pain. More advanced electronic pumps provide better control of medication delivery rates and have the ability to automatically administer pre-programmed intermittent boluses. Some pumps can also be programmed to give the patients the ability to self-administer boluses within pre-set parameters.

“While an elastomeric pump delivers a consistent, moderate amount of analgesia, some experts believe electronic pumps offer better, more controlled pain control because the medicine fills the incision space when you want it to instead of continuously running at a higher volume,” says Emily Winchester, RN, a block nurse at the San Francisco (Calif.) Surgery Center.

Electronic pumps have integrated sensors that detect if medication delivery is interrupted and alarms that alert the patient to the malfunction. With elastomeric pumps, unresolved pain is often the first indication that the local anesthetic isn’t being delivered consistently.

• Precise placement. Most blocks are now placed with ultrasound guidance, making placement easier and more precise. Anesthesia providers can see exactly where nerve bundles are located, and place catheters to deliver local anesthetic precisely around the bundles where it will provide the most benefit.

Emerging catheter and needle systems make the placement of nerve blocks even more exact. “Echogenic needles are more reflective than traditional ones,” says Dr. Margulis. “They show up clearer on ultrasound displays, making it easier to place the catheter in the correct location.”

Catheter-over-needle systems, which allow for a more efficient single-step block placement, can also be used instead of the more traditional catheter-through technology, according to Ms. Winchester.

“Some doctors prefer them because they more closely mimic the ease of placing single-shot blocks,” she says. “Other physicians say catheter-over-needle systems make it harder to get the catheter to stay where it’s placed.”

• Dedicated rooms and block nurses. Placing blocks in procedure rooms decreases patient time in the OR and improves a facility’s workflow, as the blocks can be performed while the operating room is being turned over from the previous case.

Block rooms should be outfitted with the equipment and supplies needed to place blocks, including monitoring equipment, a nerve stimulator, needles, local anesthetics and infusion pumps.

Complications can occur when you send patients home with indwelling catheters and pain pumps. The catheter can kink or clog and the pump can malfunction, meaning the patient won’t get the analgesic needed to prevent breakthrough pain. The other, more serious complications to watch for are infection, bleeding, migration of the catheter and the catheter getting ripped or torn with a residual piece remaining inside the patient. These are all potential and worrisome possibilities.

“Call patients at home — several times a day if necessary — to ensure the pain pump is working as intended, the patient’s pain is adequately controlled and to answer any questions they might have,” says Dr. Margulis.

During the calls, ask patients about these potential problems:

• Pump/catheter issues. If patients continue to experience excessive pain or the pain pump isn’t emptying at a steady rate, the pump could be malfunctioning, an obstruction could be preventing the medication from reaching the patient or the anesthetic could be slowly leaking from the catheter.

Ms. Winchester says most at-home issues occur when the section of the catheter that sits outside the body bends as the patient moves and the dressing shifts. The part of the catheter that’s under the skin isn’t truly kinked or clogged. “If this happens,” she says, “nurses can instruct patients on how to troubleshoot the problem.”

If, however, the catheter does become clogged or kinked, the patient will have to see a doctor or a nurse to have it removed and replaced. Depending on the comfort level of patients, they could remove catheters themselves before seeing a healthcare provider.

It’s a fairly straightforward process. Patients should carefully remove the dressing and tape, so as to not tug on the catheter. They should then hold the catheter at its base, near the entry point, and slowly remove it. Patients need to make sure the tip of the catheter comes out intact — holding and pulling the medication delivery tube away from the entry point during the removal process could cause the catheter to break. They should also check to make sure there’s no swelling or redness at the insertion site. Minor bleeding isn’t uncommon after removal and can be stopped with a small bandage.

• Toxicity. Ms. Winchester says patients should know to look for the signs and symptoms of local anesthetic systemic toxicity (LAST). Although rare, LAST can occur if the large amounts of the local anesthetic reaches the bloodstream or surrounding tissue.

LAST increases risk of cardiac complications and can cause seizures. Red flags include ringing in the ears and tingling throughout the blocked extremity. “If a patient reports any of these symptoms, they should clamp the catheter on an elastomeric pump or turn an electronic pump off, and immediately go to an emergency room for care,” says Ms. Winchester.

• Infection. Infection rates associated with continuous catheters are very low, says Ms. Winchester. Indications of infection include fever, red or warm-to-the-touch skin at the insertion site, or a foul-smelling discharge present where the catheter is placed. Patients who suspect the incision site is infected should contact a healthcare provider, remove the catheter and seek follow-up care.

“You have to explain to patients very carefully in a short period of time how the system they’ll be going home with will work, how to monitor the catheter placement, when it’s supposed to come out and what to look for while it’s still inside them,” says Dr. Margulis. “I’ve therefore found that continuous catheters are most effective for patients who are active participants in their own care and able to follow detailed discharge instructions, and who have a support structure in place at home.”

Choosing to place CNBs should ultimately be done on a case-by-case basis. Don’t let concerns about managing the blocks from afar prevent your patients from experiencing the benefits of longer-lasting pain relief that CNBs provide. With proper oversight and planning, the analgesic benefits far outweigh the potential patient safety risks. OSM