Complications of Regional Anesthesia: Don’t Touch the Needle Until You Know Them
David A. Burns MD
With the ever-growing number of older persons that need joint replacements and the never-ending orthopedic trauma of the entire population, the practice of regional anesthesia is a growing wave of the future. Regional anesthesia, however, is not without risks or complications. This chapter discusses these risks and and how to manage them.
Whenever the integrity of the integument is violated, the risk of introducing infection is present, and, when a foreign body (like a peripheral nerve catheter) is left in situ, that increases the risk by maintaining a conduit for skin flora to bypass the protective barriers of the skin. Further, the location of the regional technique is important as an epidural abscess or spinal meningitis can cause significant morbidity or mortality. Infection localized to the insertion site would contaminate the needle as it passes through, allowing direct access of the microorganisms to the nerve plexus. Finally, systemic infection or bacteremia can allow infection to be spread hematogenously to the foreign body.
Factors predisposing toward infection:
Sepsis or concurrent infection
Extended duration of use
Sterile technique not employed
Techniques for avoiding infection:
Sterile preparation of the site
Sterile occlusive dressings
Techniques for avoiding or limiting gross contamination:
Limit duration or tunnel the catheter (or both).
Avoid placement through sites of infection.
Administer a dose of antibiotics before placement of invasive lines or nerve-block catheters in patients with sepsis. Studies of placement of such lines and catheters have shown the risk of infection with bacteremia is reduced to baseline if administration of antibiotics has been started before placement. Therefore, you should carefully weigh the risks and benefits of the technique and make sure an appropriate antibiotic has been given at least 1 hour before the procedure.
Limit breaks in tubing for bag changes. Every time the integrity of the tubing system is violated by reservoir changes, contamination of the local anesthetic solution is possible-limit such opportunities for contamination.
Follow the patient daily and inspect the patient for signs of infection, including erythema, pus, tenderness at the site, and fever.
Treatments for infection:
If infection is suspected, remove the catheter. Usually such removal leads to avoidance or resolution of infection, unless the patient is immunocompromised.
Ensure that the patient is receiving appropriate antibiotics.
Continue to follow the patient’s case to ensure resolution of infection.
In the case of suspected epidural abscess, speed of diagnosis and treatment is of the essence to avoid permanent neurologic injury.
The anatomic locations where many peripheral nerves are blocked contain major blood vessels (for example, axillary, infraclavicular, supraclavicular, femoral, popliteal fossa, and sciatic). Many are deep locations at which applying direct pressure would be difficult or impossible (for example, epidural, spinal, classic paravertebral, infraclavicular, supraclavicular, lumbar plexus). Because the epidural space has an extensive venous plexus, bleeding can easily be caused by epidural or spinal anesthesia, inducing an expanding hematoma in a fixed and enclosed space that would cause spinal cord compression and paralysis.
Techniques for avoiding bleeding:
While placing the block, maintain continuous aspiration for blood.
If you are proficient in ultrasound techniques, use visualization of the vessels in real-time with the passage of the needle to avoid vascular puncture and to place the local anesthetic more precisely.
If anticoagulant drugs are being used before or during surgery (the incidence of such use has grown tremendously), understand the drugs being used, know their duration of effect, and closely monitor the patient during their use. In addition, know which anticoagulant drugs the patient received before surgery and which the patient is receiving
upon placement of the block and upon removal of the continuous catheter.
American Society of Regional Anesthesia (ASRA) guidelines for anticoagulants are followed for all neuraxial anesthetics and for placement of deep peripheral-nerve blocks at our institution (Table 99.1).
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