ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine: Infectious complications in regional anesthesia

Myron Yaster MD, Lynn Martin MD MBA, and David Polaner MD, FAAP

Today’s PAAD by Provenzano et al.1 is a must read for EVERY practicing anesthesiologist and pain management specialist. This encyclopedic review by a taskforce of the American Society of Regional Anesthesia and Pain Medicine (ASRA) provides evidence-based recommendations on risk mitigation of infectious complications associated with the practice of regional anesthesia and pain management. “The scope of these current recommendations extends beyond neuraxial blocks and includes various nerve blocks (peripheral and spinal), chronic pain procedures, and minimally invasive surgical techniques used in acute and chronic pain management.”1 This is the 3d PAAD we’ve posted on the recommendations from these guidelines. Today we will discuss infectious complications in regional anesthesia. Myron Yaster MD

Original article

Provenzano DA, Hanes M, Hunt C, Benzon HT, Grider JS, Cawcutt K, Doshi TL, Hayek S, Hoeltzer B, Johnson RL, Kalagara H, Kopp S, Loftus RW, Macfarlane AJR, Nagpal AS, Neuman SA, Pawa A, Pearson ACS, Pilitsis J, Sivanesan E, Sondekoppam RV, Van Zundert J, Narouze S. ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine. Reg Anesth Pain Med. 2025 Jan 20:rapm-2024-105651. doi: 10.1136/rapm-2024-105651. Epub ahead of print. PMID: 39837579

“Infectious complications broadly include insertion-site inflammation, localized abscesses, systemic infection, necrotizing fasciitis, or the devastating complication of CNS infections. Serious infectious complications following regional anesthesia are rare events, in that the probability of an event occurring in a small sample of patients typically employed in a clinical trial is low to none. Clinical trials and databases may not provide information on the factors linked to these rare events. Therefore, it is crucial to study the occurrence, causes, contributory factors, clinical features, diagnosis, and management in case reports or series.” Fortunately, in pediatrics we have the Pediatric regional anesthesia (PRAN) registry that has more than 100,000 blocks in its registry to help provide us with some pediatric specific guidance.2 In the PRAN registry the number of infections was was small. There was only one deep infection- an epidural abscess. This gives an incidence of 0.76:10,000 epidural catheters (CI 0 – 4.8:10,000). There were no deep infections reported with extra-neuraxial blocks, and no infections at all reported with single injection blocks of any type. PRAN employs a similar definition as in the RAPM guidelines, which, due to methodological difficulties, cannot distinguish between local cutaneous infections and non-infectious inflammation at the catheter insertion site. Like RAPM, PRAN employed a conservative approach, labeling all these infectious events even though many of them might not have been of infectious etiology. That only one third of the 92 PRAN cases received antibiotic therapy (as opposed to just catheter removal) reinforces this supposition. The incidence of cutaneous infections was about 2.5 times higher with neuraxial catheters compared with peripheral ones, although it is possible that this is also due in part to such caution and the potential consequences of a parameningeal infection. Catheters deemed infected were in place about twice as long as those not (a median of 2 versus 4 days), and the risk of infection (or inflammation) increased by 6.7% for each day beyond 2 postoperative days.

Catheter/Insertion-site colonization

Numerous studies evaluated the incidence of catheter-tip colonization with epidural and intrathecal catheters3 including one by Sabine Kost Byerly and colleagues4 who looked at the rate of caudal catheter colonization in pediatric patients. Colonization of catheter tips measured in colony forming units (CFUs) is a time-tested method used in all kinds of catheters like central lines and in spinal, epidural, and peripheral nerve catheters. In theory the higher the CFUs the greater risk and in most studies the colonization rate is between 4 and 50%. However, it is important to realize that although catheter colonization is common, local and systemic infections are rare. Tunneling catheters significantly reduces colonization rates and in my experience (MY) is particularly important when the catheter insertion site is dirty (think caudals) or if prolonged use is required.5,6

“Catheter infections can arise from bloodstream spread, drug infusion contamination, or pathogens entering through the catheter site, with the latter being the primary cause of most catheter-related infections.”1 Although very rare, infections of the central nervous system following epidural or spinal catheterization require immediate catheter removal and aggressive antibiotic and surgical treatment. The most common organisms colonizing PNB and epidural catheters are the Coagulase-negative staphylococci (CoNS), mainly S. epidermidis. The most common cause of infectious complications is S. aureus.

In summary: (quoted directly from the guidelines)1

· Catheter colonization is common and is directly related to the duration of catheterization, and a greater incidence of colonization may be seen with the use of catheters beyond 4 days. Level of certainty: moderate.

· PNBs have a greater incidence of catheter colonization compared with central neuraxial catheters. Level of certainty: moderate.

· The reported incidence of infection associated with percutaneous tunneled neuraxial catheters is approximately 10%. Level of certainty: moderate. (this appears to be applicable to long term catheters, not short term ones)

· With indwelling catheters, the probability of remaining infection-free decreases with time. Level of certainty: moderate.

· Implanting a subcutaneous port for neuraxial catheters decreases the risk of infection compared with percutaneous neuraxial catheters (again, applicable for long-term therapy, not postoperative catheters). Level of certainty: moderate.

· Spinal anesthesia is associated with fewer infectious complications compared with epidural anesthetic techniques. Level of certainty: moderate.

· Infections may occur with tunneled neuraxial catheters with likely lower rates in intrathecal compared with epidural catheters. Level of certainty: moderate.

· The duration of infusion may not be a determinant of the risk for infection, although the probability of remaining infection-free decreases with time. The risk of meningitis appears to be higher after the first 2 weeks of infusion with externalized (not internalized or tunneled) intrathecal catheters. Level of certainty: moderate.

Recommendations

· Consider limiting the duration of infusion in a percutaneous tunneled catheter and placing a subcutaneous port to minimize the risk of infection. Evidence: grade B.

· Prolonged use of regional nerve block catheters may increase the risk of infection. Extended use beyond 4–5 post-procedure days should be decided on the risk-to-benefit profile of continuing such therapies while carefully monitoring for any signs and symptoms of infection. Evidence: grade C.

· If using an externalized neuraxial catheter, prolonged use beyond 2 weeks should be avoided when possible to reduce the risk of meningitis. Evidence: grade B.

Do you use tunneled catheters for spinal or peripheral nerve blocks in your practice? Do you ever measure the rates of catheter colonization in your practice? Send your thoughts and comments to Myron who will post in a Friday reader response.

References

1. Provenzano DA, Hanes M, Hunt C, et al. ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine. Regional anesthesia and pain medicine 2025 (In eng). DOI: 10.1136/rapm-2024-105651.

2. Walker BJ, Long JB, Sathyamoorthy M, et al. Complications in Pediatric Regional Anesthesia: An Analysis of More than 100,000 Blocks from the Pediatric Regional Anesthesia Network. Anesthesiology 2018;129(4):721-732. (In eng). DOI: 10.1097/aln.0000000000002372.

3. Aveline C, Le Hetet H, Le Roux A, et al. Perineural ultrasound-guided catheter bacterial colonization: a prospective evaluation in 747 cases. Regional anesthesia and pain medicine 2011;36(6):579-84. (In eng). DOI: 10.1097/AAP.0b013e31822e665a.

4. Kost-Byerly S, Tobin JR, Greenberg RS, Billett C, Zahurak M, Yaster M. Bacterial colonization and infection rate of continuous epidural catheters in children. AnesthAnalg 1998;86(4):712-716.

5. Kost-Byerly S, Jackson EV, Yaster M, Kozlowski LJ, Mathews RI, Gearhart JP. Perioperative anesthetic and analgesic management of newborn bladder exstrophy repair. JPediatrUrol 2008;4(4):280-285.

6. Aram L, Krane EJ, Kozloski LJ, Yaster M. Tunneled epidural catheters for prolonged analgesia in pediatric patients. AnesthAnalg 2001;92(6):1432-1438.