When Are Catheters Used in Anesthesia? 

In the last two decades, continuous regional anesthesia (CRA) has emerged as a valuable tool for improving perioperative pain management and reducing morbidity and mortality in surgical patients [1,2]. Involving indwelling peripheral or epidural catheters that allow continuous access to the patient’s vein, CRA surpasses conventional opioid-based analgesia by providing superior pain relief while minimizing side effects like sedation, nausea, and pruritus [1,3]. CRA covers a large portion of cases in which catheters are used during anesthesia. 

This approach also offers flexibility in duration and block density compared to single injection nerve blocks, which is particularly beneficial in orthopedic surgery known for its painful procedures [3,4]. Following orthopedic surgery, where pain scores can persist for 2 to 3 days, single injection nerve blocks with a 24-hour analgesia duration necessitate concentrated local anesthetics, leading to dense motor and sensory effects [3]. In contrast, CRA allows prolonged analgesia with low volumes of dilute local anesthetic, ensuring flexibility without the need for potentially toxic doses [3]. Opting for low-density nerve blocks is preferred, providing excellent analgesia without the undesirable and potentially dangerous effects of dense motor and sensory blocks [3]. Indwelling catheters are used for such purposes, allowing more prolonged administration of anesthesia. For example, interscalene catheters offer superior analgesia with an initial injection of only 20 mL of 0.125% bupivacaine, a substantially lower dose than typically used for single-injection nerve blocks [3]. Demonstrating enhanced patient satisfaction and safety, CRA, with its infusions of dilute local anesthetic, proves to be a cost-effective and patient-friendly approach to pain management [3]. 

Recent literature underscores an increased risk of chronic opioid use in opioid-naive patients post-surgery, emphasizing the potential benefits of analgesic interventions in the postoperative period to mitigate this risk [4]. CRA has been shown to decrease the risk of chronic opioid use in this patient population [4]. Prospective randomized studies, such as one on continuous interscalene blocks after arthroscopic rotator cuff repair, have shown that CRA provides superior analgesia without increasing side effects, supporting its effectiveness up to 48 hours after major orthopedic surgery [4]. 

However, this beneficial approach has challenges, particularly concerning the risk of catheter-related infections, which can result in pain, heightened morbidity, and extended hospital stays [1]. Though catheters being used allows access for more controlled anesthesia over time, they also can allow access to the body for pathogens. The incidence of such infections varies depending on the catheter insertion site, with reported rates ranging from 0% to 7% for peripheral catheters and 0.8% to 4.9% for epidural catheters [1]. One 2018 study comprising 44,555 patients with continuous nerve blocks revealed an incidence of 2.9% for peripheral catheter-related infections and 3.9% for non-obstetric epidural catheter-related infections [1]. Prolonged catheter use, beginning on the fourth day after insertion, significantly increased the risk of catheter-related infection for both peripheral and epidural catheters [1]. Mild infection signs, such as redness, swelling, or local pain, were generally observed, likely because of daily catheter site inspections, with catheters promptly removed upon detecting signs of infection [1]. Catheters left in place with initial infections progressed to more severe stages, underscoring the need for daily catheter insertion site checks, given the rapid progression of symptoms, typically within 48 hours [1]. 

In conclusion, the utilization of catheters, particularly in the context of CRA, has become integral in modern perioperative care [1]. The multifaceted benefits of catheters, ranging from superior pain management and flexibility in duration to the potential for cost-effective approaches, make them a valuable tool in surgical settings, notably in orthopedic procedures [1]. However, the question of when catheters are used in anesthesia and elsewhere must be approached judiciously [2,3]. While their advantages are evident, the associated risk of catheter-related infections necessitates a meticulous balance between benefits and potential complications [2,3]. The decision to use catheters should be guided by a comprehensive understanding of the patient’s needs, the nature of the surgery, and a commitment to stringent infection prevention measures. 

References 

1. Bomberg, H., Bayer, I., Wagenpfeil, S. et al. (2018). Prolonged catheter use and infection in regional anesthesia: a retrospective registry analysis. Anesthesiology, 128(4), 764-773. 

2. Fredrickson, M. (2017). Promoting the use of peripheral nerve catheters: better catheter accuracy or more user‐friendliness?. Anaesthesia, 72(8), 939-943. 

3. Swenson, J., Cheng, G., Axelrod, D., & Davis, J. (2010). Ambulatory anesthesia and regional catheters: when and how. Anesthesiology Clinics, 28(2), 267-280. 

4. Capdevila, X., Iohom, G., Choquet, O., Delaney, P., & Apan, A. (2019). Catheter use in regional anesthesia: pros and cons. Minerva anestesiologica, 85(12), 1357-1364.