Continuous Peripheral Nerve Block Catheters Research Articles

Percutaneously Inserted Continuous Peripheral Nerve Block Catheter as a Novel Minimal Invasive Treatment of Abdominal Cutaneous Nerve Entrapment Syndrome (ACNES): A Pilot Study to Assess Efficacy of This Novel Treatment

Percutaneously Inserted Continuous Peripheral Nerve Block Catheter as a Novel Minimal Invasive Treatment of Abdominal Cutaneous Nerve Entrapment Syndrome (ACNES): A Pilot Study to Assess Efficacy of This Novel Treatment

Perioperative pain management in COVID-19 patients: Considerations and recommendations by the Saudi Anesthesia Society (SAS) and Saudi Society of Pain Medicine (SSPM).

The COVID-19 pandemic has swept across the world over the past few months. Many articles have been published on the safety of anesthetic medications and procedures used in COVID-19 positive patients presenting for surgery. Several other articles covered the chronic pain management aspect during the pandemic. Our review aimed to focus on perioperative pain management for COVID-19 patients. We conducted a literature search for pertinent recent articles that cover considerations and recommendations concerning perioperative pain management in COVID-19 patients. We also searched the literature for the relevant adverse effects of the commonly used medications in the treatment of COVID-19, and their potential drug–drug interactions with the common medications used in perioperative pain management. Professional societies recommend prioritizing regional anesthesia techniques, which have many benefits over other perioperative pain management options. When neuraxial and continuous peripheral nerve block catheters are not an option, patient-controlled analgesia (PCA) should be considered if applicable. Many of the medications used for the treatment of COVID-19 and its symptoms can interfere with the metabolism of medications used in perioperative pain management. We formulated an up-to-date guide for anesthesia providers to help them manage perioperative pain in COVID-19 patients presenting for surgery.

Considerations for Takayasu Arteritis Undergoing General Anesthesia in a Resource-Limited Setting: Case Report and Literature Review

The use of continuous peripheral nerve block catheters (CPNB) is widespread for the control of intraoperative and postoperative pain with the benefits espoused in the literature; CPNB catheters provide effective pain control in the perioperative period which may facilitate earlier discharge, improve postoperative rehabilitation, improve patient satisfaction, and decrease the use of opioids postoperatively6.

Team Approach: Multimodal Perioperative Pain Management in Upper-Extremity Surgery: Combating the Opioid Epidemic.

* Rates of opioid use and abuse continue to rise in the United States, as do opioid-related deaths. Many patients who misuse opioids receive their first exposure in the perioperative setting.* Postoperative opioid use reduction in patients who have undergone an upper-extremity procedure can be difficult secondary to the often-painful nature of orthopaedic procedures. Postoperative pain can prevent timely discharge from hospitals and is a major cause for emergency medicine visits following outpatient upper-extremity surgical procedures.* Utilization of a multidisciplinary, multimodal, home-going continuous peripheral nerve block catheter protocol may be able to comfortably allow patients to recover in an outpatient setting after an upper-extremity surgical procedure, with a diminished opioid requirement.

Six Month Follow-Up of a Patient With a Retained Fascia Iliaca Catheter: A Case Report.

Retained catheters are a rare but known complication of continuous peripheral nerve block. To date there have been several case reports of retained catheters but none that include longer-term follow-up of the patient experience and outcomes. Here, we present the case of a retained fascia iliaca catheter used for analgesia after total hip arthroplasty that fractured during removal and was ultimately never retrieved. The patient initially experienced paresthesias emanating from the site of continuous peripheral nerve block catheter placement, but these issues resolved completely over several weeks. No infectious or serious sequelae were encountered during 6 months of follow-up.

A comparison of strength for two continuous peripheral nerve block catheter dressings.

BackgroundDespite the benefits of continuous peripheral nerve blocks, catheter dislodgment remains a major problem, especially in the ambulatory setting. However, catheter dressing techniques to prevent such dislodgment have not been studied rigorously. We designed this simulation study to test the strength of two commercially available catheter dressings.MethodsUsing a cadaver model, we randomly assigned 20 trials to one of two dressing techniques applied to the lateral thigh: 1) clear adhesive dressing alone, or 2) clear adhesive dressing with an anchoring device. Using a digital luggage scale attached to a loop secured by the dressing, the same investigator applied steadily increasing force with a downward trajectory towards the floor until the dressing was removed or otherwise disrupted.ResultsThe weight, measured (median [10th–90th percentile]) at the time of dressing disruption or removal, was 1.5 kg (1.3–1.8 kg) with no anchoring device versus 4.9 kg (3.7–6.5 kg) when the dressing included an anchoring device (P < 0.001).ConclusionsBased on this simulation study, using an anchoring device may help prevent perineural catheter dislodgement and therefore premature disruption of continuous nerve block analgesia.

New Techniques in Pediatric Pain Management: Continuous Peripheral Nerve Block

OPTIMUM PERI-OPERATIVE pain management in children requires significant communication and coordination among the patient, the family, and the health care team. A plan that permits adequate pain control after major orthopedic surgery permits pediatric patients to recover sooner and provides for a shorter length of hospitalization. Advances in pain management through the use of a continuous peripheral nerve block (CPNB), provides children with regional anesthesia that creates sensory numbness in the extremity while at the same allowing for motor control (Moos, 2011). This column will review indications for CPNB in the pediatric population and the nursing implications for caring for children in the post-operative period. A CPNBwith continuous or intermittent analgesia and a local anesthetic, such as Ropivacaine, provides exceptional localized pain control and minimizes the need for systemic opioids (Polomano, Rathmell, Krenzischek, & Dunwood, 2008). Compared to a single injection of local anesthetic that provides for only 12–16 hours of pain control, infusions through a CPNB catheter extends the length of post-operative analgesia with minimal side effects (Gurnaney et al., 2014; Polomano et al., 2008). CPNB catheters, inserted through the guidance of ultrasound, can be used for numerous types of surgery with

Effects of Postoperative Continuous Femoral Nerve Block Analgesia with Braun Continuous Peripheral Nerve Block Catheter Set versus Novel Needle-Over-Cannula after Total Knee Arthroplasty.

BackgroundThe aim of this study was to compare the novel needle-over-cannula vs. the Braun continuous peripheral nerve block catheter set (Contiplex A) in postoperative analgesics after total knee arthroplasty (TKA).Material/MethodsSixty patients undergoing total knee arthroplasty were randomly assigned to Braun continuous peripheral nerve block catheter set group (Braun Group, n=30) or the novel needle-over-cannula group (Cannula Group, n=30). All the patients in the 2 groups received continuous femoral nerve block (CFNB) for postoperative analgesics.ResultsWe found no significant difference in analgesic effect between the 2 groups. The time of catheter or cannula insertion was shorter in the Cannula Group than in the Braun Group. Four (13.32%) out of 30 patients had failed catheter insertions in the Braun Group compared to none in the Cannula Group. Twelve (46%) out of 26 patients in the Braun Group had serious local anesthetic leakage at puncture sites during 12 h compared to none in the Cannula Group.ConclusionsThe novel needle-over-cannula is effective, convenient, and safe in CFNB after TKA.

Serum Free Ropivacaine Concentrations Among Patients Receiving Continuous Peripheral Nerve Block Catheters

Serum Free Ropivacaine Concentrations Among Patients Receiving Continuous Peripheral Nerve Block Catheters

Serum Free Ropivacaine Concentrations Among Patients Receiving Continuous Peripheral Nerve Block Catheters

Ropivacaine is a long-acting local anesthetic used for continuous peripheral nerve catheter infusions. Catheters may remain in situ for prolonged time periods. In the present study, patients were enrolled to receive continuous peripheral nerve catheters with measurement of free serum ropivacaine concentrations. Peripheral nerve catheters were placed for postoperative pain management in trauma patients and infused with ropivacaine 0.2% or bolused with 0.5%. Blood samples were obtained from each subject on days 0 (preinfusion), 3, 5, 7, 10, and every third day until catheter removal. Serum free ropivacaine concentrations were measured via high-performance liquid chromatography and were compared using the Wilcoxon signed rank test. One hundred thirty-three blood samples were analyzed in 35 patients; all serum free ropivacaine concentrations after infusion initiation (99 samples from 35 subjects) were below 0.34 mg/L (previously determined toxic threshold). The highest concentration achieved in a blood sample was 0.19 mg/L; all other values were <0.09 mg/L. The total amount of drug received during the study ranged from 1146 to 22,320 mg (median of 3722 mg). Catheters remained in situ for a median of 7 days (range: 3-23). From day 0 to 3 (preinfusion), 77% of the study participants had an increase in the serum free-fraction ropivacaine concentrations. The median concentration on day 3 was 0.025 mg/L (95% upper confidence limit for mean: 0.05, range: <0.01-0.19); P < 0.001 compared with preinfusion levels). From day 3 to 5, 68% of the participants had a decrease in the serum free ropivacaine concentrations (median level 0.016 mg/L [95% upper confidence limit for mean: 0.021] P = 0.007 for day 5 compared with day 3). In this study, free serum ropivacaine concentrations remained well below toxic values despite large amounts of drug administration in combat-wounded patients. The administration of continuous ropivacaine infusions over prolonged time periods, coupled with multiple drug boluses, did not produce toxic or near-toxic serum concentrations.

Fluoroscopy Study of Peripheral Nerve Block Catheter Tip Movement?Its Clinical Implication in Guiding Catheter Adjustment

Background: Continuous peripheral nerve block catheter has been widely used clinically.A small percentage of catheters usually need adjustment after placement.However, there is no study on how to adjust catheter in the literature. Methods: Twelve fresh pork legs were randomly allocated into one of two groups, perineural catheter advanced 5 cm or less beyond needle tip (N=6), or more than 5 cm beyond needle tip (N=6). For both groups, ultrasound guided sciatic nerve block was performed with the “in-plane” approach.The anatomic landmarks and the locations of the sciatic nerve block equate to the Labat approach in humans. Thirty milliliter of normal saline was used to dissect the epineuron space before threading 20G soft non-stimulating catheter. The catheter was pulled back in onecentimeter increments at the level of the skin while the location of the tip of the catheter was identified by fluoroscopy after each centimeter pull back. The main outcome was the catheter tip movement. Results: The catheter tips advanced either cephalic or caudally without dominance trend, while most catheter tips located superficially to the needle tip (11 out of 12). In T 5 cm group, the catheter tip movement was initially 0.17 ± 0.11 cm per centimeter pull back, then increased to 0.25 ± 0.12 cm once the catheter tip was less than 5 cm beyond the initial depth of needle tip. Conclusions: We recommend that adjustment of the CPNC should base on the initial depth of the needle tip since the initial catheter tip movements among these over threaded catheters are very limited, and it would not be efficient in clinical practice to adjust peripheral nerve block catheter by pulling by centimeter increment.

In Reply

References 2–6 of our colleagues' letter all involved epidural infusion,1–5with references 2–4 suggesting analgesia is improved using repeated bolus doses compared with a simple basal infusion. But all subjects had multi-orifice epidural catheters.1–3References 5 and 6 suggest that with the same infusion method, multi-orifice epidural catheters improve analgesia compared with single-orifice designs. But all had the same local anesthetic administration technique.4,5In other words, whereas for epidural infusions repeated boluses appear to improve analgesia compared with a simple basal infusion, all of these studies involved only multi-port catheters, and thus it remains unknown if using a single-orifice catheter would have resulted in different findings (the authors of those reports did not purport such a theory).1–3Therefore, we do not believe the data supports our colleagues' statement that a “better differential sensory-motor block” is “thought to be enhanced by multi-orifice flow.”However, even if our colleagues' speculation was correct for epidural infusion, local anesthetic pharmacodynamics varies considerably among various introduction modalities. For example, local anesthetic dose, as opposed to volume or concentration, appears to be the primary determinant of block effects during continuous femoral and posterior lumbar plexus nerve blocks.6,7In contrast, the effects are mixed for epidural local anesthetic infusions: total dose is the primary determinant of analgesia quality and dermatomal spread, whereas concentration is the primary determinant of motor block and sympathectomy/hypotension.8It is for this very reason that we undertook our investigation: data from the literature involving central nervous system infusions (unfortunately) cannot be directly applied to those of the peripheral nervous system, such as the continuous femoral nerve blocks (cFNB) of our study.9We therefore do not believe that the references cited in our colleagues' letter, or any published data, supports their supposition that for continuous peripheral nerve blocks “a multi-orifice catheter is required” to “maximize” benefits.Regarding continuous peripheral nerve blocks, there are two investigations involving popliteal-sciatic local anesthetic administration suggesting that repeated boluses improve analgesia compared with a basal infusion (our colleagues cited one of these two).10,11However, both of these studies involved single-orifice perineural catheters. Therefore, there are actually more investigations suggesting the superiority of repeated boluses that used single-orifice perineural catheters than there are studies (just one involving interscalene catheters) using a multiple-orifice design.12It appears that the references cited by our colleagues contradict their theory regarding the importance of multi-orifice catheters on bolus-versus -basal administration effects.10–12Regardless, dramatic pharmacodynamic differences exist even among various continuous peripheral nerve block catheter anatomic locations, and thus the results for popliteal-sciatic and interscalene catheters are not automatically applicable to cFNB.13Our colleagues' speculation that the results of our study might be different with a multi-orifice catheter may prove accurate in the future. However, given (1) our investigation's randomized, triple-masked, split-body study design using extremely precise sensory and motor outcome measures with established reliability and validity; (2) the lack of data suggesting that the number of catheter orifice(s) impact the success of bolus-versus -basal local anesthetic administration for the peripheral (or central) nervous system; and, (3) the dramatic, often opposite, differences in pharmacodynamics among various continuous peripheral nerve block catheter anatomic locations, we believe that our concluding statement is both accurate and warranted: “this study did not find evidence to support the hypothesis that varying the method of local anesthetic administration–basal infusion versus repeated bolus doses–influences cFNB effects to a clinically significant degree. Thus, it is doubtful that, when using a cFNB, varying the method of local anesthetic administration will provide an increased sensory-to-motor block ratio and minimize motor block and the risk of falling while optimizing cutaneous analgesia.”9

Continuous Peripheral Nerve Block Catheter Infections in Combat-related Injuries: A Case Report of Five Soldiers from Operation Enduring Freedom/Operation Iraqi Freedom

Case series. Military medical facility providing acute care for soldiers injured while fighting in the war in Iraq and Afghanistan. To report a series of infections related to use of continuous peripheral nerve catheters for postoperative pain control in the military polytraumatic setting. The analysis of the above infections includes similarities and differences in infection patterns and attempts to clarify possible risk factors for such infections to include duration of catheter placement, type of catheter, preprocedural antibiotics, and tunnel vs nontunneled catheters. The goal of this analysis is to assist in the development of protocols that may prevent future catheter infections. Clinical data were obtained from five previously healthy male soldiers receiving acute care at Brooke Army Medical Center using continuous peripheral nerve catheters for postoperative pain for multiple and frequent procedures. In a total of six catheter infections, two were noted to have superficial skin infections while four were shown to have deep tissue involvement confirmed by imaging studies. All patients were started on initial or additional antibiotics after catheter removal. Three catheter infections, all with stimulating catheters, required surgical irrigation and debridement in the operating room. Continuous peripheral nerve catheters are not without complications and risks including infection. Duration of catheter use was the most significant factor with the development of a catheter-related infection in our series. This series also highlights how stimulating and nonstimulating catheter infections may present differently, as stimulating catheters may have a greater tendency to present as deep space infections with minimal superficial findings.

Treatment of Pain in Children after Limb-Sparing Surgery: An Institution's 26-Year Experience

A significant proportion of patients report long-term pain that is ≥5 on a 0-10 intensity scale after limb-sparing surgery for malignancies of the long bones. Patients experience several distinct types of pain after limb-sparing surgery which constitute a complex clinical entity. This retrospective study examined 26 years of experience in a pediatric institution (1981-2007) in pain management as long as 6 months after limb-sparing surgery and reviewed the historical evolution of pain interventions. One hundred fifty patients underwent 151 limb-salvage surgeries for bone cancer of the extremities in this series. Pain treatment increased progressively in complexity. Therapies included opioids, nonsteroidal antiinflammatory drugs, acetaminophen-opioid combinations, postoperative continuous epidural infusion, anticonvulsants and tricyclic antidepressants for neuropathic pain, local anesthetic wound catheters, and continuous peripheral nerve block catheters. Management of pain after limb-sparing surgery has evolved over the 26 years of this review. It currently relies on multiple “layers” of pharmacologic and nonpharmacologic strategies to address the complex mixed nociceptive and neuropathic mechanisms of pain in this patient population.

Serum Ropivacaine Concentrations and Systemic Local Anesthetic Toxicity in Trauma Patients Receiving Long-Term Continuous Peripheral Nerve Block Catheters

Ropivacaine is a long-acting local anesthetic used frequently for peripheral nerve blocks and continuous peripheral nerve block catheters. Combat trauma patients at Walter Reed Army Medical Center often receive continuous peripheral nerve block catheters as part of their pain regimen. These catheters remain in situ for several days to weeks. In this study, we evaluated the free ropivacaine drug levels over time in trauma patients by measuring the serum concentration of bound and unbound local anesthetic. The corresponding alpha(1)-acid glycoprotein concentration in patients with prolonged ropivacaine infusions was also measured. Fifteen patients were enrolled in the study; 2 patients were excluded because only a single ropivacaine level was obtained. Of the remaining 13 patients in the study, 2 had peripheral nerve catheters placed at the time of enrollment; the remaining 11 patients had catheters placed before enrollment. These patients were already receiving 0.2% ropivacaine infusions for a period of 18-126 h before the first assessment of local anesthetic level. Catheters infused 0.2% ropivacaine at a rate of 6-14 mL/h; catheter boluses were administered with 0.5% ropivacaine. Local anesthetic blood concentrations were scheduled to be measured on Days 1, 3, 5, 7, and 10 and every 3 days thereafter until all catheters were removed, although not all patients underwent each assessment. Specimens were assayed using high-performance liquid chromatography for total and free serum ropivacaine concentrations. Alpha(1)-acid glycoprotein was also measured. Thirteen patients remained in the study, for a total of 59 blood samples. The median number of days catheters remained in situ for the duration of acute pain therapy was 7 days (range: 6-27 days). The median number of days catheters remained in situ after enrollment into the study was 7 days (range: 4-25 days). The median number of blood samples collected per patient was 4 (range: 2-10 samples). Two patients had isolated increased concentrations of free ropivacaine into a previously identified toxic range with no obvious mitigating factors; both patients had received a 300-mg bolus of 0.5% ropivacaine approximately 24 h before that blood collection. The median ropivacaine concentration over the length of the study was 0.11 mg/L (range: undetectable to 0.63 mg/L). During the first week of the study, the median change in ropivacaine concentration per patient was 0.00 mg/L (range: -0.35 to 0.47 mg/L). Although 2 patients demonstrated isolated serum ropivacaine concentration spikes into a previously identified toxic range, continuous peripheral nerve block catheter management and local anesthetic doses as practiced at Walter Reed Army Medical Center did not result in clinically evident systemic ropivacaine toxicity. There was no correlation between free ropivacaine concentration and alpha(1)-acid glycoprotein concentration except in patients who had already been receiving ropivacaine infusions before entering the study. Despite this lack of correlation, the total duration of local anesthetic infusion did not seem to influence the free concentration of the drug.

Analysis of Common Reasons for Acute Pain Consultations in an Academic University Practice

The Acute Pain Service provides a variety of services to our hospital. They include management of epidural analgesia, continuous peripheral nerve block catheters, epidural blood patches, and consultations for management of uncontrolled pain. The purpose of this study was to identify common reasons for acute pain management consultations in an academic university practice.

Infectious Risk of Continuous Peripheral Nerve Blocks

Infectious Risk of Continuous Peripheral Nerve Blocks

Development of a technique for continuous perineural blockade of the palmar nerves in the distal equine thoracic limb

ObjectiveTo develop a technique for placing continuous peripheral nerve block (CPNB) catheters adjacent to palmar nerves in horses and to evaluate the effect of low-volume local anesthetic (LA) infusion on nociception in the distal equine thoracic limb. Study designIn vitro and in vivo laboratory investigation.Study material and animals Forty-two thoracic limbs from 22 equine cadavers and five horses. MethodsThoracic limb specimens were dissected to find landmarks for catheter insertion adjacent to medial and lateral palmar nerves. Based on the anatomy of the proximal metacarpus, a technique for placing palmar CPNB catheters was developed and the potential for catheter dislodgement studied in vitro by fluoroscopic visualization during passive carpal flexion and dye injection following simulated limb motion. The feasibility of CPNB catheter instrumentation in standing, sedated horses was tested in five animals, with ultrasound control. Electrical and mechanical stimulation thresholds and response latencies for hoof withdrawal responses (HWR) were determined following saline or LA infusion. ResultsMedial and lateral CPNB catheters were inserted percutaneously 2 and 4–5 cm, respectively, distal to the accessory carpal bone and advanced for ∼7 and 10 cm, respectively, to place the tip just proximal to the communicating branch of the nerves. Catheters were placed correctly in 88% and 85% of cadaver limbs. In the standing horses, LA infusion not only increased HWR thresholds and latencies to noxious mechanical or electrical stimulation but also caused vasodilation and limb swelling over time. ConclusionThe technique, developed in vitro, for placing and maintaining palmar CPNB catheters in the equine thoracic limb was successfully applied in vivo. Catheters were well tolerated but LA infusion may cause limb swelling, suggesting a need for further exploration of drug and infusion regimens. Clinical relevanceContinuous perineural LA infusion along palmar nerves may develop into an effective analgesic technique in horses suffering from lower limb pain.

Safety of Multiple, Simultaneous Continuous Peripheral Nerve Block Catheters in a Patient Receiving Therapeutic Low-Molecular-Weight Heparin

The application of continuous peripheral nerve block (CPNB) has been an important anesthetic tool in the management of combat soldiers wounded from current conflicts. Placing and maintaining CPNBs becomes a challenge in this patient population due to concomitant prophylactic and therapeutic anticoagulation. A 32-year-old male sustained multiple traumatic injuries from an improvised explosive device, including a right tibial fracture, a left tibial fracture, and a left ulnar fracture. His pain was originally well controlled with a left infraclavicular CPNB (0.2% ropivacaine at 10 mL/h with 3 mL bolus every 20 minutes) and an epidural (0.2% ropivacaine at 10 mL/h with 5 mL bolus every 30 minutes). He subsequently developed a common femoral vein thrombus and was treated with low-molecular-weight heparin. His epidural catheter was discontinued; however, his pain was not well controlled with intravenous and oral pain medication. We elected to place bilateral, tunneled sciatic CPNBs and a left, tunneled femoral CPNB. We started infusions of 0.2% ropivacaine at 10 mL/h in each catheter, in addition to 5 mL every 30 minutes demand dose in each sciatic catheter. The patient's serum ropivacaine levels were analyzed 24 hours after the start of the infusions and were found to be 5.8 mg/L and <0.1 mg/L for total and free concentrations, respectively. This case highlights the application of simultaneous CPNB techniques in a patient with multiple extremity injuries receiving anticoagulant therapy.

Continuous peripheral nerve block in combat casualties receiving low-molecular weight heparin

Continuous peripheral nerve block (CPNB) is an important therapeutic tool in the anaesthetic and analgesic management of combat casualties at Walter Reed Army Medical Center (WRAMC). We describe our experience using CPNB techniques in combat trauma patients treated with low-molecular weight heparin (LMWH). Guidelines used at our institution for managing CPNB catheters in patients being treated with LMWH are introduced. From March 2003 to April 2005, 187 combat casualties treated by the WRAMC regional anaesthesia/acute pain section using CPNB were evaluated retrospectively by electronic chart review. Patient characteristic data, CPNB type, duration of CPNB, indication for LMWH [enoxaparin sodium injection (Lovenox-Sanofi Aventis, Bridgewater, NJ, USA)], enoxaparin dose (mg) before and after catheter insertion and removal, time from CPNB placement and removal to enoxaparin dose, and complications were recorded. Median enoxaparin dose and time given before catheter insertion were 30 mg and 21 h, respectively. Median enoxaparin dose was also 30 mg given a median of 12 h after peripheral nerve catheter placement. Catheters remained in situ for a median of 8 days (range 1-33 days). Catheter specific complications were infrequent and identified in 7 (3.7%) patients (two catheter malfunction-kinking, catheter tip dislodgement in situ, two superficial catheter site infections and two catheter dislocations). There were no catheter-related bleeding complications evident in this study. Information regarding the safety of CPNB in patients treated with LMWH for perioperative venous thromboembolism prevention is scarce. Our initial experience with CPNB and concurrent LMWH has not been complicated by catheter-related bleeding.