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An 18-year-old man with metastatic femoral osteosarcoma had inadequate pain control with gabapentin, naproxen, and intravenous fentanyl. A tunneled femoral nerve catheter was used to administer a continuous infusion of 0.2% ropivacaine and 4 μg/mL clonidine (10 mL/h) until his death 88 days later. During discharge from hospital, catheter disconnection resulted in severe pain and readmission. Tunneling, aseptic insertion technique, antibiotics, and sterile infusate prepared by pharmacy may have reduced the chance of infection. We propose that this is a suitable and effective technique in the long-term management of patients with terminal cancer and should be considered on a case-by-case basis.
Continuous peripheral nerve blocks (CPNBs) are often used to provide postoperative analgesia, during which catheters typically remain in situ for 2-7 days1. In some cases, CPNBs have been used in palliative care for up to 45 days2,3.We report the case of an 18-year-old with terminal cancer for whom a continuous tunneled femoral nerve block provided adequate pain relief for 88 days.
Patient consent was given prior to presenting the following information. An 18-year-old African-American male weighing 71 kg was diagnosed with osteosarcoma of the left distal femur with a pathological fracture and bilateral pulmonary metastases. He received a course of chemotherapy but declined palliative above-knee amputation.
Four months before his death, he began to experience breakthrough pain despite oral and transdermal opioids, gabapentin and naproxen. Intravenous patient-controlled analgesia (IV PCA) fentanyl was commenced, but pain control remained inadequate.
A tunneled left femoral nerve catheter for a CPNB was inserted under general anaesthesia. The procedure was performed with a strict aseptic technique, using a cap, face mask, sterile gloves, and sterile gown. The nerve was identified by ultrasound and then localized with a stimulating needle. Patellar snap was elicited at 0.7 mA. A catheter (Stimuplex®, B Braun, Melsungen, Germany) was then threaded along the nerve sheath. After a negative aspiration of blood, an initial bolus of 0.5% bupivacaine (10 mL) was injected in increments of 2 mL.
A 9 cm, 18 gauge Tuohy needle was used to tunnel the catheter. The stylet of the needle was inserted at the exact point of entry of the catheter, and tunneled subcutaneously to a convenient point approximately 6 cm laterally. At the exit point of the stylet, the needle was fed back (over the stylet as a guide) to emerge at the site of the catheter insertion. The catheter was then fed through the needle until it exited from the proximal end of the Tuohy needle. Finally the needle was removed and the catheter remained in its tunneled position. No procedural complications were encountered.
A continuous infusion of 0.2% ropivacaine and 4 μg/mL clonidine (10 mL/h) was initiated, using a CADD-Prizm® Variable Infusion Profile Ambulatory Infusion Pump, Model 6101 (Smiths Medical MD, Inc., St. Paul, MN). A 5% lidocaine patch (12 h/day) was also applied to treat persistent posterior thigh pain. The patient’s pain scores dramatically decreased.
The patient was briefly discharged with the femoral catheter 58 days after insertion but returned the following day with excruciating pain after the catheter had become accidentally disconnected from the “snap-lock” 10 hours previously. The catheter was cleaned with alcohol and connected to a fresh “snap-lock”. He was given 20 mL of 3% chloroprocaine and 20 mL of 0.2% ropivacaine and his pain dramatically decreased over the next 15 min. He was readmitted and a fresh infusion set was connected and restarted. He remained inpatient for social reasons until his death.
Management that may have been relevant to the femoral catheter included the administration of sulfamethoxazole/trimethoprim thrice a week before and after catheter insertion and catheter dressing changes thrice a week. Solutions for infusion were prepared in the pharmacy, using a sterile technique, and changed at least every 96 h.
Additional end-of-life care consisted of IV PCA hydromorphone (average at time of death 14.2 mg/h), a 5% lidocaine patch (posterior thigh), ketorolac 30 mg IV every 8 h, and gabapentin 800 mg BID. Although the tumor was very large in the last month of his life (Figure), the patient died comfortably with minimal pain. His femoral nerve block had remained in place for 88 days.
The tunneled catheter for continuous femoral nerve block provided adequate pain control for 88 days for our immunocompromised patient, and he showed no signs of infection. Although his mobility was extremely limited because of the large size of the tumor and pathological fracture, the nerve block was helpful in controlling his pain both while he was immobile and when he was moving for dressing changes.
CPNBs have been extensively used post-operatively as they provide good-quality analgesia with few side effects1. Studies on the use of CPNBs for palliative care are fewer than those on post-operative analgesia, however, 10% of patients with advanced-stage cancer have unmanageable pain despite the use of opioids. The procedure is especially useful in patients for whom escalating doses of opioids or unacceptable side effects limit the ability to control pain3.
Catheters are typically left in place for 2-7 days for post-operative analgesia1, however infusions via catheters in the sacral root and brachial plexus have been used for up to 42 days for chronic pain3,4, and the longest reported use of a femoral nerve block was 45 days2. In our patient, the nerve block was continuously infused for 88 days.
For all interventional procedures the risks must be considered. When our patient was discharged with the femoral block in situ, the catheter was accidentally disconnected from the pump. Such technical complications are the most common adverse event in studies of CPNBs1,5, but are usually resolved quickly without affecting patient care1. A technical complication may become clinically significant if there is a delay in recognizing the problem and transporting the patient back to the hospital5. Despite this risk, CPNBs can be effective in an outpatient setting if the family is educated about the nerve block and pump and the medical team is available for follow-up assessment5.
An important concern with the extended use of peripheral nerve blocks is infection, as studies have found a correlation between the duration of catheter use and the risk of inflammation and infection1,6. Catheter infections may result in serious complications such as cellulitis, and, for femoral blocks, a psoas abscess1,7,8. One protective practice is the use of antibiotic prophylaxis, as studies have shown that the risk of infection and inflammation increases if prophylactic antibiotics are not used1,9. At the time of catheter insertion, our patient was taking trimethoprim/sulfamethoxazole. Another factor is the manner in which the solution is prepared and the “hang-time” of each infusion bag, as nonsterile infusates have been implicated in the development of nerve catheter-related infections8. For our patient, the hospital pharmacy prepared the solution in compliance with U.S. Pharmacopeia’s Revised General Chapter <797> Pharmaceutical Compounding - Sterile Preparations, and each bag was hung for a maximum of 96 h.
Subcutaneous tunneling of the catheter may help reduce the risk of catheter infection, as infections from nerve blocks are usually thought to arise from bacteria on the skin at the catheter insertion site1,6,7. The goal of subcutaneous tunneling is to increase the distance between the insertion site and the nerve that is blocked10. Studies of critically ill patients have shown a significant reduction in central venous catheter-related sepsis when tunneling was used11 and the mechanism for CPNB sepsis is believed to be similar10.
Compere et al.10 recently evaluated the effect of subcutaneous tunneling in 402 patients receiving nerve blocks for 48 h postoperatively. A catheter colonization rate of only 6.2%10 was found, which is much lower than rates of 17%–57% reported in studies that did not use tunneling1,9,12. In the same study, in which all catheters were tunneled, no correlation was found between extended duration of catheter use and increased risk of inflammation and infection10. This contrasts with studies of non-tunneled catheters in which increased duration of catheter usage has been found to be associated with increased risk of inflammation and infection1,6.
In addition to the decreased risk of infection, tunneling also secures the placement of the catheter, thus decreasing the risk of catheter dislodgement13,14. It a simple technique, that is easy to learn, and uses equipment that is readily available and familiar to all anaesthesia providers.
Although the risks must be considered, in our patient the potential benefits outweighed the possibility of complications. The lack of any serious infectious complication may be attributed to subcutaneous tunneling, prophylactic antibiotics, and infusate preparation under sterile conditions. Subcutaneous tunneling is a technically easy procedure which may also reduce the risk of catheter dislodgement. We propose that continuous tunneled peripheral nerve block is an effective technique for the management of patients with terminal cancer.
St. Jude Children’s Research Hospital is funded by ALSAC. Holly Pacenta was supported by grant 5R25CA023944 from the National Cancer Institute. We wish to thank Mary Edna Parish for clerical support and Vani Shanker for scientific editing.
Holly L Pacenta, University of Toledo, Toledo, OH.
Roland N Kaddoum, Division of Anesthesia, St. Jude Children’s Research Hospital, Memphis, TN.
Lilia A Pereiras, Division of Anesthesia, St. Jude Children’s Research Hospital, Memphis, TN.
Elie J Chidiac, Department of Anesthesiology, Wayne State University/The Detroit Medical Center, Detroit, MI.
Laura L Burgoyne, Division of Anesthesia, St. Jude Children’s Research Hospital, Memphis, TN.