Continuous peripheral nerve blocks (CPNB) are commonly used for intraoperative and postoperative analgesia. Our study aimed at describing our experience with ambulatory peripheral nerve catheters. After Institutional Review Board approval, records for all patients discharged with supraclavicular or popliteal catheters between January 1, 2009 and December 31, 2011 were reviewed. A licensed practitioner provided verbal and written instructions to the patients prior to discharge. Daily follow-up phone calls were conducted. Patients either removed their catheters at home with real-time simultaneous telephone guidance by a member of the Acute Pain Service or had them removed by the surgeon during a regular office visit. The primary outcome of this analysis was the incidence of complications, categorized as pharmacologic, infectious, or other. The secondary outcome measure was the average daily pain score. Our study included a total of 1059 patients with ambulatory catheters (769 supraclavicular, 290 popliteal). The median infusion duration was 5 days for both groups. Forty-two possible complications were identified: 13 infectious, 23 pharmacologic, and 6 labeled as other. Two patients had retained catheters, 2 had catheter leakage, and 2 had shortness of breath. Our study showed that prolonged use of ambulatory catheters for a median period of 5 days did not lead to an increased incidence of complications.
Continuous peripheral nerve blocks (CPNB) are often used to provide intraoperative and postoperative analgesia. Effective pain control after painful orthopedic procedures may facilitate earlier patient discharge, improve acute rehabilitation, and increase patient satisfaction. It has been shown that the use of CPNB decreases the use of intravenous (IV) and oral opioids, improves rehabilitation, and decreases length of hospital stay [
In addition, CPNB were found to provide more potent analgesia than wound catheters and fewer undesirable effects compared to epidural infusion [
In this retrospective study, we describe our experience with ambulatory CPNB in regard to infection and pharmacological complications.
After Cleveland Clinic Institutional Review Board approval, records for all patients discharged with supraclavicular or popliteal catheters between January 1, 2009 and December 31, 2011 were reviewed. Data collection was performed by investigators from the electronic medical record.
All catheters were inserted using a standard technique. Blocks were performed by a staff anesthesiologist assisting a trainee (resident/fellow). Both physicians, as well as the ancillary personnel (block room nurses and/or technicians), were wearing a new hat and mask for each patient. Both physicians practiced hand wash and removed hand watches, bracelets, and jewelry before putting on sterile gloves. Sterile gowns were not used.
The skin was cleansed with chlorhexidine gluconate in isopropyl alcohol; then a sterile drape was applied and the skin was cleaned for a second time with chlorhexidine. All catheters (Arrow, StimuCath continuous, nerve block procedural kit ASK 05060-cch 19 Ga, 60 cm catheter, insulated needle, 18 g 3.81 inch) were inserted using an in-plane ultrasound technique under strict aseptic conditions with the ultrasound probe covered with a sterile sheath. The catheter was advanced 3–5 cm beyond the needle tip. During supraclavicular catheter insertion, the catheters were placed dorsolateral to the nerve plexus. During popliteal catheter insertion, the catheters were placed next to the nerve with the needle coming from the lateral side of the thigh. The catheter was advanced 3–5 cm beyond the tip of the needle to end within the space between the semitendinosus and semimembranosus muscles medially and biceps femoris muscle laterally.
All catheters were tunneled under the skin, a sterile adhesive and chlorhexidine-impregnated patch were applied around the catheter site, and then the site was covered with clear occlusive dressing. All patients received infusions using the AmbIT pump (Summit Medical Production, Inc., Salt Lake city, UT, USA). We chose this pump as it is technically easy for patients to use and adjust. After catheter placement, an initial bolus dose of 20 mL ropivacaine 0.75% was administered. All patients were evaluated for sensory and motor block prior to surgery. Before discharge, the catheters were connected to AmbIT pumps infusing ropivacaine 0.2% with an 8 mL/hour basal rate and a 12 mL demand dose once per hour. In addition, patients were given a prescription for oxycodone 5 mg every 4 hours with acetaminophen 500 mg (1-2 tablets) every 8 hours; both were to be used as needed for pain for five days. After meeting the discharge criteria, patients with ambulatory catheters were discharged home. Patients needed to have access to a phone to be reached daily, and needed an access to a nearby emergency facility if urgent care was needed.
A licensed practitioner (physician assistant or registered nurse) provided verbal and written discharge instructions to the patients, (Appendix
On the fifth day, patients were instructed to stop the infusion for 6 hours and then remove the catheter if their pain scores were less than 5 and well tolerated by the patients. If pain was more than or equal to 5 we asked patients to restart their infusions and we did the same every day until the catheter was removed. The primary outcome of this analysis was the incidence of which were categorized as pharmacologic, infectious, or other, for example, retained catheter. The secondary outcome measure was the average daily verbal response pain score.
The patients were compared with basic descriptive statistics by catheter type. Variables of interest included patient demographics, surgery location and type, and infusion duration. Categorical variables are presented as number (percent). Continuous variables are presented as medians with interquartile ranges. R version 2.12.0 (The R Foundation for Statistical Computing, Vienna, Austria).
Any adverse neurologic symptom reported by a patient was listed as a pharmacological complication, regardless of type or severity. Any sign or symptom of infection at the catheter site (erythema, drainage, or swelling) was labeled as an infectious complication. Any other complications such as a retained catheter were labeled as other.
A total of 1059 patients with ambulatory catheters (769 supraclavicular, 290 popliteal) were reviewed. The median infusion duration was 5 days for both groups. Table
Supraclavicular and popliteal catheters.
Catheter type | Surgery site | Procedure | Age (y) | Sex | Duration (days) | Average |
Infection | Pharmacologic |
Other |
---|---|---|---|---|---|---|---|---|---|
Supraclavicular |
Shoulder 498 |
Arthroplasty* 257 |
57 |
M 410 |
5 |
2 |
11 (1.4%) | 22 (2.9%) | 6 (0.8%) |
|
|||||||||
Popliteal |
Leg 16 |
Arthrodesis 138 |
53 |
M 103 |
5 |
2 |
2 (0.7%) |
1 (0.3%) |
0 (0%) |
M: male; F: female.
Categorical variables are presented as number of patients.
Continuous variables are presented as median (interquartile range).
*“Arthroplasty” includes total and hemiarthroplasty.
ORIF: open reduction and internal fixation.
Forty-two complications were identified: 13 were infectious (11 in the supraclavicular group and 2 in the popliteal group), 23 were pharmacologic (22 in the supraclavicular group and 1 in the popliteal group), and 6 were labeled as other. Tables
Infectious complications.
Age | Sex | Catheter | Duration (days) | Symptoms | Treatment | Comorbidities |
---|---|---|---|---|---|---|
42 | F | Popliteal | 4 | Swelling and drainage | Resolved with catheter removal | Thigh abscess |
|
||||||
61 | F | SC | 2 | Redness and swelling | Resolved with catheter removal | Hyperlipidemia |
|
||||||
52 | M | SC | 13 | Redness and tenderness | Instructed to remove the catheter and see his surgeon, symptoms resolved with no intervention | Hypertension, DM |
|
||||||
76 | F | SC | 4 | Redness and swelling | Resolved with catheter removal | Steroid treatment |
|
||||||
43 | F | SC | 2 | Redness and swelling | Resolved with catheter removal | Hypertension, hyperlipidemia |
|
||||||
35 | F | SC | 4 | Redness and swelling | Resolved with catheter removal | Anemia |
|
||||||
38 | M | SC | 3 | Blisters underneath the dressing, redness at the insertion site | Catheter removed in ED, symptoms were resolved within 2 days | None |
|
||||||
46 | M | SC | 5 | Redness and tenderness | Resolved with catheter removal | Hypertension, DM, seizures |
|
||||||
56 | M | SC | 7 | Redness, swelling, and tenderness | Resolved with catheter removal | None |
|
||||||
63 | F | SC | 3 | Redness and purulent discharge | Removed in ED, one dose of IV daptomycin, and oral linezolid | Gastritis, irritable bowel syndrome |
|
||||||
60 | F | Sc | 5 | Blisters underneath the dressing and redness | Resolved with catheter removal | None |
|
||||||
45 | F | Popliteal | 6 | Redness and tenderness | Resolved with catheter removal | Hypertension, DM |
|
||||||
63 | M | SC | 4 | Redness, swelling at the site, nodule 1 inch from the site | CT Of the neck in ED showed no fluid collection, no antibiotics, symptoms resolved within few days | CRPS, hypertension, chronic renal disease, seizures, |
SC: supraclavicular catheter; COPD: chronic obstructive pulmonary disease; DM: diabetes mellitus; CT: computerized tomography; CRPS: complex regional pain syndrome; ED: emergency department.
Pharmacological complications.
Age | Sex | Catheter | Duration (day) | Symptoms | Treatment | Comorbidities |
---|---|---|---|---|---|---|
23 | F | Popliteal | 4 | Ringing in the ears with the initial injection | Resolved completely with no intervention | None |
|
||||||
22 | F | SC | 5 | Ipsilateral ptosis | Resolved with holding the infusion for 2 hours | None |
|
||||||
73 | M | SC | 2 | Hoarseness | Resolved after catheter removal | Hypertension |
|
||||||
48 | M | SC | 7 | Ipsilateral ptosis | Resolved with pump off, returned with infusion, resolved with catheter removal | Hypothyroidism |
|
||||||
72 | F | SC | 7 | Numbness of ipsilateral hand | Resolved with catheter removal | None |
|
||||||
51 | M | SC | 3 | Ringing in the ears, started at home | Instructed to hold the infusion, but the ringing persists, instructed to remove the catheter, and it was resolved completely | Psoriasis |
|
||||||
51 | M | SC | 5 | Hoarseness, ipsilateral numbness, and weakness of the hand | Improved with holding the infusion, resolved with catheter removal | Obesity, DM, smoking |
|
||||||
38 | F | SC | 4 | Ipsilateral ptosis | Resolved with catheter removal | Hypothyroidism, smoking |
|
||||||
29 | M | SC | 3 | Ipsilateral ptosis and fingers tingling | Resolved with catheter removal | Hyperlipidemia |
|
||||||
45 | M | SC | 4 | Ringing and numbness in ipsilateral ear | Resolved with holding the infusion | None |
|
||||||
75 | F | SC | 8 | Ipsilateral ptosis and facial hyperemia | Resolved with decreasing the concentration to 0.1% ropivacaine | Rheumatoid arthritis, hypertension, colon cancer, and breast cancer |
|
||||||
45 | M | SC | 3 | Ipsilateral ptosis | Improved with holding the infusion, resolved with catheter removal | Obstructive sleep apnea and coronary artery disease |
|
||||||
65 | M | SC | 5 | Ipsilateral numbness of the face | Improved with holding the infusion, resolved with catheter removal | Hypertension, gout |
|
||||||
38 | M | SC | 3 | Tingling and numbness of ipsilateral fingers | Improved with holding the infusion, resolved with catheter removal | None |
|
||||||
42 | F | SC | 4 | Ipsilateral ptosis, stuffy nose, and metallic taste in mouth | Improved with holding the infusion, resolved with catheter removal | None |
|
||||||
43 | M | SC | 4 | Ipsilateral ptosis | Improved with holding the infusion, resolved with catheter removal | Osteoarthritis |
|
||||||
56 | M | SC | 7 | Weakness and numbness of ipsilateral hand | Gradually improved, resolved with catheter removal | None |
|
||||||
65 | F | SC | 6 | Hoarseness | Resolved with catheter removal | Hypertension, anxiety |
|
||||||
49 | F | SC | 5 | Hoarseness | Resolved with catheter removal | None |
|
||||||
60 | F | Sc | 5 | Hoarseness, ipsilateral ptosis | Improved with holding the infusion, resolved with catheter removal | Anxiety, hypothyroidism |
|
||||||
56 | F | SC | 3 | Numbness of ipsilateral fingers | Resolved with catheter removal | Obesity, hypertension, obstructive sleep apnea, and DM |
|
||||||
45 | F | SC | 6 | Ipsilateral ptosis and numbness of fingers | Resolved with catheter removal | None |
|
||||||
39 | F | SC | 5 | Ipsilateral ptosis | Resolved with catheter removal | Anxiety |
Other complications.
Age | Sex | Catheter | Duration (days) | Symptoms | Treatment | Comorbidities |
---|---|---|---|---|---|---|
30 | F | SC | 3 | Retained catheter | Removed in ED by surgical extraction at bed side | Depression |
|
||||||
62 | M | SC | 6 | Retained catheter | Removed in ED by slight traction with no complication | Coronary artery disease (CAD) |
|
||||||
68 | F | SC | 5 | Small amount clear leakage at catheter insertion site | Resolved with reinforced dressing | Osteoarthritis, hypertension |
|
||||||
57 | M | SC | 4 | Leakage from catheter tubing | Catheter found to be disconnected at the hub, in ED catheter cleaned with chlorhexidine, cut with sterile scissors, sterile hub applied | Hypertension |
|
||||||
70 | M | SC | 10 | Shortness of breath (SOB) | Patient advised to turn off the pump and to go to hospital, chest X-ray showed pneumonia, started on antibiotics, catheter removed | CAD, hypertension |
|
||||||
62 | F | SC | 3 | SOB, dizziness, and sweating | Patient advised to turn off the pump and go to the emergency department. Found to have myocardial infarction and pulmonary embolism. Catheter removed. Subsequently discharged home | Hypertension, DM |
All infections were superficial, presenting as redness and tenderness at the catheter site. In all cases, patients were instructed to remove the catheter. In only one case did the patient require antibiotics; the remainder of the infections resolved without any intervention other than catheter removal.
Pharmacological complications consisted of ringing in the ears, ipsilateral numbness, hoarseness, and significant ptosis. All pharmacological complications resolved after discontinuing the infusion for 2-3 hours or removing the catheter without any sequelae. Most of the pharmacological complications presented in patients with supraclavicular catheters.
The time-weighted average for daily verbal pain scores (0–10) at the time of telephone contact for patients with supraclavicular or popliteal catheters was 2, showing overall satisfactory postoperative pain control.
Expanded use of regional anesthesia has increased patients’ benefit in terms of better control of intraoperative and postoperative pain, increased patient satisfaction, decreased postoperative nausea and vomiting, and early mobilization and rehabilitation.
One of the major concerns regarding the use of CPNB has been the potential for complications, such as catheter site infection, nerve injury, and local anesthetic toxicity. A recent meta-analysis evaluating 19 studies showed that major complications were rare. The most frequent minor complication attributable to peripheral nerve block was excessive motor block [
The frequency of infection associated with peripheral nerve catheters remains poorly defined. Recent studies have shown that between 23 and 57% of peripheral nerve catheters become colonized, but only 0–3% result in localized infection and less than 1% result in serious infections [
A review of the literature shows few cases describing difficulty in removing peripheral nerve catheters mostly secondary to knotting or excessive advancement under the skin, as previous investigators have demonstrated a relationship between length of catheter advancement and subsequent knotting [
Despite the rise in popularity of continuous regional techniques for ambulatory surgery, little has been studied regarding patient perception of the technique. Retrospective surveys have shown that patients are generally satisfied with ambulatory perineural infusions including the removal of catheters themselves [
The results of our study demonstrate that the prolonged use of ambulatory catheters for a period up to 5 days did not lead to an increased incidence of complications as compared to other studies. Our main complications were minor infections and pharmacological symptoms, which resolved with catheter removal and without the need for additional medical intervention. Patients who presented to the emergency department with shortness of breath had other underlying comorbidities such as myocardial infarction and pulmonary embolism. Vigilance in dealing with patients with ambulatory catheters is crucial to prevent complications.
Your surgeon and anesthesiology pain management team have determined that a continuous peripheral nerve block is an option for pain management following your surgical procedure. This information is provided for you regarding the outpatient management of the AmbIT pump. The peripheral nerve block catheter and infusion pump are intended to help reduce your postoperative pain. Not all surgical pain may be relieved by this method of pain control. Therefore, you will likely need oral pain medication prescribed by your surgeon. Please carefully follow the directions for these oral pain medications. The local anesthetic medication infusing via the AmbIT pump will produce some degree of numbness in the intended surgical area supplied by those nerves. Due to this numbness it is imperative that you remain protective of your surgical limb from heat, pressure, chemicals, or other objects to avoid injury. You will likely have some degree of muscle weakness in your arm, hand, leg, or foot from the effect of the local anesthetic. Do not support yourself or bear weight on the arm, hand, leg, or foot while the local anesthetic nerve block is infusing. There are no narcotics in the solution. This medication will not interfere with any medications you are currently taking. It will also not interfere with any pain medications you have ordered. The pump does not require height for infusion as opposed to an IV infusion. The solution and AmbIT pump are placed in a fanny pack for your convenience. Please note that it is important to keep the dressing over the catheter clean and dry. Do not change the dressing. NO SHOWERS.
This pump is disposable and is to be thrown out. It is not reusable. Left over solution can be disposed of down the sink. The AmbIT pump runs on 2 AA batteries. New batteries have been placed in the pump. The AmbIT pump makes a noise while it is infusing, a type of “grinding noise.” It will make this noise about every 20–30 seconds while the pump is on. When you give yourself a bolus dose the AmbIT pump will make a loud continuous grinding noise for about 10 min. This is normal, when the bolus dose is complete the noise will stop. The AmbIT pump has already been preset with rates.
This is the Run/Pause button. This is the bolus dose button. When the green light is blinking on the bolus dose button it means that the AmbIT pump is on and working. The screen on the pump reads with a decimal point; it will look like this 136.5 mL. That number continues to count up as the solution infuses. It is designed to turn off when the number reaches 1000.0 mL.
Before removing the catheter, make sure that the AmbIT pump has been off for 6–8 hours. We want all of the numbness to be gone and normal sensation returned. If normal sensation has not returned please call the Acute Pain Service. Wash your hands. Remove all of the tape. Gently pull on the catheter; it is in about 5-6 inches. It should come out easily. If there is resistance or you cannot pull the catheter out, cover the site back up with the provided Tegaderm and call the Acute Pain Service. After catheter removal, the site may bleed a small amount; this is normal. You may hold pressure over the catheter site for 5–10 minutes and then apply a band aid to the area. The band aid may be removed later in the day. Notify the Acute Pain Service for any pain, redness, continued bleeding, or drainage from the catheter insertion site and also notify for persistent numbness or weakness in the arm, hand, leg, or foot following the catheter removal.
Please contact the Acute Pain Service if you have any questions or notice the following symptoms during or following the nerve block infusion. Increase in pain. Redness, tenderness, swelling, or drainage at the nerve block catheter insertion site. Lightheadedness, dizziness, or sedation. Blurred vision. Ringing in your ears, metallic taste in your mouth, numbness, or tingling around your mouth. Any shortness of breath. Difficulty in swallowing. Drowsiness. Confusion. Any discoloration (redness, bluish color changes) of the hand, fingers, foot, or toes.
Acute Pain Service number: (number was provided here). If no response call: Consultant: (number is provided here). If no response call: The Cleveland Clinic Foundation operator at (number was provided here) and ask for consultant pager (number was provided here).
If the pump shows If the pump shows
Day of surgery: Type of surgery: Catheter site: Solution: Rate of infusion: Called and talked to patient, states pain level is: Patient states the catheter dressing is (intact or specify if otherwise) and denies: (redness, fever, draining, edema, pain, or specify if otherwise). Patient denies metallic taste in mouth, ringing in ears, dizziness, shortness of breath, hoarseness of voice, or specify if otherwise. Patient is able to move fingers: Yes or No. Comments. Patient is satisfied with pain control, will continue with pump, or specify if otherwise.
Day of surgery: Type of surgery: Catheter site: Solution: Rate of infusion: Called and talked to patient, states pain level is: Patient states the catheter dressing is (intact or specify if otherwise) and denies: (redness, fever, draining, edema, pain or specify if otherwise). Patient denies metallic taste in mouth, ringing in ears, dizziness, shortness of breath, hoarseness of voice, or specify if otherwise. Patient is able to move toes: Yes or No. Comments. Patient is satisfied with pain control, will continue with pump, or specify if otherwise.
The authors declare that there is no conflict of interests regarding the publication of this paper.