Objectives To review the analgesic efficacy (by means of pain scores and opioid consumption) and adverse events after interscalene catheter (ISC) placement for ambulatory shoulder surgery in a series of adolescent patients.
Methods A retrospective review was performed of 36 patients who underwent ISC placement. Intraoperative and postoperative data regarding block placement, opioid consumption and pain scores were recorded. Via telephone, patients were assessed on postoperative days (PODs) 1-3 for pain scores, oxycodone use, global satisfaction and adverse effects of treatment.
Results The mean age was 15.4±1.8 years. The average time of ISC placement was 11.8±3.8 min. The mean postanaesthesia care unit maximum pain score was 1.6±2.4 with four patients who received rescue intravenous morphine. Mean pain scores for POD 1- 3 at rest were 2.5±2.3, 2.1±1.5 and 1.8±1.6, respectively. Mean number of doses of oxycodone on POD 1–3 were 1.1±1.4, 1.5±1.8 and 0.7±1.3, respectively. Satisfaction was reported in 94% of patients and 97% would have the catheter again. Adverse events included two accidental catheter removals at the end of the procedure or in the recovery unit, one catheter replacement at the end of surgery due to dislodgement, two early catheter removals on POD 2 because of dressing failure and insertion site discomfort, three cases of Horner’s Syndrome and one patient with transient ipsilateral facial numbness on POD 3.
Conclusion The use of ISCs in adolescent ambulatory shoulder surgery is beneficial, providing effective intraoperative and early postoperative analgesia as evidenced by low pain scores and minimal opioid use. Their routine use should be considered as they minimise perioperative opioid use with minimal adverse events.
Level of evidence Level IV, case series.
- repair / reconstruction
- medical aspects
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What are the new findings
Interscalene catheters (ISCs) are feasible in adolescents undergoing ambulatory shoulder surgery with high patient satisfaction.
Use of ISCs results in excellent pain-related postoperative outcomes, including low postanaesthesia care unit pain scores, and minimal perioperative and home opioid consumption.
Use of ISCs results in low rates of postoperative nausea and vomiting and no complications requiring readmission, reoperation or ongoing medical treatment.
Continuous peripheral nerve catheters have been extensively used in adult ambulatory surgery and are effective with appropriate patient selection and education.1–5 Benefits include reduction in postoperative pain, postoperative opioid requirements, occurrence of postoperative nausea and vomiting and postanaesthesia care unit (PACU) length of stay, in addition to increased patient satisfaction.5 6 When compared with opioid-based analgesia, continuous peripheral nerve catheters, regardless of catheter location, provide superior postoperative analgesia and fewer opioid-related side effects.7
When used in shoulder surgery, interscalene catheters (ISCs) have been shown to be an effective analgesic technique.8 9 Compared with parenteral analgesics alone, ISCs result in lower pain intensity scores at 24 and 72 hours, lower supplemental opioid administrations and significantly lower postoperative nausea and vomiting.10 In addition, ISCs have been shown to result in significantly lower pain scores in the early postoperative period, an overall increased time to first opioid consumption and increased total hours of sleep in the first week in comparison with single injection interscalene nerve blocks.11 Furthermore, ISCs compared with general anaesthesia result in a significantly shorter PACU length of stay and time to hospital discharge, without any lasting complications.11 The safety of ISC placement in adolescents was well demonstrated in the review of 154 patients by Gurnaney et al.12 However, the data on placement, dosing and analgesic effectiveness and patient satisfaction of ISCs in the paediatric and adolescent ambulatory setting is limited.
The purpose of this study was to review the analgesic efficacy (by means of pain scores and opioid consumption) and adverse events after ISC placement for ambulatory shoulder surgery in a series of adolescent patients. Secondarily, the time for catheter placement, postoperative nausea and vomiting requiring rescue medication, PACU length of stay and patient and family satisfaction were reviewed. It was hypothesised that the use of ISCs for ambulatory shoulder surgery in adolescent patients is feasible and would result in low pain scores and minimal opioid use within the acute postoperative period.
A consecutive series of patients who underwent shoulder surgery by a single sports medicine fellowship trained orthopaedic surgeon at an ambulatory surgery centre from June 2017 to October 2019 were retrospectively reviewed. Inclusion criteria were those patients (aged 12–19 years) who received ultrasound-guided ISCs. Exclusion criteria included those with inadequate data in the medical record or greater than 19 years old. In total, 36 patients were eligible for inclusion in this study (figure 1).
All patients received a general anaesthetic with either a laryngeal mask airway or endotracheal tube. Induction was achieved with inhalation agents and/or the anaesthesiologists’ choice of intravenous induction medications. A combination of volatile agents and a low dose propofol infusion (for mainly antiemetic purposes) were generally used for maintenance. In addition to intravenous acetaminophen and ketorolac, short-acting or long-acting opioids were administered when intraoperative analgesia was determined to be inadequate based on haemodynamic variables. Dexamethasone and ondansetron were given for nausea prevention.
Except for one patient who had a catheter placed postoperatively, all ISCs were placed under ultrasound guidance after induction of general anaesthesia and prior to incision by a paediatric anaesthesia fellowship-trained anaesthesiologist, who performs nerve blocks on a regular basis (some have an additional paediatric regional anaesthesia fellowship). The patient was positioned supine with a blanket under the ipsilateral shoulder as a bump. Long-axis, in-plane needle technique under continuous ultrasound (15–6 or 13–6 MHz linear probe) guidance was used to facilitate deposition of the local anaesthetic bolus and the final position of the catheter next to the visualised C5 and 6 nerve roots, usually located between the anterior and middle scalene muscles. Nerve stimulation was not used. The initial bolus of local anaesthetic given consisted of 0.2% or 0.5% ropivacaine. The concentration and initial volume of this ropivacaine bolus was up to the individual anaesthesiologist’s discretion but in general depended on the size of the patient and the calculated maximum safe dose of local anaesthetics, in addition to the observation of adequate spread around the nerves visualised under ultrasound guidance. The Pajunk Echogenic Catheter over Needle System was used (PAJUNK Medizintechnologie GmbH, Geisingen, Germany). Catheters were secured in place with Pajunk Fixocath Catheter Fixation Device (PAJUNK Medizintechnologie GmbH) and clear adhesive dressing. No tissue adhesives or other bandages were used. Prior to the end of the surgical case, the continuous infusion of 0.2% ropivacaine in an ON-Q (Avanos Medical Inc, Irvine, California, USA) pump (335 mL or 550 mL, filled by pharmacy) was initiated with the rate determined by the anaesthesiologist based on patient weight (most often 0.1–0.15 mL/kg) but less than or equal to the institution standard maximum dose of 0.2 mL/kg and/or 6 mL/hour.
All patients were taken to the PACU where pain intensity was assessed using a validated Numeric Rating Scale ranging from 0 to 10.13 Intravenous morphine (dose of 0.025–0.05 mg/kg as needed) or oral oxycodone (dose of 0.1 mg/kg as needed) was administered at the nurse’s discretion. Antiemetics were administered as necessary. Nurses performed all home care teaching related to the ISCs (including instructions for removal) and medication administration. All patients were discharged from the PACU with prescriptions for acetaminophen, an NSAID (ibuprofen or naproxen) and oxycodone. The dose of oxycodone was 5 mg tabs, except in one patient who was >100 kg and used 10 mg. Patients were instructed to take scheduled acetaminophen and ibuprofen/naproxen independent of pain level and oxycodone only on an as needed basis.
An anaesthesiologist called the families on postoperative days (PODs) 1, 2 and 3 (or until it was confirmed the catheter was safely removed) to obtain data regarding pain intensity scores, opioid and other medication usage, catheter dressing integrity, signs of local anaesthetic toxicity and overall satisfaction.
Descriptive statistics were calculated. Continuous variables (ie, age) were expressed as means and ranges or SD, and categorical variables (ie, side) were expressed as number and percentage. All data were tabulated in Microsoft Excel (version 2012; Microsoft), and analyses conducted using STATA 14.2 (StataCorp).
Patient characteristics are summarised in table 1. The mean age at the time of surgery was 15.4±1.8 years (range 12–19 years). Seventy-two per cent were male, and the mean weight was 75.8±19.8 kg. 88.9% of surgeries were arthroscopic labral repairs and/or capsulorrhaphies. The mean time for ISC placement was 11.8±3.8 min. Eighty-six per cent of the patients had 0.5% ropivacaine (mean dose 0.17±0.05 mL/kg) for the initial bolus dose of local anaesthetic during placement of the ISC; 14% were bolused with 0.2% ropivacaine (0.22±0.04 mL/kg). The 0.2% ropivacaine infusions were set at mean rates of 0.06±0.02 mL/kg/hour, which is a range of 3–6 mL/hour and a mode of 4 mL/hour. These rates were not changed (or bolused) in the postoperative period.
Intraoperative and PACU analgesic data are presented in tables 2 and 3, respectively. The most common PACU pain intensity score was 0, with 22 patients (63%) reporting no pain. The mean maximum pain intensity score of 1.6±2.4 excluded one patient who described pain outside of the surgical area (back pain). Four patients (11%) received rescue morphine doses (from 0.025 mg/kg to 0.05 mg/kg) for analgesia. This did not include the patient who had back pain.
POD 1–3 data are summarised in table 4, with data acquisition rates between 60% and 75%. Notably, 44% of patients on POD 1, 41% of patients on POD 2% and 63% of patients on POD three did not require any oxycodone for pain management. Of the 31 patients who responded with satisfaction data, 94% were very or somewhat satisfied and 97% would elect to have a catheter placed again.
Adverse events are summarised in table 5. Adverse events were noted in three patients who developed possible Horner’s syndrome with telephone reported symptoms including the subjective feeling of ipsilateral facial swelling, nasal congestion and/or ptosis at some point in the postoperative period (ranged from POD 1–3), though none of the cases had these symptoms for all three PODs. No adjustments were made to the catheter infusion rates as all symptoms were transient and tolerable, and additionally, families were not instructed to self-adjust the pumps for safety reasons. One patient reported having ipsilateral facial numbness on the morning of POD 3. She removed the catheter that morning at the time she was already planning on removing it, and the numbness had resolved by the time a follow-up call occurred a few hours later. Early catheter removal occurred in five patients (prior to POD 3). Two occurred at the end of surgery, likely while pulling off the drapes. The team attempted to replace one of the catheters, but the anatomy was distorted enough from the initial bolus dose of local anaesthetic that the procedure was aborted. The second patient was able to have their catheter replaced prior to emergence (it was not rebolused with local anaesthetic). One occurred accidentally in the PACU and was not replaced. The remaining two were on POD 2. One was due to dressing failure (adhesive dressing had ‘lifted off’, no documented leaking) and one due to insertion site discomfort (though good pain control otherwise). No catheters were removed because of Horner’s syndrome. There were no signs of local toxicity and no complications requiring readmission, reoperation or ongoing medical treatment. Additionally, while pain scores were not documented regularly on POD 4, there were no patients requiring increased opioid prescription or admission due to rebound pain after catheter removal.
The principal finding of this study is that ISCs are feasible in adolescents, and similar to the adult literature, provide effective intraoperative and early postoperative analgesia in patients undergoing ambulatory shoulder surgery. Patients in this study had excellent pain-related postoperative outcomes, including low PACU pain scores, minimal perioperative and home opioid consumption, low rates of postoperative nausea and vomiting and no complications requiring readmission, reoperation or ongoing medical treatment. The routine use of ISCs should be considered as they minimise perioperative opioid use with minimal adverse events.
Multimodal analgesia is strongly recommended to limit the use of opioids in the postoperative period.14 Our study found that the use of ISCs resulted in 86% of patients having a surgical (intraoperative and PACU) experience completely free of long-acting opioids. Moreover, 11 patients (31%) had a completely opioid-free surgery day (no short-acting or long-acting opioids administered intraoperatively or in the PACU). Postoperatively, patients required, on average, <2 doses of oral opioids per 24-hour period. Patients required <1 dose on POD 3. Likely, this is a combination of both the regional technique and an effective oral multimodal analgesia plan. Note the low intraoperative and PACU opioid use could be completely illustrative of the bolus of local anaesthetic used during placement of the catheter, while data for the remaining PODs is reflective of the catheter efficacy.
Overall, the majority of patients were satisfied with their ISC and would have them again if needed for future surgery. However, the two patients and families who reported being unsatisfied were due to multifactorial reasons: inadequate analgesia plus either bothersome catheter dressing location or transient symptoms consistent with Horner’s syndrome. Despite being unsatisfied to some degree, both families would consider having an ISC placed for future surgeries.
When compared with two adult meta-analyses of peripheral nerve catheters, and specifically the ISC subgroup, the postoperative pain scores in this study are similar.7 15 These studies measured rest and dynamic (or maximum) pain scores on POD 1–3 at values less than 2 or 4, respectively.7 15 While there are not readily available paediatric cohorts of solely ISCs looking at analgesic data, large reviews of peripheral nerve catheters of all types (upper and lower extremities, all surgeries) in paediatric patients have also demonstrated similar results. In a retrospective review of 37 patients, Visoiu et al 16 demonstrated postoperative maximum pain scores less than 4 on all POD 1–3, while Gurnaney et al 17 reported 75% of 1285 patients either required no opioids postoperatively or used only as needed dosing (less than scheduled dosing). The majority of complications in that study were related to catheter malfunction, either leaking or accidental dislodgment. Additionally, the satisfaction scores in this study are comparable with those reported in multiple reviews in mixed populations.15 16
In 2015, Gurnaney et al 12 published a large cohort of 154 paediatric and adolescent patients who received ISCs and demonstrated safety with placement under general anaesthesia. Later that year, the European and American Societies of Regional Anesthesia jointly published guidelines recommending that paediatric regional anaesthesia performed under deep sedation or general anaesthesia should be the standard of care, supporting their results.18 The findings in this study additionally support these same recommendations. In addition to reporting adverse events, additional objectives were to collect the details of block placement, dosing strategies and analgesic effectiveness. ISCs in this study were placed using a different technique than that of Gurnaney et al 12 (lateral positioning, out-of-plane needle technique, nerve stimulation and fluoroscopy). Also there were lower infusion rates in this study (6–8 mL/hour vs 3–6 mL/hour), and surgeries in this study were performed solely in the ambulatory setting. This study demonstrated different practice of performing the block, collecting opioid consumption and pain scores for 3 days postoperatively, as well as patient and family satisfaction information.
According to the 2015 analysis of the Pediatric Regional Anesthesia Network database, the most common complications of peripheral nerve catheters were catheter malfunction, block failure, infection and vascular puncture.19 Of the 2074 peripheral nerve catheters included in the database, there were no reports of local anaesthetic systemic toxicity, persistent neurological problems or deep tissue infections.19 Similarly, there were no concerns for infection (deep or superficial), toxicity or persistent neurological problems in this study. The most common complications also revolved around catheter malfunction: dislodgement, dressing malfunction and so on. Two of the ISCs were dislodged at the end of surgery (one was replaced immediately), and another was accidentally removed in the recovery room. There was one dressing failure at home (adhesive bandage lifted off and no documentation of leaking) that led to early removal.
There were three likely cases of Horner’s syndrome, though all were transient (meaning no symptoms lasted for all three PODs). They occurred on different days from each other, and no patient was ever examined by a medical professional. This is a known potential side effect, which was explained during the consent process, due to the spread of local anaesthetic to the superior cervical ganglion. No family felt the need to remove the catheter because of the symptoms, and none required any follow-up as all the symptoms resolved in less than 24 hours. There were no adjustments to the infusion rates in effort to avoid any patient or family manipulation of the infusion for safety reasons. Additionally, there were no clear associations between volume of initial loading bolus dose, infusion rates and the development of Horner’s syndrome symptoms. The rates of Horner’s syndrome in the literature (adolescents to adults) range from 1.5% to 37.5%.12 20 Stasiowski et al 20 suggests that a higher water concentration in the prevertebral space of younger patients might encourage local anaesthetic spread and increase their rates of Horner’s syndrome. This is not reliably reproduced in the literature, likely because of high under-reporting rates and significant variability in dosing of local anaesthetics.
A few notable limitations are worth mentioning. Largely, this was a retrospective review of a small cohort of patients of a single surgeon. As there was no control group, the superiority of postoperative pain control using ISCs over any other technique cannot be determined. Some variables that could potentially affect the results (eg, race, ethnicity, socioeconomic status, private vs public insurance) were not included. Larger studies in the future should take those variables into account. Another significant detriments to this dataset was the lack of documented follow-up data on PODs 1, 2 and 3. This is due to a multitude of reasons: the anaesthesiologist was unable to reach the patient via telephone, the patient was unable to quantify their pain score in a number or the anaesthesiologist did not fully transcribe the pain scores or opioid consumption. The patients are not required to record pain scores or medication usage; therefore, their daily accounts are reliant on their subjective memory of the last 24 hours. The institution of a pain journal/medication log in the future can more accurately detail opioid usage to help direct future prescribing practices. Physical exams were not performed during PODs 1–3, so additional adverse events may not have been identified.
Limitations due to clinical heterogeneity in the anaesthesia and nursing care are also present. A subset of anaesthesiologists from the department work at the ambulatory centre, somewhat decreasing the variety of providers placing the ISCs; however, there was still some variability—mainly in the concentration and volume of local anaesthetic. While the majority of providers used 0.5% ropivacaine for the initial loading dose during catheter placement, five elected to use a more dilute concentration of 0.2% ropivacaine. While one would expect the patients with a less potent loading dose to have increased pain scores in the recovery room (and potentially into POD 1), four of the patients had PACU pain scores of 0 at the surgical site, one had score of 1 and none received any opioids. Over the first 24 hours, these patients had mean pain scores and opioid usage within 1 SD of the cohort (scores of 2 and 3 out of 10). The concentration of the initial loading dose with respect to postoperative analgesia will need to be further examined with future studies.
The use of ISCs in adolescent ambulatory shoulder surgery is beneficial, providing effective intraoperative and early postoperative analgesia as evidenced by low pain scores and minimal opioid use. Their routine use should be considered as they minimise perioperative opioid use with minimal adverse events.
Contributors EH (lead author): data curation and writing – original draft. DL: conceptualisation, methodology, writing – review and editing, and supervision. VB: formal analysis and writing – review and editing. MS (corresponding/senior author): conceptualisation, data curation, writing – original draft, review and editing, and visualisation.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests MS has received consulting fees and research support from Arthrex, Inc.
Patient consent for publication Not required.
Ethics approval Institutional review board approved.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information. Not applicable.
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