ISSN NUMBER: 1938-7172
Issue 12.9 VOLUME 12 | NUMBER 9

Editor:
Michael A. Fiedler, PhD, CRNA

Associate Editor:
Mary A Golinski, PhD, CRNA

Contributing Editors:
Mary A Golinski, PhD, CRNA
Dennis Spence, PhD, CRNA

Assistant Editor
Jessica Floyd, BS

A Publication of Lifelong Learning, LLC © Copyright 2018

New health information becomes available constantly. While we strive to provide accurate information, factual and typographical errors may occur. The authors, editors, publisher, and Lifelong Learning, LLC is/are not responsible for any errors or omissions in the information presented. We endeavor to provide accurate information helpful in your clinical practice. Remember, though, that there is a lot of information out there and we are only presenting some of it here. Also, the comments of contributors represent their personal views, colored by their knowledge, understanding, experience, and judgment which may differ from yours. Their comments are written without knowing details of the clinical situation in which you may apply the information. In the end, your clinical decisions should be based upon your best judgment for each specific patient situation. We do not accept responsibility for clinical decisions or outcomes.

Table of Contents

PHARMACOLOGY
Multimodal analgesia decreases opioid consumption after shoulder arthroplasty: a prospective cohort study
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A randomized comparison between intravenous and perineural dexamethasone for ultrasound-guided axillary block
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Cost-effectiveness of intravenous acetaminophen and ketorolac in adolescents undergoing idiopathic scoliosis surgery
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None of the editors or contributors have any real or potential conflicts of interest to disclose.
 
This is the final issue of five issues by Dr. Mary Golinski about acute and chronic postoperative pain management.
 
This program has been prior approved by the American Association of Nurse Anesthetists for 20 Class A CE credits; Code Number 1035464; Expiration Date 10/31/2020.

Pharmacology
Multimodal analgesia decreases opioid consumption after shoulder arthroplasty: a prospective cohort study

J Shoulder Elbow Surg 2018;27:686–691

DOI: 10.1016/j.jse.2017.11.015

McLaughlin DC, Cheah JW, Aleshi P, Zhang AL, Ma CB, Feeley BT


Abstract

 

Purpose   The purpose of this study was to test the hypothesis that postoperative multimodal analgesia would provide superior pain relief after shoulder arthroplasty compared to a standard opioid-based analgesia regimen. Secondary purposes included comparing total postoperative opioid consumption, hospital length of stay, readmission rates, emergency department visits after discharge, and total cost of perioperative care.

 

Background   The volume of shoulder arthroplasty procedures performed in the USA has grown exponentially over the years. Postoperative pain however remains the most common complaint voiced by patients. Multimodal analgesia approaches have been deemed efficacious in managing postoperative pain, coupled with decreased opioid consumption, in lower extremity total joint procedures. There is, however, a lack of evidence supporting multimodal analgesia in shoulder arthroplasty. The use of peripheral nerve blocks is common for pain management following shoulder arthroplasty. These appear to be most effective in the PACU and on postoperative day one. They are often used in conjunction with opioids. Since postoperative pain is significant in this surgical population, strategies to better control pain without solely depending on opioids and risking the numerous adverse effects from opioids, is sought after.

 

Methodology   The study was a prospective two – cohort comparative analysis design. Patients undergoing elective primary or revision shoulder arthroplasty were sequentially placed in one of two groups. Group 1, the first 75 participants scheduled for elective shoulder arthroplasty, received an interscalene brachial plexus block with 15-20 mL of 0.5% ropivacaine. Adjunct analgesia consisted of hydrocodone/acetaminophen 2 tabs (10 mg/325 mg) every 4 hours and oxycodone and/or hydromorphone PRN for breakthrough pain. Group 2, the second 75 participants, received the same interscalene brachial plexus block but received multimodal analgesia consisting of preoperative celecoxib 400 mg, gabapentin 600 mg, and 1,000 mg of either IV or PO acetaminophen. Postoperative analgesia included naproxen 500 mg every 12 hours, gabapentin 300 mg every 8 hours, and acetaminophen 1,000mg PO or IV. Oxycodone, 5 mg every 4 hours was administered for breakthrough pain if needed.

 

Comparisons were made between groups for pain scores, total opioid consumption, length of hospital stay, total hospital cost, 30-90 day readmission rates, emergency department visits, and all adverse/side effects of opioids.

 

The study was powered to detect a difference of 10% in oral morphine equivalent consumption. A minimum sample size of 62 was required.

 

Result   There were no differences in the demographic profiles of the two groups, including surgery type, mean surgery time, or ASA physical status. The average pain score on the day of surgery for Group 1 was 2.2 (on a scale of 0-10) compared with Group 2 mean score of 1.5. Mean pain scores on post operative day (POD) 1 and 2 were slightly, but not significantly, lower in Group 2 (3.4) compared to Group 1 (4.1).

 

Opioid consumption, interestingly, was significantly lower on surgery days 0, and postoperative days 1 and 2, in Group 2, the multimodal analgesia group. Opioid use was decreased by 40% on day 0, 37% on POD 1, and 44% on POD 2, compared to Group 1 (P < 0.01). Antiemetic requirements were lower in the multimodal group (Group 2) as was the average hospital cost ($1,000 less), but neither were statistically significant. Significance was established for hospital length of stay: 1.4 + 0.7 days for Group 2 compared to 1.9 + 1.1 days for Group 1 (P < 0.01). Lastly, there was no significant difference between groups in the 30 or 90-day emergency department visits or in unplanned hospital readmissions.

 

Conclusion   A multimodal pain regimen significantly decreased opioid consumption and hospital length of stay, and demonstrated lower pain scores throughout hospitalization after shoulder arthroplasty. Perioperative complications, readmission rates, and emergency department visits were not significantly different between the two groups.

 

Comment

 

Multimodal analgesia is commonly described as capitalizing on the efficacy of individual drugs and their distinct mechanisms of action, in optimal doses that lessen the pain response, and therefore have potential to avoid side effects from any one analgesic, mainly opioids. The theory behind this concept is that mechanisms of analgesia demonstrate synergistic effects in treating acute postoperative pain; obviously most beneficial when used in multiple combinations. Acute pain is commonly rated very high on the pain rating scales following shoulder arthroplasty. The literature reports the prevalence of persistent pain 1–2 years after primary shoulder replacement ranges ~ 22% (higher in fracture and osteoarthritis patients). It is critical to know that blocking the neuronal pain pathways with local anesthetics, i.e. prior to incision interscalene nerve blocks, does not decrease the humeral biochemical responses that occur because of surgery (tissue trauma). Systemic pharmacological therapy must inhibit these. This research offered evidence that multimodal pharmacologic therapy does decrease the pain response secondary to surgery induced tissue trauma. Additionally, when used in combination with an interscalene block, the results are superior to mono therapy with opioids.

 

Another very useful report was the cost comparison. Anesthetists may assume that because multimodal therapy means the administration of several drugs, the cost benefit ratio is not favorable. But the actual costs were lower for both OR and perioperative services, and in- patient hospitalization, in the multi modal group. It begs the question, was the recovery period better tolerated because of reduced pain, and therefore those in the multimodal group had a less expensive encounter and a more expedient discharge? While not statistically significant, the overall benefits of early hospital discharge – even if related to several variables – is extremely important. Below is the breakdown of hospital costs by study group.

 

 

Standard Therapy Group

Multimodal Group

OR and Perioperative Services

$3,686

$3,248

Implant cost

$6,451

$6,507

Medications

$668

$746

Supplies

$2,520

$2,432

In-patient room/board

$2,433

$1,844

 

Mary A Golinski, PhD, CRNA


© Copyright 2018 Anesthesia Abstracts · Volume 12 Number 9, May 30, 2018





A randomized comparison between intravenous and perineural dexamethasone for ultrasound-guided axillary block

Can J Anaesth 2017;64:29-36

DOI: 10.1007/s12630-016-0741-8

Aliste J, Leurcharusmee P, Engsusophon P, Gordon A, Michelagnoli G, et al


Abstract

 

Purpose   The purpose of this study was to compare two different routes of dexamethasone administration for length of sensory and motor block in an ultrasound-guided axillary block. The routes were perineurally in combination with a local anesthetic and intravenously (IV).

 

Background   Dexamethasone is commonly added to the local anesthetic for brachial plexus block. The efficacy of this route of administration on prolongation of both sensory and motor block has not been well established. Contradictory findings have been theorized to be the result of varying doses of both dexamethasone and local anesthetic, as well as sample sizes that were too small to detect significant differences. Research previously conducted by the authors of this study revealed that perineurally administered dexamethasone prolonged sensory and motor block for infraclavicular brachial plexus block. This study sought to validate their findings using a different approach to the brachial plexus.

 

Methodology   This was a prospective, double blinded, randomized, comparison of two groups. One hundred and fifty subjects from two different hospitals were randomized into an IV Dexamethasone group or a Perineural Dexamethasone group. All participants received an axillary block in a standardized fashion with 1% lidocaine and 0.25% bupivacaine (obtained by mixing equal parts of 2% lidocaine and 0.5% bupivacaine). Additionally, epinephrine 5 µg/mL was added to the local anesthetic admixture. A total of 24 mL of solution, that included either dexamethasone or normal saline, was injected in the following manner:

  • Perineural Dexamethasone – 8 mg preservative free dexamethasone mixed with local anesthetic & normal saline IV
  • IV Dexamethasone – normal saline mixed with local anesthetic & 8 mg preservative free dexamethasone IV.

All aspects of axillary block technique were recorded including: performance time, number of needle passes, procedural pain scores, unintentional vascular puncture, and occurrence of paresthesias. Sensory block of the musculocutaneous, median, radial, and ulnar nerves were graded individually using a 3- point scale.

  • 0 = no block
  • 1 = analgesia
  • 2 = anesthesia

Motor block was graded on a 3-point scale for the same nerves.

  • 0 = no block
  • 1 = paresis
  • 2 = paralysis

The maximal composite score any one patient could receive was 16 points; 2 points for each of 4 nerves for both sensory and motor block (2x4x2=16). A successful block was operationally defined as a score of 14 or more points. A blinded observer documented the presence of surgical anesthesia – the ability to proceed with surgery without any supplemental opioids, conversion to general anesthesia, rescue blocks or local anesthetic infiltration. If the patient exhibited anxiety during the procedure, sedation was provided with propofol via controlled infusion. The goal was to maintain a level that allowed for positive responses to verbal stimuli. The following was recorded postoperatively for those who had a successful block:

  • duration of motor block (movement of fingers)
  • duration of sensory block (sensation in fingers)
  • duration of analgesia (time to pain at the surgical site)

One week after surgery the participants were contacted and assessed for complications of the axillary block.

 

Result   A total of 150 patients were randomized, 75 in each group. After exclusions for failed blocks, loss at follow up, and the block wearing off during sleep cycles, the IV Dexamethasone group had 67 subjects. The Perineural Dexamethasone group had 64 subjects. There were no significant differences in the demographic profiles of the two groups nor the technical aspects of the axillary blocks.

Compared to the IV Dexamethasone group, the Perineural Dexamethasone group had a:

  • Longer motor block: 17.5 (4.6) h vs. 13 (4.5) h (P<0.001)
  • Longer sensory block: 18 (5) h vs. 14 (5) h (P< 0.001)
  • Longer postoperative analgesia: 21 (4.6) hours vs. 17 (4.6) h (P<0.001)

There were no complications noted upon postoperative follow up.

 

Conclusion   This randomized trial validated the results of the investigators’ previous research. Compared to IV dosing, 8 mg perineurally administered dexamethasone added to the local anesthetic for axillary blocks provided longer motor and sensory blockade and prolonged postoperative analgesia by about 4 hours each.

 

Comment

 

The authors of this clinical trial discuss the substantial benefits of adding dexamethasone to local anesthetic for perineural administration; these include prolongation of analgesia that can result in uninterrupted rest and sleep cycles, and the decreased reliance on strong analgesics throughout the recovery period. The safety concerns of perineural dexamethasone are specific to neurotoxicity. This is most likely because of preservatives and/or particulates in the solution. The use of preservative free dexamethasone should prevent these complications. In addition, while the drug is not approved for use in this fashion, off label use is allowed and we have been using numerous adjuvants added to local anesthetics to enhance aspects of regional anesthesia for decades. The axillary block technique employed included a separate injection at the musculocutaneous nerve (6 mL of solution deposited around the nerve). The remainder of the local anesthetic solution was injected dorsal to the axillary artery. It was assumed that blockade of the median, radial, and ulnar nerves was by simple diffusion. Limitations of the study included reporting pain by patient report. However, I personally never underestimate the ability of a patient to offer detail of discomfort and pain.

 

Mary A Golinski, PhD, CRNA


NOTES: Dexamethasone sodium phosphate is an adrenocortical steroid anti-inflammatory drug. It is approved for intravenous, intramuscular, intra-articular, and soft-tissue injections, but is off label for perineural use. Each mL of dexamethasone sodium phosphate injection, USP (Preservative Free), contains dexamethasone sodium phosphate, USP equivalent to 10 mg dexamethasone phosphate; 24.75 mg sodium citrate, dihydrate; and water for injection. It is pH adjusted with citric acid or sodium hydroxide, if necessary for pH: 7.0 to 8.5.

 

For more information regarding the safety and efficacy of perineural dexamethasone, Dr. Golinski recommends:

 

Zhao WL, Ou XF, Liu J, Zhang WS. Perineural versus intravenous dexamethasone as an adjuvant in regional anesthesia: a systematic review and meta-analysis. J Pain Res. 2017;10:1529–1543.


© Copyright 2018 Anesthesia Abstracts · Volume 12 Number 9, May 30, 2018





Cost-effectiveness of intravenous acetaminophen and ketorolac in adolescents undergoing idiopathic scoliosis surgery

Paediatr Anaesth. 2018;28:237-248

DOI: 10.1111/pan.13329

Chidambaran V, Subramanyam R, Ding L, Sadhasivan S, Geisler K, et al


Abstract

 

Purpose   The purpose of this study was twofold; first to determine if IV acetaminophen and/or ketorolac was an efficacious analgesic for children between the ages of 10 and 16 years having surgery for idiopathic scoliosis. Second, to determine if these analgesics were associated with fewer adverse effects compared to opioids alone, thus resulting in a more cost-effective perioperative experience.

 

Background   Spinal fusion surgery is used for correcting idiopathic scoliosis, an abnormal curvature of the spine that appears in late childhood or adolescence, typically between the ages of 10 and 16 years. It has also been identified as a procedure associated with significant healthcare costs. Most of the expenditures are due to the multifaceted components of inpatient care including the perioperative period and postoperative pain management. Enhanced recovery after surgery (ERAS) protocols have become critically important in this subset of the population. The postoperative analgesic needs are relatively high. As a result, recovery is very often prolonged and fraught with complications. Identifying efficacious pain management modalities that minimize the adverse effects of opioids have potential to positively influence outcomes, and reduce healthcare costs. Decision-analytic modeling is a useful tool for synthesizing available evidence. It is increasingly used to estimate the safety and efficiency of healthcare interventions. Using this model, the researchers evaluated the value of including IV acetaminophen and IV ketorolac in a postoperative pain management treatment regime post spinal fusion surgery, and the “cost-per-opioid” side effects avoided for this patient group.

 

Methodology   This study was prospective and included 106 otherwise healthy children and adolescents aged 10 -18 years undergoing spinal fusion surgery for idiopathic scoliosis. Participants received a standardized total intravenous anesthetic that included midazolam, fentanyl, propofol, and remifentanil. Dexamethasone 8 mg and ondansetron 0.1 mg/Kg were administered for PONV prevention. After surgery, PCA analgesia with either morphine or hydromorphone was initiated via a standardized weight based protocol. Three distinct groups were formed a priori by discretion of a pain team and based upon surgeon preferences and patient demographic profile:

  • Opioid: opioids as the sole analgesic therapy - morphine or hydromorphone IVPCA
  • Opioid Acetaminophen: Opioid plus Acetaminophen 15mg/Kg (max 1 gm) every 6 hours for 3 days; first dose intraoperative
  • Opioid Acetaminophen Ketorolac: Opioid, Acetaminophen as above, Ketorolac 0.5 mg/Kg (max 30 mg) every 6 hours for 8 doses starting intraoperatively or postop day one

Additionally, a standardized pain protocol was implemented for all groups:

  • Continuous monitoring for respiratory depression
  • Diazepam as needed for muscle spasms
  • Methocarbamol every eight hours for three days
  • Oxycodone started at 0.1mg/Kg every four hours once on oral diet after PCA discontinued
  • Standardized bowel regimen
  • PO acetaminophen after PCA discontinued for those NOT receiving IV acetaminophen
  • PO acetaminophen after PCA discontinued in those in IV acetaminophen group after course completed

The effectiveness of each of the three analgesia regimes was operationally defined as avoiding opioid side effects. The three groups were compared for differences in:

  • surgical variables
  • perioperative opioid use
  • perioperative diazepam use
  • pain scores (0-10)
  • PONV
  • respiratory depression
  • PO intake
  • GI paralysis (constipation)
  • total hospital length of stay
  • total cost of service

A cost effectiveness comparison was also made between the three groups and was used to determine if a more effective strategy for minimizing opioid side effects also demonstrated a reduction in total cost of care. In other words, the outcomes of “no opioid side effects,” or “fewer side effects,” was calculated as cost data via a fairly complex decision analytical model, and comparisons made between groups.

 

Results   Demographics did not vary significantly between groups. No patients received hydromorphone therefore calculating morphine equivalents was unnecessary. For the entire cohort:

  • mean morphine use POD 1 = 1.2 + 0.5 mg/Kg
  • Length of hospital stay = 4.8 days + 1.4 days
  • Time to PO intake = 2.3 days + 1.3 days
  • Treatment for gut immobility = 3.6 days + 2.9 days

Total cost of care:

  • Opioid = $15,474
  • Opioid Acetaminophen = $14,964
  • Opioid Acetaminophen Ketorolac = $14,527

Compared to the Opioid only group, both the Opioid Acetaminophen group (P = 0.006) and the Opioid Acetaminophen Ketorolac group (P = 0.002) used significantly less morphine postoperatively (1.6 mg/Kg vs. 2 mg/Kg). Furthermore, the Opioid Acetaminophen Ketorolac group tolerated PO intake and had less constipation than the Opioid only group (P < 0.001). Hospital length of stay, while not statistically significant, was an average of 0.5 days shorter in both the Opioid Acetaminophen group and the Opioid Acetaminophen Ketorolac group.

 

Using the decision analytical model, the Opioid Acetaminophen Ketorolac group was determined to be the least costly and most effective strategy. Conversely, the Opioid only group was the most expensive and least effective strategy. The addition of IV Acetaminophen to the Opioid only strategy, with or without ketorolac, saved $510 to $947 per patient and decreased opioid side effects. Adding ketorolac to the Opioid Acetaminophen group further increased net savings and improved efficacy.

 

Conclusion   The strategy of combining opioids with acetaminophen and ketorolac for pain management after spine surgery for scoliosis avoided significant opioid adverse effects, such as delayed oral intake and gut paralysis, and resulted in significant cost savings relative to an opioid only therapeutic regimen.

 

Comment

 

While this was an extremely involved read, due to the analytic and statistical procedures used, the take home message was clear. The overall cost of care for this specific clinical scenario is very high. This is the result of a lengthy and complex surgical procedure, the magnitude of surgical tissue trauma, the course of recovery/rehabilitation, and the intricacies of postoperative pain management. Understandably, the analgesic needs are typically moderate to very high. Many may have been skeptical of the use of over-the-counter pain relievers, even in IV form, to provide adequate pain relief for such a complex surgery. But, the addition of IV acetaminophen and ketorolac to opioids actually resulted in less overall opioid use, fewer opioid related side effects, and ultimately a reduced total cost of care. This is a universally desired clinical outcome – a therapeutic regimen that provides the needed analgesia allowing for an enhanced recovery, a very low adverse effect profile, safety that is NOT compromised, and cost savings that are significant. This is exactly how we should approach so many decision making processes but it isn’t always how it is.

 

My clinical experiences, and those of our colleagues, note that we are still challenged on the use of analgesics such as IV acetaminophen because of its “cost.” The bigger picture is not always appreciated by decision makers. This research can be used to educate and inform those who may not understand the clinical complexities our patients are faced with and the challenges we are faced with when providing care. I would encourage all to obtain a copy of the full manuscript and share it with financial decision makers. It has great potential to change clinical regimens with a result of improved outcomes, higher quality, and significant cost savings.

 

Mary A Golinski, PhD, CRNA


Editor’s Note: I want to chime in and agree wholeheartedly with Dr. Golinski’s analysis. The cheapest drug is not always the least expensive; it may not do the job or may make things worse. The most expensive drug is not always the most costly. It may, as seen in this study, actually decrease the total cost of care while at the same time reducing side effects and improving patient outcomes. A win, Win, WIN.

 

Thank you, Dr. Golinski, for this series of five outstanding issues about acute pain management. I’m betting that everyone who has read them has learned something they can immediately use in their practice.

Michael A. Fiedler, PhD, CRNA


© Copyright 2018 Anesthesia Abstracts · Volume 12 Number 9, May 30, 2018