Observational study of the effect of ketamine infusions on sedation depth, inflammation, and clinical outcomes in mechanically ventilated patients with SARS-CoV-2

Severely ill patients with COVID-19 are challenging to sedate and often require high-dose sedation and analgesic regimens. Ketamine can be an effective adjunct to facilitate sedation of critically ill patients but its effects on sedation level and inflammation in COVID-19 patients have not been studied. This retrospective, observational cohort study evaluated the effect of ketamine infusions on inflammatory biomarkers and clinical outcomes in mechanically ventilated patients with SARS-CoV-2 infection. A total of 186 patients were identified (47 received ketamine, 139 did not). Patients who received ketamine were significantly younger than those who did not (mean (standard deviation) 59.2 (14.2) years versus 66.3 (14.4) years; P = 0.004), but there was no statistically significant difference in body mass index (P = 0.25) or sex distribution (P = 0.91) between groups. Mechanically ventilated patients who received ketamine infusions had a statistically significant reduction in Richmond Agitation-Sedation Scale score (-3.0 versus -2.0, P < 0.001). Regarding inflammatory biomarkers, ketamine was associated with a reduction in ferritin (P = 0.02) and lactate (P = 0.01), but no such association was observed for C-reactive protein (P = 0.27), lactate dehydrogenase (P = 0.64) or interleukin-6 (P = 0.87). No significant association was observed between ketamine administration and mortality (odds ratio 0.971; 95% confidence interval 0.501 to 1.882; P = 0.93). Ketamine infusion was associated with improved sedation depth in mechanically ventilated COVID-19 patients and provided a modest anti-inflammatory benefit but did not confer benefit with respect to mortality or intensive care unit length of stay.

Emergence of xylazine as a public health threat: what does the anesthesiologist need to know for perioperative care?

This paper explores the rapid emergence of xylazine exposure in the USA and its implications for anesthesiologists. Xylazine, a non-opioid sedative and analgesic often used in veterinary medicine, has increasingly been found as an adulterant in the illicit substance supply, leading to serious health implications. The pharmacological properties of xylazine, its clinical effects, and the challenges it poses for clinicans will be discussed. Perioperative strategies for anesthesiologists to manage these potential cases are provided. Furthermore, this paper necessitates an epidemiological understanding for detection and multidisciplinary collaboration in addressing this emerging public health threat. The manuscript concludes by emphasizing the role anesthesiologists will have to play in managing the clinical implications of xylazine and contributing to public health strategies aimed at curbing its misuse.

Real-world study of intranasal ketamine for use in patients with refractory chronic migraine: a retrospective analysis

INTRODUCTION

Subanesthetic ketamine infusion has been used for managing refractory headache in inpatient or outpatient infusion settings. Intranasal ketamine may be an alternative option for outpatient care.

METHODS

A retrospective study was conducted at a single tertiary headache center to assess the clinical effectiveness and tolerability of intranasal ketamine in patients with refractory chronic migraine. Candidates who received intranasal ketamine between January 2019 and February 2020 were screened through an electronic medical record query. Manual chart reviews and structured telephone interviews were conducted on obtaining informed consent.

RESULTS

Of 242 subjects screened, 169 (79.9% women) of median (IQR) age 44 (22) years were interviewed. They reported a median (IQR) of 30 (9) monthly headache days and tried 4 (1) classes of preventive medications. Overall, they used 6 (6) sprays per day, with a median (IQR) of spray use of 10 (11) days per month. Intranasal ketamine was reported as 'very effective' in 49.1% and the quality of life was considered 'much better' in 35.5%. At the time of the interview, 65.1% remained current intranasal ketamine users and 74.0% reported at least one adverse event.

CONCLUSION

In this descriptive study, intranasal ketamine served as an acute treatment for refractory chronic migraine by reducing headache intensity and improving quality of life with relatively tolerable adverse events. Most patients found intranasal ketamine effective and continued to use it despite these adverse events. Given the potential for overuse, it should be reserved for those clearly in need of more effective rescue treatment with appropriate safety precautions. Well-designed prospective placebo-controlled trials are necessary to demonstrate the efficacy and safety of intranasal ketamine in patients with migraine.

Population pharmacokinetic and safety analysis of ropivacaine used for erector spinae plane blocks

INTRODUCTION

Erector spinae plane blocks have become popular for thoracic surgery. Despite a theoretically favorable safety profile, intercostal spread occurs and systemic toxicity is possible. Pharmacokinetic data are needed to guide safe dosing.

METHODS

Fifteen patients undergoing thoracic surgery received continuous erector spinae plane blocks with ropivacaine 150 mg followed by subsequent boluses of 40 mg every 6 hours and infusion of 2 mg/hour. Arterial blood samples were obtained over 12 hours and analyzed using non-linear mixed effects modeling, which allowed for conducting simulations of clinically relevant dosing scenarios. The primary outcome was the Cmax of ropivacaine in erector spinae plane blocks.

RESULTS

The mean age was 66 years, mean weight was 77.5 kg, and mean ideal body weight was 60 kg. The mean Cmax was 2.5 ±1.1 mg/L, which occurred at a median time of 10 (7-47) min after initial injection. Five patients developed potentially toxic ropivacaine levels but did not experience neurological symptoms. Another patient reported transient neurological toxicity symptoms. Our data suggested that using a maximum ropivacaine dose of 2.5 mg/kg based on ideal body weight would have prevented all toxicity events. Simulation predicted that reducing the initial dose to 75 mg with the same subsequent intermittent bolus dosing would decrease the risk of toxic levels to <1%.

CONCLUSION

Local anesthetic systemic toxicity can occur with erector spinae plane blocks and administration of large, fixed doses of ropivacaine should be avoided, especially in patients with low ideal body weights. Weight-based ropivacaine dosing could reduce toxicity risk.

TRIAL REGISTRATION NUMBER

NCT04807504; clinicaltrials.gov.

Caring for Our Patients With Opioid Use Disorder in the Perioperative Period: A Guide for the Anesthesiologist

Opioid use disorder (OUD) is a rising public health crisis, impacting millions of individuals and families worldwide. Anesthesiologists can play a key role in improving morbidity and mortality around the time of surgery by informing perioperative teams and guiding evidence-based care and access to life-saving treatment for patients with active OUD or in recovery. This article serves as an educational resource for the anesthesiologist caring for patients with OUD and is the second in a series of articles published in Anesthesia & Analgesia on the anesthetic and analgesic management of patients with substance use disorders. The article is divided into 4 sections: (1) background to OUD, treatment principles, and the anesthesiologist; (2) perioperative considerations for patients prescribed medications for OUD (MOUD); (3) perioperative considerations for patients with active, untreated OUD; and (4) nonopioid and nonpharmacologic principles of multimodal perioperative pain management for patients with untreated, active OUD, or in recovery. The article concludes with a stepwise approach for the anesthesiologist to support OUD treatment and recovery. The anesthesiologist is an important leader of the perioperative team to promote these suggested best practices and help save lives.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

Celecoxib-tramadol co-crystal in patients with moderate-to-severe pain following bunionectomy with osteotomy: A phase 3, randomized, double-blind, factorial, active- and placebo-controlled trial

BACKGROUND

Celecoxib-tramadol co-crystal (CTC) is a first-in-class analgesic co-crystal of celecoxib and racemic tramadol with an improved pharmacologic profile, conferred by the co-crystal structure, compared with its active constituents administered alone/concomitantly.

AIM

We evaluated CTC in moderate-to-severe acute postoperative pain.

MATERIALS AND METHODS

This randomized, double-blind, factorial, active- and placebo-controlled phase 3 trial (NCT03108482) was conducted at 6 US clinical research centers. Adults with moderate-to-severe acute pain following bunionectomy with osteotomy were randomized to oral CTC (200 mg [112 mg celecoxib/88 mg rac-tramadol hydrochloride] every 12 h), tramadol (50 mg every 6 h), celecoxib (100 mg every 12 h), or placebo for 48 h. Patients, investigators, and personnel were blinded to assignment. The primary endpoint was the 0-48 h sum of pain intensity differences (SPID0-48) in all randomized patients. Pain intensity was assessed on a 0-10 numerical rating scale (NRS). Safety was analyzed in patients who received study medication. Funded by ESTEVE Pharmaceuticals.

RESULTS

In 2017 (March to November), 1323 patients were screened and 637 randomized to CTC (n = 184), tramadol (n = 183), celecoxib (n = 181), or placebo (n = 89). Mean baseline NRS was 6.7 in all active groups. CTC had a significantly greater effect on SPID0-48 (least-squares mean: -139.1 [95% confidence interval: -151.8, -126.5]) than tramadol (-109.1 [-121.7, -96.4]; p < 0.001), celecoxib (-103.7 [-116.4, -91.0]; p < 0.001), or placebo (-74.6 [-92.5, -56.6]; p < 0.001). Total treatment-emergent adverse events (TEAEs) were 358 for CTC and 394 for tramadol. Drug-related TEAEs occurred in 37.7% patients in the CTC group, compared with 48.6% in the tramadol group. There were no serious TEAEs/deaths.

CONCLUSION

CTC provided greater analgesia than comparable daily doses of tramadol and celecoxib, with similar tolerability to tramadol. CTC is approved in the United States.

A critical review of oliceridine injection as an IV opioid analgesic for the management of severe acute pain

INTRODUCTION

Oliceridine is a G protein-selective (biased) agonist at the μ-opioid receptor, with less recruitment of β-arrestin-2, a signaling pathway associated with opioid-related adverse events. Nonclinical evidence showed that oliceridine elicits a rapid systemic analgesic effect while attenuating opioid-related adverse events.

AREAS COVERED

Three pivotal studies in patients with moderate to severe acute pain, including two randomized, double-blind, placebo- and morphine-controlled efficacy studies following either orthopedic surgery-bunionectomy or plastic surgery-abdominoplasty; and an open-label safety study following a surgical procedure or due to a medical condition.

EXPERT OPINION

Poorly controlled acute postoperative pain is associated with poorer recovery, longer hospitalization, increased complications, and worse healthcare outcomes. Recently, oliceridine intravenous injection was approved for use in adults for the management of acute pain severe enough to require an intravenous opioid analgesic and for whom alternative treatments are inadequate. Introduction of this new IV opioid provides a valuable option to manage postoperative pain.

Effect of difelikefalin, a selective kappa opioid receptor agonist, on respiratory depression: A randomized, double-blind, placebo-controlled trial

Difelikefalin, a selective kappa opioid receptor agonist designed to limit central nervous system (CNS) penetration, is under development for the treatment of pruritus. Its hydrophilic, small-peptidic structure limits CNS entry, minimizing potential CNS-mediated adverse events (AEs). This study assessed the effect of difelikefalin on key relevant measures of respiratory depression in healthy volunteers. This single-center, randomized, double-blind, placebo-controlled, three-way crossover study enrolled healthy, nonsmoking volunteers. Subjects were randomized to 1 of 3 treatment sequences of difelikefalin (1.0 or 5.0 mcg/kg i.v.) or placebo on sequential days with an intervening 24 (±2) h washout period. The primary end points included incidence of increased end-tidal carbon dioxide (ETCO2 ) greater than or equal to 10 mm Hg versus baseline or a level greater than 50 mm Hg sustained greater than or equal to 30 seconds, and incidence of reduction in saturation of peripheral oxygen (SpO2 ) to less than 92% sustained greater than or equal to 30 seconds. Secondary end points included incidence of reduced respiratory rate and other safety assessments. Fifteen subjects were randomized and completed the study. No subject on placebo or difelikefalin met the increased ETCO2 or reduced SpO2 primary end point criteria for respiratory depression. All respiratory measures in each group remained near baseline values during 4-h postdose observations. No subject met the reduced respiratory rate criterion or experienced clinically significant changes in ETCO2 , SpO2 , or respiratory rate. The most commonly reported treatment-emergent AEs (TEAEs; ≥20% of subjects) were paresthesia, hypoesthesia, and somnolence in the difelikefalin arms. All TEAEs were mild and resolved without intervention. Difelikefalin 1.0 and 5.0 mcg/kg i.v. did not produce respiratory depression.

Ketamine in the Past, Present, and Future: Mechanisms, Metabolites, and Toxicity

PURPOSE OF REVIEW

While ketamine's analgesia has mostly been attributed to antagonism of N-methyl-D-aspartate receptors, evidence suggests multiple other pathways are involved in its antidepressant and possibly analgesic activity. These mechanisms and ketamine's role in the nociplastic pain paradigm are discussed. Animal studies demonstrating ketamine's neurotoxicity have unclear human translatability and findings from key rodent and human studies are presented.

RECENT FINDINGS

Ketamine's metabolites, and (2R,6R)-hydroxynorketamine in particular, may play a greater role in its clinical activity than previously believed. The activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and the mammalian target of rapamycin by ketamine are mechanisms that are still being elucidated. Ketamine might work best in nociplastic pain, which involves altered pain processing. While much is known about ketamine, new studies will continue to define its role in clinical medicine. Evidence supporting ketamine's neurotoxicity in humans is lacking and should not impede future ketamine clinical trials.

Peripherally Acting μ-Opioid Receptor Antagonists in the Management of Postoperative Ileus: a Clinical Review

Postoperative ileus (POI) and constipation are common secondary effects of opioids and carry significant clinical and economic impacts. μ-Opioid receptors mediate opioid analgesia in the central nervous system (CNS) and gastrointestinal-related effects in the periphery. Peripherally acting μ-opioid receptor antagonists (PAMORAs) block the peripheral effects of opioids in the gastrointestinal tract, while maintaining opioid analgesia in the CNS. While most are not approved for POI or postoperative opioid-induced constipation (OIC), PAMORAs have a potential role in these settings via their selective effects on the μ-opioid receptor. This review will discuss recent clinical trials evaluating the safety and efficacy of PAMORAs, with a focus on alvimopan (Entereg^®) and methylnaltrexone (Relistor^®) in patients with POI or postoperative OIC. We will characterize potential factors that may have impacted the efficacy observed in phase 3 trials and discuss future directions for the management and treatment of POI.

Oliceridine is Associated with Reduced Risk of Vomiting and Need for Rescue Antiemetics Compared to Morphine: Exploratory Analysis from Two Phase 3 Randomized Placebo and Active Controlled Trials

INTRODUCTION

Use of parenteral opioids is a major risk factor for postoperative nausea and vomiting. Conventional opioids bind to µ-opioid receptors (MOR), stimulate both the G-protein signaling (achieving analgesia); and the β-arrestin pathway (associated with opioid-related adverse effects). Oliceridine, a next-generation IV opioid, is a G-protein selective MOR agonist, with limited recruitment of β-arrestin. In two randomized, placebo- and morphine-controlled phase 3 studies of patients with moderate-to-severe acute pain following bunionectomy or abdominoplasty, oliceridine at demand doses of 0.1, 0.35, and 0.5 mg provided rapid and sustained analgesia vs. placebo with favorable gastrointestinal (GI) tolerability. In this exploratory analysis, we utilized a clinical endpoint assessing gastrointestinal tolerability, "complete GI response" defined as the proportion of patients with no vomiting and no use of rescue antiemetic to characterize the GI tolerability profile of oliceridine vs. morphine.

METHODS

A logistic regression model was utilized to compare oliceridine (pooled regimens) vs. morphine, after controlling for analgesia (using the sum of pain intensity difference [SPID]-48/24 [bunionectomy/abdominoplasty] with pre-rescue scores carried forward for 6 h). This analysis excluded patients receiving placebo and was performed for each study separately and for pooled data from both studies.

RESULTS

In the unadjusted analysis, a significantly greater proportion of patients in the placebo (76.4%), oliceridine 0.1 mg (68.0%), and 0.35 mg (46.2%) demand dose achieved complete GI response vs. morphine 1 mg (30.8%), p ≤ 0.005. In the adjusted analysis, after controlling for analgesia, the odds ratio of experiencing a complete GI response with oliceridine (pooled regimens) vs. morphine was 3.14 (95% CI: 1.78, 5.56; p < 0.0001) in bunionectomy study and 1.92 (95% CI: 1.09, 3.36; p = 0.024) in abdominoplasty study.

CONCLUSIONS

When controlled for the analgesic effects (constant SPID-48/24), the odds ratio for complete GI response was higher with oliceridine than morphine, suggesting better GI tolerability with oliceridine.

Neuraxial and peripheral misconnection events leading to wrong-route medication errors: a comprehensive literature review

We conducted a search of the literature to identify case reports of neuraxial and peripheral nervous system misconnection events leading to wrong-route medication errors. This narrative review covers a 20-year period (1999-2019; English-language publications and abstracts) and included the published medical literature (PubMed and Embase) and public access documents. Seventy-two documents representing 133 case studies and 42 unique drugs were determined relevant. The most commonly reported event involved administering an epidural medication by an intravenous line (29.2% of events); a similar proportion of events (27.7%) involved administering an intravenous medication by an epidural line. Medication intended for intravenous administration, but delivered intrathecally, accounted for 25.4% of events. In the most serious cases, outcomes were directly related to the toxicity of the drug that was unintentionally administered. Patient deaths were reported due to the erroneous administration of chemotherapies (n=16), muscle relaxants (n=4), local anesthetics (n=4), opioids (n=1), and antifibrinolytics (n=1). Severe outcomes, including paraplegia, paraparesis, spinal cord injury, and seizures were reported with the following medications: vincristine, gadolinium, diatrizoate meglumine, doxorubicin, mercurochrome, paracetamol, and potassium chloride. These case reports confirm that misconnection events leading to wrong-route errors can occur and may cause serious injury. This comprehensive characterization of events was conducted to better inform clinicians and policymakers, and to describe an emergent strategy designed to mitigate patient risk.

Blood-brain barrier: mechanisms governing permeability and interaction with peripherally acting μ-opioid receptor antagonists

The blood-brain barrier (BBB) describes the unique properties of endothelial cells (ECs) that line the central nervous system (CNS) microvasculature. The BBB supports CNS homeostasis via EC-associated transport of ions, nutrients, proteins and waste products between the brain and blood. These transport mechanisms also serve as physiological barriers to pathogens, toxins and xenobiotics to prevent them from contacting neural tissue. The mechanisms that govern BBB permeability pose a challenge to drug design for CNS disorders, including pain, but can be exploited to limit the effects of a drug to the periphery, as in the design of the peripherally acting μ-opioid receptor antagonists (PAMORAs) used to treat opioid-induced constipation. Here, we describe BBB physiology, drug properties that affect BBB penetrance and how data from randomized clinical trials of PAMORAs improve our understanding of BBB permeability.

Meeting the Challenge of Analgesia in a Pregnant Woman With Burn Injury Using Subanesthetic Ketamine: A Case Report and Literature Review

Pain management guidelines for burn injury in pregnant women are scarce. Maternal and fetal morbidity and mortality in pregnant burn patients have been shown to be higher than that of the general population, especially in severe burns. Early intervention and interdisciplinary treatment are critical to optimize maternal and fetal outcomes. Proper pain management is central to wound treatment, as poor control of pain can contribute to delayed healing, re-epithelialization, as well as persistent neuropathic pain. We present this case of a 34-year-old female patient who suffered an 18% total body surface area burn during the third trimester of pregnancy to demonstrate that ketamine can be considered as an adjunct for procedural and background analgesia during the third trimester, as part of a multimodal strategy in a short-term, monitored setting after a thorough and complete analysis of risks and benefits and careful patient selection.

Improving the therapeutic window of conventional opioids: novel differential signaling modulators

Conventional opioids are widely used for acute pain management in the postoperative setting. However, a primary concern with conventional opioids is their therapeutic window-the range between doses that produce the desired therapeutic effect (analgesia) and doses that produce unwanted opioid-related adverse events (ORAEs). Conventional µ receptor opioids have a narrow therapeutic window in part because of their mechanism of action (MoA): they bind to µ receptors and non-selectively activate two intracellular signaling pathways, leading to analgesia and to ORAEs. This review explores the clinical potential of µ receptor ligands with differential signaling. Agents with a 'differential signaling" MoA represent an innovative approach that may enhance the therapeutic window. These agents modulate µ receptor activity to selectively engage downstream signaling pathways associated with analgesia while limiting activity in downstream signaling pathways that lead to ORAEs. Differential signaling may fulfill an unmet need in the management of postoperative pain.

Mechanism of action of HTX-011: a novel, extended-release, dual-acting local anesthetic formulation for postoperative pain

BACKGROUND AND OBJECTIVES

Obtaining consistent efficacy beyond 12-24 hours with local anesthetics, including extended-release formulations, has been a challenging goal. Inflammation resulting from surgery lowers the pH of affected tissues, reducing neuronal penetration of local anesthetics. HTX-011, an investigational, nonopioid, extended-release dual-acting local anesthetic combining bupivacaine and low-dose meloxicam, was developed to reduce postsurgical pain through 72 hours using novel extended-release polymer technology. Preclinical studies and a phase II clinical trial were conducted to confirm the mechanism of action of HTX-011.

METHODS

In a validated postoperative pain pig model and a phase II bunionectomy trial, the analgesic effects of HTX-011, oral meloxicam (preclinical only), liposomal bupivacaine (preclinical only) and saline placebo were evaluated. The optimal meloxicam:bupivacaine ratio for HTX-011 and the effect of HTX-011 on incisional tissue pH were also evaluated preclinically.

RESULTS

Preclinical data demonstrate the ability of HTX-011 to address local tissue inflammation as demonstrated by a less acidic tissue pH, which was associated with potentiated and prolonged analgesic activity. In the phase II bunionectomy study, HTX-011 achieved superior and sustained pain relief through 72 hours after surgery compared with each component in the polymer.

CONCLUSIONS

Preclinical animal and clinical results confirm that the low-dose meloxicam in HTX-011 normalizes the local pH in the incision, resulting in superior and synergistic analgesic activity compared with extended-release bupivacaine. HTX-011 represents an extended-release local anesthetic with a dual-acting mechanism of action that may provide an important advancement in the treatment of postoperative pain.

TRIAL REGISTRATION NUMBER

NCT02762929.

Anaesthetic care of patients undergoing primary hip and knee arthroplasty: consensus recommendations from the International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) based on a systematic review and meta-analysis

BACKGROUND

Evidence-based international expert consensus regarding anaesthetic practice in hip/knee arthroplasty surgery is needed for improved healthcare outcomes.

METHODS

The International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) systematic review, including randomised controlled and observational studies comparing neuraxial to general anaesthesia regarding major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, genitourinary, thromboembolic, neurological, infectious, and bleeding complications. Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, from 1946 to May 17, 2018 were queried. Meta-analysis and Grading of Recommendations Assessment, Development and Evaluation approach was utilised to assess evidence quality and to develop recommendations.

RESULTS

The analysis of 94 studies revealed that neuraxial anaesthesia was associated with lower odds or no difference in virtually all reported complications, except for urinary retention. Excerpt of complications for neuraxial vs general anaesthesia in hip/knee arthroplasty, respectively: mortality odds ratio (OR): 0.67, 95% confidence interval (CI): 0.57-0.80/OR: 0.83, 95% CI: 0.60-1.15; pulmonary OR: 0.65, 95% CI: 0.52-0.80/OR: 0.69, 95% CI: 0.58-0.81; acute renal failure OR: 0.69, 95% CI: 0.59-0.81/OR: 0.73, 95% CI: 0.65-0.82; deep venous thrombosis OR: 0.52, 95% CI: 0.42-0.65/OR: 0.77, 95% CI: 0.64-0.93; infections OR: 0.73, 95% CI: 0.67-0.79/OR: 0.80, 95% CI: 0.76-0.85; and blood transfusion OR: 0.85, 95% CI: 0.82-0.89/OR: 0.84, 95% CI: 0.82-0.87.

CONCLUSIONS

Recommendation: primary neuraxial anaesthesia is preferred for knee arthroplasty, given several positive postoperative outcome benefits; evidence level: low, weak recommendation.

RECOMMENDATION

neuraxial anaesthesia is recommended for hip arthroplasty given associated outcome benefits; evidence level: moderate-low, strong recommendation. Based on current evidence, the consensus group recommends neuraxial over general anaesthesia for hip/knee arthroplasty.

TRIAL REGISTRY NUMBER

PROSPERO CRD42018099935.

APOLLO-2: A Randomized, Placebo and Active-Controlled Phase III Study Investigating Oliceridine (TRV130), a G Protein-Biased Ligand at the μ-Opioid Receptor, for Management of Moderate to Severe Acute Pain Following Abdominoplasty

Objectives

The clinical utility of conventional IV opioids is limited by the occurrence of opioid‐related adverse events. Oliceridine is a novel G protein–biased μ‐opioid receptor agonist designed to provide analgesia with an improved safety and tolerability profile. This phase III, double‐blind, randomized trial (APOLLO‐2 [NCT02820324]) evaluated the efficacy and safety of oliceridine for acute pain following abdominoplasty.

Methods

Patients received a loading dose of either placebo, oliceridine (1.5 mg), or morphine (4 mg), followed by demand doses via patient‐controlled analgesia (0.1, 0.35, or 0.5 mg oliceridine; 1 mg morphine; or placebo) with a 6‐minute lockout interval. The primary endpoint was the proportion of treatment responders over 24 hours for oliceridine regimens compared to placebo. Secondary outcomes included a predefined composite measure of respiratory safety burden (RSB, representing the cumulative duration of respiratory safety events) and the proportion of treatment responders vs. morphine.

Results

A total of 401 patients were treated with study medication. Effective analgesia was observed for all oliceridine regimens, with responder rates of 61.0%, 76.3%, and 70.0% for the 0.1‐, 0.35‐, and 0.5‐mg regimens, respectively, compared with 45.7% for placebo (all P < 0.05) and 78.3% for morphine. Oliceridine 0.35‐ and 0.5‐mg demand dose regimens were equi‐analgesic to morphine using a noninferiority analysis. RSB showed a dose‐dependent increase across oliceridine regimens (mean hours [standard deviation], 0.1 mg: 0.43 [1.56]; 0.35 mg: 1.48 [3.83]; 0.5 mg: 1.59 [4.26]; all comparisons not significant at P > 0.05 vs. placebo: 0.60 [2.82]). The RSB measure for morphine was 1.72 (3.86) (P < 0.05 vs. placebo). Gastrointestinal adverse events increased in a dose‐dependent manner across oliceridine demand dose regimens (0.1 mg: 49.4%; 0.35 mg: 65.8%; 0.5 mg: 78.8%; vs. placebo: 47.0%; and morphine: 79.3%). In comparison to morphine, the proportion of patients experiencing nausea or vomiting was lower with the 2 equi‐analgesic dose regimens of 0.35 and 0.5 mg oliceridine.

Conclusions

Oliceridine is a safe and effective IV analgesic for the relief of moderate to severe acute postoperative pain in patients undergoing abdominoplasty. Since the low‐dose regimen of 0.1 mg oliceridine was superior to placebo but not as effective as the morphine regimen, safety comparisons to morphine are relevant only to the 2 equi‐analgesic dose groups of 0.35 and 0.5 mg, which showed a favorable safety and tolerability profile regarding respiratory and gastrointestinal adverse effects compared to morphine. These findings support that oliceridine may provide a new treatment option for patients with moderate to severe acute pain where an IV opioid is warranted.

Tapentadol immediate release for moderate to severe acute post-surgery pain

OBJECTIVE

To investigate efficacy and tolerability of tapentadol immediate release (IR) in the treatment of moderate to severe acute pain in three surgical pain models.

DESIGN

Three randomized, double-blind, placebo- and active-controlled, multicenter, phase 3 trials were performed in total hip replacement surgery, abdominal hysterectomy, and bunionectomy with trial medications administered every 4-6 hours as needed for up to 72 hours. Tapentadol IR was included in all trials, oxycodone IR in the total hip replacement trial, and morphine IR in the abdominal hysterectomy and bunionectomy trials; active controls ensured assay sensitivity.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was the sum of pain intensity differences over the first 24 hours of treatment (SPID₂₄) in the abdominal hysterectomy trial and SPID₄₈ in the other two trials. Tolerability was assessed by adverse events reporting.

RESULTS

A total of 330, 832, and 285 patients with total hip replacement, abdominal hysterectomy, and bunionectomy, respectively, were assessed for efficacy. All three trials demonstrated statistically significant improvements of tapentadol IR on the primary endpoint versus placebo and similar improvements compared to morphine IR or oxycodone IR. These findings were consistent with results of total pain relief assessments and patients' global impressions of change in their overall health status after 72 hours (abdominal hysterectomy, bunionectomy). The tolerability profile of tapentadol IR was as expected for a centrally acting analgesic in the post-surgery setting.

CONCLUSIONS

Tapentadol IR has strong analgesic efficacy and is well tolerated in multiple post-surgery conditions of moderate to severe pain.

APOLLO-1: a randomized placebo and active-controlled phase III study investigating oliceridine (TRV130), a G protein-biased ligand at the µ-opioid receptor, for management of moderate-to-severe acute pain following bunionectomy

Purpose

Oliceridine is a novel G protein-biased µ-opioid receptor agonist designed to provide intravenous (IV) analgesia with a lower risk of opioid-related adverse events (ORAEs) than conventional opioids.

Patients and methods

APOLLO-1 (NCT02815709) was a phase III, double-blind, randomized trial in patients with moderate-to-severe pain following bunionectomy. Patients received a loading dose of either placebo, oliceridine (1.5 mg), or morphine (4 mg), followed by demand doses via patient-controlled analgesia (0.1, 0.35, or 0.5 mg oliceridine, 1 mg morphine, or placebo). The primary endpoint compared the proportion of treatment responders through 48 hours for oliceridine regimens and placebo. Secondary outcomes included a composite measure of respiratory safety burden (RSB, representing the cumulative duration of respiratory safety events) and the proportion of treatment responders vs morphine.

Results

Effective analgesia was observed for all oliceridine regimens, with responder rates of 50%, 62%, and 65.8% in the 0.1 mg, 0.35 mg, and 0.5 mg regimens, respectively (all P<0.0001 vs placebo [15.2%]; 0.35 mg and 0.5 mg non-inferior to morphine). RSB showed a dose-dependent increase across oliceridine regimens (mean hours [SD]: 0.1 mg: 0.04 [0.33]; 0.35 mg: 0.28 [1.11]; 0.5 mg: 0.8 [3.33]; placebo: 0 [0]), but none were statistically different from morphine (1.1 [3.03]). Gastrointestinal adverse events also increased in a dose-dependent manner in oliceridine regimens (0.1 mg: 40.8%; 0.35 mg: 59.5%; 0.5 mg: 70.9%; placebo: 24.1%; morphine: 72.4%). The odds ratio for rescue antiemetic use was significantly lower for oliceridine regimens compared to morphine (P<0.05).

Conclusion

Oliceridine is a novel and effective IV analgesic providing rapid analgesia for the relief of moderate-to-severe acute postoperative pain compared to placebo. Additionally, it has a favorable safety and tolerability profile with regard to respiratory and gastrointestinal adverse effects compared to morphine, and may provide a new treatment option for patients with moderate-to-severe postoperative pain where an IV opioid is required.

Intravenous meloxicam for the treatment of moderate to severe acute pain: a pooled analysis of safety and opioid-reducing effects

BACKGROUND AND OBJECTIVES

To describe the safety and tolerability of intravenous meloxicam compared with placebo across all phase II/III clinical trials.

METHODS

Safety data and opioid use from subjects with moderate to severe postoperative pain who received ≥1 dose of intravenous meloxicam (5-60 mg) or placebo in 1 of 7 studies (4 phase II; 3 phase III) were pooled. Data from intravenous meloxicam 5 mg, 7.5 mg and 15 mg groups were combined (low-dose subset).

RESULTS

A total of 1426 adults (86.6% white; mean age: 45.8 years) received ≥1 dose of meloxicam IV; 517 (77.6% white; mean age: 46.7 years) received placebo. The incidence of treatment-emergent adverse events (TEAEs) in intravenous meloxicam and placebo-treated subjects was 47% and 57%, respectively. The most commonly reported TEAEs across treatment groups (intravenous meloxicam 5-15 mg, 30 mg, 60 mg and placebo, respectively) were nausea (4.3%, 20.8%, 5.8% and 25.3%), headache (1.5%, 5.6%, 1.6% and 10.4%), vomiting (2.8%, 4.6%, 1.6% and 7.4%) and dizziness (0%, 3.5%, 1.1% and 4.8%). TEAE incidence was generally similar in subjects aged >65 years with impaired renal function and the general population. Similar rates of cardiovascular events were reported between treatment groups. One death was reported (placebo group; unrelated to study drug). There were 35 serious adverse events (SAEs); intravenous meloxicam 15 mg (n=5), intravenous meloxicam 30 mg (n=15) and placebo (n=15). The SAEs in meloxicam-treated subjects were determined to be unrelated to study medication. Six subjects withdrew due to TEAEs, including three treated with intravenous meloxicam (rash, localized edema and postprocedural pulmonary embolism). In trials where opioid use was monitored, meloxicam reduced postoperative rescue opioid use.

CONCLUSIONS

Intravenous meloxicam was generally well tolerated in subjects with moderate to severe postoperative pain.

TRIAL REGISTRATION NUMBERS

NCT01436032, NCT00945763, NCT01084161, NCT02540265, NCT02678286, NCT02675907 and NCT02720692.

Clinical Overview and Considerations for the Management of Opioid-induced Constipation in Patients With Chronic Noncancer Pain

OBJECTIVES

Opioid analgesics may be associated with chronic adverse effects, such as opioid-induced constipation (OIC). Available and emerging prescription medications for OIC in patients with chronic noncancer pain are described, including concerns and challenges associated with OIC management.

METHODS

Narrative review.

RESULTS

OIC is characterized by a change in bowel habits and defecation patterns that occurs when initiating opioid therapy and is associated with reduced bowel frequency, straining, sensation of incomplete evacuation, and/or patient distress related to bowel habits. Prescription medications are indicated when OIC persists despite conservative approaches (eg, increased fiber and fluid intake, exercise, over-the-counter laxatives and stool softeners). Phase 3 studies have demonstrated the efficacy of peripherally acting µ-opioid receptor antagonists (PAMORA; methylnaltrexone, naloxegol, naldemedine), and a chloride channel activator (lubiprostone) for improving OIC in patients with chronic noncancer pain. Although head-to-head studies are lacking, a meta-analysis demonstrated that μ-opioid receptor antagonists were more effective than placebo for the treatment of OIC. The most common adverse effects associated with prescription medications for OIC are gastrointestinal related (eg, nausea, diarrhea, abdominal pain, or distention), with most being mild or moderate in severity. Therapy currently in development for OIC includes the PAMORA axelopran.

DISCUSSION

Health care providers should be aware of this complication in patients receiving opioids and should monitor and address constipation-related symptoms to optimize pain management and improve patient quality of life.

Managing Prolonged Pain After Surgery: Examining the Role of Opioids

A notable minority of patients experience persistent postsurgical pain and some of these patients consequently have prolonged exposure to opioids. Risk factors for prolonged opioid use after surgery include preoperative opioid use, anxiety, substance abuse, and alcohol abuse. The window to intervene and potentially prevent persistent opioid use after surgery is short and may best be accomplished by both surgeon and anesthesiologist working together. Anesthesiologists in particular are well positioned in the perioperative surgical home model to affect multiple aspects of the perioperative experience, including tailoring intraoperative medications and providing consultation for possible discharge analgesic regimens that can help minimize opioid use. Multimodal analgesia protocols reduce opioid consumption and thereby reduce exposure to opioids and theoretically the risk of persistent use. Regional anesthesia and analgesia techniques also reduce opioid consumption. Although many patients will recover without difficulty, the small minority who do not should receive customized care which may involve multiple office visits or consultation of a pain specialist. Enhanced recovery pathways are useful in optimizing outcomes after surgery.

Updates on Multimodal Analgesia for Orthopedic Surgery

Pain control after orthopedic surgery is challenging. A multimodal approach provides superior analgesia with fewer side effects compared with opioids alone. This approach is particularly useful in light of the current opioid epidemic in the United States. Several new nonopioid agents have emerged into the market in recent years. New agents included in this review are intravenous acetaminophen, intranasal ketorolac, and newer nonsteroidal anti-inflammatory drugs, and the established medications ketamine and gabapentinoids. This article evaluates the evidence supporting these drugs in a multimodal context, including a brief discussion of cost.

Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Acute Pain Management From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists

BACKGROUND

Ketamine infusions have been used for decades to treat acute pain, but a recent surge in usage has made the infusions a mainstay of treatment in emergency departments, in the perioperative period in individuals with refractory pain, and in opioid-tolerant patients. The widespread variability in patient selection, treatment parameters, and monitoring indicates a need for the creation of consensus guidelines.

METHODS

The development of acute pain ketamine guidelines grew as a corollary from the genesis of chronic pain ketamine guidelines. The charge for the development of acute pain ketamine guidelines was provided by the Boards of Directors of both the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine, who approved the document along with the American Society of Anesthesiologists' Committees on Pain Medicine and Standards and Practice Parameters. The committee chair developed questions based on input from the committee during conference calls, which the committee then refined. Groups of 3 to 5 panel members and the committee chair were responsible for answering individual questions. After preliminary consensus was achieved, the entire committee made further revisions via e-mail and conference calls.

RESULTS

Consensus guidelines were prepared in the following areas: indications, contraindications for acute pain and whether they differ from those for chronic pain, the evidence for the use of ketamine as an adjunct to opioid-based therapy, the evidence supporting patient-controlled ketamine analgesia, the use of nonparenteral forms of ketamine, and the subanesthetic dosage range and whether the evidence supports those dosages for acute pain. The group was able to reach consensus on the answers to all questions.

CONCLUSIONS

Evidence supports the use of ketamine for acute pain in a variety of contexts, including as a stand-alone treatment, as an adjunct to opioids, and, to a lesser extent, as an intranasal formulation. Contraindications for acute pain are similar to those for chronic pain, partly based on the observation that the dosage ranges are similar. Larger studies evaluating different acute pain conditions are needed to enhance patient selection, determine the effectiveness of nonparenteral ketamine alternatives, define optimal treatment parameters, and develop protocols optimizing safety and access to care.

Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Chronic Pain From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists

BACKGROUND

Over the past 2 decades, the use of intravenous ketamine infusions as a treatment for chronic pain has increased dramatically, with wide variation in patient selection, dosing, and monitoring. This has led to a chorus of calls from various sources for the development of consensus guidelines.

METHODS

In November 2016, the charge for developing consensus guidelines was approved by the boards of directors of the American Society of Regional Anesthesia and Pain Medicine and, shortly thereafter, the American Academy of Pain Medicine. In late 2017, the completed document was sent to the American Society of Anesthesiologists' Committees on Pain Medicine and Standards and Practice Parameters, after which additional modifications were made. Panel members were selected by the committee chair and both boards of directors based on their expertise in evaluating clinical trials, past research experience, and clinical experience in developing protocols and treating patients with ketamine. Questions were developed and refined by the committee, and the groups responsible for addressing each question consisted of modules composed of 3 to 5 panel members in addition to the committee chair. Once a preliminary consensus was achieved, sections were sent to the entire panel, and further revisions were made. In addition to consensus guidelines, a comprehensive narrative review was performed, which formed part of the basis for guidelines.

RESULTS

Guidelines were prepared for the following areas: indications; contraindications; whether there was evidence for a dose-response relationship, or a minimum or therapeutic dose range; whether oral ketamine or another N-methyl-D-aspartate receptor antagonist was a reasonable treatment option as a follow-up to infusions; preinfusion testing requirements; settings and personnel necessary to administer and monitor treatment; the use of preemptive and rescue medications to address adverse effects; and what constitutes a positive treatment response. The group was able to reach consensus on all questions.

CONCLUSIONS

Evidence supports the use of ketamine for chronic pain, but the level of evidence varies by condition and dose range. Most studies evaluating the efficacy of ketamine were small and uncontrolled and were either unblinded or ineffectively blinded. Adverse effects were few and the rate of serious adverse effects was similar to placebo in most studies, with higher dosages and more frequent infusions associated with greater risks. Larger studies, evaluating a wider variety of conditions, are needed to better quantify efficacy, improve patient selection, refine the therapeutic dose range, determine the effectiveness of nonintravenous ketamine alternatives, and develop a greater understanding of the long-term risks of repeated treatments.

Human abuse potential studies of abuse-deterrent opioids: lessons from oral and intranasal studies with morphine abuse-deterrent, extended-release, injection-molded tablets

BACKGROUND

The development and use of abuse-deterrent (AD) opioids is part of a multifaceted strategy to reduce misuse, abuse, and diversion, while maintaining access for patients with severe pain who may benefit from their analgesic efficacy. Morphine AD, extended-release (ER), injection-molded tablets (morphine-ADER-IMT; ARYMO ER; Egalet US Inc., Wayne, PA) is approved by the FDA as an AD opioid. As part of the characterization of AD opioids, assessments of their human abuse potential (HAP) are required. Evidence from HAP studies can guide clinicians on the use of AD opioids in clinical practice. Herein, we describe HAP study design, and how specific AD features can impact the conduct of a study and interpretation of its results.

OBJECTIVES

To review the design features and results of the oral and intranasal HAP studies with morphine-ADER-IMT in order to improve the understanding of key elements of HAP studies of AD opioids.

CONCLUSIONS

Results from HAP studies with morphine-ADER-IMT and other AD opioids suggest that key study design features include the release profile (immediate-release vs extended-release) of the positive control, study drug doses, and the way the products are manipulated. These elements can directly impact the outcomes of the pharmacokinetic and pharmacodynamic (e.g. Maximum Drug Liking, Overall Drug Liking, and Take Drug Again) results. When evaluating HAP studies, it is important to understand study design features to assist in the interpretation of the results and understand the clinical relevance of the data to help guide clinical decision-making about the use of AD opioids.

Use of Ketamine in a Multimodal Analgesia Setting for Rapid Opioid Tapering in a Profoundly Opioid-Tolerant Patient: A Case Report

Opioids are frequently used for the treatment of chronic pain, and patients taking high doses are at increased risk of complications and adverse opioid-related events. Ketamine is appealing as an opioid adjunct because of its lack of respiratory depression and potential prevention of hyperalgesia and central sensitization. We present a case in which a ketamine infusion was utilized over a 7-day period to provide rapid taper of a daily dose of 400 mg of morphine equivalents to less than one-third of that dose on discharge with unchanged pain levels and no symptoms of opioid withdrawal.

Perioperative Complications in Patients With Sleep Apnea Undergoing Total Joint Arthroplasty

BACKGROUND

This study aims to evaluate the effect of sleep apnea (SA) on perioperative complications after total joint arthroplasty (TJA) and whether the type of anesthesia influences these complications.

METHODS

Using the ninth and tenth revisions of the International Classification of Diseases, coding systems, we queried our institutional TJA database from January 2005 to June 2016 to identify patients with SA who underwent TJA. These patients were matched in a 1:3 ratio based on age, gender, type of surgery, and comorbidities to patients who underwent TJA but were not coded for SA. Perioperative complications were identified using the same coding systems. Multivariate analysis was used to test if SA is an independent predictor of perioperative complications and if type of anesthesia can affect these complications.

RESULTS

A total of 1246 patients with SA were matched to 3738 patients without SA. Pulmonary complications occurred more frequently in patients with SA (1.7% vs 0.6%; P < .001), confirmed using multivariate analysis (odds ratio = 2.91; 95% confidence interval, 1.58-5.36; P = .001). Use of general anesthesia increased risk of all but central nervous system complications and mortality (odds ratio = 15.88; 95% confidence interval, 3.93-64.07; P < .001) regardless of SA status compared with regional anesthesia. Rates of pulmonary and gastrointestinal complications, acute anemia, and mortality were lower in SA patients when regional anesthesia was used (P < .05).

CONCLUSION

SA increases risk of postoperative pulmonary complications. The use of regional anesthesia may reduce risk of pulmonary complications and mortality in SA patients undergoing TJA.

The Efficacy and Safety of the Fentanyl Iontophoretic Transdermal System (IONSYS®) in the Geriatric Population: Results of a Meta-Analysis of Phase III and IIIb Trials

Background and Objectives

Acute postoperative pain management in the geriatric patient can be challenging, including their response to medications. The purpose of this analysis was to evaluate whether the efficacy and safety profile of fentanyl iontophoretic transdermal system (ITS) (IONSYS^®) was similar in geriatric (≥65 years) and non-geriatric (<65 years) patients.

Methods

Efficacy and safety data from three randomized, double-blind, placebo-controlled trials and four randomized, open-label, active-comparator trials were utilized for this analysis. Efficacy was assessed via the patient global assessment (PGA) and the investigator global assessment (IGA) scales. The PGA and IGA are categorical 4-point scales (excellent, good, fair, or poor) with treatment success defined as excellent or good. Safety was evaluated via adverse events.

Results

A total of 1763 patients were assigned to the fentanyl ITS treatment group. Of the 1763 patients in the fentanyl ITS group, 499 patients were ≥65 years of age; 65.1% were 65–74 years of age, 31.7% were 75–84 years of age, and 3.2% were ≥85 years of age. In the fentanyl ITS treatment groups, there were no statistically significant differences between the non-geriatric and geriatric patients in terms of patients reporting success on the PGA at 24 h (80.0 vs. 83.0%, respectively; p = 0.3415). There were no statistically significant differences between the groups in success rates on the IGA at study discharge (82.8 vs. 87.5%, respectively; p = 0.1195). The safety profile was similar between the age groups.

Conclusions

Overall, efficacy and safety of the fentanyl ITS were similar between the geriatric and non-geriatric patients.

Ketamine Infusions for Treatment Refractory Headache

BACKGROUND

Management of chronic migraine (CM) or new daily persistent headache (NDPH) in those who require aggressive outpatient and inpatient treatment is challenging. Ketamine has been suggested as a new treatment for this intractable population.

METHODS

This is a retrospective review of 77 patients who underwent administration of intravenous, subanesthetic ketamine for CM or NDPH. All patients had previously failed aggressive outpatient and inpatient treatments. Records were reviewed for patients treated between January 2006 and December 2014.

RESULTS

The mean headache pain rating using a 0-10 pain scale was an average of 7.1 at admission and 3.8 on discharge (P < .0001). The majority (55/77, 71.4%) of patients were classified as acute responders defined as at least 2-point improvement in headache pain at discharge. Some (15/77, 27.3%) acute responders maintained this benefit at their follow-up office visit but sustained response did not achieve statistical significance. The mean length of infusion was 4.8 days. Most patients tolerated ketamine well. A number of adverse events were observed, but very few were serious.

CONCLUSIONS

Subanesthetic ketamine infusions may be beneficial in individuals with CM or NDPH who have failed other aggressive treatments. Controlled trials may confirm this, and further studies may be useful in elucidating more robust benefit in a less refractory patient population.

High Body Mass Index and Use of Fentanyl Iontophoretic Transdermal System in Postoperative Pain Management: Results of a Pooled Analysis of Six Phase 3/3B Trials

INTRODUCTION

Postoperative pain management can be challenging in patients with a high body mass index (BMI) especially as a result of poor venous access and delayed ambulation that can result in serious complications. Fentanyl iontophoretic transdermal system (ITS) is a needle-free, patient-controlled analgesic method available for use in acute postoperative pain. The primary objective of these analyses was to determine if there were any differences between patients with high BMI (>40 kg/m²) and lower BMIs (<30 kg/m² and 35-40 kg/m²) in terms of efficacy or safety.

METHODS

Data from three registration, placebo-controlled trials and three active-comparator trials using fentanyl ITS (IONSYS^®, The Medicines Company, Parsippany, NJ) for the management of postoperative pain were analyzed using BMI categories of <35 kg/m², 35-40 kg/m², and >40 kg/m². The majority of patients had lower abdominal or orthopedic surgery. For these analyses, the primary efficacy variables were assessed via patient global assessment of pain control (PGA) at 24 h and investigator global assessment (IGA) at study discharge. PGA and IGA are categorical 4-point scales (excellent, good, fair, or poor) with treatment "success" defined as either excellent or good. Safety was evaluated via treatment emergent adverse events (TEAEs).

RESULTS

There were 1403 patients randomly assigned and treated with fentanyl ITS for at least 3 h (BMI <35 kg/m²: 1180; 35-40 kg/m²: 136, BMI >40 kg/m²: 85; and 2 missing). PGA treatment success, which evaluates the method of pain control, at 24 h was consistent in the high and low BMI groups in patients treated with fentanyl ITS (<35 kg/m²: 946/1180 [80.2%]; 35-40 kg/m²: 103/136 [75.7%]; and >40 kg/m²: 65/85 [76.5%]). The IGA results at study discharge were similar to the PGA. Safety appeared similar with fentanyl ITS across the BMI groups.

CONCLUSION

In these analyses, fentanyl ITS was as efficacious, as assessed by the PGA ratings of treatment "success", in patients with high BMI (>40 kg/m²) as it was for those with lower BMIs (<35 kg/m² or 35-40 kg/m²) and was generally well tolerated across all BMI categories.

Managing Opioid-Tolerant Patients in the Perioperative Surgical Home

Management of acute postoperative pain is important to decrease perioperative morbidity and improve patient satisfaction. Opioids are associated with potential adverse events that may lead to significant risk. Uncontrolled pain is a risk factor in the transformation of acute pain to chronic pain. Balancing these issues can be especially challenging in opioid-tolerant patients undergoing surgery, for whom rapidly escalating opioid doses in an effort to control pain can be associated with increased complications. In the perioperative surgical home model, anesthesiologists are positioned to coordinate a comprehensive perioperative analgesic plan that begins with the preoperative assessment and continues through discharge.

The use of opioid analgesics for chronic pain: minimizing the risk for harm

Chronic noncancer pain is common and consequential, affecting ∼100 million people in the United States alone and costing, when direct and indirect costs are combined, in excess of $635 billion. For certain individuals, opioids may be an effective option for the management of chronic pain; however, a series of critical decisions must be made before prescribing opioids to ensure that their potential benefits and possible risks are appropriately and realistically addressed. A thorough history, physical examination, and appropriate testing, including an assessment of risk for substance abuse, misuse, or addiction, should be conducted in patients who are being considered for opioid therapy. Proactively developing a treatment plan that matches the needs and expectations of the patient, while minimizing the potential for substance abuse, is central to the success of pain management. Current standard of care suggests that for most patients, a trial of nonopioid therapies should generally be tried first. There is no single opioid of choice that universally provides the best outcomes for all patients; thus, it is critical for the health-care practitioner to become familiar with the available subclasses, formulations, and modes of administration, and base the treatment plan on clinical experience with the drug, prior patient experience, the availability of the formulation, and cost and coverage. Pain is a dynamic phenomenon in that its characteristics and response to treatment evolve over time, as does the patient's general health state. Both positive and negative changes over time may necessitate a change in medication. Opioids can be prescribed safely and effectively, and when used with appropriate attention to individual patient characteristics may have a positive impact on pain and function. When contemplating initiation of opioid analgesics, clinicians would do well to make it clear to their patient that they will be prescribed on a trial basis with a clear exit strategy for discontinuing such treatment if there is no clear benefit including lack of analgesia, insurmountable adverse effects, and/or frank misuse or abuse of the prescribed drug.

The Acute to Chronic Pain Transition: Can Chronic Pain Be Prevented?

Chronic postsurgical pain (CPSP) is a distressing disease process that can lead to long-term disability, reduced quality of life, and increased health care spending. Although the exact mechanism of development of CPSP is unknown, nerve injury and inflammation may lead to peripheral and central sensitization. Given the complexity of the disease process, no novel treatment has been identified. The preoperative use of multimodal analgesia has been shown to decrease acute postoperative pain, but it has no proven efficacy in preventing development of CPSP.

The safety of liposome bupivacaine 2 years post-launch: a look back and a look forward

The need for better post-surgical pain management continues to be unmet, despite clinicians' awareness and concern for many years. Opioids remain the standard of care because of their analgesic efficacy; however, opioid use is often associated with adverse effects and poor patient outcomes. Multimodal analgesic regimens have recently been endorsed as a way to provide adequate post-surgical pain control while reducing opioid consumption. Liposome bupivacaine is a liposomal formulation of bupivacaine indicated for a single administration into the surgical site. Based on the available clinical trial data compiled to date, as well as the author's review of publicly available post-marketing safety information, liposome bupivacaine may be a viable addition to currently available therapeutic options for post-surgical analgesia while reducing potential risks associated with use of opioid analgesics, and may represent a useful addition to the multimodal analgesic modalities currently used for post-operative pain management. The potential for its use in other areas is also being investigated. The purpose of this review is to examine the currently available post-marketing safety information on liposome bupivacaine.

A comparison of opioid-related adverse events with fentanyl iontophoretic transdermal system versus morphine intravenous patient-controlled analgesia in acute postoperative pain

OBJECTIVE

This analysis compared opioid-related adverse events (ORADEs) observed with fentanyl iontophoretic transdermal system (ITS) versus morphine intravenous (iv.) patient-controlled analgesia (PCA) in the management of postoperative pain.

METHODS

Safety data from four Phase IIIB randomized, active-comparator trials were pooled for this analysis (n = 1288 fentanyl ITS and 1313 morphine iv. PCA patients). Treatment-emergent adverse events were collected via spontaneous report. In this post hoc analysis, ORADEs were defined as apnea, confusion, constipation, dyspnea, hypotension, hypoventilation, hypoxia, ileus, nausea, pruritus, somnolence, tachycardia, urinary retention and vomiting. Odds ratios (OR) and 95% CI were calculated for all ORADEs and p-values were based on logistic regression with treatment as effect.

RESULTS

There were fewer patients in the fentanyl ITS group compared with the morphine iv. PCA group who experienced at least one ORADE (52.7 vs 59.1%, respectively; OR: 0.772: 95% CI: 0.661-0.901; p = 0.0011). The ORADEs that occurred less frequently in the fentanyl ITS group than in the morphine iv. PCA group included hypotension (3.7 vs 5.5%, respectively; OR: 0.667; 95% CI: 0.459-0.969; p = 0.0338), hypoventilation (0.9 vs 1.9%, respectively; OR: 0.444; 95% CI: 0.217-0.906; p = 0.0256), nausea (40.3 vs 44.5%, respectively; OR: 0.842; 95% CI: 0.721-0.984; p = 0.0310), pruritus (5.5 vs 9.4%, respectively; OR: 0.559; 95% CI: 0.413-0.757; p = 0.0002) and tachycardia (1.6 vs 2.8%, respectively; OR: 0.489; 95% CI: 0.277-0.863; p = 0.0136). No ORADEs occurred more frequently in the fentanyl ITS group compared with the morphine iv. PCA group.

CONCLUSION

Fentanyl ITS, in the management of acute postoperative pain, offered safety advantages in terms of ORADEs compared with morphine iv. PCA.

Meta-analysis of the efficacy of the fentanyl iontophoretic transdermal system versus intravenous patient-controlled analgesia in postoperative pain management

OBJECTIVE

This meta-analysis was conducted to analyze and compare the efficacy outcomes associated with the fentanyl iontophoretic transdermal system (ITS) and morphine intravenous (IV) patient-controlled analgesia (PCA) in the management of postoperative pain.

RESEARCH DESIGN AND METHODS

This meta-analysis assessed the efficacy of the fentanyl ITS versus morphine IV PCA using data from four randomized, active-controlled trials (n = 1271 fentanyl ITS and 1298 morphine IV PCA patients). Main outcome measures were patient global assessment (PGA) of the method of pain control at 24 h.

RESULTS

Fentanyl ITS and morphine IV PCA did not significantly differ regarding 'good' and 'excellent' ratings on the PGA of the method of pain control at 24 h (odds ratio = 0.95, p = 0.66), however, fentanyl ITS was superior in terms of 'excellent' PGA ratings at that time point (odds ratio = 1.53, p < 0.0001). No significant differences were found in weighted mean pain intensity scores at 24, 48 and 72 h.

CONCLUSIONS

In this meta-analysis, fentanyl ITS was as efficacious as morphine IV PCA and may offer additional benefits as demonstrated by its 'excellent' PGA ratings.

Improving acute pain management in emergency medicine

Undertreatment of pain (oligoanalgesia) in the emergency department is common, and it negatively impacts patient care. Both failure of appropriate pain assessment and the potential for unsafe analgesic use contribute to the problem. As a result, achieving satisfactory analgesia while minimizing side effects remains particularly challenging for emergency physicians, both in the emergency department and after a patient is discharged. Improvements in rapid pain assessment and in evaluation of noncommunicative populations may result in a better estimation of which patients require analgesia and how much pain is present. New formulations of available treatments, such as rapidly absorbed, topical, or intranasal nonsteroidal anti-inflammatory drug formulations or intranasal opioids, may provide effective analgesia with an improved risk-benefit profile. Other pharmacological therapies have been shown to be effective for certain pain modalities, such as the use of antidepressants for musculoskeletal pain, γ-aminobutyric acid agonists for neuropathic and postsurgical pain, antipsychotics for headache, and topical capsaicin for neuropathic pain. Nonpharmacological methods of pain control include the use of electrical stimulation, relaxation therapies, psychosocial/manipulative therapies, and acupuncture. Tailoring of available treatment options to specific pain modalities, as well as improvements in pain assessment, treatment options, and formulations, may improve pain control in the emergency department setting and beyond.