Management of Postoperative Pain: A Clinical Practice Guideline From the American Pain Society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists' Committee on Regional Anesthesia, Executive Committee, and Administrative Council. J Pain. 2016;17:131-157. [PMID: 26827847 DOI: 10.1016/j.jpain.2015.12.008]

What Is New in Recovery After Gynecologic Surgery for Benign Indications?: Best Articles From the Past Year

This month we focus on current research in recovery after gynecologic surgery for benign indications. Dr. Whiteside discusses four recent publications, which are concluded with a "bottom line" that is the take-home message. A complete reference for each can be found on on this page along with direct links to the abstracts.

The Association Between Analgesia Gap and Type of Surgery, Analgesic Drugs, and Timing of Analgesic Administration: What Do We Know?

Background

Inadequate postoperative pain management poses unique challenges for anesthesiologists. The transition from epidural analgesia to other analgesic drugs has its own challenges. Increasing pain during this period is defined as analgesia gap.

Objectives

This study aimed at determining the incidence of analgesia gap and its associated factors, such as type of surgery, analgesic drugs, and timing of analgesic administration.

Methods

This was a prospective cohort among acute pain service patients at a tertiary hospital from July to October 2018. There were 220 subjects included in this study. All subjects were scheduled for elective surgery with epidural analgesia. Following last epidural regimen administration, the pain scale was assessed using VAS. If the patient had VAS more than four, then they were classified as having analgesia gap. Type of surgery, type of analgesic drugs, and timing of drugs administration were measured as the associating factors.

Results

The incidence of analgesia gap in this tertiary hospital was 26.6%. Type of surgery was not significantly associated with the incidence of analgesia gap (P = 0.057). However, type of analgesic drugs and timing of analgesic administration were related to incidence of analgesic gap (P = 0.016 and P < 0.001).

Conclusions

The incidence of analgesia gap in this study was 26.6%. Type of analgesic drugs and timing of analgesic administration had a significant association with the incidence of analgesia gap. However, type of surgery did not have a significant association with the incidence of analgesia gap.

Efficacy of Transcutaneous Electronic Nerve Stimulation in Postoperative Analgesia After Pulmonary Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of the study was to identify the analgesic efficacy and safety of transcutaneous electronic nerve stimulation in postoperative pain after pulmonary surgery.

DESIGN

Electronic databases (PubMed, Embase, Web of Science, and CENTRAL) were systematically searched from their inception to June 2019. The continuous variables were pooled as the weighted mean difference with correlated 95% confidence interval. Results were recognized as significant when a P value is less than 0.05. Subgroup analyses, sensitivity analyses, and quality assessment were performed.

RESULTS

Altogether, 10 studies were included. The pooled results indicated that transcutaneous electronic nerve stimulation group conferred lower pain intensity score on the first postoperative day (weighted mean difference = -0.93, 95% confidence interval = -1.56 to -0.30, P = 0.004), postoperative day 2 (weighted mean difference = -1.00, 95% confidence interval = -1.64 to -0.35, P = 0.002), postoperative day 3 (weighted mean difference = -0.92, 95% confidence interval = -1.76 to -0.09, P = 0.03), postoperative day 4 (weighted mean difference = -0.90, 95% confidence interval = -1.24 to -0.56, P < 0.001), and postoperative day 5 (weighted mean difference = -1.39, 95% confidence interval = -2.20 to -0.57, P < 0.001) compared with the placebo transcutaneous electronic nerve stimulation group. No publication bias was found. No significant discovery was obtained in sensitivity analyses.

CONCLUSIONS

Transcutaneous electronic nerve stimulation might be an effective supplementary analgesic regimen in multimodal analgesia to decrease pain intensity after pulmonary surgery.

Co-crystals as a new approach to multimodal analgesia and the treatment of pain

Pain is highly prevalent, but frequently untreated or under-treated, and health care professionals are faced with a range of treatment challenges. Multimodal therapy is recommended and can be achieved using open combinations (ie, concomitant administration) of individual agents, fixed-dose combinations (FDCs), or multimodal agents (ie, single agents with multiple mechanisms of action). Co-crystallization of active pharmaceutical ingredients (APIs) offers another approach, with the potential to provide drugs with unique properties and advantages for therapeutic applications compared to combinations. API–API co-crystals are single-entity forms that offer a unique possibility of improving the physicochemical properties of both constituent APIs, as well as permitting their synchronous release. Consequently, this may positively impact on their pharmacokinetic (PK) properties and profiles, providing a potential advantage over FDCs and translating into improved clinical efficacy and safety profiles. We report here a revision of the literature concerning API–API co-crystals for the treatment of pain. It becomes apparent that identifying APIs with complementary mechanisms of action that can be adequately co-crystallized in an appropriate molecular ratio applicable for therapeutic use is challenging. In addition, API–API co-crystals normally result in a mere increased exposure of an API without defined clinical benefits (since, to maintain the benefit-risk, the dose needs to be proportionally reduced to adjust for the increased exposure). An exception to this is the co-crystal of tramadol-celecoxib (CTC), that represents a unique concept in co-crystal technology. In CTC neither of its three active components that have complementary mechanisms of action (ie, the two enantiomers of tramadol and celecoxib) show increased exposure levels versus commercially available single-entity reference products, but rather show a change in their PK profile with potential clinical advantages. CTC is in Phase III clinical development for the treatment of pain.

Postoperative Analgesic Requirement and Pain Perceptions after Nonaerodigestive Head and Neck Surgery

OBJECTIVES

Little data exist on associations between patient factors and postoperative analgesic requirement after head and neck (H&N) surgeries. Such information is important for optimizing postoperative care considering concerns regarding opioid misuse. We analyzed factors associated with narcotic use and pain perception following H&N surgery sparing the upper aerodigestive tract.

STUDY DESIGN

Prospective cohort.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

From May to October 2017, data were collected for patients undergoing nonaerodigestive H&N procedures requiring hospitalization. Patients completed a preoperative survey querying chronic pain history, narcotic usage, and postoperative pain expectation. Demographics, surgical data, postoperative narcotic use defined by morphine milligram equivalents (MME), pain scores, and Overall Benefit of Analgesia Score (OBAS) were analyzed.

RESULTS

Seventy-six patients, 44 (57.9%) females and 32 (42.1%) males with a mean age of 54.0 years, met inclusion criteria. The most common procedures were parotidectomy (27.6%) and total thyroidectomy (19.7%). Average cumulative 24-hour postoperative MME and calculated MME per hospital day (MME/HD, cumulative MME for hospitalization divided by length of stay) were 40.5 ± 30.6 and 60.8 ± 60.1, respectively. Average pain score throughout the initial 24 hours after surgery was 3.7/10 ± 2.0. Female sex and prior chronic pain diagnosis were associated with higher OBAS after multivariate linear adjustments.

CONCLUSION

Postoperative narcotic requirement in nonaerodigestive H&N surgery is overall low. Female sex and prior chronic pain diagnosis may be associated with higher postoperative OBAS, a validated assessment of pain and opioid-related side effects. This study may serve as a comparison for future studies evaluating narcotic-sparing analgesia and pain perception in nonaerodigestive H&N surgery.

Optimizing opioid prescribing and pain treatment for surgery: Review and conceptual framework

Purpose

Millions of Americans who undergo surgical procedures receive opioid prescriptions as they return home. While some derive great benefit from these medicines, others experience adverse events, convert to chronic opioid use, or have unused medicines that serve as a reservoir for potential nonmedical use. Our aim was to investigate concepts and methods relevant to optimal opioid prescribing and pain treatment in the perioperative period.

Methods

We reviewed existing literature for trials on factors that influence opioid prescribing and optimization of pain treatment for surgical procedures and generated a conceptual framework to guide future quality, safety, and research efforts.

Results

Opioid prescribing and pain treatment after discharge from surgery broadly consist of 3 key interacting perspectives, including those of the patient, the perioperative team, and, serving in an essential role for all patients, the pharmacist. Systems-based factors, ranging from the organizational environment’s ability to provide multimodal analgesia and participation in enhanced recovery after surgery programs to other healthcare system and macro-level trends, shape these interactions and influence opioid-related safety outcomes.

Conclusions

The severity and persistence of the opioid crisis underscore the urgent need for interventions to improve postoperative prescription opioid use in the United States. Such interventions are likely to be most effective, with the fewest unintended consequences, if based on sound evidence and built on multidisciplinary efforts that include pharmacists, nurses, surgeons, anesthesiologists, and the patient. Future studies have the potential to identify the optimal amount to prescribe, improve patient-focused safety and quality outcomes, and help curb the oversupply of opioids that contributes to the most pressing public health crisis of our time.

Health Care Burden Associated with Outpatient Opioid Use Following Inpatient or Outpatient Surgery

BACKGROUND

The treatment of postsurgical pain with prescription opioids has been associated with persistent opioid use and increased health care utilization and costs.

OBJECTIVE

To compare the health care burden between opioid-naive adult patients who were prescribed opioids after a major surgery and opioidnaive adult patients who were not prescribed opioids.

METHODS

Administrative claims data from the IBM Watson Health MarketScan Research Databases for 2010-2016 were used. Opioid-naive adult patients who underwent major inpatient or outpatient surgery and who had at least 1 year of continuous enrollment before and after the index surgery date were eligible for inclusion. Cohorts were defined based on an opioid pharmacy claim between 7 days before index surgery and 1 year after index surgery (opioid use during surgery and inpatient use were not available). To ensure an opioid-naive population, patients with opioid claims between 365 and 8 days before surgery were excluded. Acute medical outcomes, opioid utilization, health care utilization, and costs were measured during the post-index period (index surgery hospitalization and day of index outpatient surgery not included). Predicted costs were estimated from multivariable log-linked gamma-generalized linear models.

RESULTS

The final sample consisted of 1,174,905 opioid-naive patients with an inpatient surgery (73% commercial, 20% Medicare, 7% Medicaid) and 2,930,216 opioid-naive patients with an outpatient surgery (74% commercial, 23% Medicare, and 3% Medicaid). Opioid use after discharge was common among all 3 payer types but was less common among Medicare patients (63% inpatient/43% outpatient) than patients with commercial (80% inpatient/75% outpatient) or Medicaid insurance (86% inpatient/81% outpatient). Across all 3 payers, opioid users were younger, were more likely to be female, and had a higher preoperative comorbidity burden than nonopioid users. In unadjusted analyses, opioid users tended to have more hospitalizations, emergency department visits, and pharmacy claims. Adjusted predicted 1-year post-period total health care costs were significantly higher (P< 0.001) for opioid users than nonopioid users for commercial insurance (inpatient: $22,209 vs. $14,439; outpatient: $13,897 vs. $8,825), Medicare (inpatient: $31,721 vs. $26,761; outpatient: $24,529 vs. $15,225), and Medicaid (inpatient: $13,512 vs. $9,204; outpatient: $11,975 vs. $8,212).

CONCLUSIONS

Filling an outpatient opioid prescription (vs. no opioid prescription) in the 1 year after inpatient or outpatient surgery was associated with increased health care utilization and costs across all payers.

DISCLOSURES

Funding for this study was provided by Heron Therapeutics, which participated in analysis and interpretation of data, drafting, reviewing, and approving the publication. All authors contributed to the development of the publication and maintained control over the final content. Brummett is a paid consultant for Heron Therapeutics and Recro Pharma and reports receipt of research funding from MDHHS (Sub K Michigan Open), NIDA (Centralized Pain Opioid Non-Responsiveness R01 DA038261-05), NIH0DHHS-US-16 PAF 07628 (R01 NR017096-05), NIH-DHHS (P50 AR070600-05 CORT), NIH-DHHS-US (K23 DA038718-04), NIH-DHHS-US-16-PAF06270 (R01 HD088712-05), NIH-DHHS-US-17-PAF02680 (R01 DA042859-05), and UM Michigan Genomics Initiative and holding a patent for peripheral perineural dexmedetomidine. Oderda is a paid consultant for Heron Therapeutics. Pawasauskas is a paid consultant to Heron Therapeutics and Mallinckrodt Pharmaceuticals. England and Evans-Shields are employees of Heron Therapeutics. Kong, Lew, Zimmerman, and Henriques are employees of IBM Watson Health, which was compensated by Heron Therapeutics for conducting this research. Portions of this work were presented as a poster at the AMCP Managed Care and Specialty Pharmacy Annual Meeting 2019; March 25-28, 2019; San Diego, CA.

Association Between Preoperative Opioid and Benzodiazepine Prescription Patterns and Mortality After Noncardiac Surgery

Importance

The number of patients prescribed long-term opioids and benzodiazepines and complications from their long-term use have increased. Information regarding the perioperative outcomes of patients prescribed these medications before surgery is limited.

Objective

To determine whether patients prescribed opioids and/or benzodiazepines within 6 months preoperatively would have greater short- and long-term mortality and increased opioid consumption postoperatively.

Design, Setting, and Participants

This retrospective, single-center, population-based cohort study included all patients 18 years or older, undergoing noncardiac surgical procedures at a national hospital in Iceland from December 12, 2005, to December 31, 2015, with follow-up through May 20, 2016. A propensity score-matched control cohort was generated using individuals from the group that received prescriptions for neither medication class within 6 months preoperatively. Data analysis was performed from April 10, 2018, to March 9, 2019.

Exposures

Patients who filled prescriptions for opioids only, benzodiazepines only, both opioids and benzodiazepines, or neither medication within 6 months preoperatively.

Main Outcomes and Measures

Long-term survival compared with propensity score-matched controls. Secondary outcomes were 30-day survival and persistent postoperative opioid consumption, defined as a prescription filled more than 3 months postoperatively.

Results

Among 41 170 noncardiac surgical cases in 27 787 individuals (16 004 women [57.6%]; mean [SD] age, 56.3 [18.8] years), a preoperative prescription for opioids only was filled for 7460 cases (17.7%), benzodiazepines only for 3121 (7.4%), and both for 2633 (6.2%). Patients who filled preoperative prescriptions for either medication class had a greater comorbidity burden compared with patients receiving neither medication class (Elixhauser comorbidity index >0 for 16% of patients filling prescriptions for opioids only, 22% for benzodiazepines only, and 21% for both medications compared with 14% for patients filling neither). There was no difference in 30-day (opioids only: 1.3% vs 1.0%; P = .23; benzodiazepines only: 1.9% vs 1.5%; P = .32) or long-term (opioids only: hazard ratio [HR], 1.12 [95% CI, 1.01-1.24]; P = .03; benzodiazepines only: HR, 1.11 [95% CI, 0.98-1.26]; P = .11) survival among the patients receiving opioids or benzodiazepines only compared with controls. However, patients prescribed both opioids and benzodiazepines had greater 30-day mortality (3.2% vs 1.8%; P = .004) and a greater hazard of long-term mortality (HR, 1.41; 95% CI, 1.22-1.64; P < .001). The rate of persistent postoperative opioid consumption was higher for patients filling prescriptions for opioids only (43%), benzodiazepines only (23%), or both (66%) compared with patients filling neither (12%) (P < .001 for all).

Conclusions and Relevance

The findings suggest that opioid and benzodiazepine prescription fills in the 6 months before surgery are associated with increased short-and long-term mortality and an increased rate of persistent postoperative opioid consumption. These patients should be considered for early referral to preoperative clinic and medication optimization to improve surgical outcomes.

Pain is vital in resuscitation in trauma

Implementation of the ATLS algorithm has remarkably improved the resuscitation of trauma patients and has significantly contributed to the systematic management of multi-trauma patients. However, pain remains the most prevalent complaint in trauma patients, and can induce severe complications, further deterioration of health, and death of the patient. Providing appropriate and timely pain management to these patients prompts early healing, reduces stress response, shortens hospital Length of Stay (LOS), diminishes chronic pain, and ultimately reduces morbidity and mortality. Pain has been proposed to be evaluated as the fifth vital sign and be recorded in the vital sign charts in order to emphasize the importance of pain on short- and long-term outcomes of the patients. However, although the quality of pain treatment seems to be improving we believe that pain has been underestimated in trauma. This article aims to provide evidence for the importance of pain in trauma, to support its management in the emergency setting and the acute phase of patients’ resuscitation, and to emphasize on the necessity to introduce the letter P (pain) in the ATLS alphabet.

The Preclinical Pharmacological Study of a Novel Long-Acting Local Anesthetic, a Fixed-Dose Combination of QX-OH/Levobupivacaine, in Rats

Introduction: Previous studies demonstrated that 35 mM QX-OH/10 mM Levobupivacaine (LL-1), a fixed-dose combination, produced a long-acting effect in rat local anesthesia models. All preclinical pharmacodynamic results indicated that LL-1 had potential for postsurgical pain treatment. The objective of this study was to investigate the pharmacokinetics of LL-1. Then, the possible mechanism of the extended duration by the combination was examined.

Methods and Results: All experiments were examined and approved by the Committee of Animal Care of the West China Hospital Sichuan University (Ethical approval number, 2015014A). The compound action potentials were recorded to verify the pharmacodynamic result in ex vivo. In frog sciatic nerve, LL-1 produced an effective inhibition with rapid onset time. The concentration-time profiles of LL-1 were determined in plasma and local tissues after sciatic nerve block. The maximum concentration of QX-OH and levobupivacaine were 727.22 ± 43.38 µg/g and 256.02 ± 28.52 µg/g in muscle, 634.26 ± 36.04 µg/g and 429.63 ± 48.64 µg/g in sciatic nerve, and 711.71 ± 25.14 ng/ml and 114.40 ± 10.19 ng/ml in plasma, respectively. The absorption of QX-OH into circulation was very rapid at 0.71 ± 0.06 h, which was faster than that of levobupivacaine (4.11 ± 0.39 h, p = 0.003). The half-time of QX-OH in plasma and local tissues had no significant difference (p = 0.329), with the values of 2.64 h, 3.20 h, and 3.79 h in plasma, muscle, and sciatic nerve, respectively. The elimination profile of levobupivacaine differed from that of QX-OH, which was slower eliminated from plasma (4.89 ± 1.77 h, p = 0.036) than from muscle (1.38 ± 0.60 h) or sciatic nerve (1.28 ± 0.74 h). When levobupivacaine was used alone, the Tmax in plasma was 1.07 ± 0.16 h. Interestingly, the Tmax of levobupivacaine in the plasma was increased by four times in combination with QX-OH (4.11 ± 0.39 h). Levobupivacaine promotes cellular QX-OH uptake.

Conclusion: The preclinical pharmacokinetic study of LL-1 in the rat plasma, muscle, and sciatic nerve was accomplished. Then, the possible mechanism of the prolonged duration was that QX-OH delayed the absorption of levobupivacaine from the injection site into circulation, and levobupivacaine accelerated QX-OH to accumulate into cells.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Perioperative Opioid Minimization in Opioid-Naïve Patients

Surgical care episodes place opioid-naïve patients at risk for transitioning to new persistent postoperative opioid use. With one of the central principles being the application of multimodal pain interventions to reduce the reliance on opioid-based medications, enhanced recovery pathways provide a framework that decreases perioperative opioid use. The fourth Perioperative Quality Initiative brought together a group of international experts representing anesthesiology, surgery, and nursing with the objective of providing consensus recommendations on this important topic. Fourth Perioperative Quality Initiative was a consensus-building conference designed around a modified Delphi process in which the group alternately convened for plenary discussion sessions in between small group discussions. The process included several iterative steps including a literature review of the topics, building consensus around the important questions related to the topic, and sequential steps of content building and refinement until agreement was achieved and a consensus document was produced. During the fourth Perioperative Quality Initiative conference and thereafter as a writing group, reference applicability to the topic was discussed in any area where there was disagreement. For this manuscript, the questions answered included (1) What are the potential strategies for preventing persistent postoperative opioid use? (2) Is opioid-free anesthesia and analgesia feasible and appropriate for routine operations? and (3) Is opioid-free (intraoperative) anesthesia associated with equivalent or superior outcomes compared to an opioid minimization in the perioperative period? We will discuss the relevant literature for each questions, emphasize what we do not know, and prioritize the areas for future research.

Innovative pain management solutions in animals may provide improved wound pain reduction during debridement in humans: An opinion informed by veterinary literature

Painful animal husbandry procedures are routinely performed in a range of livestock species without analgesia. Recently, innovative strategies have been developed to address wound pain in these animals. In particular, a farmer-applied "spray and stay" approach that is administered directly to open wounds was developed (Tri-Solfen® Medical Ethics Pty Ltd., Melbourne, Victoria, Australia). This strategy anaesthetises the wounds immediately upon their formation, with long-lasting effect. This development, described as a "pain management revolution," has become firmly established in the Australian livestock industries and has global potential. The positive outcomes of this approach provide insights and highlight potential benefits that may be accrued from its use in human wound care, providing rapid-onset wound analgesia and/or anaesthetising wounds prior to cleansing and debridement procedures. If these benefits are realised from a clinician and patient perspective for wound debridement as an initial indication, it could provide new horizons in pain management for a spectrum of wound-related procedures. Evidence from use in animal husbandry does support the concept that multimodal anaesthesia holds great potential in the field of wound management across many procedures.

Perioperative pain management and chronic postsurgical pain after elective foot and ankle surgery: a scoping review

PURPOSE

Chronic postsurgical pain (CPSP) can occur after elective mid/hindfoot and ankle surgery. Effective treatment approaches to prevent the development of CPSP in this population have not been extensively investigated. The impact of multimodal strategies to prevent CPSP following elective mid/hindfoot surgery is unknown because of both the heterogeneity of acute pain management and the lack of a recognized definition particular to this surgery. This review aimed to identify and evaluate current pain management strategies after elective mid/hindfoot and ankle surgery.

SOURCES

Manual and electronic searches (MEDLINE, Embase, and Cochrane Library) were conducted of literature published between 1990 and July 2017. Comparative studies of adults undergoing elective mid/hindfoot and ankle surgery were included. Two reviewers independently reviewed studies and assessed their methodological quality.

PRINCIPAL FINDINGS

We found seven randomized-controlled trials meeting our inclusion criteria. Interventions focused on regional anesthesia techniques such as continuous popliteal sciatic and femoral nerve blockade. Participants were typically followed up to 48 hr postoperatively. Only one study assessed pain six months following elective mid/hindfoot and ankle surgery.

CONCLUSION

There is an overwhelming lack of evidence regarding CPSP and its management for patients undergoing elective mid/hindfoot and ankle surgery. The lack of a recognized and standard definition of CPSP after this group of surgeries precludes accurate and consistent evaluation.

Current Status and Future Directions of Pain-Related Outcome Measures for Post-Surgical Pain Trials

Background: Clinical trials remain vital in order to: A) develop new treatment interventions, and also, B) to guide optimal use of current interventions for the treatment and prevention of acute and chronic postsurgical pain. Measures of pain (e.g. intensity and relief) and opioid use have been validated for the settings of postsurgical pain and continue to effectively guide research in this field..

Methods: This narrative review considers needs for innovation in postsurgical pain trial outcomes assessment.

Results: Future improvements are needed and include: A) more widespread measurement of movement-evoked pain with validation of various procedure-relevant movemen-tevoked pain maneuvers; B) new validated analytical approaches to integrate early postoperative pain scores with opioid use; and, C) closer attention to the measurement of postoperative opioid use after hospital discharge. In addition to these traditional measures, consideration is being given to the use of new pain-relevant outcome domains that include: 1) other symptoms (e.g. nausea and vomiting), 2) recovery of physiological function (e.g. respiratory, gastrointestinal, genitourinary and musculoskeletal), 3) emotional function (e.g. depression, anxiety) and, 4) development of chronic postsurgical pain. Also, there is a need to develop pain-related domains and measures for evaluating both acute and chronic post-operative pain. Finally, evidence suggests that further needs for improvements in safety assessment and reporting in postsurgical pain trials is needed, e.g. by using an agreed upon, standardized collection of outcomes that will be reported as a minimum in all postsurgical pain trials.

Conclusions: These proposed advances in outcome measurement methodology are expected to improve the success by which postsurgical pain trials guide improvements in clinical care and patient outcomes.

Metamizole for Postoperative Pain in Pediatric Patients Undergoing Subarachnoid Anesthesia

BACKGROUND

Efficient postoperative pain management, which is aimed at decreasing the risk of complications and drug-induced side effects, without affecting the quality of analgesia, is part of today's concept of enhanced recovery after surgery, that is, fast-track surgery.

STUDY QUESTION

The objective of this study was to determine whether effective management of acute postoperative pain was possible without opioids, while avoiding complications, drug-induced side effects, and suboptimal treatment. Introduction of metamizole, which has regained popularity, into a multimodal analgesia regimen was used, as opioids are not routinely administered.

STUDY DESIGN

The study was prospective, observational, unrandomized, and without the control group.

MEASURES AND OUTCOMES

This study was performed in a pediatric hospital with 300 beds and an average of 1700 annual surgical interventions. The study group comprised 378 patients aged 1-17 years, undergoing lower abdominal or limb surgery between June 2016 and June 2017. Children underwent subarachnoid anesthesia combined with intravenous sedation and received not routinely but on demand postoperative opioid analgesia. The pain was self-assessed by the pediatric patient or was assessed by the nurse using pain scores.

RESULTS

Metamizole proved to be safe, efficient, and very well tolerated by children. Multimodal analgesia using acetaminophen, nonsteroidal anti-inflammatory drug with metamizole for the treatment of moderate to severe pain in children undergoing surgery, required a single opioid dose in 292 patients (77.24%) of the 378 in this study.

CONCLUSIONS

In pediatric patients undergoing surgery, subarachnoid anesthesia combined with intravenous sedation, multimodal analgesia that includes metamizole, and nonpharmacological complementary therapies in pain management enable avoidance or reduction of opioids to a single dose, without undertreatment. There is also a minimum of anesthesia, accelerated children's recovery and a rapid return to presurgical levels of function.

Distal acupoint stimulation versus peri-incisional stimulation for postoperative pain in open abdominal surgery: a systematic review and implications for clinical practice

BACKGROUND

Acute postoperative pain remains a major clinical problem that affects patient recovery. Distal acupoint and peri-incisional stimulation are both used for relieving acute postoperative pain in hospital. Our objective was to assess and compare the effects of distal and peri-incisional stimulation on postoperative pain in open abdominal surgery.

METHODS

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Chinese databases CNKI and Wanfangdata were searched to identify eligible randomized controlled trials. Intensity of postoperative pain, opioid consumption and related data were extracted and analyzed using a random effects model. Risk of bias was assessed. Subgroup analyses were conducted when data were enough.

RESULTS

Thirty-five trials were included, in which 17 trials studied distal stimulation, another 17 trials studied peri-incisional stimulation and one studied the combination of the two approaches. No studies that directly compared the two approaches were identified. Subgroup analysis showed that both distal and peri-incisional stimulation significantly alleviated postoperative resting and movement pain from 4 h to 48 h after surgery by 6 to 25 mm on a 100 mm visual analogue scale. Peri-incisional stimulation showed a better reduction in postoperative opioid consumption. No studies compared the effects of the combined peri-incisional and distal stimulation with either mode alone. Overall the quality of evidence was moderate due to a lack of blinding in some studies, and unclear risk of allocation concealment.

CONCLUSION

Both distal and peri-incisional modes of stimulation were effective in reducing postoperative pain. Whether a combined peri-incisional stimulation and distal acupuncture has superior results requires further studies.

Sufentanil Sublingual Tablet System (SSTS) for the management of postoperative pain after major abdominal and gynecological surgery within an ERAS protocol: an observational study

Background

The Sufentanil Sublingual Tablet System (SSTS) is a new, pre-programmed, noninvasive, handheld system for patient-controlled analgesia (PCA) which may allow a faster postoperative recovery compared with standard PCA. The efficacy of SSTS in controlling pain after open abdominal surgery has already been documented. However, to our knowledge SSTS has never been investigated in patients undergoing major surgery within an Enhanced Recovery After Surgery (ERAS) protocol.

Methods

This observational, retrospective analysis included consecutive patients undergoing elective major abdominal and gynecological surgery. All patients received the SSTS device once they were fully awake and had a good control of pain at the end of the surgery. We analyzed changes in pain intensity according to the numerical rating scale (NRS) throughout the treatment as well as its duration, the number of administrations, and possible related adverse events. Patients were also interviewed to assess their quality of sleep and overall satisfaction with the SSTS device.

Results

The study included 308 patients. Compared to the first SSTS administration, pain intensity decreased from a median NRS of 6 to 0 at day 3, for an overall reduction of 79%. Results were already statistically significant at postoperative day 1 (p<0.01). Adverse reactions were observed in 62 patients, with nausea being the most frequent (12%), and in 93% of patients SSTS was discontinued because it was considered no longer necessary. Patient satisfaction was high, with 89% of them judging the device as “easy” or “very easy” to use.

Conclusions

Although the retrospective and observational nature of the study as well as the absence of a comparative group limits the strength of evidence, our results consider SSTS an effective and safe tool for the management of postoperative pain after major abdominal and gynecological surgery within an ERAS protocol.

Defining trajectories of acute pain in surgical patients short title: acute pain follow-up

INTRODUCTION

Assessment of acute postoperative pain is mandatory for effective treatments. Pain trajectories may help professionals improve treatments. It has been suggested that uncontrolled pain in the immediate postoperative period generates higher pain intensities on the following days of hospital stay.

OBJECTIVE

To determine the relationship between pain during the first postoperative hour and the first 24 postoperative hours.

METHODS

Setting: a general university hospital. Study design: a prospective observational, analytical study of patients undergoing surgical procedures under general anesthesia and hospitalized for at least 24 hours. Five assessments of pain were carried out during the first hour in the recovery room followed by three assessments during the first 24 hours. The slopes of pain trajectories were calculated, and the relationship between them was analyzed.

RESULTS

234 patients were recruited, 31.3% had uncontrolled pain on arrival at the recovery room; at the end of the first 24 hours after surgery, 5.5% of the patients had uncontrolled pain. The first pain intensity score in the recovery room correlated negatively with the slope for the first hour (P1): rS = -0.657 (p = 0.000). Similarly, the first pain intensity score had a negative association with the pain trajectory slope during the hospital stay (P2): rS = -0.141 (p = 0.032). When comparing the two slopes, a nonsignificant negative correlation was found: rS = -0.126.

CONCLUSIONS

the trajectory of pain during the first hour does not predict the behavior of the trajectory during the first day after surgery.

Impact of epidural bupivacaine on perioperative opioid requirements, recovery characteristics, and duration of hospitalization in dogs undergoing cystotomy: A retrospective study of 56 cases

OBJECTIVE

To compare perioperative opioid consumption and duration of hospitalization (DOH) in anesthetized dogs receiving opioid-based analgesia (OBA) vs those receiving bupivacaine epidural-based analgesia (EPID) during cystotomy.

STUDY DESIGN

Retrospective cross-sectional study.

ANIMALS

Fifty-six client-owned dogs undergoing cystotomy.

METHODS

Clinical records of dogs undergoing cystotomy between January 2015 and December 2017 were reviewed. Demographic data, duration of anesthesia and surgery, anesthetic management, perioperative opioid consumption expressed in morphine equivalents (ME), perioperative use of adjuvant analgesics, time to first micturition, time to eat, time to ambulate, and DOH were recorded. Opioid consumption and DOH were compared with a Wilcoxon rank-sum test, followed by linear regression analysis as appropriate. Time to first micturition, time to eat, and time to walk unassisted were modeled with Cox-proportional hazard models.

RESULTS

Dogs treated with EPID during surgery required 1.5 mg/kg ME less compared with those treated with OBA (P = .04) during surgery. Three of 19 dogs treated with EPID vs 15 of 37 dogs receiving OBA required intraoperative adjuvant analgesics (P = .06). Dogs treated with EPID regained motor function slower than dogs treated with OBA (P = .01); however, there was no difference in time to urinate, time to eat, or DOH between treatments.

CONCLUSION

Perioperative lumbosacral epidural with bupivacaine reduced intraoperative opioid consumption in dogs anesthetized for cystotomy.

CLINICAL SIGNIFICANCE

The use of epidural bupivacaine in dogs undergoing cystotomy may reduce intraoperative opioid requirements without affecting return of bladder function or DOH.

Adjuvant analgesics in spinal surgery

Peri- and postoperative pain control can present a challenge to any doctor, particularly in the setting of spinal surgery. The use of adjuvant pain agents and multimodal analgesia is changing the face of modern anaesthesia and offering clinicians more avenues to control perioperative pain. This article discusses the use of adjuvant medications and some of the evidence surrounding their use in spinal surgery.

[Agreement of the Professional Association of German Anesthesiologists and the Professional Association of German Surgeons for the Organization of Postoperative Pain Therapy for Surgical Patients (revised version 2019)]

The treatment of any causal, procedure-specific and/or concomitant acute pain is an essential quality feature in any surgical subspecialty. An interdisciplinary and interprofessional pain therapy aims for an immediate improvement of the patients' quality of life, a reduction of the risk of postoperative morbidity and mortality in the medium term, prevention of any pain chronification in the long run as well as a reduction of hospitalization and sick leave. The "Agreement of the Professional Association of German Anesthesiologists and the Professional Association of German Surgeons for the Organization of Postoperative Pain Therapy" exists since 1992. In view of the continuously developing scientific evidence, updated guideline recommendations and interprofessionally designed treatment pathways, these agreements have been adapted to the current requirements and structural conditions of the German healthcare system. Thus, both aforementioned professional associations promote an up to date version of an "Agreement for the Organization of Pain Therapy for Surgical Patients", a precise recommendation and a manual for the acting partners in order to realize the abovementioned goals.

Development of evidence-based recommendations for procedure-specific pain management: PROSPECT methodology

Effective peri‐operative pain management is a prerequisite for optimal recovery after surgery. Despite published evidence‐based guidelines from several professional groups, postoperative pain management remains inadequate. The procedure‐specific pain management (PROSPECT) collaboration consists of anaesthetists and surgeons with broad international representation that provide healthcare professionals with practical and evidence‐based recommendations formulated in a way that facilitates clinical decision‐making across all stages of the peri‐operative period on a procedure‐specific basis. The aim of this manuscript is to provide a detailed description of the current PROSPECT methodology with the intention of providing the rigour and transparency in which procedure‐specific pain management recommendations are developed. The high methodological standards of the recommendations should improve the quality of clinical practice.

Opioid Use in the Postoperative Arena: Global Reduction in Opioids After Surgery Through Enhanced Recovery and Gynecologic Surgery

Enhanced recovery programs aim to reduce surgical stress to improve the patient perioperative experience. Through a combination of multimodal analgesia and maintaining a physiological state, postoperative recovery is improved. Many analgesic adjuncts are available that improve postoperative pain control and limit opioid analgesia requirements. Adjuncts are often used in combination, but different interventions may be incorporated for patient-specific and procedure-specific needs. Postoperative pain control can be optimized by continuing nonopioid adjuncts, and prescribing opioid analgesia to address breakthrough pain. Prescribing practices should balance optimizing pain relief, minimizing the risk of chronic pain, while limiting the potential for opioid misuse.

Preemptive analgesia after lumbar spine surgery by pregabalin and celecoxib: a prospective study

Objective

To evaluate the preemptive analgesic effect of combination pregabalin with celecoxib for lumbar spine surgery.

Methods

A prospective, randomized study was conducted among 60 lumbar spine surgery patients and divided into two groups. Postoperative pain relief was achieved with intravenous patient-controlled analgesia with morphine. The preemptive analgesia group received oral pregabalin (150 mg) and celecoxib (200 mg) 2 hrs before surgery, and the control group received a placebo. Pain was assessed by visual analogue scale (VAS). Side effects and morphine consumption were monitored until 48 hrs after surgery.

Results

VAS score at rest and during movement was statistically significantly lower in the preemptive analgesia group at most time points (p<0.05). Morphine consumption was significantly lower in the preemptive analgesia group compared with control group in the 24 first hours (29.03±4.38 mg vs 24.43±4.94) and 48 hrs (52.23±9.57 mg vs 44.20±10.21 mg), p<0.05. Hemodynamics, respiratory rate, and SpO₂ were similar for both groups. The sedation score was only statistically significant at H8 time point. The incidence of nausea/vomiting in the preemptive group did not statistically differ from the control group.

Conclusion

Preoperative administration of pregabalin combined with celecoxib had a good preemptive analgesia effect and reduced intravenous morphine consumption after lumbar spine surgery. Side effects were mild and transient.

Rates of New Persistent Opioid Use After Vaginal or Cesarean Birth Among US Women

IMPORTANCE

Research has shown an association between opioid prescribing after major or minor procedures and new persistent opioid use. However, the association of opioid prescribing with persistent use among women after vaginal delivery or cesarean delivery is less clear.

OBJECTIVE

To assess the association between opioid prescribing administered for vaginal or cesarean delivery and rates of new persistent opioid use among women.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used national insurance claims data for 988 036 women from a single private payer from January 1, 2008, to December 31, 2016. Participants included reproductive age, opioid-naive women with 1 year of continuous enrollment before and after delivery. For participants with multiple births, only the first birth was included.

EXPOSURES

Peripartum opioid prescription (1 week before delivery to 3 days after discharge) captured by pharmacy claims, including prescription timing and size in oral morphine equivalents. Multivariable adjusted odds ratios were estimated using regression models.

MAIN OUTCOMES AND MEASURES

Rates of new persistent opioid use, defined as pharmacy claims for 1 or more opioid prescription 4 to 90 days after discharge and 1 or more prescription 91 to 365 days after discharge among women who filled peripartum opioid prescriptions.

RESULTS

In total, 308 226 deliveries were included: 195 013 (63.3%) vaginal deliveries and 113 213 (36.7%) cesarean deliveries. Participant mean (SD) age was 31.3 (5.3) years, and 70 567 (51.0%) were white patients. Peripartum opioid prescriptions were filled by 27.0% of women with vaginal deliveries and 75.7% of women with cesarean deliveries. Among them, 1.7% of those with vaginal deliveries and 2.2% with cesarean deliveries had new persistent opioid use. By contrast, among women not receiving a peripartum opioid prescription, 0.5% with vaginal delivery and 1.0% with cesarean delivery had new persistent opioid use. From 2008 to 2016, opioid prescription fills decreased for vaginal deliveries from 26.9% to 23.8% (P < .001) and for cesarean deliveries from 75.5% to 72.6% (P < .001), and fewer women had new persistent use (vaginal delivery, from 2.2% to 1.1%; P < .001; cesarean delivery, from 2.5% to 1.3%; P < .001). The strongest modifiable factor associated with new persistent opioid use after delivery was filling an opioid prescription before delivery (adjusted odds ratio, 1.40; 95% CI, 1.05-1.87). For vaginal deliveries, receiving a prescription equal to or more than 225 oral morphine equivalents was associated with new persistent opioid use (adjusted odds ratio, 1.25; 95% CI, 1.06-1.48). Women who underwent cesarean delivery and had a hysterectomy were more likely to develop persistence (AOR, 2.75; 95% CI, 1.33-5.70), although women who underwent a nonelective (AOR, 0.97; 95% CI, 0.88-1.07) or repeat cesarean (AOR, 1.45; 95% CI, 0.93-2.28) were not more likely. For cesarean deliveries, risk factors were associated with patient attributes such as tobacco use (adjusted odds ratio, 1.82; 95% CI, 1.56-2.11), psychiatric diagnoses, history of substance use (adjusted odds ratio, 1.43; 95% CI, 1.10-1.86), and pain conditions.

CONCLUSIONS AND RELEVANCE

The results of the present study suggested that opioid prescribing and new persistent use after vaginal delivery or cesarean delivery have decreased since 2008. However, modifiable prescribing patterns were associated with persistent opioid use for patients who underwent vaginal delivery, and risk factors following cesarean delivery mirrored those of other surgical conditions. Judicious opioid prescribing and preoperative risk screening may be opportunities to decrease new persistent opioid use after childbirth.

Perioperative activation of spinal α7 nAChR promotes recovery from preoperative stress-induced prolongation of postsurgical pain

Preoperative stress could delay the recovery of postoperative pain and has been reported to be a risk factor for chronic postsurgical pain. As stress could facilitate the proinflammatory activation of microglia, we hypothesized that these cells may play a vital role in the development of preoperative stress-induced pain chronification after surgery. Our experiments were conducted in a rat model that consists of a single prolonged stress (SPS) procedure and plantar incision. A previous SPS exposure induced anxiety-like behaviors, prolonged incision-induced mechanical allodynia, and potentiated the activation of spinal microglia. Based on the results from ex vivo experiments, spinal microglia isolated from SPS-exposed rats secreted more proinflammatory cytokines upon challenge with LPS. Our results also demonstrated that microglia played a more important role than astrocytes in the initiation of SPS-induced prolongation of postsurgical pain. We further explored the therapeutic potential of agonism of α7 nAChR, an emerging anti-inflammatory target, for SPS-induced prolongation of postsurgical pain. Multiple intrathecal (i.t.) injections of PHA-543613 (an α7 nAChR agonist) or PNU-120596 (a type II positive allosteric modulator) during the perioperative period shortened the duration of postsurgical pain after SPS and suppressed SPS-potentiated microglia activation, but their effects were abolished by pretreatment with methyllycaconitine (an α7 nAChR antagonist; i.t.). Based on the results from ex vivo experiments, the anti-inflammatory effects of PHA-543613 and PNU-120596 may have been achieved by the direct modulation of microglia. In conclusion, stress-induced priming of spinal microglia played a key role in the initiation of preoperative stress-induced prolongation of postsurgical pain, and PHA-543613 and PNU-120596 may be potential candidates for preventing pain chronification after surgery.

Reliability, validity and generalizability of multidimensional pain assessment tools used in postoperative adult patients: a systematic review protocol

OBJECTIVE

The objective of this review is to evaluate the measurement properties of multidimensional pain assessment tools for postoperative pain in adults.

INTRODUCTION

Effective postoperative pain management increases patient safety and satisfaction, and reduces healthcare costs. The most commonly used postoperative pain assessment tools only evaluate pain intensity, which is only one aspect of the sensory dimension of pain. Pain is a subjective phenomenon, and variability exists among patients. Efforts are underway to incorporate multidimensional assessment tools for postoperative pain assessment in clinical practice.

INCLUSION CRITERIA

Eligible studies will include postoperative patients aged 18 years and older from all surgical disciplines. Studies evaluating multidimensional assessment instruments for the measurement of postoperative pain during the first two weeks following surgery will be considered. Studies will include the following measurement properties of assessment tools as outcomes: reliability, validity and generalizability.

METHODS

MEDLINE, CINAHL, Embase, PsycINFO and Cochrane Trials (CENTRAL) will be searched, as well as ClinicalTrials.gov and multiple gray literature sources. There will be no limitations on publication date. Titles and abstracts will be screened by independent reviewers for inclusion. The full text of selected papers will be retrieved and assessed against the inclusion criteria. Two independent reviewers will assess papers for methodological quality using the COSMIN checklist, and papers with poor scores on relevant items will be excluded. Data will be extracted by two independent reviewers using a standardized data extraction tool. Statistical pooling will be performed, if possible.

Bilateral erector spinae plane blocks using a small volume of local anesthetic for acute pain control after single-port laparoscopic surgery

In the era of enhanced recovery after surgery, clinicians are encouraged to develop optimized programs for patients who require surgery. Minimal intervention with laparoscopic surgery and multimodal pain management mostly with peripheral nerve block are key components. We are developing a departmental program for enhanced recovery after surgery for single-port laparoscopic surgery. We applied an erector spinae plane block, a novel, newly recognized block, bilaterally at the T10 transverse process with a small dose (10 mL) of local anesthetic. This method was effective and safe and resulted in successful analgesia in a patient who received single-port surgery. This surgery requires a 3-5 cm horizontal or longitudinal periumbilical incision, which was performed in this case, and our results were promising and encouraging.

[Evaluation of the neurotoxic effects of intrathecal administration of (S)-(+)-Ketoprofen on rat spinal cords: randomized controlled experimental study]

BACKGROUND AND OBJECTIVES

Intrathecal administration of non-steroidal anti-inflammatory drugs is more efficacious for post-operative pain management. Cyclooxygenase inhibiting non-steroidal anti-inflammatory drugs like (S)-(+)-Ketoprofen, may be effective at lower intrathecal doses than parenteral ones. Preclinical safety regarding possible neurotoxicity associated with the intrathecal (S)-(+)-Ketoprofen was not evaluated. Here we analysed the neurotoxicity of intrathecally administered (S)-(+)-Ketoprofen in rats.

METHODS

A randomized placebo-controlled experimental study was conducted. Sprague-Dawley rats (250-300g) aged 12-16 weeks were randomly divided into 2 treatments [100 and 800μg (S)-(+)-Ketoprofen] and control (sterile water) groups. Intrathecal catheters were placed via the atlantoaxial space in anesthetized rats. Pinch-toe tests, motor function evaluations and histopathological examinations of the spinal cord and nerve roots were performed at days 3, 7 and 21. Spinal cord sections were evaluated by light microscopy for the dorsal axonal funiculus vacuolation, axonal myelin loss, neuronal chromatolysis, neuritis, meningeal inflammation, adhesions, and fibrosis.

RESULTS

Rats in all the groups exhibited normal pinch-toe testing response (score=0) and normal gait at each observed time (motor function evaluation score=1). Neurotoxicity was higher with treatments on days 3 and 7 than that on day 21 (2, 3, 0, p=0.044; 2, 5, 0, p=0.029, respectively). On day 7, the total scores reflecting neuronal damage were higher in the 800μg group than those in the 100μg and Control Groups (5, 3, 0, p=0.048, respectively).

CONCLUSION

Intrathecal (S)-(+)-Ketoprofen caused dose-dependent neurohistopathological changes in rats on days 3 and 7 after injection, suggesting that (S)-(+)-Ketoprofen should not be intrathecally administered.

Evaluation of the neurotoxic effects of intrathecal administration of (S)-(+)-Ketoprofen on rat spinal cords: randomized controlled experimental study

Background and objectives

Intrathecal administration of non-steroidal anti-inflammatory drugs is more efficacious for post-operative pain management. Cyclooxygenase inhibiting non-steroidal anti-inflammatory drugs like (S)-(+)-Ketoprofen, may be effective at lower intrathecal doses than parenteral ones. Preclinical safety regarding possible neurotoxicity associated with the intrathecal (S)-(+)-Ketoprofen was not evaluated. Here we analysed the neurotoxicity of intrathecally administered (S)-(+)-Ketoprofen in rats.

Methods

A randomized placebo-controlled experimental study was conducted. Sprague-Dawley rats (250–300 g) aged 12–16 weeks were randomly divided into 2 treatments [100 and 800 μg (S)-(+)-Ketoprofen] and control (sterile water) groups. Intrathecal catheters were placed via the atlantoaxial space in anesthetized rats. Pinch-toe tests, motor function evaluations and histopathological examinations of the spinal cord and nerve roots were performed at days 3, 7 and 21. Spinal cord sections were evaluated by light microscopy for the dorsal axonal funiculus vacuolation, axonal myelin loss, neuronal chromatolysis, neuritis, meningeal inflammation, adhesions, and fibrosis.

Results

Rats in all the groups exhibited normal pinch-toe testing response (score = 0) and normal gait at each observed time (motor function evaluation score = 1). Neurotoxicity was higher with treatments on days 3 and 7 than that on day 21 (2, 3, 0, p = 0.044; 2, 5, 0, p = 0.029, respectively). On day 7, the total scores reflecting neuronal damage were higher in the 800 μg group than those in the 100 μg and Control Groups (5, 3, 0, p = 0.048, respectively).

Conclusion

Intrathecal (S)-(+)-Ketoprofen caused dose-dependent neurohistopathological changes in rats on days 3 and 7 after injection, suggesting that (S)-(+)-Ketoprofen should not be intrathecally administered.

A Swiss nationwide survey shows that dual guidance is the preferred approach for peripheral nerve blocks

Ultrasound has significantly increased safety and effectiveness in regional anesthesia. However, little is known about its clinical use. We studied clinical approaches currently used by anesthesiologists, conducted a nationwide survey, and analyzed data collected in ordered logistic regression models. All active members of the Swiss Society for Anaesthesiology and Resuscitation (SSAR/SGAR) were asked to participate. Reported practice in nerve localization, safety, and techniques used for peripheral nerve blocks (PNB) were main outcome measures. Experience ranged from 3 to >30 years. The mean number of block techniques mastered was 11.5 ± 5.9. Standard monitoring was regularly used, whereas sterile coats were less frequently used by anesthesiologists who self-estimated a higher level of expertise in PNB (ordered logit coefficient −0.05, 95% CI −0.07 to −0.02, P < 0.001; pseudo r2 = 0.019; probability > Chi2 = 0.02). The more self-estimated expertise anesthesiologists had, the less likely they were to use nerve stimulation in combination with ultrasound (dual guidance) (ordered logit coefficient −0.31; 95% CI −0.85 to −0.03: P = 0.03; pseudo r2 = 0.007; probability > Chi2 = 0.05). The high share of reported standard monitoring meets the recommendations of the Helsinki Patient Safety Declaration. Dual guidance appears to be the preferred approach for safely localizing nerves for PNB in Switzerland.