Present-day challenges and future solutions in postoperative pain management: results from PainForum 2014

Developing expert international consensus statements for opioid-sparing analgesia using the Delphi method

INTRODUCTION

The management of postoperative pain in anaesthesia is evolving with a deeper understanding of associating multiple modalities and analgesic medications. However, the motivations and barriers regarding the adoption of opioid-sparing analgesia are not well known.

METHODS

We designed a modified Delphi survey to explore the perspectives and opinions of expert panellists with regard to opioid-sparing multimodal analgesia. 29 anaesthetists underwent an evolving three-round questionnaire to determine the level of agreement on certain aspects of multimodal analgesia, with the last round deciding if each statement was a priority.

RESULTS

The results were aggregated and a consensus, defined as achievement of over 75% on the Likert scale, was reached for five out of eight statements. The panellists agreed there was a strong body of evidence supporting opioid-sparing multimodal analgesia. However, there existed multiple barriers to widespread adoption, foremost the lack of training and education, as well as the reluctance to change existing practices. Practical issues such as cost effectiveness, increased workload, or the lack of supply of anaesthetic agents were not perceived to be as critical in preventing adoption.

CONCLUSION

Thus, a focus on developing specific guidelines for multimodal analgesia and addressing gaps in education may improve the adoption of opioid-sparing analgesia.

QX-OH/Levobupivacaine: A Structurally Novel, Potent Local Anesthetic Produces Fast-Onset and Long-Lasting Regional Anesthesia in Rats

Purpose

Local anesthetics (LAs) are an important alternative for postoperative analgesia; however, the short duration of LAs limits their use. Thus, we previously developed LL-1, a mixture of QX-OH and levobupivacaine (LB) that produces regional anesthesia for more than 10 h in rats. The aim of this study is to investigate the long-acting mechanism of LL-1 in vivo and in vitro.

Methods

Regional anesthetic effects and local toxicity of the LL-1, QX-OH and LB treatment groups were investigated in a sciatic nerve block rat model. Whole-cell patch-clamping recordings were used to measure the inhibition Na_v currents (I_Na) in ND7/23 cells.

Results

The onset of LL-1 (35mM QX-OH+10mM LB) and 10 mM LB was 10 min, which was much faster than 35 mM QX-OH (27 [18, 60] min, t[12] = −4.535, p = 0.001). The duration of LL-1 (35mM QX-OH+10 mM LB) was significantly longer than 35 mM QX-OH or 10 mM LB alone (F[3, 35] = 191.336, p < 0.0001). No differences in local tissue toxicity were found between LL-1 and LB. In patch-clamping recordings, 5 mM QX-OH produced ~20% inhibition of I_Na currents. LB at 40 μM inhibited I_Na by 65.51%±3.63%, while QX-OH 2 mM+LB 40 μM inhibited I_Na by 77.37%±3.36% (t[14] = 2.358, p = 0.025), and QX-OH 5 mM+LB 40 μM inhibited I_Na by 83.88%±1.57% (t[13] = 4.191, p = 0.0003). Furthermore, I_Na inhibition by QX-OH+LB was more persistent than that of LB alone during washout.

Conclusion

LL-1 can produce an additive and stable inhibition of Nag_v currents, which can contribute to the long-lasting regional anesthetic action.

Tramadol/Diclofenac Fixed-Dose Combination: A Review of Its Use in Severe Acute Pain

Pain is a health issue affecting all populations, regardless of age, gender, economic status, race, or geography. Acute pain is the most common type of pain, with a complex aetiology. Inadequately managed acute pain adversely affects quality of life and imposes significant economic burden. The majority of the available pain-relieving drugs have monomodal mechanisms of analgesia, which necessitates combining drugs with non-redundant mechanisms of action in order to provide adequate pain relief and reduce the side effects from higher doses of individual drugs. In this regard, combining an oral opioid (such as codeine or tramadol) and a non-opioid (such as paracetamol or non-steroidal anti-inflammatory drug) offers a plausible option. Tramadol/diclofenac fixed-dose combination (FDC) is one such analgesic combination which has demonstrated promising clinical activity via its multimodal mechanisms of action. This review seeks to provide an up-to-date narrative on the current scientific literature regarding the pharmacological properties, clinical efficacy, and tolerability of tramadol/diclofenac FDC in the treatment of acute severe pain. A comprehensive, qualitative review of the literature was conducted using a structured search strategy in Medline/PubMed and additional Internet-based sources to identify relevant studies. Based on the available scientific literature, evidence of the efficacy and safety of tramadol/diclofenac FDC for treatment of patients with acute severe pain, including musculoskeletal pain, postoperative pain, and acute flare-up of osteoarthritis or rheumatoid arthritis, appears to be substantial. Although additional comparative studies would be required to definitively position tramadol/diclofenac FDC with respect to other analgesic combinations, the available data suggest that tramadol/diclofenac FDC is a valuable treatment option for patients with acute severe pain.

Effect of evening primrose oil on postoperative pain after appendectomy: A double-blind, randomized, clinical trial

Background and objective

Despite advances in surgical techniques and pharmacology, postoperative pain remains a common problem after appendectomy, and its management continues to be suboptimal. The aim of this study was to evaluate the effect of evening primrose oil on the reduction of postoperative pain after appendectomy.

Materials and methods

In a double-blind, randomized, clinical trial, a total of 80 adults patients with acute appendicitis who were undergoing appendectomy at the Shahid Beheshti Emdad Hospital in Sabzevar, were included. Patients were randomly allocated into two equally sized groups (n = 40). In postoperative period and after recovering from the anesthesia, each of the intervention and control groups received one evening primrose (1000 mg) or placebo capsules every 30 min for 3 times, respectively. All patients in both groups were asked to rate the intensity of their pain on a 0-10 point Visual Analogue Scale (VAS) and also McGill pain questionnaire, before and 1 h after the last administration of the drug, postoperatively.

Results

In patients who received evening primrose, both VAS and McGill pain intensity scores significantly decreased after intervention, when compared prior to initiation of the intervention (p < 0.0001). While in the control group, changes of pain intensity scores were not significantly different before and after the intervention (p > 0.05).

Conclusion

It seems that oral evening primrose can be used as a simple and safe potential adjunctive treatment for postoperative pain control after appendectomy.

Pain Management and Its Possible Implementation Research in North Ethiopia: A before and after Study

BACKGROUND

Though there is an effective intervention, pain after surgical intervention is undermanaged worldwide. A systematic implementation is required to increase the utilization of available evidence-based intervention to manage the inevitable pain after surgery. The aim of this research project is to develop a scalable model for managing pain after cesarean section by implementing the World Health Organization's (WHO) pain management guidelines through a combination of implementation research and quality improvement methods.

METHODS

We implemented the World Health Organization (WHO) pain management guidelines using effective implementation strategies. First, we conducted a formative qualitative exploration to identify enablers and obstacles. In addition, we took base-line assessment on pain management implementation process and outcome using a checklist prepared from the guideline and an adapted American Pain Outcome assessment tool version 2010, respectively. Then, we integrated the guidelines into the existing practice by using collaborative iterative learning strategy. We analyzed the data by Statistical Packages for Social Sciences (SPSS) version 21. We compared the before and after data using chi-squared and Fischer's exact test. A change in any measurement was considered as significant at p value 0.05.

RESULT

We collected data from 106 mothers before and 110 mothers after intervention implementation. We successfully integrated pain as a fifth vital sign in more than 87% (p value <0.001) of patient, and fidelity was approximately 59% (p value <0.001). In addition, we significantly improved pain outcome measures after the implementation of the intervention. Conclusion and Recommendations. A systematic approach to implement pain management guidelines was successful. We recommend the ward sustain these gains and that hospital, the region, and the nation to replicate the success.

Quality of postoperative pain management in Ethiopia: A prospective longitudinal study

Background

The annual number of surgical operations performed is increasing throughout the world. With this rise in the number of surgeries performed, so too, the challenge of effectively managing postoperative pain. In Africa, there are scanty data available that make use of multi-center data to characterize the quality of postoperative pain management. In this study using a longitudinal data, we have attempted to characterize the quality of postoperative pain management; among patients scheduled for major elective orthopedic, gynecologic and general surgery.

Methods

This prospective longitudinal study evaluated the quality of postoperative pain management in patients undergoing elective general, gynecologic, and orthopedic surgery. We quantified the prevalence of moderate to severe postoperative pain with the International Pain Outcome Questionnaire and the corresponding adequacy of treatment with the pain management index. At four time points after surgery, we estimated pain severity, its physical and emotional interference, and patient satisfaction.

Results

Moderate to severe postoperative pain was present in 88.2% of patients, and pain was inadequately treated in 58.4% of these patients. Chronic pain (β = 0.346, 95% CI: 0.212, 0.480) predicted patients’ worst pain intensity. Gender was not associated with the worst pain intensity or percentage of time spent in severe pain. Patient’s pain intensity did not predicted the level of satisfaction.

Conclusions

The prevalence of moderate to severe postoperative pain and its functional interference is high in Ethiopian patients. The treatment provided to patients is inadequate and not in line with international recommendations and standards.

New Advances in Acute Postoperative Pain Management

PURPOSE OF REVIEW

Postoperative pain remains one of the most common challenges following inpatient and outpatient surgeries. With our advances in modern medicine, pain following surgical procedures still remains a challenge, though significant accomplishments have been made over the past few decades. This article highlights some of the promising new advances and approaches in postoperative pain management.

RECENT FINDINGS

Over the last decade, Enhanced Recovery after Surgery (ERAS) pathways and protocols are becoming the benchmark standards for enhancing postoperative recovery. Multimodal analgesia (MMA) is an essential component of such care. Further, in the wake of serious and persistent concern on the opioid epidemic in the USA, there has been a recent renewal of interest in non-opioid alternatives or adjuncts in controlling postoperative pain, often in the context of MMA. Intravenous (IV) acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), magnesium, ketamine, dexmedetomidine, liposomal bupivacaine, and newer neuraxial and peripheral regional techniques as well as patient-controlled modalities are gaining importance. Gabapentinoids have become popular but recent meta-analytic reviews have cast doubt on their routine use in perioperative settings. Among opioids, sublingual sufentanil, IV oxycodone, and iontophoretic transdermal fentanyl hold promise. Acupuncture and transcutaneous electrical nerve stimulation may be useful as adjuncts in MMA packages. Genetic testing, derivatives of herbal preparations, and an extended role of acute pain services may emerge as potential areas of importance in the future. There are, however, critical gaps in good quality evidence in many of the practice guideline recommendations. In the era of opioid epidemic, several lines of evidence have emerged to support non-opioid-based drugs and approaches along with a few newer opioid formulations for postoperative pain management, although more research is needed to find the right balance of efficacy and safety.

The quaternary lidocaine derivative QX-314 in combination with bupivacaine for long-lasting nerve block: Efficacy, toxicity, and the optimal formulation in rats

OBJECTIVE

The quaternary lidocaine derivative (QX-314) in combination with bupivacaine can produce long-lasting nerve blocks in vivo, indicating potential clinical application. The aim of the study was to investigate the efficacy, safety, and the optimal formulation of this combination.

METHODS

QX-314 and bupivacaine at different concentration ratios were injected in the vicinity of the sciatic nerve in rats; bupivacaine and saline served as controls (n = 6~10). Rats were inspected for durations of effective sensory and motor nerve blocks, systemic adverse effects, and histological changes of local tissues. Mathematical models were established to reveal drug-interaction, concentration-effect relationships, and the optimal ratio of QX-314 to bupivacaine.

RESULTS

0.2~1.5% QX-314 with 0.03~0.5% bupivacaine produced 5.8~23.8 h of effective nerve block; while 0.5% bupivacaine alone was effective for 4 h. No systemic side effects were observed; local tissue reactions were similar to those caused by 0.5% bupivacaine if QX-314 were used < 1.2%. The weighted modification model was successfully established, which revealed that QX-314 was the main active ingredient while bupivacaine was the synergist. The formulation, 0.9% QX-314 plus 0.5% bupivacaine, resulted in 10.1 ± 0.8 h of effective sensory and motor nerve blocks.

CONCLUSION

The combination of QX-314 and bupivacaine facilitated prolonged sciatic nerve block in rats with a satisfactory safety profile, maximizing the duration of nerve block without clinically important systemic and local tissue toxicity. It may emerge as an alternative approach to post-operative pain treatment.