Acute pain: Journals & articles

Abstract
Minimum clinically important differences (MCIDs) in acute pain intensity have not been well established. Conventional approaches for estimating MCIDs require an independent reference scale, with a threshold that must be presumed to accurately classify meaningful change in pain for all study participants, to serve as an anchor. The double stopwatch technique is the gold standard for measuring the time to meaningful relief, where participants actively press the second stopwatch when they experience pain relief that is meaningful to them. This technique eliminates the problem of misclassification with arbitrary anchors at a single time point, but the censored nature of the data is not amenable for determining MCIDs using standard methods. We propose a stopwatch-based MCID methodology that employs the double stopwatch technique to identify individualized thresholds for meaningful change in pain. This approach enables direct classification of changes in pain for each participant based on whether they perceived the change as meaningful and whether it exceeded the study cut-off being tested. Pain values of participants who do not achieve meaningful relief are incorporated into the analysis to address censoring and avoid bias. The performance (e.g., sensitivity, specificity) of different thresholds to serve as an MCID can be estimated using standard approaches with variance estimates derived by cluster bootstrapping. The advantages of the stopwatch-based MCID methodology are illustrated relative to a conventional approach using data from a randomized trial in third molar extraction. PERSPECTIVE: This article describes a methodology for determining MCIDs using the double stopwatch technique, the gold standard for assessing meaningful changes in acute pain. This methodology can be used to establish MCIDs in different acute pain settings, providing a useful basis to evaluate the meaningfulness of clinical trial results.

Abstract
Background: The prevalence of postoperative pain is notably high among the elderly population, which poses significant challenges for their postoperative recovery. In this study, we aimed to identify preoperative predictors for acute and chronic postoperative pain in patients undergoing lumbar spinal surgery through a longitudinal investigation.

Methods: We recruited 75 patients (mean age 68.29 ± 5.60 years) and collected their resting-state electroencephalography (EEG) data two hours before the surgery. The aperiodic and periodic signal components were extracted from the resting-state EEG using the Fitting Oscillations and One-Over-F algorithm. We also collected the preoperative pain ratings, demographic information and the Hospital Anxiety and Depression Scale from all patients. The postoperative pain ratings were collected ten times from Day 1 to Week 12 after surgery.

Results: We observed a high incidence of postoperative acute and chronic pain among older patients. Preoperative pain and peak alpha frequency in resting-state EEG were the primary predictors of acute postoperative pain. Although age is a significant predictor of chronic postoperative pain, its predictive performance is poor.

Conclusions: Overall, our study provides valuable insights into the complex pattern of preoperative EEG features, preoperative pain and age in predicting postoperative pain at different stages. Our findings highlight the significance of exploring preoperative features to identify patients who are at a higher risk of developing severe postoperative pain, which can aid in the development of more personalized and effective pain management strategies.

Significance: The heightened occurrence of postoperative pain among the elderly presents formidable obstacles to their recuperation. This study delves into identifying preoperative factors influencing acute and chronic postoperative pain. Our findings indicate that preoperative pain and peak alpha frequency are crucial predictors of acute postoperative pain. However, the predictive performance for chronic postoperative pain is limited, although age was a significant predictor of chronic postoperative pain. These insights contribute to the identification of patients at elevated risk for severe acute and chronic postoperative pain, offering valuable guidance for pre-surgical risk assessment.

Abstract
Background: Postoperative pain management is a challenge after robot-assisted cystectomy (RAC). Methadone has a long duration of action, and we therefore hypothesized that a single dose of intraoperative methadone would reduce postoperative opioid requirements and pain intensity in bladder cancer patients undergoing RAC.

Methods: We conducted a blinded randomized controlled clinical trial from July 2020 to August 2023. Patients scheduled to undergo RAC because of bladder cancer were randomized to receive intraoperative methadone (0.15 mg/kg-1) or morphine (0.15 mg kg-1) 1 h before endotracheal extubation. The primary outcome was opioid requirements after 24 h. Secondary outcomes were opioid requirements after 3 h, pain intensity at rest and during coughing, postoperative nausea and vomiting (PONV), sedation, hypoxemia, hypoventilation, time spent in the post-anesthetic care unit, and patient satisfaction.

Results: A total of 114 patients were randomized. Data from 99 patients (14 females, 85 males; mean age 69.8 ± 8.9 years) were available for analysis; 52 received methadone and 47 received morphine. Opioid consumption was similar between the methadone group and morphine group at 3 h (median, mg, 45 (IQR 30 to 75) vs. 45 (IQR 15 to 82.5) p = .97) and at 24 h (median, mg, 125 (IQR 75 to 198.5) versus 105 (IQR 72 to 157.5), p = .29). Pain intensity was significantly lower in the morphine group at 48 h compared with the methadone group. Patient satisfaction at 24 h was increased in the methadone group compared with the morphine group (median, (IQR), NRS; 9 (IQR 7 to 10) versus 7 (IQR 4 to 9), p = .020). There were no differences between treatment groups in terms of time spent in the post-anesthetic care unit and the occurrence of opioid-related side effects.

Conclusion: A single dose of intraoperative methadone does not reduce postoperative opioid requirements compared with a single dose of morphine in bladder cancer patients undergoing RAC.

Abstract
Objectives: Chronic pain disorders are among the most common and affect approximately 20% of the US population, leading to disproportionately high medical expenditures and negative economic impact. Behavioral factors of pain catastrophizing and perceived injustice are associated with pain intensity in chronic pain. Diminished heart rate variability (HRV) is also strongly associated with chronic pain. These factors have been less explored earlier in the pain experience and it is unclear whether they play a role in the transition from acute to chronic pain. The aim of this study was to determine the relationship between pain catastrophizing, perceived injustice, pain intensity and HRV in naturally occurring acute pain.

Methods: Ninety-seven subjects were recruited from local outpatient physical therapy clinics. Seated HRV was captured on ninety-four subjects via Polar chest strap while subjects were taking a survey via iPad. In addition to sociodemographic data, the survey included the Pain Catastrophizing Scale (PCS), Injustice Experience Questionnaire (IEQ), and Numeric Pain Rating Scale (NPRS). The natural log of high frequency power (lnHFP) HRV was used in the statistical analysis.

Results: Multiple regression modeling revealed that lower pain catastrophizing, higher perceived injustice, and lower pain intensity were associated with lower HRV, and accounted for 11.4% of the variance in HRV.

Discussion: While greater chronic pain intensity is associated with lower HRV, the relationship is reversed in the setting of acute pain. These findings highlight the need to better understand the unique factors that contribute to lower HRV in the acute phase.

Abstract
Many patients experience acute pain, which has been associated with numerous negative consequences. Pain education has been proposed as a strategy to improve acute pain management. However, studies report limited effects with educational interventions for acute pain in adults, which can be explained by the underuse of the person-centered approach. Thus, we aimed to systematically review and synthetize current evidence from quantitative, qualitative and mixed-methods studies describing patients' needs and preferences for acute pain education in adults. We searched original studies and gray literature in 7 databases, from January 1990 to October 2023. Methodological quality was assessed with the Mixed Methods Appraisal Tool. A total of 32 studies were included (n = 1847 patients), two-thirds of which were qualitative studies of high methodological quality. Most of the studies were conducted over the last 15 years in patients with postsurgical and posttraumatic pain, identified as White, with a low level of education. Patients expressed the greatest need for education when it came to what to expect in pain intensity and duration, as well how to take the medication and its associated adverse effects. The most frequently reported educational preferences were for in-person education while involving caregivers and to obtain information first from physicians, then by other professionals. This review has highlighted the needs and preferences to be considered in pain education interventions, which should be embedded in an approach cultivating communication and partnership with patients and their caregivers. The results still need to be confirmed with different patient populations.

Abstract
Purpose of review: Acute facial pain presents a complex challenge in medical practice, requiring a comprehensive and interdisciplinary approach to its management. This narrative review explores the contemporary landscape of treating acute facial pain, delving into pharmacological, non-pharmacological, and advanced interventions. The significance of tailored treatment strategies, rooted in the diverse etiologies of facial pain, such as dental infections, trigeminal neuralgia, temporomandibular joint disorders, sinusitis, or neurological conditions like migraines or cluster headaches, is underscored. We particularly emphasize recent advances in treating trigeminal neuralgia, elucidating current treatment concepts in managing this particular acute facial pain.

Recent findings: Recent research sheds light on various treatment modalities for acute facial pain. Pharmacotherapy ranges from traditional NSAIDs and analgesics to anticonvulsants and antidepressants. Non-pharmacological interventions, including physical therapy and psychological approaches, play pivotal roles. Advanced interventions, such as nerve blocks and surgical procedures, are considered in cases of treatment resistance. Moreover, we explore innovative technologies like neuromodulation techniques and personalized medicine, offering promising avenues for optimizing treatment outcomes in acute facial pain management. Modern management of acute facial pain requires a nuanced and patient-centric approach. Tailoring treatment strategies to the individual's underlying condition is paramount. While pharmacotherapy remains a cornerstone, the integration of non-pharmacological interventions is essential for comprehensive care. Advanced interventions should be reserved for cases where conservative measures prove inadequate. Furthermore, leveraging innovative technologies and personalized medicine holds promise for enhancing treatment efficacy. Ultimately, a holistic approach that considers the diverse needs of patients is crucial for effectively addressing acute facial pain.

Abstract
Background: Persistent postsurgical pain (PPSP) after lung cancer surgery is common and current definitions are based on evaluations at a single time point after surgery. Pain intensity and symptoms may however fluctuate and change over time, and be impacted by multiple and shifting factors. Studies of postoperative recovery patterns and transition from acute to chronic pain are needed for further investigation of preventive measures and treatments to modify unfavourable recovery paths.

Methods: In this explorative study, 85 patients undergoing surgery due to either presumptive or confirmed lung cancer reported pain intensities bi-monthly for 12 months. Pain trajectories during recovery were investigated, using group-based trajectory modelling. Associations with possible risk factors for PPSP, including clinical variables and anxiety and depression score (HADS), were also explored.

Results: A trajectory model containing three 12-month pain recovery groups was computed. One group without PPSP fully recovered (50%) within two to three months. Another group with mild-intensity PPSP followed a protracted recovery trajectory (37%), while incomplete recovery was observed in the last group (13%). Acute postoperative pain and younger age were associated with a less favourable recovery trajectory. More neuropathic pain symptoms were observed in patients with incomplete recovery.

Conclusions: Three clinically relevant recovery trajectories were identified, based on comprehensive pain tracking. Higher acute postoperative pain intensity was associated with an unfavourable pain recovery trajectory.

Significance statement: Understanding the transition from acute to chronic postoperative pain and identifying preoperative risk factors is essential for the development of targeted treatments and the implementation of preventive measures. This study (1) identified distinct recovery trajectories based on frequent pain assessment follow-ups for 12 months after surgery and (2) evaluated risk factors for unfavourable postoperative pain recovery paths. Findings suggest that early higher postoperative pain intensity is associated with an unfavourable long-term recovery path.

Abstract
Secreted microRNAs (miRNAs) have been detected in various body fluids including the cerebrospinal fluid, yet their direct role in regulating synaptic transmission remains uncertain. We found that intrathecal injection of low dose of let-7b (1 μg) induced short-term (<24 hours) mechanical allodynia and heat hyperalgesia, a response that is compromised in Tlr7-/- or Trpa1-/- mice. Ex vivo and in vivo calcium imaging in GCaMP6-report mice revealed increased calcium signal in spinal cord afferent terminals and doral root ganglion/dorsal root ganglia neurons following spinal perfusion and intraplantar injection of let-7b. Patch-clamp recordings also demonstrated enhanced excitatory synaptic transmission (miniature excitatory postsynaptic currents [EPSCs]) in spinal nociceptive neurons following let-7b perfusion or optogenetic activation of axonal terminals. The elevation in spinal calcium signaling and EPSCs was dependent on the presence of toll-like receptor-7 (TLR7) and transient receptor potential ion channel subtype A1 (TRPA1). In addition, endogenous let-7b is enriched in spinal cord synaptosome, and peripheral inflammation increased let-7b in doral root ganglion/dorsal root ganglia neurons, spinal cord tissue, and the cerebrospinal fluid. Notably, let-7b antagomir inhibited inflammatory pain and inflammation-induced synaptic plasticity (EPSC increase), suggesting an endogenous role of let-7b in regulating pain and synaptic transmission. Furthermore, intrathecal injection of let-7b, at a higher dose (10 μg), induced persistent mechanical allodynia for >2 weeks, which was abolished in Tlr7-/- mice. The high dose of let-7b also induced microgliosis in the spinal cord. Of interest, intrathecal minocycline only inhibited let-7b-induced mechanical allodynia in male but not female mice. Our findings indicate that the secreted microRNA let-7b has the capacity to provoke pain through both neuronal and glial signaling, thereby establishing miRNA as an emerging neuromodulator.

Abstract
Objectives: Understanding adolescent perspectives on prescribed opioids in the context of medical care for acute pain is needed to prevent opioid-related adverse outcomes. We explored factors that may influence opioid decision-making and use behaviors among adolescents prescribed opioids for acute pain.

Methods: We conducted semi-structured interviews with nineteen adolescents (63% females, ages 12-17) prescribed opioids upon discharge from surgery or intensive care unit admission. Interview transcripts were coded using inductive thematic analysis.

Results: Five themes were identified: "Opioid use to reduce extreme pain and facilitate acute recovery"; "Familiarity with risks and negative effects of opioids"; "Assessment of opioid risk based on individual characteristics and use behaviors"; "Careful balance of risks, benefits, and symptoms when taking opioids"; "Importance of trusted adults for adolescent opioid management". Adolescents commonly believed opioids are only appropriate for severe pain that cannot be managed with other strategies. Most (but not all) adolescents were aware of addiction and other potential opioid harms, and generally disapproved of misuse. However, a few adolescents would consider taking unprescribed opioids for severe pain. Adolescents wanted to be well informed for opioid decision-making, considering guidance from trusted adults.

Discussion: Adolescents often demonstrated active and sound participation in shared opioid decision-making, influenced by complex integration of inputs and self-reflection. Conversely, potential factors that could contribute to risky behaviors included low personal risk perceptions, uncertainty about what constitutes opioid misuse, and avoidance of prescribed opioids despite extreme pain. Future studies may explore associations of adolescents' opioid decision-making with longer-term pain and opioid-related outcomes.

Abstract
Objectives: Our purpose was to explore the effect of remifentanil on acute and chronic postsurgical pain after cardiac surgery.

Methods: Randomized controlled trials (RCTs) were retrieved in electronic databases such as PubMed, Cochrane Library, CNKI databases, Scopus, and Web of Science. A systematic review, meta-analysis, trial sequential analysis (TSA) was performed. Basic information and outcomes were extracted from the included studies. The primary outcome was chronic postsurgical pain. Secondary outcomes were scores of postsurgical pain and morphine consumption within 24 hours after cardiac surgery. Our risk of bias assessment was based on the Cochrane risk of bias tool version 2 (ROB 2.0). The overall quality of the evidence was rated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

Results: Seven studies consisting of 658 patients were enrolled in the meta-analysis. A single study had a high risk of bias and two studies had a moderate risk of bias. The incidence of chronic postsurgical pain (four studies [415 patients]; RR, 1.02 [95% CI, 0.53-1.95]; P =0.95; I2=59%; TSA-adjusted CI, 0.78-1.20) and the postsurgical pain score (two studies [196 patients]; MD 0.09 [95% CI, -0.36-0.55]; P =0.69; I2=0%; TSA-adjusted CI, -0.36-0.55）were not statistically different between the two groups. However, morphine consumption (six studies [569 patients]; MD 6.94 [95% CI, 3.65-10.22]; P<0.01; I2=0%; TSA-adjusted CI, 0.00-0.49) was higher in the remifentanil group than in the control group.

Discussion: There was not enough evidence to prove that remifentanil can increase the incidence of chronic postsurgical pain after cardiac surgery, but interestingly, the results tended to support a trend toward increased complications in the intervention group. However, there was moderate-certainty evidence that the use of remifentanil increases the consumption of morphine for analgesia, and more direct comparison trials are needed to inform clinical decision-making with greater confidence.

Abstract
The molecular processes driving the transition from acute to chronic low back pain (LBP) remain poorly understood and are likely to be sexually dimorphic. This study aimed to explore sex-differences in the serum proteomic profile of people experiencing an acute LBP episode and determine if serum protein concentrations were associated with three-month outcome. Serum samples were collected through venepuncture from 30 female and 29 male participants experiencing an acute LBP episode. Serum samples underwent trypsin digestion and fractionation using hydrophobic interaction chromatography and were then analysed using mass-spectrometry (MS). MS spectra were searched in the Swissprot database for protein identification. Sex differences in protein abundance changes were evident upon inspection of fold changes. Multivariable data analysis identified 21 serum proteins during the acute episode that correctly classified 93% of males and 23 serum proteins that correctly classified 90% of females with ongoing LBP at three months. Pathway analysis suggested the differentially expressed proteins during acute LBP were frequently involved in immune, inflammatory, complement or coagulation responses. This data provides preliminary evidence that biological processes during an acute LBP episode may contribute to resolution, or persistence, of LBP symptoms at three months, however, these processes differ between males and females. PERSPECTIVE: Differential expression of serum proteins was observed between male and female participants during an acute LBP episode. This preliminary work provides a foundation for future research targeting distinct immune system processes in males and females that may interfere with the transition from acute to chronic LBP.

Abstract
There is general agreement that acute pain management is an important component of perioperative medicine. However, there is no consensus on the best model of care for perioperative pain management, mainly because evidence is missing in many aspects. Comparing the similarities and differences between countries might reveal some insights into different organisational models and how they work. Here, we performed a narrative review to describe and compare the structures, processes and outcomes of perioperative pain management in the healthcare systems of four European countries using Donabedian's framework as a guide. Our comparison revealed many similarities, differences and gaps. Different structures of acute pain services in the four countries with no common definition and standards of care were found. Protocols have been implemented in all countries and guidelines in some. If outcome is assessed, it is mainly pain intensity, and many patients experiencing more intense pain than others have common risk factors (e.g. preoperative pain, preoperative opioid intake, female sex and young age). Outcome assessment beyond pain intensity (such as pain-related physical function, which is important for early rehabilitation and recovery) is currently not well implemented. Developing common quality indicators, a European guideline for perioperative pain management (e.g. for patients at high risk for experiencing severe pain and other outcome parameters) and common criteria for acute pain services might pave the way forward for improving acute pain management in Europe. Finally, the education of general and specialist staff should be aligned in Europe, for example, by using the curricula of European Pain Federation (EFIC).

Abstract
Purpose: The study aims to compare the analgesic efficacy of two analgesic interventions, continuous paravertebral (PVB) nerve block alone with continuous paravertebral and intercostal nerve block (PVB/ICB) in patients undergoing thoracotomy.

Methods: A total of 70 patients undergoing thoracotomy were randomly enrolled in either continuous paravertebral nerve block (PVB) group or in continuous paravertebral and intercostal nerve block (PVB/ICB) group and received corresponding blocks. Analgesic efficacy measured by Visual Analog Scale (VAS) pain score, hemodynamic effects, total narcotic consumption, sedation score, patient's length of stay in hospital and patient's satisfaction with the analgesic technique were recorded.

Results: Demographic characteristics of the patients were similar in both groups. The mean VAS pain score was not statistically significant in both groups at 24 h. The mean pulse rate and blood pressures were comparable in both groups for the first 24 h. Nalbuphine consumption was significantly higher in PVB group as compared to PVB/ICB group at 1 h (p = 0.01), 6 h (p = 0.03) and 12 h (p = 0.009) and 24 h (p = 0.03). The mean total nalbuphine consumption in the PVB group was higher (28.29 mg vs. 22.63 mg) and statistically significant then PVB/ICB group (p = 0.03). The total tramadol consumption as a rescue analgesic was higher in the PVB group (131.42 mg) as compared to PVB/ICB group (120 mg) after 24 h but not statistically significant (p = 0.17).

Conclusion: Continuous paravertebral nerve block with intercostal nerve block provides effective post-operative pain relief after thoracotomy with reduced narcotic consumption compared to continuous paravertebral nerve block alone.

Keywords: Acute pain; Analgesics; Bupivacaine; Nalbuphine; Nerve block; Opioid; Pain; Thoracotomy; Tramadol.

Abstract
Background and objective: A network analysis can be used to quantitatively assess and graphically describe multiple interactions. This study applied network analyses to determine the interaction between physical and pain-related factors and fear of movement in people with whiplash-associated disorders (WAD) during periods of acute and chronic pain.

Methods: Physical measurements, including pressure pain-thresholds (PPT) over neural structures, cervical range of motion, neck flexor and extensor endurance and the cranio-cervical flexion test (CCFT), in addition to subjective reports including the Tampa Scale of Kinesiophobia (TSK-11), Neck Disability Index (NDI) and neck pain and headache intensity, were assessed at baseline in 47 participants with acute WAD. TSK-11, NDI and pain intensity were assessed for the same participants 6 months later (n = 45). Two network analyses were conducted to estimate the associations between features at baseline and at 6 months and their centrality indices.

Results: Both network analyses revealed that the greatest weight indices were found for NDI and CCFT at baseline and for neck pain and headache intensity and NDI and TSK-11 at both time points. Associations were also found betweeen cervical muscle endurance and neck pain intensity in the acute phase. Cervical muscle endurance assesssed during the acute phase was also associated with NDI after 6 months - whereas PPT measured at baseline was associsated with headache intensity after 6 months.

Conclusion: The strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute pain and when mesured 6 months later. The extent of neck endurance and measures of PPT at baseline may be associated with neck disability and headache, respectively, 6 months after a whiplash injury.

Significance: Through two network analyses, we evaluated the interaction between pain-related factors, fear of movement, neck disability and physical factors in people who had experienced a whiplash injury. We demonstrated that physical factors may be involved in the maintenance and development of chronic pain after a whiplash injury. Nevertheless, the strongest associations were found for headache and neck pain intensity and neck disability and fear of movement, both during acute and chronic phases.

Abstract
Objective: Transforaminal epidural steroid injections (TESIs) are widely administered for sciatica. The aim of this trial was to evaluate the effectiveness of TESIs in patients with acute sciatica (<8 wk).

Methods: This study was conducted in two Dutch hospitals. Participants (n=141) were randomly assigned to: 1) usual care and TESI of 1ml of 40mg/ml Methylprednisolone plus 1ml of 0.5% Levobupivacaine (intervention 1); 2) usual care and transforaminal epidural injection with 1 ml of 0.5% Levobupivacaine and 1ml NaCl 0.9% (intervention 2); 3) usual care consisting of oral pain medication with or without physiotherapy (control). Co-primary outcomes were back- and leg pain intensity, physical functioning and recovery measured during 6-month follow-up.

Results: There were no significant mean differences in co-primary outcomes between groups during follow-up, except for leg pain when comparing intervention group 1 with control (-0.96 95%CI:-1.83 to -0.09). For secondary outcomes, some significant between group differences were found for treatment satisfaction and surgery, but only when comparing intervention group 2 to control. Post-hoc analyses showed a significant difference in response (50% improvement of leg pain [yes/no]) between intervention 1 and the control group at 3 months and that both intervention groups used less opioids.

Discussion: Except for a statistically significanteffect of TESI on leg pain for patients with acute sciatica compared to usual care, there were no differences in co-primary outcomes. Nonetheless, transforaminal epidural injections seem to be associated with less opioid use, which warrants further exploration.

Abstract
Background: To investigate the effects of body mass index (BMI) on intensity postoperative pain in patients who underwent thoracic paravertebral block (TPVB) for postoperative analgesia after video-assissted thoracoscopic surgery (VATS).

Methods: Patients aged 18-80 years, ASA I-III, and BMI 18-40 kg/m2 who underwent elective VATS were included in the study. The patients were divided into 3 groups according to their BMI levels. TPVB was performed under ultrasound-guidance at the fifth thoracic vertebrae, and 30 ml of 0.25% bupivacaine was injected. The patient-controlled analgesia (PCA) was performed by using morphine and multimodal analgesia was performed. As a rescue analgesic agent, 0.5 mg/kg tramadol was given to patients intravenously when a score of visual analog scale (VAS) at rest was ≥ 4. The primary outcome was determined as VAS scores at rest and cough. Secondary outcomes were determined as postoperative morphine consumption, additional analgesic requirement, and side effects.

Results: The post-hoc test revealed that the VAS resting scores at the 4th hour (p: 0.007), 12th hour (p: 0.014), and 48th hour (p: 0.002) were statistically significantly lower in Group I compared to Group II. Additionally, VAS resting scores were also statistically significantly lower in Group I compared to Group III at all time points (p < 0.05). Similarly, the post-hoc test indicated that the VAS coughing scores at the 4th hour (p: 0.023), 12th hour (p: 0.011), and 48th hour (p: 0.019) were statistically significantly lower in Group I compared to Group II. Moreover, VAS coughing scores were statistically significantly lower in Group I compared to Group III at all time points (p < 0.001). Furthermore, there were statistically significant differences in terms of additional analgesic use between the groups (p: 0.001). Additionally, there was a statistically significant difference in terms of morphine consumption via PCA and morphine milligram equivalent consumption between the groups (p < 0.001).

Conclusions: Higher postoperative VAS scores with TPVB applied in obese patients and the consequent increase in additional analgesics and complications require more specific postoperative management in this patient group.

Keywords: Acute pain; Body mass index; Paravertebral block; Patient-controlled analgesia; Postoperative analgesia; Video-assissted thoracoscopic surgery.

Abstract
Introduction: Ultrasound-guided peripheral nerve blockade is a common pain management strategy to decrease perioperative pain and opioid/general anesthetic use. In this article our goal was to systematically review publications supporting upper extremity nerve blocks distal to the brachial plexus. We assessed the efficacy and safety of median, ulnar, radial, suprascapular, and axillary nerve blocks by reviewing previous studies.

Methods: We searched MEDLINE and Embase databases to capture studies investigating these nerve blocks across all specialties. We screened titles and abstracts according to agreed-upon inclusion/exclusion criteria. We then conducted a hand search of references to identify studies not found in the initial search strategy.

Results: We included 20 studies with 1,273 enrolled patients in qualitative analysis. Both anesthesiology (12, 60%) and emergency medicine (5, 25%) specialties have evidence of safe and effective use of radial, ulnar, median, suprascapular, and axillary blocks for numerous clinical applications. Recently, multiple randomized controlled trials show suprascapular nerve blocks may result in lower pain scores in patients with shoulder dislocations and rotator cuff injuries, as well as in patients undergoing anesthesia for shoulder surgery.

Conclusion: Distal upper extremity nerve blocks under ultrasound guidance may be safe, practical strategies for both acute and chronic pain in perioperative, emergent, and outpatient settings. These blocks provide accessible, opioid-sparing pain management, and their use across multiple specialties may be expanded with increased procedural education of trainees.

Abstract
Objectives: Acute postoperative pain (APP) is the main cause of postoperative dissatisfaction; however, traditional methods of pain assessment provide limited insights into the dynamics and development of APP. This study used the experience sampling method (ESM) to understand the dynamics of APP over time in relation to various patient factors.

Methods: Forty patients scheduled to undergo total knee replacement surgery were recruited in this study. Following an initial assessment, a short report questionnaire was sent to the patients via 10 digital alerts per day to assess the pain levels during two preoperative and the first 6 postoperative days. The data were analyzed using multilevel regression including random intercept and slope.

Abstract
Background: Opioid analgesics are commonly used for acute low back pain and neck pain, but supporting efficacy data are scarce. We aimed to investigate the efficacy and safety of a judicious short course of an opioid analgesic for acute low back pain and neck pain.

Methods: OPAL was a triple-blinded, placebo-controlled randomised trial that recruited adults (aged ≥18 years) presenting to one of 157 primary care or emergency department sites in Sydney, NSW, Australia, with 12 weeks or less of low back or neck pain (or both) of at least moderate pain severity. Participants were randomly assigned (1:1) using statistician-generated randomly permuted blocks to guideline-recommended care plus an opioid (oxycodone-naloxone, up to 20 mg oxycodone per day orally) or guideline-recommended care and an identical placebo, for up to 6 weeks. The primary outcome was pain severity at 6 weeks measured with the pain severity subscale of the Brief Pain Inventory (10-point scale), analysed in all eligible participants who provided at least one post-randomisation pain score, by use of a repeated measures linear mixed model. Safety was analysed in all randomly assigned eligible participants. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615000775516).

Keywords: acute pain; chronic kidney failure pain management; continuous catheter analgesia; erector spinae plane (esp) blockade; opioid-free analgesia; perioperative analgesia; regional anaesthesiology; transplant

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