Effect of individualized anesthesia and analgesia on postoperative pain in patients stratified for pain sensitivity: A study protocol for the PeriOPerative individualization trial randomized controlled trial.

BACKGROUND: Despite advancements in surgical and anesthesia techniques, acute and persistent postoperative pain are still a common challenge. Postoperative pain has direct effects on individual patient care and outcome, as well as putting strain on limited health care resources. Several prediction methods for postoperative pain have been described. One such method is the assessment of pain during peripheral venous cannulation (VCP). It is not known if different approaches to anesthesia and analgesia, depending on the evaluation of risk for postoperative pain, can improve outcome. The aim of this study is to evaluate if individualized anesthesia and analgesia can affect postoperative pain and recovery after surgery, in patients stratified by VCP. METHODS: Adult patients scheduled for laparoscopic surgery undergo pain-sensitivity stratification using VCP on the day of surgery. Patients scoring VCP ≥2.0 on the visual analogue scale (pain-sensitive) are randomized to multimodal anaesthesia and analgesia with opioids or standard of care. Patients scoring VCP ≤1.9 (pain-tolerant) are randomized to opioid-free anaesthesia or standard of care. The primary outcome is acute postoperative pain measured with numeric rating scale in the postoperative care unit. Secondary outcomes include analysis of pain after 24 h, persistent postoperative pain and quality of recovery. DISCUSSION: Individualized perioperative pain management has the potential to improve patient care. This study will examine the impact of different anesthesia and analgesia regimes, in patients with differing pain sensitivity, on postoperative pain. TRIAL REGISTRATION: Prospectively posted at ClinicalTrials.gov, identifier NCT04751812.

Capabilities Toward Intravenous Patient-Controlled Analgesia: A Cross-Sectional Study of Registered Nurses Working in Two Tertiary Hospitals in China and Thailand.

BACKGROUND: An increased interest has been observed in the wide use of intravenous patient-controlled analgesia (IV-PCA) to control acute postoperative pain in both China and Thailand. The safety and efficacy of IV-PCA in patient care requires competent and capable staff nurses. This study aimed to appraise the capabilities of Thai and Chinese registered nurses regarding IV-PCA as a guide to develop educational programs. METHOD: A descriptive cross-sectional survey was conducted with 203 Chinese and 270 Thai registered nurses. An anonymous self-report questionnaire addressing 6 domains of capabilities toward IV-PCA was used to collect the data. Descriptive and inferential statistics were employed to analyze the data. RESULTS: The study found that the mean percentage scores (MPS) of the overall capability on IV-PCA of the Thai and Chinese nurse participants were 55.5 (mean [M] = 57.3, standard deviation [SD] = 4.9) and 62.6 (M = 58.7, SD = 13.0), respectively, which indicated very low and low levels. Barriers to the use and care of patients receiving IV-PCA after surgery according to the Thai and Chinese nurse participants included a lack of knowledge and systematic training regarding IV-PCA and a lack of first-hand experience in providing care for IV-PCA patients. CONCLUSION: The study results call for intensive and effective training and education concerning all domains for registered nurses involved with patients receiving IV-PCA.

The impact of using pain scales by untrained students on the decision to provide analgesia to multiple species.

OBJECTIVE: To evaluate if students without training assess pain similarly to an expert, and to compare indications for analgesic intervention based on student opinions versus scale scoring. STUDY DESIGN: Prospective, blind, randomized, cross-sectional study. ANIMALS: Video recordings of a bull, horse, cat, pig and sheep. METHODS: First-year veterinary medicine students assessed one video of a horse (n = 44) and one video of a bull (n = 39). Third-year veterinary medicine students assessed one video of a cat (n = 23) and one video of a pig (n = 21). Fourth-year animal science students (n = 16) assessed one video of a sheep. The species assessed by different student classes were determined randomly. Students were unaware of animal history or existing pain assessment and decided whether they would provide analgesia according to their opinion. They then scored each video using species-specific validated pain scales. Scores were compared with those of a board-certified anesthesiologist (expert). Chi-square test was used to compare students and expert. RESULTS: Students underestimated the expert's score by 8-20%, except for the horse. There was no difference between the analgesic indication according to the assessment of the expert (143/143, 100%) and students (141/143, 98.6%) considering the defined analgesic intervention threshold for each scale (p = 0.478). The indication for analgesic intervention according to students' opinion (116/143, 81.1%) was lower than that according to their scale scores (141/143, 98.6%) (p < 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE: Students tended to underestimate pain; however, they detected pain that requires analgesic intervention in animals similarly to an expert. The use of scales optimized the indication for providing analgesia when animals were experiencing pain that required analgesic intervention.

STING-IFN-I pathway relieves incision induced acute postoperative pain via inhibiting the neuroinflammation in dorsal root ganglion of rats.

BACKGROUND: The purpose of this study was to study the effect of STING-IFN-I pathway on incision induced postoperative pain in rats and its possible mechanisms. METHODS: The pain thresholds were evaluated by measuring the mechanical withdrawal threshold and the thermal withdrawal latency. The satellite glial cell and macrophage of DRG were analyzed. The expression of STING, IFN-a, P-P65, iNOS, TNF-α, IL-1ß and IL-6 in DRG was evaluated. RESULTS: The activation of STING-IFN-I pathway can reduce the mechanical hyperalgesia, thermal hyperalgesia, down-regulate the expression of P-P65, iNOS, TNF-α, IL-1ß and IL-6, and inhibit the activation of satellite glial cell and macrophage in DRG. CONCLUSIONS: The activation of STING-IFN-I pathway can alleviate incision induced acute postoperative pain by inhibiting the activation of satellite glial cell and macrophage, which reducing the corresponding neuroinflammation in DRG.

Comparative efficacy and safety of non-neuraxial analgesic techniques for midline laparotomy: a systematic review and frequentist network meta-analysis of randomised controlled trials.

BACKGROUND: Fascial plane blocks provide effective analgesia after midline laparotomy; however, the most efficacious technique has not been determined. We conducted a systematic review and network meta-analysis of randomised controlled trials to synthesise the evidence with respect to pain, opioid consumption, and adverse events. METHODS: We searched Ovid MEDLINE, Embase, Cochrane Central, and Scopus databases for studies comparing commonly used non-neuraxial analgesic techniques for midline laparotomy in adult patients. The co-primary outcomes of the study were 24-h cumulative opioid consumption and 24-h resting pain score, reported as i.v. morphine equivalents and 11-point numerical rating scale, respectively. We performed a frequentist meta-analysis using a random-effects model and a cluster-rank analysis of the co-primary outcomes. RESULTS: Of 6115 studies screened, 67 eligible studies were included (n=4410). Interventions with the greatest reduction in 24-h cumulative opioid consumption compared with placebo/no intervention were single-injection quadratus lumborum block (sQLB; mean difference [MD] -16.1 mg, 95% confidence interval [CI] -29.9 to -2.3, very low certainty), continuous transversus abdominis plane block (cTAP; MD -14.0 mg, 95% CI -21.6 to -6.4, low certainty), single-injection transversus abdominis plane block (sTAP; MD -13.7 mg, 95% CI -17.4 to -10.0, low certainty), and continuous rectus sheath block (cRSB; MD -13.2 mg, 95% CI -20.3 to -6.1, low certainty). Interventions with the greatest reduction in 24-h resting pain score were cRSB (MD -1.2, 95% CI -1.8 to -0.6, low certainty), cTAP (MD -1.0, 95% CI -1.7 to -0.2, low certainty), and continuous wound infusion (cWI; MD -0.7, 95% CI -1.1 to -0.4, low certainty). Clustered-rank analysis including the co-primary outcomes showed cRSB and cTAP blocks to be the most efficacious interventions. CONCLUSIONS: Based on current evidence, continuous rectus sheath block and continuous transversus abdominis plane block were the most efficacious non-neuraxial techniques at reducing 24-h cumulative opioid consumption and 24-h resting pain scores after midline laparotomy (low certainty). Future studies should compare techniques for upper vs lower midline laparotomy and other non-midline abdominal incisions. CLINICAL TRIAL REGISTRATION: PROSPERO Registration Number: CRD42021269044.

A Single Preoperative Dose of S-Ketamine Has No Beneficial Effect on Chronic Postsurgical Pain in Patients Undergoing Video-Assisted Thoracoscopic Surgical Lung Lesion Resection: A Prospective Randomized Controlled Study.

OBJECTIVES: To evaluate the efficacy of a single preoperative dose of S-ketamine for chronic postsurgical pain (CPSP) in patients undergoing video-assisted thoracoscopic surgical lung lesion resection (VATS). DESIGN: A prospective randomized, double-blind controlled study. SETTING: Patients were enrolled from March 17, 2021, to November 18, 2021, at a single tertiary academic hospital. PARTICIPANTS: Patients were 18-to-65 years of age and undergoing VATS. INTERVENTIONS: The experiment was divided into an S-ketamine group (0.5 mg/kg intravenous injection before anesthesia induction) or a placebo group (the same volume of normal saline). MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the incidence of CPSP and its neuropathic component. The secondary endpoints included acute postoperative pain, the use of postoperative analgesics, anxiety and sleep quality scores, and the occurrence of adverse effects. There were no significant differences between the 2 groups in the incidences of CPSP, neuropathic pain, acute postoperative pain, and postoperative use of analgesics. The sleep quality scores on the first postoperative day differed significantly between the groups (47.45 ± 27.58 v . 52.97 ± 27.57, p = 0.049), but not the anxiety scores. In addition, adverse effects were similar between the 2 groups. CONCLUSIONS: A single preoperative dose of S-ketamine in patients who underwent VATS had no significant effect on acute and chronic postoperative pain or the consumption of analgesics after surgery. A single preoperative dose of S-ketamine could improve sleep on the first day after surgery, whereas it had no significant effect on anxiety levels.

A service evaluation of the impact of parental information provision on analgesia administration at home posttonsillectomy.

INTRODUCTION: Tonsillectomy and adenotonsillectomy are together the most common pediatric surgical procedure and are increasingly performed as day cases. Postoperative pain is commonly severe for 1-2 weeks, but parental analgesia concerns lead to poor analgesia prescription compliance and under administration. This service evaluation assessed parental compliance with analgesia, elicited parental concerns, and obtained parental suggestions for improving the current written advice. METHODS: Telephone questionnaires were completed on postoperative Days 3/4 and 7 with 42 parents of pediatric (adeno)-tonsillectomy patients over a 6-month period, peri-pandemic. The questionnaire collected categorical data on: analgesia prescribed and administered, the child's symptoms, and healthcare resource use. Qualitative data on barriers to analgesia administration and suggestions for written advice improvement were grouped thematically. RESULTS: Sore throats were reported by 93.3% parents between discharge and Day 3/4 but only 43.3% parents had 100% compliance with regular paracetamol and ibuprofen in the same time period. Parents frequently avoided morphine administration, expressing concerns about side effects, addiction, and previous experience. Parents were also concerned about using ibuprofen, discrepancies between weight-based and bottle instruction doses, and the length of the analgesia course. Parents would like further written information and reassurance on these topics as well as guidance on tapering or stopping analgesics and whether to wake their child at night. CONCLUSION: The breadth of unmet information needs identified in this service evaluation, alongside parental suggestions, will be used to improve the current written advice with the aim to improve the postoperative pain experience at home. These include information on length of analgesic course, safety of ibuprofen and paracetamol coadministration for analgesia, and details about morphine administration, including safety, side effects, and indication.

Gender differences on preoperative psychologic factors affecting acute postoperative pain in patients with lumbar spinal disorders.

BACKGROUND: Psychosexual factors are one of the preoperative factors influencing acute postoperative pain. Because of gender differences in pain, the preoperative factors that influence acute postoperative pain may also differ between males and females. However, there have been no reports on such factors in patients with spinal disorders that focused on gender differences. Therefore, the purpose of this study was to examine the preoperative factors that influence acute postoperative pain, focusing on gender differences. METHODS: The subjects were 75 males and 60 females admitted for surgery for lumbar spinal disorders. Preoperatively, the following were assessed: low back pain using the Numeric Rating Scale (NRS); anxiety and depression using the Japanese version of the Hospital Anxiety and Depression Scale (HADS); catastrophic thinking using the Pain Catastrophizing Scale (PCS); psychiatric problems using the Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP); and neurological assessments. Acute postoperative pain was also assessed using the NRS within 48 h, postoperatively. Based on these data, we analyzed gender differences in preoperative factors affecting acute postoperative pain in patients with lumbar spinal disorders. RESULTS: Postoperative NRS and preoperative PCS scores were higher in females compared to males. In the males, the coefficient of determination of the multiple regression equation was 0.088, and PCS (ß = 0.323, p = 0.015) was extracted as a significant factor. In the females, the coefficient of determination of the multiple regression equation was 0.075, and BS-POP (ß = 0.300, p = 0.019) was extracted as a significant factor. CONCLUSION: Preoperative factors influencing acute postoperative pain for patients with lumbar spinal disorders vary by gender. It was suggested that males should be screened using PCS. In females, on the other hand, PCS alone is not sufficient for evaluation. It was suggested that evaluation using BS-POP should be considered in addition to PCS.

Prediction of acute postoperative pain based on intraoperative nociception level (NOL) index values: the impact of machine learning-based analysis.

The relationship between intraoperative nociception and acute postoperative pain is still not well established. The nociception level (NOL) Index (Medasense, Ramat Gan, Israel) uses a multiparametric approach to provide a 0-100 nociception score. The objective of the ancillary analysis of the NOLGYN study was to evaluate the ability of a machine-learning aglorithm to predict moderate to severe acute postoperative pain based on intraoperative NOL values. Our study uses the data from the NOLGYN study, a randomized controlled trial that evaluated the impact of NOL-guided intraoperative administration of fentanyl on overall fentanyl consumption compared to standard of care. Seventy patients (ASA class I-III, aged 18-75 years) scheduled for gynecological laparoscopic surgery were enrolled. Variables included baseline demographics, NOL reaction to incision or intubation, median NOL during surgery, NOL time-weighted average (TWA) above or under manufacturers' recommended thresholds (10-25), and percentage of surgical time spent with NOL > 25 or < 10. We evaluated different machine learning algorithms to predict postoperative pain. Performance was assessed using cross-validated area under the ROC curve (CV-AUC). Of the 66 patients analyzed, 42 (63.6%) experienced moderate to severe pain. NOL post-intubation (42.8 (31.8-50.6) vs. 34.8 (25.6-41.3), p = 0.05), median NOL during surgery (13 (11-15) vs. 11 (8-13), p = 0.027), percentage of surgical time spent with NOL > 25 (23% (18-18) vs. 20% (15-24), p = 0.036), NOL TWA < 10 (2.54 (2.1-3.0) vs. 2.86 (2.48-3.62), p = 0.044) and percentage of surgical time spent with NOL < 10 (41% (36-47) vs. 47% (40-55), p = 0.022) were associated with moderate to severe PACU pain. Corresponding ROC AUC for the prediction of moderate to severe PACU pain were 0.65 [0.51-0.79], 0.66 [0.52-0.81], 0.66 [0.52-0.79], 0.65 [0.51-0.79] and 0.67 [0.53-0.81]. Penalized logistic regression achieved the best performance with a 0.753 (0.718-0.788) CV-AUC. Our results, even if limited by the small number of patients, suggest that acute postoperative pain is better predicted by a multivariate machine-learning algorithm rather than individual intraoperative nociception variables. Further larger multicentric trials are highly recommended to better understand the relationship between intraoperative nociception and acute postoperative pain.Trial registration Registered on ClinicalTrials.gov in October 2018 (NCT03776838).

Effectiveness of listening to music and playing with Lego on children's postoperative pain.

PURPOSE: The present study aimed to compare the effectiveness of music and playing with Lego in postoperative management pain in children. DESIGN AND METHODS: In this three-group quasi-experimental study, the participants in this interventional study were 96 children aged 6 to 12 years admitted to the pediatric surgery ward of Mofid Hospital and Medical Center in Tehran. The participants were selected using convenience sampling. They were then randomly placed into three intervention groups. Pain intensity was measured for the participants in all three groups before the intervention. The intervention was performed in two 15-min sessions with an interval of 5 min in three intervention groups. Then pain intensity was measured using the Oucher Pain Scale before the intervention and in four intervals: Immediately after the intervention, half an hour, one hour, and 3 h after the intervention, respectively. Pain intensity was also measured at the same time intervals for the participants in the control group. The collected data were analyzed with SPSS-25 software using descriptive statistics, the Bonferroni test, and Tukey's test. RESULTS: The data showed that the three groups were identical in terms of demographic characteristics (p > 0.05).A comparison of the music listening group and the control group showed statistically significant difference in terms of postoperative pain (P < 0.05).However, the data showed significant differences between the control group and the Lego group in terms of pain intensity immediately after the intervention, half an hour, one hour, and 3 h after the intervention, respectively (p < 0.05).The data also revealed a significant difference between the children in the music group and the Lego group at all phases (p < 0.05), and the children in the Lego group reported less pain after the intervention compared to the children in the music listening group. Nevertheless, there was a statistically significant difference between the three groups in terms of reported pain intensity half an hour, one hour, and three hours after the intervention (p < 0.05). CONCLUSION: The results showed that playing with Legos had a greater effect on reducing postoperative pain in children than listening to music. Thus, nurses are recommended to make arrangements for children to play with Legos after surgery. PRACTICE IMPLICATION: Playing with Legos can be used to control postoperative pain in school-age children in medical centers and wards of pediatric hospitals.

Tapentadol Immediate Release (IR) versus Morphine Hydrochloride for Postoperative Analgesia of Patients Undergoing Total Abdominal Hysterectomy-A Prospective Cohort Study.

Background and Objectives: This study aimed to examine the efficacy of tapentadol immediate release (IR) and morphine hydrochloride in the treatment of acute postoperative pain after total abdominal hysterectomy, as well as to examine the frequency of opioid-related side effects in observed patients. Materials and Methods: The prospective observational study was conducted over five months, and it included a total number of 100 patients. The two cohorts had different types of postoperative analgesia, and the effects were observed for 24 h postoperatively, by following the pain scores on NRS (Numerical Pain Scale), contentment with analgesia, and opioid-related side effects. Results: Statistical significance was found when assessing pain 24 h after surgery while coughing, where patients in the tapentadol IR group had significantly higher mean pain scores (p < 0.01). The subjective feeling of satisfaction with postoperative analgesia was statistically significant in the tapentadol IR group (p = 0.005). Vertigo appeared significantly more in patients from the morphine group (p = 0.03). Conclusions: Tapentadol IR (immediate release) and morphine hydrochloride are both effective analgesics used in the first 24 h after total transabdominal hysterectomy. Overall satisfaction of patients with analgesia was good. The frequency of side effects was higher in the morphine group, with statistical significance regarding the vertigo.

Association of postoperative complications with persistent post-surgical pain: a multicentre prospective cohort study.

BACKGROUND: Persistent post-surgical pain is an important and under-recognised problem that is difficult to treat. Postoperative complications have been identified as possible risk factors for persistent post-surgical pain. We conducted a secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) cohort study to characterise the association of major postoperative complications with post-surgical pain at 30 days and 1 yr after major surgery. METHODS: The analysis included 1313 participants (≥40 yr old) who had inpatient noncardiac surgery and survived for 1 yr. The co-primary outcomes were 30-day post-surgical pain and 1-yr post-surgical pain. Post-surgical pain was defined as pain or discomfort that was of moderate or severe intensity (EuroQoL-5D [EQ-5D] instrument) and unimproved compared with preoperative pain or discomfort. The principal exposure was major in-hospital complications (moderate or severe by modified Clavien-Dindo criteria). Multivariable logistic regression modelling was used to characterise the adjusted association of major complications with outcomes. RESULTS: Of the cohort, 12% (n=163) experienced major complications, 51% (n=674) reported 30-day post-surgical pain, and 42% (n=545) reported 1-yr post-surgical pain. Major complications were associated with 30-day post-surgical pain (adjusted odds ratio [aOR]=1.54; 95% confidence interval [CI], 1.05-2.23) and possibly 1-yr post-surgical pain (aOR=1.42; 95% CI, 0.98-2.06). When analyses were repeated after multiple imputation of missing covariate and outcome data, complications were associated with both 30-day and 1-yr post-surgical pain. CONCLUSIONS: Patients who developed major complications were more likely to report pain at 30 days and possibly 1 yr after surgery. Research is necessary to validate these findings and delineate underlying mechanisms.

The duration of chronic low back pain is associated with acute postoperative pain intensity in lumbar fusion surgery: a prospective observational study.

BACKGROUND: Pre-existing chronic pain has been associated with severe postoperative pain. In this study, we sought to prospectively analyse the association between the duration of chronic low back pain and the intensity of acute postoperative pain after lumbar fusion surgery. METHODS: A total of 330 patients who underwent lumbar fusion surgery were divided into three groups (chronic low back pain less than 1 year, one to 5 years, and more than 5 years) based on the duration of chronic pain. On the first postoperative day, the maximum pain scores of each patient were recorded during the day and at night. Bivariate correlation and logistic regression were performed to identify relationships between acute postoperative pain and related variables (age, sex, smoking history, body mass index, operation history, duration of surgery, level of preoperative pain, aetiology of back pain, Self-rating Anxiety Scale, Self-rating Depression Scale, FRAIL scale, and duration of chronic low back pain). If the postoperative pain score was > 3 when the patient reported was at rest, the patients were treated with postoperative intravenous self-controlled analgesia or rescue analgesics if necessary. RESULTS: There was an association between severe acute postoperative pain and the duration of chronic low back pain. In terms of VAS day, multivariable logistic regression showed the duration of chronic low back pain was not statistically significant (OR = 2.48, 95% CI: 0.900 to 6.828, p = 0.0789). The result is uncertain because the confidence interval included the null after controlling for SAS, SDS, BMI, and aetiology of back pain. In terms of VAS night, patients with a duration of chronic low back pain of more than 5 years were more likely having moderate to severe acute postoperative pain (VAS > 3) compared to patients with a duration of chronic low back pain less than 1 year (OR = 3.546, 95% CI: 1.405 to 8.95, p = 0.0074). Hospital stay, the pain score on the day of discharge and the pain score after 3 months displayed no significant difference among the three groups (P > 0.05). However, the need for postoperative rescue analgesics was different among the three groups (P < 0.05). CONCLUSION: The longer the duration of chronic pain was, the higher the incidence of moderate to severe acute postoperative pain was and the greater the amount of analgesics required after surgery. TRIAL REGISTRATION: This study was registered at the Chinese Clinical Trial Registration Center ( http://www.chictr.org.cn/index.aspx , clinical trial number: ChiECRCT20200165, date of registration: July 6, 2020).

Analgesic efficacy of ultrasound guided unilateral erector spinae plane block for laparoscopic inguinal hernia repair: a randomized controlled study.

BACKGROUND: Although laparoscopic inguinal herniorrhaphy is associated with faster return to daily activity, inadequate postoperative pain control can cause prolonged hospital stays and patient discomfort. Erector spinae plane block (ESP) can be administered for postoperative pain management in abdominal and thoracic surgery. We investigated the effects of unilateral ESP block application in laparoscopic hernia surgery. METHODS: A total of 60 patients who were scheduled for laparoscopic inguinal hernia surgery were included. ESP block was performed in group E (n = 30) after induction of anesthesia. There was no intervention in Group C (n = 30). Postoperative pain was assessed by the patient using the numeric rating scale (NRS) at postanesthetic care unit (PACU),1, 4, 6, 12, and 24 h after surgery. The quality of postoperative functional recovery was evaluated using the quality of recovery-40 questionnaire. RESULTS: NRS scores were lower in Group E (n = 30) than in Group C (n = 30) at PACU, 1th, 4th, 6th hours in both rest and movement. Total tramadol consumption was reduced at postoperative 24 h by the ESP block [median(IQR), 60(40) versus 85(30)]. Quality of recovery score of the patients after operation was better in the ESP group than in the control group [mean(SD), 177.9(6.5) in group E and 173.2(7.09) in group C with mean differences: 4.633 and CI: 95% (1.11 to 8.15) respectively]. DISCUSSION: Unilateral ESP blocks in laparoscopic inguinal hernia surgery reduce both postoperative pain levels and analgesic consumption. In addition, the ESP block could be used safely in pain management of this type of surgery and improve the quality of recovery.

Systematic Review on Pain-Related Outcome Domains After Sternotomy: A First Step Toward the Development of a Core Outcome Set.

OBJECTIVES: Pain after surgery has a major impact on acute and long-term recovery and quality of life, but its management is often insufficient. To enhance the quality of research and to allow for better comparability between studies, it is important to harmonize outcomes for assessing the efficacy and effectiveness of pain management interventions after surgery. As a first step in developing a core outcome set, this study aimed to systematically search for outcome domains assessed in research regarding acute pain management after sternotomy as an example of a typically painful surgical procedure. METHODS: A systematic literature review was performed using MEDLINE, Embase, and CENTRAL. Eligibility criteria consisted of randomized controlled trials and observational trials targeting pain management after sternotomy in adults in the acute postoperative setting (≤2 weeks). After duplicate removal and title and abstract screening by 2 independent reviewers, study characteristics and outcome domains were identified, which were extracted from full texts and summarized qualitatively. RESULTS: Of 1350 studies retrieved by database searching, 156 studies were included for full-text extraction. A total of 80 different outcome domains were identified: pain intensity, analgesic consumption, physiological function, and adverse events were the most frequent ones. Outcome domains were often not explicitly reported, and the combination of domains and assessment tools was heterogeneous. The choice of outcomes is commonly made within clinicians; patients' perspectives are not considered. CONCLUSIONS: The wide variety of commonly applied outcome domains, the nonexplicit wording, and the heterogeneous combination of the domains indicating treatment benefit demonstrate the need for harmonization of outcomes assessing perioperative pain management after surgery.

Transient Reductions in Postoperative Pain and Anxiety with the Use of Virtual Reality in Children.

OBJECTIVE: Virtual reality is a promising method to manage pain. Distraction-based virtual reality (VR-D) is thought to reduce pain by redirecting attention. Although VR-D can reduce pain associated with acutely painful procedures, it is unclear whether VR-D can reduce pain after surgery. We assessed the ability of a single VR-D session to decrease postoperative pain and anxiety and explored whether pain catastrophizing and anxiety sensitivity influenced these outcomes in children after surgery. DESIGN: Single-center, prospective, pilot study. SETTING: Cincinnati Children's Hospital Medical Center (CCHMC). SUBJECTS: Fifty children (7-21 years of age) with postoperative pain followed by the Acute Pain Service. METHODS: Patients received one VR-D session after surgery. Before the session, patients completed pain catastrophizing (Pain Catastrophizing Scale for Children) and anxiety sensitivity (Child Anxiety Sensitivity Index) questionnaires. The primary outcome consisted of changes in pain intensity after VR-D (immediately, 15 minutes, and 30 minutes). Secondary outcomes included changes in pain unpleasantness and anxiety. RESULTS: VR-D use was associated with a decrease in pain intensity immediately and 15 minutes after VR-D. Reductions in pain unpleasantness were observed up to 30 minutes after VR-D. VR-D was also associated with a reduction in anxiety immediately and at 15 minutes. Although patients with higher pain catastrophizing had higher baseline pain intensity and unpleasantness, they did not show larger pain reductions after VR-D than those with lower pain catastrophizing. CONCLUSIONS: VR-D may be beneficial in transiently reducing pain intensity, unpleasantness, and anxiety in children with postoperative pain. This study informs the design of a larger, randomized, controlled study assessing VR-D for acute postoperative pain and anxiety management.

Quantitative Sensory Testing to Predict Postoperative Pain.

PURPOSE OF REVIEW: We review the relevance of quantitative sensory testing (QST) in light of acute and chronic postoperative pain and associated challenges. RECENT FINDINGS: Predicting the occurrence of acute and chronic postoperative pain with QST can help identify patients at risk and allows proactive preventive management. Generally, central QST testing, such as temporal summation of pain (TSP) and conditioned pain modulation (CPM), appear to be the most promising modalities for reliable prediction of postoperative pain by QST. Overall, QST testing has the best predictive value in patients undergoing orthopedic procedures. Current evidence underlines the potential of preoperative QST to predict postoperative pain in patients undergoing elective surgery. Implementing QST in routine preoperative screening can help advancing traditional pain therapy toward personalized perioperative pain medicine.

Relationships of sleep disturbance, intestinal microbiota, and postoperative pain in breast cancer patients: a prospective observational study.

PURPOSE: Our study was designed to examine the possible relationship between gut microbiota, sleep disturbances, and acute postoperative pain. METHODS: Using 16S rRNA sequencing, we analyzed preoperative fecal samples from women undergoing breast cancer surgery. Preoperative sleep disturbance was evaluated with the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Peak and average pain at rest and movement were evaluated 24 h after surgery, using a numerical rating scale (NRS). Preoperative symptoms of depression and anxiety were assessed with the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), respectively. Inflammation was measured using white blood cell and neutrophil counts, together with platelet-lymphocyte ratio, and neutrophil-lymphocyte ratio. RESULTS: Preoperative sleep disturbance was associated with more severe acute postoperative pain. At the phylum level, women with poor sleep quality had higher relative abundance of Firmicutes (p = 0.021) and lower relative abundance of Bacteroidetes (p = 0.013). At the genus level, women with poor sleep quality harbored higher relative abundance of Acidaminococcus and lower relative abundance of several genera. The genus Alloprevotella was negatively associated with peak pain at movement during the first 24 h (r = - 0.592, p < 0.001). The genus Desulfovibrio was negatively associated with symptoms of anxiety (r = - 0.448, p = 0.006). However, partial correlations suggested that the relationship between Alloprevotella and peak pain at movement during the first 24 h was not statistically significant after controlling for sleep (r = - 0.134, p = 0.443). CONCLUSION: These findings suggest that the changed gut microbiota may be involved in sleep-pain interaction and could be applied as a potential preventive method for postoperative pain. TRIAL REGISTRATION: The present clinical study has been registered on Chinese Clinical Trial Registry ( www.chictr.org.cn ); the clinical trial registration number is ChiCTR1900021730; the date of registration is March 7, 2019.

TNF-α - mediated peripheral and central inflammation are associated with increased incidence of PND in acute postoperative pain.

BACKGROUND: Acute postoperative pain plays an important role in the perioperative neurocognitive disorders (PND). The pathogenesis of PND is still unknown, but it is generally believed that peripheral and central nervous system inflammation play an important role, and acute postoperative pain is also thought to aggravate postoperative inflammatory response. The aim of the present study is to explore the effect of acute postoperative pain on peripheral and central nervous system inflammation and related cognitive impairment behaviour in elderly rats after surgery. METHODS: Rats were assigned into four groups: control, surgery for internal fixation for tibial fracture, surgery with analgesia using intraperitoneal morphine, and morphine without surgery. Pain was assessed by the Subjective Pain Scale. The spatial memory of rats was assessed by the Morris water maze (delayed matching task) from the second day to the seventh day after surgery (POD2-POD7). In part of the rats, the pro-inflammatory cytokines TNF-α in plasma, the medial prefrontal cortex (mPFC), and the hippocampus were determined by ELISA on the POD2. The activation of microglia and the expression of c-Fos in the hippocampal CA1 regions and mPFC were detected by the immunohistochemical method on the POD2. RESULTS: Acute postoperative pain and spatial memory impairment occurred after operation, and postoperative analgesia could significantly improve the both parameters. Additionally, on the POD2, the levels of TNF-α in plasma, hippocampus and mPFC were significantly increased, while the activation of microglia cells and the expression c-Fos in the hippocampal CA1 regions and mPFC were significantly increased. And postoperative analgesia with morphine significantly inhibited the above reactions. CONCLUSION: Our data suggest that acute postoperative pain increases the incidence of perioperative neurocognitive disorders. Peripheral and central nervous system inflammation may be involved in this cognitive impairment. And reducing the intensity of acute postoperative pain may be one of the main preventive strategies for PND.

Intravenous patient-controlled analgesia plus psychoeducational intervention for acute postoperative pain in patients with pulmonary nodules after thoracoscopic surgery: a retrospective cohort study.

BACKGROUND: The association of psychological factors with postoperative pain has been well documented. The incorporation of psychoeducational intervention into a standard analgesia protocol seems to be an attractive approach for the management of acute postoperative pain. Our study aimed to evaluate the impact of psychoeducational intervention on acute postoperative pain in pulmonary nodule (PN) patients treated with thoracoscopic surgery. METHODS: In this study, 76 PN patients treated with thoracoscopic surgery and intravenous patient-controlled analgesia (IV-PCA) plus psychoeducational evaluation and intervention were selected as the psychoeducational intervention group (PG). Another 76 PN patients receiving IV-PCA without psychoeducational intervention after thoracoscopic surgery, treated as the control group (CG), were identified from the hospital database and matched pairwise with PG patients according to age, sex, preoperative body mass index (BMI), opioid medications used for IV-PCA and the educational attainment of patients. RESULTS: The most common psychological disorders were anxiety and interpersonal sensitivity, which were recorded from 82.9% (63/76) and 63.2% (48/76) of PG patients. The numerical rating scale (NRS) pain scores of the PG patients were significantly lower than those of the CG patients at 2 and 24 h after surgery (P < 0.001). Total opioid consumption for acute postoperative pain in the PG was 52.1 mg of morphine equivalent, which was significantly lower than that (67.8 mg) in the CG (P = 0.038). PG patients had a significantly lower incidence of rescue analgesia than CG patients (28.9% vs. 44.7%, P = 0.044). Nausea/vomiting was the most common side effect of opioid medications, recorded for 3 (3.9%) PG patients and 10 (13.2%) CG patients (P = 0.042). In addition, no significant difference was observed between PG and CG patients in terms of grade 2 or higher postoperative complications (10.5% vs. 17.1%, P = 0.240). CONCLUSIONS: Psychoeducational intervention for PN patients treated with thoracoscopic surgery resulted in reduced acute postoperative pain, less opioid consumption and fewer opioid-related side effects.