Acute Postoperative Pain Intensity Research Articles

Pain trajectories and neuropathic pain symptoms following lung cancer surgery: A prospective cohort study.

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. 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. 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. 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. 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.

Acute postoperative pain prevalence and intensity in the first 72 hour in Dessie Comprehensive Specialized Hospital, Ethiopia: a prospective single center observational study.

Postoperative pain is poorly studied in developing countries. Severe pain after surgery remains a major problem, occurring in 50-70% of the patients. Differences exist across countries. Despite numerous published studies, the degree of pain following many types of surgery in everyday clinical practice is unknown. To improve postoperative pain-treatment and develop procedure-specific, optimized pain-treatment protocols, the prevalence and severity of postoperative pain must first be identified. This study aimed to determine the prevalence and intensity of acute postoperative pain and the practice of postoperative pain management. A total of 180 patients were enrolled in the study, with 160 calculated using a single population proportion formula and a 10% attrition rate added, with proportionate stratification according to the size of each ward to obtain the number of participants from each specialty ward. A multistage sampling with stratified proportionate at the initial stages and a simple random sampling technique at the final stage was used. The patients completed a numerical pain rating scale for pain immediately after surgery for the first 72h after surgery. The prevalence of mild, moderate, or severe pain was calculated. The evaluation was performed at eight time points including immediately after surgery: T2, T4, T8, T12, T24, T48, and T72. The prevalence of severe pain in patients who underwent elective surgery in the study period measured by numeric rating scale was 21.6, 43.9, 45.6, 28.9, 39.4, 10.5, and 13.4% at 2nd, 4th, 8th, 12th, 24th, 48th and 72h, respectively. The prevalence of moderate-to-severe pain within 72h postoperatively was slightly lower than that other studies conducted in Ethiopia reported. This was still high, indicating better pain management in the postoperative period. Involvement of the anesthetist in pain management is crucial for better patient management.

A Prospective Cohort Study of Acute Pain and In-Hospital Opioid Consumption After Cardiac Surgery: Associations With Psychological and Medical Factors and Chronic Postsurgical Pain.

Understanding the association of acute pain intensity and opioid consumption after cardiac surgery with chronic postsurgical pain (CPSP) can facilitate implementation of personalized prevention measures to improve outcomes. The objectives were to (1) examine acute pain intensity and daily mg morphine equivalent dose (MME/day) trajectories after cardiac surgery, (2) identify factors associated with pain intensity and opioid consumption trajectories, and (3) assess whether pain intensity and opioid consumption trajectories are risk factors for CPSP. Prospective observational cohort study design conducted between August 2012 and June 2020 with 1-year follow-up. A total of 1115 adults undergoing cardiac surgery were recruited from the preoperative clinic. Of the 959 participants included in the analyses, 573 completed the 1-year follow-up. Main outcomes were pain intensity scores and MME/day consumption over the first 6 postoperative days (PODs) analyzed using latent growth mixture modeling (GMM). Secondary outcome was 12-month CPSP status. Participants were mostly male (76%), with a mean age of 61 ± 13 years. Three distinct linear acute postoperative pain intensity trajectories were identified: "initially moderate pain intensity remaining moderate" (n = 62), "initially mild pain intensity remaining mild" (n = 221), and "initially moderate pain intensity decreasing to mild" (n = 251). Age, sex, emotional distress in response to bodily sensations, and sensitivity to pain traumatization were significantly associated with pain intensity trajectories. Three distinct opioid consumption trajectories were identified on the log MME/day: "initially high level of MME/day gradually decreasing" (n = 89), "initially low level of MME/day remaining low" (n = 108), and "initially moderate level of MME/day decreasing to low" (n = 329). Age and emotional distress in response to bodily sensations were associated with trajectory membership. Individuals in the "initially mild pain intensity remaining mild" trajectory were less likely than those in the "initially moderate pain intensity remaining moderate" trajectory to report CPSP (odds ratio [95% confidence interval, CI], 0.23 [0.06-0.88]). No significant associations were observed between opioid consumption trajectory membership and CPSP status (odds ratio [95% CI], 0.84 [0.28-2.54] and 0.95 [0.22-4.13]). Those with moderate pain intensity right after surgery are more likely to develop CPSP suggesting that those patients should be flagged early on in their postoperative recovery to attempt to alter their trajectory and prevent CPSP. Emotional distress in response to bodily sensations is the only consistent modifiable factor associated with both pain and opioid trajectories.

Preoperatively assessed offset analgesia predicts acute postoperative pain following orthognathic surgery.

High intensity and longer duration of acute postoperative pain are generally associated with a higher risk of developing chronic postoperative pain. Therefore, it is important to identify the preoperative predictors for acute postoperative pain. Preoperative evaluation of offset analgesia (OA) and the Pain Catastrophising Scale (PCS) may be potential predictors for acute postoperative pain. This study aimed to investigate the relationship between preoperative OA, PCS, and acute postoperative pain following orthognathic surgery. Thirty patients (19 females) scheduled to undergo orthognathic surgery were included in this study. OA and PCS were evaluated preoperatively, and the patients reported their postoperative pain intensity using the visual analogue scale [0-100 mm] until it reached zero (number of days with pain). OA was induced on the dominant forearm via three consecutive painful heat pulses delivered for 5 s (T1=46 °C), 5 s (T2=47 °C), and 20 s (T3=46 °C). Subsequently, the associations between OA, PCS, and the number of days with pain were analysed. The median duration of postoperative pain was 10.3days. Multiple linear regression analysis showed a significant (p=0.0019) predictive value of OA (p=0.008) for the number of days with pain. The PCS-magnification component was positively correlated with the number of dayswith pain (R=0.369, p=0.045), with no predictive values of PCS-total and PCS-subscale scores observed. Preoperative evaluation of OA may be a new individualised, predictive tool for the number of days with acute postoperative pain following orthognathic surgery; hence, a possible biomarker for the patient's vulnerability to developing chronic postoperative pain. The study was approved by the Ethics Committee of Meikai University (A1624, A2113). This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) Clinical Trial (Unique ID: UMIN000026719, UMIN000046957).

Chronic post-thoracotomy pain after lung cancer surgery: a prospective study of preoperative risk factors.

The objective of this longitudinal cohort study was to investigate if preoperative pain mechanisms, anxiety, and depression increase risk of developing chronic post-thoracotomy pain (CPTP) after lung cancer surgery. Patients with suspected or confirmed lung cancer undergoing surgery by either video-assisted thoracoscopic surgery or anterior thoracotomy were recruited consecutively. Preoperative assessments were conducted by: quantitative sensory testing (QST) (brush, pinprick, cuff pressure pain detection threshold, cuff pressure tolerance pain threshold, temporal summation and conditioned pain modulation), neuropathic pain symptom inventory (NPSI), and the Hospital Anxiety and Depression Scale (HADS). Clinical parameters in relation to surgery were also collected. Presence of CPTP was determined after six months and defined as pain of any intensity in relation to the operation area on a numeric rating scale form 0 (no pain) to 10 (worst pain imaginable). A total of 121 patients (60.2 %) completed follow-up and 56 patients (46.3 %) reported CPTP. Development of CPTP was associated with higher preoperative HADS score (p=0.025), higher preoperative NPSI score (p=0.009) and acute postoperative pain (p=0.042). No differences were observed in relation to preoperative QST assessment by cuff algometry and HADS anxiety and depression sub-scores. High preoperative HADS score preoperative pain, acute postoperative pain intensity, and preoperative neuropathic symptoms were was associated with CPTP after lung cancer surgery. No differences in values of preoperative QST assessments were found. Preoperative assessment and identification of patients at higher risk of postoperative pain will offer opportunity for further exploration and development of preventive measures and individualised pain management depending on patient risk profile.

A prospective study of chronic postsurgical pain in elderly patients: incidence, characteristics and risk factors

BackgroundDue to the continued growth of surgical procedures in older adults and the significant impact of chronic postsurgical pain (CPSP), it is crucial to improve our understanding of the occurrence of CPSP as well as the appropriate prevention and treatment. We therefore conducted this study to determine the incidence, characteristics and risk factors of CPSP in elderly patients at both 3 and 6 months after surgery.MethodsElderly patients (aged ≥ 60 years) undergoing elective surgery in our institution between April 2018 and March 2020 were prospectively enrolled in this study. Data on demographics, preoperative psychological well-being, intraoperative surgical and anesthesia management, and acute postoperative pain intensity were collected. At 3 and 6 months after surgery, patients received telephone interview and completed the questionnaires regarding chronic pain characteristics, analgesic consumption, and interference of the pain with activities of daily living (ADL).ResultsA total of 1065 elderly patients were followed up for 6 postoperative months and included in final analysis. At 3 and 6 months after operation, the incidence of CPSP was 35.6% [95% confidence interval (95% CI) 32.7 − 38.8%] and 21.5% (95% CI 19.0% − 23.9%), respectively. CPSP cause negative impacts on patient’s ADL and most particularly on mood. Neuropathic features were found in 45.1% of the patients with CPSP at 3 months. At 6 months, 31.0% of those with CPSP reported that the pain had neuropathic features. Preoperative anxiety [3 months: Odds ratio (OR) 2.244, 95% CI 1.693 to 2.973; 6 months: OR 2.397, 95% CI 1.745 to 3.294], preoperative depression (3 months: OR 1.709, 95% CI 1.292 to 2.261; 6 months: OR 1.565, 95% CI 1.136–2.156), orthopedic surgery (3 months: OR 1.927, 95% CI 1.112 to 3.341; 6 months: OR 2.484, 95% CI 1.220 to 5.061), higher pain severity on movement within postoperative 24 h (3 months: OR 1.317, 95% CI 1.191 to 1.457; 6 months: OR 1.317, 95% CI 1.177 to 1.475) were associated with a higher risk for CPSP independently at both 3 and 6 months after surgery.ConclusionsCPSP is a common postoperative complication in elderly surgical patients. Preoperative anxiety and depression, orthopedic surgery, and greater intensity of acute postoperative pain on movement are associated with an increased risk for CPSP. It should be kept in mind that developing psychological interventions to reduce anxiety and depression and optimizing the management of acute postoperative pain will be effective in reducing the development of CPSP in this population.

Pain threshold and pain tolerance as predictors of acute postoperative pain: Pain threshold and pain tolerance

Introduction Acute postoperative pain can lead to various complications, affecting cardiovascular, respiratory , gastrointestinal, and renal systems, increases the costs of treatment and affects patient satisfaction. The pain prediction contributes to optimization of acute pain treatment with pain threshold and tolerance serving as key predictors of pain. Pain threshold measures the intensity of a stimulus causing pain, while pain tolerance is the maximum pain a person can endure. Objective/Aim This review aims to investigate whether pain threshold and pain tolerance can predict the intensity of acute postoperative pain. Methods We assessed published data on pain threshold, tolerance and acute postoperative pain from the past 10 years. Five relevant studies were included after screening 26 papers. Various study types were considered, including systematic reviews, prospective observational and randomized control studies. Results Patients with higher preoperative pain tolerance reported higher pain scores postoperatively. Another investigation found that patients with a higher threshold for pressure pain before surgery experienced less pain after surgery. Preoperative pain tolerance strongly predicts intensity of acute postoperative pain. Pain threshold derived from EEG has predictive accuracy for acute postoperative pain. Research on postoperative pain demonstrated that transcutaneous electrical nerve stimulation increased pain thresholds. A systematic review concluded that lower preoperative heat pain thresholds were associated with higher postoperative pain after various surgeries. Conclusion Pain threshold and pain tolerance could serve as good predic-tors of acute postoperative pain. While these tests show promise, challenges include time consumption and resource demands. Further research is needed to develop cost-effective and time-efficient tests for timely identification of patients at risk for acute postoperative pain.

The Lack of Analgesic Efficacy of Nefopam after Video-Assisted Thoracoscopic Surgery for Lung Cancer: A Randomized, Single-Blinded, Controlled Trial.

Nefopam is a centrally acting non-opioid analgesic, and its efficacy in multimodal analgesia has been reported. This study aimed to assess the analgesic efficacy of intraoperative nefopam on postoperative pain after video-assisted thoracoscopic surgery (VATS) for lung cancer. Participants were randomly assigned to either the nefopam or the control group. The nefopam group received 20 mg of nefopam after induction and 15 min before the end of surgery. The control group received saline. The primary outcome was cumulative opioid consumption during the 6 h postoperatively. Pain intensities, the time to first request for rescue analgesia, adverse events during the 72 h postoperatively, and the incidence of chronic pain 3 months after surgery were evaluated. Ninety-nine patients were included in the analysis. Total opioid consumption during the 6 h postoperatively was comparable between the groups (nefopam group [n = 50] vs. control group [n = 49], 19.8 [13.5–25.3] mg vs. 20.3 [13.9–27.0] mg; median difference: −1.55, 95% CI: −6.64 to 3.69; p = 0.356). Pain intensity during the 72 h postoperatively and the incidence of chronic pain 3 months after surgery did not differ between the groups. Intraoperative nefopam did not decrease acute postoperative opioid consumption or pain intensity, nor did it reduce the incidence of chronic pain after VATS.

Worst pain intensity and opioid intake during the early postoperative period were not associated with moderate-severe pain 12months after total knee arthroplasty- a longitudinal study.

There are several known predictors of pain after total knee arthroplasty (TKA). However, it is unclear whether acute postoperative pain intensity and postoperative opioid intake are associated with pain 12months after TKA. Thus, the aim of this study was to assess whether worst pain intensity and opioid intake during the early postoperative period are associated with moderate-severe pain 12months after TKA. A total of 202 patients undergoing primary TKA between October 2012 and September 2014 were prospectively enrolled. Age, sex, contralateral knee pain, BMI, physical status and opioid intake were collected preoperatively. Ketamine and daily opioid intake were collected on postoperative days (POD) 0-3. Using the Brief Pain Inventory, patients' "worst pain intensity" was measured preoperatively, on POD 0-4, and 12months after TKA. Two logistic regression models evaluated the independent association of early postoperative pain intensity (model 1) and postoperative opioid intake (model 2) with moderate-severe pain 12months after TKA, adjusting for possible confounders. In total, 187 patients with data at the 12month postoperative follow-up were included in this analysis. Pain intensity on POD2 and POD3, as well as preoperative pain and BMI, were significantly associated with pain at 12months in univariate models. However, in multivariable models adjusted for preoperative pain and BMI, neither pain intensity on POD 0-4 (model 1) nor opioid intake on POD 0-3 (model 2) were associated with pain at 12months. Preoperative pain was still significant in both models, but BMI remained significant only in model 2. Worst pain intensity and opioid intake during the early postoperative period were not associated with moderate-severe pain 12months after TKA when controlling for potential confounders. More research is needed to confirm these findings.

AMAZONE: prevention of persistent pain after breast cancer treatment by online cognitive behavioral therapy—study protocol of a randomized controlled multicenter trial

BackgroundSurviving breast cancer does not necessarily mean complete recovery to a premorbid state of health. Among the multiple psychological and somatic symptoms that reduce the quality of life of breast cancer survivors, persistent pain after breast cancer treatment (PPBCT) with a prevalence of 15–65% is probably the most invalidating. Once chronic, PPBCT is difficult to treat and requires an individualized multidisciplinary approach. In the past decades, several somatic and psychological risk factors for PPBCT have been identified. Studies aiming to prevent PPBCT by reducing perioperative pain intensity have not yet shown a significant reduction of PPBCT prevalence. Only few studies have been performed to modify psychological distress around breast cancer surgery. The AMAZONE study aims to investigate the effect of online cognitive behavioral therapy (e-CBT) on the prevalence of PPBCT.MethodsThe AMAZONE study is a multicenter randomized controlled trial, with an additional control arm. Patients (n=138) scheduled for unilateral breast cancer surgery scoring high for surgical or cancer-related fears, general anxiety or pain catastrophizing are randomized to receive either five sessions of e-CBT or online education consisting of information about surgery and a healthy lifestyle (EDU). The first session is scheduled before surgery. In addition to the online sessions, patients have three online appointments with a psychotherapist. Patients with low anxiety or catastrophizing scores (n=322) receive treatment as usual (TAU, additional control arm).Primary endpoint is PPBCT prevalence 6 months after surgery.Secondary endpoints are PPBCT intensity, the intensity of acute postoperative pain during the first week after surgery, cessation of postoperative opioid use, PPBCT prevalence at 12 months, pain interference, the sensitivity of the nociceptive and non-nociceptive somatosensory system as measured by quantitative sensory testing (QST), the efficiency of endogenous pain modulation assessed by conditioned pain modulation (CPM) and quality of life, anxiety, depression, catastrophizing, and fear of recurrence until 12 months post-surgery.DiscussionWith perioperative e-CBT targeting preoperative anxiety and pain catastrophizing, we expect to reduce the prevalence and intensity of PPBCT. By means of QST and CPM, we aim to unravel underlying pathophysiological mechanisms. The online application facilitates accessibility and feasibility in a for breast cancer patients emotionally and physically burdened time period.Trial registrationNTR NL9132, registered December 16 2020.

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

BackgroundPre-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.MethodsA 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.ResultsThere 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).ConclusionThe 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 registrationThis 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).

Comparison of Chronic Postsurgical Pain Between Single-Port and Multi-Port Video-Assisted Thoracoscopic Pulmonary Resection: A Prospective Study.

Background Little is known about the prevalence of chronic postsurgical pain (CPSP) among patients receiving single-port video-assisted thoracic surgery (SP-VATS) compared with those undergoing multi-port VATS (MP-VATS). This study aimed to compare the incidence of CPSP between SP-VATS and MP-VATS lung resection and assess how the pain affected the daily living activities of this patient population. Methods We prospectively collected data regarding the demographic features, clinical factors during surgery, the intensity of acute postoperative pain, and complications after surgery among patients receiving elective SP-VATS or MP-VATS lung resection at our institution between June 2015 and August 2018. At 3-, 6-, and 12-months following surgery, the patients were followed up through a telephonic interview. The Brief Pain Inventory-Short Form was adopted to assess the incidence, severity and location of the CPSP, analgesic consumption, as well as the interference of pain with daily activities. Results In total, 476 patients were screened for eligibility, 411 patients were followed up for 12 months and included in final analysis. Among these, 190 patients had undergone an SP-VATS pulmonary resection and 221 had an MP-VATS pulmonary resection. At both 3 and 6 months, the incidence of CPSP in the SP-VATS group was lower than that in the MP-VATS group (25.3 vs. 38.0%, p = 0.006; 11.1 vs. 19.0%, p = 0.026, respectively). At 12 months after surgery, the prevalence of CPSP was comparable between groups (4.7 vs, 9.0%, p = 0.089). In addition, the SP-VATS technique alleviated pain interference with the daily living activities of patients with CPSP in several domains, including sleep, mood, and enjoyment of life compared with the MP-VATS technique. The two predictive factors for CPSP at postoperative 3 months were the MP-VATS technique (odds ratio [OR] = 1.792, p = 0.019) and postoperative chemotherapy (OR = 1.718, p = 0.033). Conclusions This study indicated that the SP-VATS technique reduced the prevalence of CPSP at 3- and 6-months post-pulmonary resection compared with the MP-VATS technique. The SP-VATS technique also significantly alleviated pain interference with the daily living activities of the patients.

Effects of propofol-remifentanil versus sevoflurane-remifentanil on acute postoperative pain after total shoulder arthroplasty: a randomized trial.

While some evidence indicates that propofol-based anesthesia has less postoperative pain than sevoflurane-based anesthesia, these results are controversial. We compared acute postoperative pain intensity and opioid consumption after total shoulder arthroplasty between propofol-remifentanil (PR) and sevoflurane-remifentanil (SR) anesthesia. Among 48 patients undergoing shoulder arthroscopic surgery anesthetized with PR or SR, postoperative pain intensity was assessed at 30 minutes and at 2, 6, 12, and 24 hours. The total patient-controlled analgesia volume and number of patients requiring rescue analgesics were assessed. No significant difference in postoperative pain intensity was observed between the two groups. Postoperative opioid consumption and analgesic requirements were also comparable in the first 24 hours after surgery. PR and SR anesthesia for shoulder arthroscopic surgery provide comparable postoperative analgesia results.

Effects of Patient and Surgery Characteristics on Persistent Postoperative Pain: A Mediation Analysis.

Acute postoperative pain intensity is associated with persistent postsurgical pain (PPP) risk. However, it remains unclear whether acute postoperative pain intensity mediates the relationship between clinical factors and persistent pain. Participants from a mixed surgical population completed the Brief Pain Inventory and Pain Catastrophizing Scale before surgery, and the Brief Pain Inventory daily after surgery for 7 days and at 30 and 90 days after surgery. We considered mediation models using the mean of the worst pain intensities collected daily on each of postoperative days (PODs) 1 to 7 against outcomes of worst pain intensity at the surgical site endpoints reflecting PPP (POD 90) and subacute pain (POD 30). The analyzed cohort included 284 participants for the POD 90 outcome. For every unit increase of maximum acute postoperative pain intensity through PODs 1 to 7, there was a statistically significant increase of mean POD 90 pain intensity by 0.287 after controlling for confounding effects. The effects of female versus male sex (m=0.212, P=0.034), pancreatic/biliary versus colorectal surgery (m=0.459, P=0.012), thoracic cardiovascular versus colorectal surgery (m=0.31, P=0.038), every minute increase of anesthesia time (m=0.001, P=0.038), every unit increase of preoperative average pain score (m=0.012, P=0.015), and every unit increase of catastrophizing (m=0.044, P=0.042) on POD 90 pain intensity were mediated through acute PODs 1 to 7 postoperative pain intensity. Our results suggest the mediating relationship of acute postoperative pain on PPP may be predicated on select patient and surgical factors.

The Effectiveness of Transversus Abdominis Plane and Quadratus Lumborum Blocks in Acute Postoperative Pain Following Cesarean Section-A Randomized, Single-Blind, Controlled Trial.

Acute pain intensity related to cesarean section (CS) may be extensive and is often underestimated. This may influence mothers’ quality of life and their children’s development. Regional analgesia techniques that include transversus abdominis plane block (TAPB) and quadratus lumborum block (QLB) have proven their efficacy in the postoperative period after CS. Although several randomized controlled studies and one meta-analysis have investigated the utility of TAPB and QLB in the reduction of acute and chronic pain after CS, only one study directly compared both types of regional blocks and revealed superiority of QLB over TAPB. Our study aimed to reevaluate the effectiveness of transversus TAPB and QLB in controlling acute postoperative pain after CS. We recruited 197 women with singleton pregnancies undergoing CS under spinal anesthesia. The patients were randomized to receive either TAPB or QLB after CS. The acute postoperative pain was evaluated using the visual analog scale (VAS) at 2, 4, 8, 12 and 24 h after the operation. No significant difference in acute postoperative pain intensity between the groups was found. The patients who received TAPB had a higher demand for supplemental morphine injections (p < 0.039). In our study, none of the evaluated regional blocks demonstrated an advantage over the other regarding acute postoperative pain management.

Perioperative factors associated with persistent postsurgical pain after hysterectomy, cesarean section, prostatectomy, and donor nephrectomy: a systematic review and meta-analysis.

Persistent postsurgical pain (PPSP) is a common and often disabling postoperative morbidity, but many questions remain about factors associated with PPSP. This systematic review and meta-analysis aimed to identify preoperative, intraoperative, and postoperative factors associated with PPSP after gynecological surgeries, namely, hysterectomy and cesarean section, and urological surgeries, namely, prostatectomy and donor nephrectomy. Overall, 18 gynecological surgery studies, 4 prostatectomy studies, and 2 donor nephrectomy studies met the review criteria, providing data that could be meta-analyzed. The average (±SD) PPSP occurrence after gynecological surgery was 20 ± 11%; factors associated with increased risk of PPSP included smoking, preoperative abdominal or pelvic pain, preoperative pain elsewhere in the body, longer duration of surgery, more intense acute postoperative pain, and surgical wound infection. The use of neuraxial anesthesia was associated with decreased PPSP risk. The average PPSP occurrence was 20 ± 9% after prostatectomy and 15 ± 2% after donor nephrectomy. For urological procedures, the existing data did not allow for identification of significant factors associated with PPSP, except for laparoscopic and hand-assisted laparoscopic approaches that were associated with lower incidence of PPSP for donor nephrectomy, and the use of neuraxial anesthesia which was associated with lower incidence of PPSP after prostatectomy. Persistent postsurgical pain after gynecological and urological surgeries is common. This systematic review identified important factors associated with cesarean section and hysterectomy that can help identify women who are at high risk of PPSP. More high-quality studies with consistent methodology are needed to understand the factors associated with PPSP risk, particularly for surgeries such as prostatectomy and nephrectomy.

The Effect of Intraoperative Fluid Management According to Stroke Volume Variation on Postoperative Bowel Function Recovery in Colorectal Cancer Surgery.

Stroke volume variation (SVV) has been used to predict fluid responsiveness; however, it remains unclear whether goal-directed fluid therapy using SVV contributes to bowel function recovery in abdominal surgery. This prospective randomized controlled trial aimed to compare bowel movement recovery in patients undergoing colon resection surgery between groups using traditional or SVV-based methods for intravenous fluid management. We collected data between March 2015 and July 2017. Bowel function recovery was analyzed based on the gas-passing time, sips of water time, and soft diet (SD) time. Finally, we analyzed data from 60 patients. There was no significant between-group difference in the patients’ characteristics. Compared with the control group (n = 30), the SVV group (n = 30) had a significantly higher colloid volume and lower crystalloid volume. Moreover, the gas-passing time (77.8 vs. 85.3 h, p = 0.034) and SD time (67.6 vs. 85.1 h, p < 0.001) were significantly faster in the SVV group than in the control group. Compared with the control group, the SVV group showed significantly lower scores of pain on a numeric rating scale and morphine equivalent doses during post-anesthetic care, at 24 postoperative hours, and at 48 postoperative hours. Our findings suggested that, compared with the control group, the SVV group showed a faster postoperative SD time, reduced acute postoperative pain intensity, and lower rescue analgesics. Therefore, SVV-based optimal fluid management is expected to potentially contribute to postoperative bowel function recovery in patients undergoing colon resection surgery.

The Prediction of Acute Postoperative Pain Based on Neural Oscillations Measured before the Surgery.

Even with an improved understanding of pain mechanisms and advances in perioperative pain management, inadequately controlled postoperative pain remains. Predicting acute postoperative pain based on presurgery physiological measures could provide valuable insights into individualized, effective analgesic strategies, thus helping improve the analgesic efficacy. Considering the strong correlation between pain perception and neural oscillations, we hypothesize that acute postoperative pain could be predicted by neural oscillations measured shortly before the surgery. Here, we explored the relationship between neural oscillations 2 hours before the thoracoscopic surgery and the subjective intensity of acute postoperative pain. The spectral power density of resting-state beta and gamma band oscillations at the frontocentral region was significantly different between patients with different levels of acute postoperative pain (i.e., low pain vs. moderate/high pain). A positive correlation was also observed between the spectral power density of resting-state beta and gamma band oscillations and subjective reports of postoperative pain. Then, we predicted the level of acute postoperative pain based on features of neural oscillations using machine learning techniques, which achieved a prediction accuracy of 92.54% and a correlation coefficient between the real pain intensities and the predicted pain intensities of 0.84. Altogether, the prediction of acute postoperative pain based on neural oscillations measured before the surgery is feasible and could meet the clinical needs in the future for better control of postoperative pain and other unwanted negative effects. The study was registered on the Clinical Trial Registry (https://clinicaltrials.gov/ct2/show/NCT03761576?term=NCT03761576&draw=2&rank=1) with the registration number NCT03761576.

TNF-\u03b1 - mediated peripheral and central inflammation are associated with increased incidence of PND in acute postoperative pain

BackgroundAcute 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.MethodsRats 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.ResultsAcute 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.ConclusionOur 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.

Slow Dynamics of Acute Postoperative Pain Intensity Time Series Determined via Wavelet Analysis Are Associated With the Risk of Severe Postoperative Day 30 Pain.

Evidence suggests that increased early postoperative pain (POP) intensities are associated with increased pain in the weeks following surgery. However, it remains unclear which temporal aspects of this early POP relate to later pain experience. In this prospective cohort study, we used wavelet analysis of clinically captured POP intensity data on postoperative days 1 and 2 to characterize slow/fast dynamics of POP intensities and predict pain outcomes on postoperative day 30. The study used clinical POP time series from the first 48 hours following surgery from 218 patients to predict their mean POP on postoperative day 30. We first used wavelet analysis to approximate the POP series and to represent the series at different time scales to characterize the early temporal profile of acute POP in the first 2 postoperative days. We then used the wavelet coefficients alongside demographic parameters as inputs to a neural network to predict the risk of severe pain 30 days after surgery. Slow dynamic approximation components, but not fast dynamic detailed components, were linked to pain intensity on postoperative day 30. Despite imbalanced outcome rates, using wavelet decomposition along with a neural network for classification, the model achieved an F score of 0.79 and area under the receiver operating characteristic curve of 0.74 on test-set data for classifying pain intensities on postoperative day 30. The wavelet-based approach outperformed logistic regression (F score of 0.31) and neural network (F score of 0.22) classifiers that were restricted to sociodemographic variables and linear trajectories of pain intensities. These findings identify latent mechanistic information within the temporal domain of clinically documented acute POP intensity ratings, which are accessible via wavelet analysis, and demonstrate that such temporal patterns inform pain outcomes at postoperative day 30.