Prediction of post-operative pain after a laparoscopic tubal ligation procedure

Contribution of Hypersensitivity to Postureteroscopy Ureteral Stent Pain: Findings From Study to Enhance Understanding of Stent-associated Symptoms

OBJECTIVE

To examine the relationships between preoperative hypersensitivity to pain and central sensitization, and postoperative ureteral stent pain after ureteroscopy (URS) for urinary stones.

METHODS

Adults enrolled in the STudy to Enhance uNderstanding of sTent-associated Symptoms (STENTS) underwent quantitative sensory testing (QST) prior to URS and stent placement. Hypersensitivity to mechanical pain was assessed using a pressure algometer. Participants rated their pain intensity to pressure applied to the ipsilateral flank area and lower abdominal quadrant on the side of planned stent placement, and the contralateral forearm (control). Pressure pain thresholds were also assessed. Central sensitization was assessed by applying a pointed stimulator (pinprick) and calculating the temporal summation. Postoperative stent pain intensity and interference were assessed using PROMIS questionnaires. Data were analyzed using repeated-measures mixed-effects linear models.

RESULTS

Among the 412 participants, the median age was 54.0years, and 46% were female. Higher preoperative pain ratings to 2 kg and 4 kg mechanical pressure to the ipsilateral flank and abdominal areas were associated with higher postoperative stent pain intensity with the stent in situ. Greater degree of central sensitization preoperatively, manifesting as higher temporal summation, was associated with higher postoperative pain intensity. Factors associated with preoperative hypersensitivity on QST included female sex, presence of chronic pain conditions, widespread pain, and depression.

CONCLUSION

Hypersensitivity to pain and central sensitization preoperatively was associated with postoperative ureteral stent pain, suggesting a physiologic basis for stent symptom variation. QST may identify patients more likely to develop stent pain after URS and could inform selection for preventive and interventional strategies.

Altered central pain processing in patients with degenerative lumbar diseases and its association with low physical activity levels after lumbar spinal surgeries: a retrospective cohort analysis

PURPOSE

To investigate the occurrence of altered central pain modulation in patients with degenerative lumbar diseases (DLDs) and to analyze its association with physical activity (PA) 3 years after lumbar decompression and fusion.

METHODS

Preoperative assessments of pressure pain thresholds (PPTs), temporal summation (TS), conditioned pain modulation (CPM) and pain were, respectively, recorded in 304 patients. These patients further underwent International Physical Activity Questionnaire (IPAQ) and both pain-related and psychological assessments 3 years post-operation.

RESULTS

Preoperatively, the patients had lower PPTs in both local pain and pain-free areas and lower CPM and higher TS in pain-free areas than healthy subjects (P < 0.05). Postoperatively, 53.9% (164/304) patients showed PA below healthy-related thresholds (< 600 MET min/w). Low PA group showed a greater postoperative weight gain and bone loss and a higher postoperative prevalence of both moderate anxiety and marginal depression than high PA group (P < 0.05). All covariates with differences between the high and low PA groups were subjected to multivariate logistic regression, and long preoperative disease duration, low preoperative PPT in pain-free area, high preoperative TS, revision surgery, severe postoperative low back pain and significant postoperative pain catastrophizing thought were independently associated with low postoperative PA (P < 0.05).

CONCLUSIONS

This study supports the existence of central sensitization (CS) caused by abnormal central pain modulation in DLDs. Pre-existing CS in these patients may be associated with low PA after lumbar surgeries, and this low-activity lifestyle may predispose patients to multiple adverse health outcomes. Preoperative dynamic quantitative sensory testing may provide information for the identification of at-risk patients.

Preoperative pain sensitivity predicts postoperative pain severity and analgesics requirement in lumbar fusion surgery - a prospective observational study

BACKGROUND CONTENT

The goal of postoperative pain management is to facilitate the patient's return to normal activity and decrease the detrimental effects of acute postsurgical pain. In order to provide more tailored and successful pain treatment, it is necessary to identify individuals who are at a high risk of experiencing severe postoperative pain. The most precise way to assess pain sensitivity is by determining the pressure pain threshold and heat pain threshold by objective methods using a digital algometer and neurotouch respectively.

PURPOSE

The primary aim of the study is to assess the preoperative pain threshold and its influence on postoperative pain severity and analgesics requirements in patients undergoing lumbar fusion surgeries.

STUDY DESIGN

Prospective, observational study.

PATIENT SAMPLE

Sixty patients requiring a single-level lumbar fusion surgery.

OUTCOME MEASURES

Postoperative pain intensity and the amount of postoperative analgesics consumption.

METHODS

In our patients, preoperative pain sensitivity was assessed by pressure pain threshold measurements with the help of a digital algometer, and heat pain threshold using a neurotouch instrument. In addition, pain sensitivity questionnaires (PSQ) were used in all our patients to determine pain sensitivity. Preoperative psychosocial and functional assessments were performed by Hospital anxiety-depression scores (HADS), and Oswestry disability index (ODI) respectively. Preoperative visual analog scale (VAS) score was determined at three instances of needle prick (phlebotomy, glucometer blood sugar, and intradermal antibiotic test dose) and during the range of movements of the lumbar spine region. Postoperative VAS score and postoperative breakthrough analgesic requirements were recorded in all of these patients from day 0 to day 3.

RESULTS

The average age of the patients was 51.11±13.467 years and 70% were females. Females had lower mean algometry values (72.14±7.56) compared to males (77.34±6.33). Patients with higher HADS (p<.0016), higher PSQ (p<.001), higher ODI scores(p<.001), and female gender significantly correlated with a lower algometer average indicating high pain sensitivity. Patients with lower preoperative VAS scores and with higher neurotouch scores showed lower postoperative VAS scores at different time periods. Preoperative VAS scores, algometer average scores, neurotouch scores, and HADS scores were considered as independent variables (predictors) for postoperative VAS at 6 hours period. By the multivariate analysis, factors like preoperative VAS scores, algometer average scores, and HADS scores were statistically significant (p<.05). There was a significant correlation between algometer average scores (p<.001) with the breakthrough analgesics.

CONCLUSION

Preoperative assessment of pain sensitivity can predict postoperative analgesic requirements and aid in recovery. Patients with a lower pain threshold should be counseled preoperatively and also receive a better titration of analgesics perioperatively.

Maternal psychosocial factors associated with postpartum pain

BACKGROUND

The experience of pain is shaped by a host of psychological, cultural, and social factors. Although pain is the most common postpartum complaint, data on its relationship with psychosocial factors and postpartum pain are limited.

OBJECTIVE

This study aimed to examine the relationship between self-reported postpartum pain scores and patient-level psychosocial factors, including relationship status, pregnancy intendedness, employment, education, and psychiatric diagnosis.

STUDY DESIGN

This was a secondary analysis of data from a prospective observational study of postpartum patients at 1 institution (May 2017 to July 2019) who used an oral opioid at least once during their postpartum hospitalization. Enrolled participants completed a survey, which included questions regarding their social situation (including relationship status), psychiatric diagnoses, and perceptions of their pain control during their postpartum hospitalization. The primary outcome was self-reported overall pain during the postpartum hospitalization (score of 0-100). Multivariable analyses accounted for age, body mass index, nulliparity, and mode of delivery.

RESULTS

In this cohort of 494 postpartum patients, most patients (84.0%) underwent cesarean delivery, and 41.3% of patients were nulliparous. In a pain score of 0 to 100, participants reported a median pain score of 47. On bivariable analyses, there was no significant difference in pain score between patients with and without an unplanned pregnancy or a psychiatric diagnosis. Patients who were unpartnered, those without a college education, and those who were unemployed reported significantly higher pain scores (57.5 vs 44.8 [P<.01], 52.6 vs 44.6 [P<.01], and 53.6 vs 44.6 [P<.01], respectively). In multivariable analyses, patients who were unpartnered and unemployed reported significantly higher adjusted pain scores than patients who were partnered and employed (adjusted beta coefficients: 7.93 [95% confidence interval, 2.29-13.57] vs 6.67 [95% confidence interval, 2.28-11.05]).

CONCLUSION

Psychosocial factors, such as relationship and employment statuses, which are indicators of social support, are associated with the experience of pain postpartum. These findings suggest that addressing social support, such as via enhanced support from the health care team, warrants exploration as a nonpharmacologic means of improving the postpartum pain experience.

Comparison of time-dependent resistance isometric exercise and active range of motion exercise in alleviating the sensitization of postoperative axial pain after cervical laminoplasty

BACKGROUND

Postoperative axial pain (PAP) is a significant complication after cervical laminoplasty.

OBJECTIVE

To investigate pain sensitization in PAP patients and effects of time-dependent resistance isometric exercise compared to active range-of-motion exercise on PAP.

STUDY DESIGN

Retrospective cohort analysis.

METHODS

211 patients undergoing postoperative 12-week exercises were evaluated for pressure pain threshold (PPT), temporal summation (TS) and both cross-sectional area and fatty infiltration of paraspinal muscles preoperatively and 3 months postoperatively. There patients underwent Numeric rating pain scale (NRS) and neck disability index (NDI) 3 and 6 months postoperatively.

RESULTS

At postoperative 3-month assessments, fewer patients undergoing isometric exercise showed PAP compared to range-of-motion exercise group (14/98 vs. 34/113; P = 0.006), and pain-related assessments in the former were lower than the latter (NRS at rest: 0.3 ± 0.8 vs. 0.7 ± 1.4, P = 0.014; NRS with movements: 0.4 ± 1.0 vs. 1.0 ± 1.7, P = 0.015; NDI: 2.4 ± 6.3 vs. 6.7 ± 10.9, P = 0.002). Postoperative cross-sectional area was smaller in isometric exercise group (603.5 ± 190.2) than in range-of-motion exercise group (678.7 ± 215.5) (P = 0.033), and the former showed higher local-area PPT and lower TS than the latter (PPT: 3.9 ± 1.8 vs. 3.1 ± 1.6, P = 0.002; TS: 1.8 ± 0.9 vs. 2.2 ± 1.0, P = 0.003). PAP patients showed lower local-area PPT and greater TS than those without PAP in both isometric (PPT: 2.8 ± 0.7 vs. 4.0 ± 1.9, P = 0.019; TS: 2.4 ± 0.6 vs. 1.7 ± 0.9, P = 0.011) and range-of-motion (PPT: 2.2 ± 0.9 vs. 3.6 ± 1.7, P < 0.001; TS: 2.8 ± 0.8 vs. 1.9 ± 0.9, P < 0.001) exercise groups.

CONCLUSIONS

Both peripheral and central sensitization are involved in PAP. Time-dependent isometric exercise has more positive effects on PAP than range-of-motion exercise because of its advantages in improving pain sensitization.

Preoperative dynamic quantitative sensory testing in remote pain-free areas is associated with axial pain after posterior cervical spinal surgeries

BACKGROUND

Postoperative axial pain (PAP), characterized by pain and/or stiffness around the posterior neck, periscapular areas and/or shoulder region, is a vexing complication affecting 5-60% of patients undergoing posterior cervical decompression. Given its relatively high frequency and negative impact on patients' physical and mental status, efforts preoperatively to confirm patients at risk of developing PAP to offer more efficient pain management to minimize this complication have a high priority. The aim of this study is to investigate the role of preoperative dynamic quantitative sensory testing (QST) in predicting the PAP after posterior cervical decompression.

METHODS

This longitudinal observational study included 122 patients with degenerative cervical myelopathy undergoing laminoplasty or laminectomy. Preoperatively, all patients underwent the assessment of pressure pain thresholds (PPTs) at local and remote pain-free areas and both temporal summation (TS) and conditioned pain modulation (CPM) at remote pain free-areas. These patients underwent further pain-related, psychosocial and clinical function assessments before and/or after operation.

RESULTS

In the present study, 21 patients (21/122, 17.2%) developed PAP, and the 6-month postoperative follow-up demonstrated that 8 of these 21 patients developed chronic PAP (CPAP). All preoperative covariates with significant differences between the PAP and non-PAP groups were subjected to multivariate logistic regression, and the presence of preoperative axial pain, surgical plan including C2 decompression, total international physical activity questionnaire score (cutoff value [CV]: 2205.5, sensitivity: 82.4%; specificity: 61.1%) and TS value (CV: 2.5, sensitivity: 42.9%; specificity: 83.2%) were independently associated with PAP (P < 0.05). Logistic regression further revealed that the presence of preoperative axial pain, TS value (CV: 2.5, sensitivity: 62.5%; specificity: 83.2%) and CPM value (CV: 0.65, sensitivity: 87.5%; specificity: 61.4%) were significant predictors of CPAP (P < 0.05).

CONCLUSIONS

The findings of this study support the hypothesis that preoperative endogenous pain modulation efficiency may be associated with axial pain after posterior cervical decompression. Clinically, preoperative estimation of both TS and CPM in remote pain-free areas may provide additional useful information for identifying patients who may be at risk of developing both PAP and CPAP, which may be beneficial in enabling stratification in the perioperative period of patients based on individual vulnerabilities to avoid/reduce this complication.

Comparing post-operative pain between single bundle and double bundle anterior cruciate ligament reconstruction: a retrospective study

Background

In anterior cruciate ligament (ACL) reconstruction, the clinical outcome and level of post-operative pain are important factors. To date there have been no studies evaluating differences in post-operative pain between single bundle and double bundle ACL reconstruction with a hamstring graft.

Hypothesis/purpose

We hypothesized that post-operative pain in single bundle ACL reconstruction would be less than in double bundle ACL reconstruction. This study was to compare post-operative pain between patients undergoing single bundle versus double bundle ACL reconstruction.

Study design

Cohort study.

Methods

This was a retrospective study comparing post-operative pain scores between single bundle and double bundle ACL reconstruction. Each patient was given our standard regimen of oral diclofenac (25 mg/tab) three times per day and paracetamol (500 mg/tab) six times per day for 1 day post-operatively. If the patient complained of moderate to severe pain (pain numeric rating scale (PNRS) > 3), 3 mg of morphine was injected intravenously every 3 h for 24 h and 1 mg of morphine as a rescue medication every 1 h for 24 h. PNRS and morphine consumption were recorded at 4-h intervals for 24 h.

Results

209 patients were included in this study of whom 102 and 107 patients received single bundle and double bundle ACL reconstruction, respectively. The average post-operative pain scores of the single bundle group were lower at all time points. Linear mixed effect regression analyses showed that the single bungle group had lower post-operative pain than the double bundle group after adjusting for confounders (beta = − 0.45; 95% CI = − 0.838, − 0.062) but there was no statistically significant difference between numbers of bundle ACL reconstruction with regard to morphine consumption.

Conclusion

Single bundle ACL reconstruction had significantly lower post-operative pain scores than double bundle ACL reconstruction.

Clinical relevance

Double bundle ACL reconstruction results in higher post-operative pain, which may slow the start of rehabilitation and reduce patient satisfaction. In middle-aged adult patients with low-demand activities, we suggest performing a single bundle ACL reconstruction.

The risk of shoulder pain after laparoscopic surgery for infertility is higher in thin patients

Postlaparoscopic shoulder pain (PLSP) is a common clinical problem that needs to be addressed by medical professionals who are currently perform laparoscopic surgeries. The purpose of this study was to determine the perioperative clinical factors and demographic characteristics associated with PLSP. A prospective observational study was performed with 442 inpatients undergoing laparoscopic surgery for infertility. The pain visual analogue scale was used as the measuring instrument. To identify the predictors of PLSP, we performed multivariate conditional logistic regression. PLSP was correlated with body mass index (BMI, odds ratio = 0.815). The incidence of shoulder pain and more severe shoulder pain in patients with a lower BMI was significantly higher than it was in patients with a higher BMI, and BMI was significantly negatively correlated with PLSP. Most of the patients (95%) began to experience shoulder pain on the first postoperative day, and it rarely occurred on the day of surgery. Patients with lower BMI presented a higher risk of reporting shoulder pain on the first postoperative day. We should identify high-risk patients in advance and make specific treatment plans according to the characteristics of their symptoms.

Preoperative Pressure Pain Threshold Is Associated With Postoperative Pain in Short-Stay Anorectal Surgery: A Prospective Observational Study

BACKGROUND:

Postoperative pain management is key for patient satisfaction. Pressure pain threshold (PPT) has been studied in some surgical cohorts but has not been studied in relationship to acute postoperative pain in short-stay patients undergoing anorectal surgery. We hypothesized that preoperative finger PPT measurements can identify respective patients with higher postoperative pain. Aiming to understand the relationship with subjective postoperative pain perception, we tested the hypotheses that preoperative PPT is associated with postoperative Visual Analog Scale (VAS) pain scores and correlates with postoperative analgesic consumption in short-stay patients undergoing anorectal surgery.

METHODS:

We prospectively assessed preoperative PPT in a cohort undergoing anorectal surgery, known as a moderately to severely painful procedure. Linear mixed-effects models were used to assess the relationship with postoperative VAS pain scores at 1 and 3 days as well as 4 weeks postoperatively. Logistic regression was used to study the relationship with additional postoperative analgesic consumption.

RESULTS:

We studied 128 patients and found that preoperative PPT is significantly associated with postoperative pain (P value for interaction = .025). Logistic regression modeling additionally revealed an association between the preoperative PPT and the need for additional postoperative analgesics, with odds of requiring additional analgesia decreasing by about 10% for each 1-point increase in PPT (odds ratio [OR] = 0.90; 95% confidence interval [CI], 00.81–0.98; P = .012).

CONCLUSIONS:

Preoperative finger PPT is associated with postoperative pain and might help identify patients who are at risk of developing more severe postoperative pain on anorectal surgery. Especially in ambulatory and short-stay settings, this approach can help to address patients’ high variability in pain sensitivity to facilitate appropriate postoperative analgesia, timely discharge, and prevent readmission.

Predicted Versus Non-Predicted Opioid Administration Using Preoperative Pain Sensitivity in Patients Undergoing Gynecological Surgery: A Randomized-Controlled Trial

Individualized administration of opioids based on preoperative pain sensitivity may improve postoperative pain profiles. This study aimed to examine whether a predicted administration of opioids could reduce opioid-related adverse effects after gynecological surgery. Patients were randomized to the predicted group or control group. Participants received a preoperative sensory test to measure pressure pain thresholds. Patients were treated with a higher or lower (15 or 10 μg/mL) dose of fentanyl via intravenous patient-controlled analgesia. The opioid dose was determined according to pain sensitivity in the predicted group, while it was determined regardless of pain sensitivity in the control group. The primary outcome was the incidence of nausea over the first 48 h postoperative period. Secondary outcomes included postoperative pain scores and opioid requirements. There was no difference in the incidence of nausea (40.0% vs. 52.5% in predicted and control groups, respectively; p = 0.191) and postoperative pain scores (3.3 vs. 3.5 in predicted and control groups, respectively; p = 0.691). However, opioid consumptions were lower in the predicted group compared to the control group (median 406.0 vs. 526.5 μg; p = 0.042). This study showed that offering a predicted dose of opioids according to pain sensitivity did not affect the incidence of nausea and pain scores.

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.

Summary

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.

Toward Understanding Movement-evoked Pain (MEP) and its Measurement: A Scoping Review

OBJECTIVE

Individuals with chronic pain conditions often report movement as exacerbating pain. An increasing number of researchers and clinicians have recognized the importance of measuring and distinguishing between movement-evoked pain (MEP) and pain at rest as an outcome. This scoping review maps the literature and describes MEP measurement techniques.

MATERIALS AND METHODS

The scoping review utilized 6 databases to identify original studies that targeted pain or movement-related outcomes. Our search returned 7322 articles that were screened by title and abstract by 2 reviewers. The inclusion criteria focused on the measurement of MEP before, during, and after movement tasks in adults with chronic pain. Studies of children below 18 years of age or with nonhuman animals, case studies, qualitative studies, book chapters, cancer-related pain, non-English language, and abstracts with no full publish text were excluded from the study.

RESULTS

Results from 38 studies revealed great variation in the measurement of MEP, while almost all of the studies did not provide an explicit conceptual or operational definition for MEP. In addition, studies collectively illuminated differences in MEP compared with rest pain, movement provocation methods, and pain intensity as the primary outcome.

DISCUSSION

These results have clinically significant and research implications. To advance the study of MEP, we offer that consistent terminology, standardized measurement (appropriate for pain type/population), and clear methodological processes be provided in research publications. On the basis of the findings, we have put forth a preliminary definition of MEP that may benefit from the continued scholarly dialog.

Pain threshold, anxiety and other factors affect intensity of postoperative pain in gastric cancer patients: A prospective cohort study

Objective

This prospective cohort study explored factors related to postoperative pain in gastric cancer patients.

Methods

A total of 236 patients who underwent gastrectomy were enrolled. All patients enrolled in the study completed the Hospital Anxiety and Depression Scale (HADS) questionnaire and Life Orientation Test-Revised (LOT-R) questionnaire on the day before surgery. Heat pain threshold (HPT), cold pain threshold (CPT) and pressure pain threshold (PPT) were measured for all patients one day prior to surgery and demographic details were collected. All patients were connected to a patient-controlled intravenous analgesia (PCIA) pump at the end of the surgery. The occurrence of postoperative pain was used as a dependent variable, and multivariate logistic regression analyses were conducted to screen for factors affecting postoperative pain.

Results

In total, 83 patients (35.2%) had postoperative pain. Body mass index (BMI) ≥28 kg/m² [odds ratio (OR): 2.67; 95% confidence interval (95% CI): 1.07−6.67], total gastrectomy (OR: 2.64; 95% CI: 1.42−4.91), preoperative anxiety score ≥8 (OR: 2.37; 95% CI: 1.12−5.02), heat pain threshold ≤4.9 s (OR: 2.14; 95% CI: 1.06−4.32), pressure pain threshold ≤4 g (OR: 2.05; 95% CI: 1.05−4.03), and female gender (OR: 1.99; 95% CI: 1.04−3.83) were risk factors for postoperative pain.

Conclusions

Obesity, wide range of gastrectomy, high preoperative anxiety, low HPT and PPT, and female gender are associated with increased risk for postoperative pain.

Impact of anxiety levels on the perception of pain in patients undergoing office hysteroscopy

OBJECTIVE

This study aimed at assessing the impact of anxiety on pain perception during hysteroscopy and to highlight the possible contribution of factors related to pain perception.

MATERIALS AND METHODS

104 women with indication for office hysteroscopy fullfilled anonymous self-report questionnaires during the waiting time, before the procedure. The first self-report questionnaire included general patient information and an overall assessment of the degree of satisfaction with the information received before the procedure. The level of pre-procedural anxiety was measured through the State-Trait Anxiety Inventory STAI-Y1 (state anxiety). The perceived stress was assessed using the Perceived Stress Scale (PSS). The intensity of pain during the procedure and 20 min later was assessed with VAS score.

RESULTS

The average waiting time was of 192.33 ± 91 min. 59 patients (56.7%) performed the examination without analgesia while 45 women (43.3%) required analgesia. 28 women (27%) experienced mild pain, 34 (33%) moderate pain and 42 (40%) severe pain. The patients who performed the procedure without analgosedation had an average STAI-Y1 score of 44.81 ± 1.20, compared to women who required analgosedation (average score of 49.40 ± 1.64). The perceived level of stress was also associated with the use of analgosedation. Patients who did not request any anesthetic intervention obtained a PSS average score of 16.66 ± 0.75, compared to the subgroup with anesthesia (score of 19.76 ± 0.90).

CONCLUSIONS

Anxiety represents a key element for the success of ambulatory hysteroscopy. The management of anxiety can reduce the request for analgesia with a consequent optimization of time, costs and safety.

Identification of predictors for acute postoperative pain after gynecological laparoscopy (STROBE-compliant article)

While the pain after gynecological laparoscopy is assumed to be minor, many women suffer from unexpected postoperative pain in the post-anesthesia care unit (PACU). Prior identification of these patients is significant for effective analgesia. Therefore, we sought to determine the predictors for acute postoperative pain after gynecological laparoscopy. The data of 280 patients undergoing gynecological laparoscopy were analyzed. Data included demographic characteristics, previous obstetric/gynecologic surgical history, menstruation pattern including dysmenorrhea severity, gynecological hormone administration history, and surgical data (surgical time, endometriosis severity, adhesion, drainage insertion, and surgery type). Univariate analysis and binary logistic regression were used to evaluate predictors for substantial pain in the PACU after gynecologic laparoscopy. Among the 280 patients, 115 (41%) suffered from substantial postoperative pain in the PACU. Whenever the level of dysmenorrhea became more severe (none → mild → moderate → severe), the risk of substantial pain in the PACU increased 2.9-fold (odds ratio [OR] 2.92, 95% confidence interval [CI] 2.11-4.03, P < .001). Moreover, patients undergoing laparoscopy for ectopic pregnancy had a higher risk of substantial pain compared with the others (OR 3.11, 95% CI 1.36-7.12, P = .007). Other factors did not show a significant association with substantial pain. Patients with preoperative severe dysmenorrhea and those undergoing laparoscopy for ectopic pregnancy should be considered to have a high risk of substantial postoperative pain in the PACU so that they receive prompt and aggressive analgesic intervention. In particular, dysmenorrhea severity is clinically valuable as a useful predictor for substantial pain after gynecological laparoscopy.

Identification of Functioning Domains in the Presurgical Period and Their Relationships with Opioid Use and Pain Catastrophizing

OBJECTIVES

The National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) is a multidimensional screening system evaluating biopsychosocial factors affecting pain and functioning. Using a military sample, the current study 1) examined the structure and domains of the PROMIS, the Defense and Veterans Pain Rating Scale 2.0 (DVPRS), and the Pain Catastrophizing Scale (PCS) within a presurgical setting and 2) examined the relationship of these variables to pre- and postsurgical opioid use.

METHODS

This cross-sectional study included 279 adult patients scheduled for surgery at the Walter Reed National Military Medical Center and a validation sample of 79 additional patients from the Naval Medical Center, San Diego. PROMIS, DVPRS, PCS, and opioid use data were collected before surgery. Exploratory factor analysis and confirmatory factor analysis identified the latent structure for the measures. A structural equation model (SEM) examined their relationship to pre- and postsurgical opioid use.

RESULTS

Two latent factors represented Psychosocial Functioning (PROMIS Depression, PROMIS Anxiety, and PROMIS Social Isolation) and Pain Impact (DVPRS, PROMIS Pain Interference, PROMIS Physical Functioning). The remaining PROMIS scales did not load onto a single factor. In the SEM, the two latent factors and PCS were significantly related to pre- and postsurgical opioid use.

CONCLUSIONS

This study highlights the utility and relative ease of using a convenient multidimensional assessment in presurgical settings. Using such an assessment can help provide targeted interventions for individuals who may be at greatest risk for negative postsurgical outcomes.

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

Background

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

Methods

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

Results

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

Conclusions

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

Pain, psychosocial tests, pain sensitization and laparoscopic pelvic surgery

BACKGROUND AND AIMS

Individuals with non-acute pain are challenged with variable pain responses following surgery as well as psychological challenges, particularly depression and catastrophizing. The purpose of this study was to compare pre- and postoperative psychosocial tests and the associated presence of sensitization on a cohort of women undergoing elective laparoscopic surgery for non-acute pain defined as pain sufficient for surgical investigation without persistent of chronic pain.

METHODS

The study was a secondary analysis of a previous report (Am J Obstet Gynecol 2014 Oct;211(4):360-8.). The study was a prospective cohort trial of 77 women; 61 with non-acute pain and 16 women for a tubal ligation. The women had the following tests: Pain Disability Index, Pain Catastrophizing Scale, CES-D (Center for Epidemiologic Studies Depression Scale) depression scale and the McGill Pain Scale (short form) as well as their average pain score and the presence of pain sensitization. All test scores were correlated together and comparisons were done using paired t-test.

RESULTS

There were reductions in pain and psychosocial test scores that were significantly correlated. Pre-operative sensitization indicated greater changes in psychosocial tests.

CONCLUSIONS

There was a close association of tests of psychosocial status with average pain among women having surgery on visceral tissues. Incorporation of these tests in the pre- and postoperative evaluation of women having laparoscopic surgery appears to provide a means to a broader understanding of the woman's pain experience.

Heat pain detection threshold is associated with the area of secondary hyperalgesia following brief thermal sensitization: a study of healthy male volunteers

Introduction

The area of secondary hyperalgesia following brief thermal sensitization (BTS) of the skin and heat pain detection thresholds (HPDT) may both have predictive abilities in regards to pain sensitivity and clinical pain states. The association between HPDT and secondary hyperalgesia, however, remains unsettled, and the dissimilarities in physiologic properties suggest that they may represent 2 distinctively different pain entities. The aim of this study was to investigate the association between HPDT and BTS-induced secondary hyperalgesia.

Methods

A sample of 121 healthy male participants was included and tested on 2 separate study days with BTS (45°C, 3 minutes), HPDT, and pain during thermal stimulation (45°C, 1 minute). Areas of secondary hyperalgesia were quantified after monofilament pinprick stimulation. The pain catastrophizing scale (PCS) and hospital anxiety and depression scale (HADS) were also applied.

Results

A significant association between HPDT and the size of the area of secondary hyperalgesia (p<0.0001) was found. The expected change in area of secondary hyperalgesia due to a 1-degree increase in HPDT was estimated to be −27.38 cm², 95% confidence interval (CI) of −37.77 to −16.98 cm², with an R² of 0.19. Likewise, a significant association between HADS-depression subscore and area of secondary hyperalgesia (p=0.046) was found, with an estimated expected change in secondary hyperalgesia to a 1-point increase in HADS-depression subscore of 11 cm², 95% CI (0.19–21.82), and with R² of 0.03. We found no significant associations between secondary hyperalgesia area and PCS score or pain during thermal stimulation.

Conclusion

HPDT and the area of secondary hyperalgesia after BTS are significantly associated; however, with an R² of only 19%, HPDT only offers a modest explanation of the inter-participant variation in the size of the secondary hyperalgesia area elicited by BTS.

Are preoperative experimental pain assessments correlated with clinical pain outcomes after surgery? A systematic review

BACKGROUND

Pain after surgery is not uncommon with 30% of patients reporting moderate to severe postoperative pain. Early identification of patients prone to postoperative pain may be a step forward towards individualized pain medicine providing a basis for improved clinical management through treatment strategies targeting relevant pain mechanisms in each patient. Assessment of pain processing by quantitative sensory testing (QST) prior to surgery has been proposed as a method to identify patients at risk for postoperative pain, although results have been conflicting. Since the last systematic review, several studies investigating the association between postoperative pain and more dynamic measures of pain processing like temporal summation of pain and conditioned pain modulation have been conducted.

OBJECTIVES

According to the PRISMA guidelines, the aim of this systematic review was to evaluate whether assessment of experimental pain processing including measures of central pain mechanisms prior to surgery was associated with pain intensity after surgery.

METHODS

Systematic database searches in PubMed and EMBASE with the following search components: QST, association, and postoperative pain, for studies that assessed the association between QST and pain after surgery were performed. Two authors independently reviewed all titles and abstracts to assess their relevance for inclusion. Studies were included if (1) QST was performed prior to surgery, (2) pain was assessed after surgery, and (3) the association between QST and pain after surgery was investigated. Forty-four unique studies were identified, with 30 studies on 2738 subjects meeting inclusion criteria. The methodological quality of the include studies was assessed and data extraction included study population, type of surgery, QST variables, clinical pain outcome measure and main result.

RESULTS

Most studies showed moderate to high risk of bias. Type of surgery investigated include 7 studies on total knee replacement, 5 studies on caesarean section, 4 studies on thoracic surgery, 2 studies on herniotomy, 2 studies on hysterectomy/myomectomy, 1 study on tubal ligation, 1 study on gynecologic laparoscopy, 1 study on arthroscopic knee surgery, 1 study on shoulder surgery, 1 study on disc herniation surgery, 1 study on cholecystectomy, 1 study on percutaneous nephrolithotomy, 1 study on molar surgery, 1 study on abdominal surgery, and 1 study on total knee replacement and total hip replacement. The majority of the preoperative QST variables showed no consistent association with pain intensity after surgery. Thermal heat pain above the pain threshold and temporal summation of pressure pain were the QST variables, which showed the most consistent association with acute or chronic pain after surgery.

CONCLUSIONS

QST before surgery does not consistently predict pain after surgery. High quality studies investigating the presence of different QST variables in combination or along with other pain-related psychosocial factors are warranted to confirm the clinical relevance of QST prior to surgery.

IMPLICATIONS

Although preoperative QST does not show consistent results, future studies in this area should include assessment of central pain mechanisms like temporal summation of pressure pain, conditioned pain modulation, and responses to pain above the pain threshold since these variables show promising associations to pain after surgery.

Laparoscopic surgery: a narrative review of pharmacotherapy in pain management

Laparoscopic surgery is widespread, and an increasing number of surgeries are performed laparoscopically. Early pain after laparoscopy can be similar or even more severe than that after open surgery. Thus, proactive pain management should be provided. Pain after laparoscopic surgery is derived from multiple origins; therefore, a single agent is seldom sufficient. Pain is most effectively controlled by a multimodal, preventive analgesia approach, such as combining opioids with non-opioid analgesics and local anaesthetics. Wound and port site local anaesthetic injections decrease abdominal wall pain by 1-1.5 units on a 0-10 pain scale. Inflammatory pain and shoulder pain can be controlled by NSAIDs or corticosteroids. In some patient groups, adjuvant drugs, ketamine and α2-adrenergic agonists can be helpful, but evidence on gabapentinoids is conflicting. In the present review, the types of pain that need to be taken into account while planning pain management protocols and the wide range of analgesic options that have been assessed in laparoscopic surgery are critically assessed. Recommendations to the clinician will be made regarding how to manage acute pain and how to prevent persistent postoperative pain. It is important to identify patients at the highest risk for severe and prolonged post-operative pain, and to have a proactive strategy in place for these individuals.

Preoperative state anxiety, acute postoperative pain, and analgesic use in persons undergoing lower limb amputation

OBJECTIVES

The current study examined the relationship between preoperative anxiety and acute postoperative phantom limb pain (PLP), residual limb pain (RLP), and analgesic medication use in a sample of persons undergoing lower limb amputation.

MATERIALS AND METHODS

Participants included 69 adults admitted to a large level 1 trauma hospital for lower limb amputation. Participants' average pain and anxiety during the previous week were assessed before amputation surgery. RLP, PLP, and analgesic medication use were measured on each of the 5 days following amputation surgery.

RESULTS

Results of partial-order correlations indicated that greater preoperative anxiety was significantly associated with greater ratings of average PLP for each of the 5 days following amputation surgery, after controlling for preoperative pain ratings and daily postoperative analgesic medication use. Partial correlation values ranged from 0.30 to 0.62, indicating medium to large effects. Preoperative anxiety was also significantly associated with ratings of average RLP only on postoperative day 1, after controlling for preoperative pain ratings and daily postoperative analgesic medication use (r=0.34, P<0.05). Correlations between preoperative anxiety and daily postoperative analgesic medication dose became nonsignificant when controlling for preamputation and postamputation pain ratings.

DISCUSSION

These findings suggest that anxiety may be a risk factor for acute postamputation PLP and RLP, and indicate that further research to examine these associations is warranted. If replicated, the findings would support research to examine the extent to which modifying preoperative anxiety yields a reduction in postoperative acute PLP and RLP.

Does preoperative psychological status of patients affect postoperative pain? A prospective study from the Caribbean

OBJECTIVES

Patients with high anxiety states in the preoperative period often have more intense postoperative pain, despite adequate pain control during the intraoperative period. This study aimed to determine the relationship between the preoperative psychological status and the pain experienced postoperatively in a sample of Caribbean patients.

DESIGN AND METHODS

A prospective study was conducted in elective surgical adult patients at a teaching hospital in the Caribbean. Patients' preoperative psychological status was assessed using Hospital Anxiety and Depression Scale (HADS), and a preoperative 'expected' pain score was recorded. Postoperatively, 'observed' pain scores at 4 and 24 hours and the maximum pain score during 24 hours were recorded. Demographic data and clinical details including data regarding postoperative analgesia were collected. Expected and observed pain scores were compared between patients with and without anxiety and depression.

RESULTS

A total of 304 patients were enrolled. The overall prevalence of anxiety and depression was 43% and 27%, respectively, based on the HADS scores. There were significant associations between the postoperative pain scores and factors such as preoperative anxiety and depression (HADS) scores, preoperative expected pain scores, patient educational level, presence of preoperative pain and surgical duration. Age, gender, ethnicity and type of anaesthesia did not impact postoperative pain scores.

CONCLUSION

The presence of preoperative anxiety and depression as indicated by HADS score may significantly influence postoperative pain. Other factors such as educational level, presence of preoperative pain and surgical duration may also impact postoperative pain. Some of these factors may be modifiable and must be addressed in the preoperative period.

Prediction of postoperative pain from assessment of pain induced by venous cannulation and propofol infusion

BACKGROUND

Postoperative pain may lead to delayed mobilization, persisting pain, and psychosocial distress. There are no simple and reliable techniques for prediction of postoperative pain. This study was designed to evaluate if pain induced by venous cannulation or propofol injection can be used to predict postoperative pain.

METHODS

This prospective study included 180 patients scheduled for laparoscopic cholecystectomy. Pain intensity associated with peripheral venous cannulation and administration of propofol preoperatively and pain intensity, and use of opioid postoperatively was recorded.

RESULTS

Patients scoring cannulation-induced pain intensity > 2.0 VAS units were given postoperative opioid more often (65% vs. 36%; P < 0.001), earlier (12 min vs. 90 min; P < 0.001), and in higher doses (4.8 mg vs. 0 mg; P < 0.001), and also reported higher levels of postoperative pain intensity (5.8 vs. 2.9 VAS units; P < 0.001). There were also significant (P < 0.01) correlations with postoperative pain intensity (rs = 0.24), time to opioid administration (rs = -0.26), and total dose of opioid (rs = 0.25). Propofol-induced pain intensity correlated significantly (P < 0.05) with postoperative pain intensity (rs = 0.19).

CONCLUSION

Pain intensity associated with venous cannulation and propofol infusion can easily be evaluated at bedside before surgery without specific equipment or training. Patients scoring > 2.0 VAS units on venous cannulation were found to have 3.4 times higher risk of postoperative pain after laparoscopic cholecystectomy. Low pain intensity associated with venous cannulation and propofol infusion indicate lower risk of postoperative pain.

Pain Duration and Resolution following Surgery: An Inception Cohort Study

OBJECTIVE

Preoperative determinants of pain duration following surgery are poorly understood. We identified preoperative predictors of prolonged pain after surgery in a mixed surgical cohort.

METHODS

We conducted a prospective longitudinal study of patients undergoing mastectomy, lumpectomy, thoracotomy, total knee replacement, or total hip replacement. We measured preoperative psychological distress and substance use, and then measured pain and opioid use after surgery until patients reported the cessation of both opioid consumption and pain. The primary endpoint was time to opioid cessation, and those results have been previously reported. Here, we report preoperative determinants of time to pain resolution following surgery in Cox proportional hazards regression.

RESULTS

Between January 2007 and April 2009, we enrolled 107 of 134 consecutively approached patients undergoing the aforementioned surgical procedures. In the final multivariate model, preoperative self-perceived risk of addiction predicted more prolonged pain. Unexpectedly, anxiety sensitivity predicted more rapid pain resolution after surgery. Each one-point increase (on a four point scale) of self-perceived risk of addiction was associated with a 38% (95% CI 3-61) reduction in the rate of pain resolution (P = 0.04). Furthermore, higher anxiety sensitivity was associated with an 89% (95% CI 23-190) increased rate of pain resolution (P = 0.004).

CONCLUSIONS

Greater preoperative self-perceived risk of addiction, and lower anxiety sensitivity predicted a slower rate of pain resolution following surgery. Each of these factors was a better predictor of pain duration than preoperative depressive symptoms, post-traumatic stress disorder symptoms, past substance use, fear of pain, gender, age, preoperative pain, or preoperative opioid use.

Anxiety at outpatient hysteroscopy

This review summarises current understanding and research on the association between anxiety and outpatient hysteroscopy. Women undergoing hysteroscopy suffer from significant levels of anxiety, with repercussions on pain perception, success rates and satisfaction. Using validated tools such as the Spielberger State-Trait Anxiety Index (STAI) or the Hospital Anxiety and Depression Scale (HADS) in the outpatient hysteroscopy setting, average state anxiety scores similar or greater than those measured before more invasive procedures under general anaesthesia have been consistently reported. This clearly suggests a significant gap between our clinical viewpoint of what is "minimally invasive" and patients' expectations. In spite of its potential role of confounder in studies on pain-reduction interventions, we found that patient anxiety was evaluated in only 9 (13 %) out of a sample of 70 randomised controlled trials on outpatient hysteroscopy published since 1992. Factors such as trait anxiety, age, indication and the efficiency of the clinic can be correlated to state anxiety before hysteroscopy, but more robust data are needed. Promising non-pharmacological interventions to reduce anxiety at hysteroscopy include patient education, communication through traditional or multimedia approaches, interaction and support during the procedure and music listening.

Prediction of postoperative pain after gynecologic laparoscopy for nonacute pelvic pain

OBJECTIVE

The primary objectives of this study were to explore the pain experience after gynecologic laparoscopy that is performed for nonacute pain conditions and to determine whether preoperative psychologic tests and quantitative tests of sensitization can predict postoperative pain.

STUDY DESIGN

Participants included 61 women who underwent laparoscopy for nonacute pain (n = 61). A second group of 16 women who had undergone tubal ligation was included to explore whether laparoscopy induced a painful postoperative response in women without preoperative pain. Subjective tests included numeric pain scale, pain catastrophizing scale, depression scale, global assessment of change, and the McGill Pain Questionnaire Short Form. Quantitative sensory testing included abdominal cutaneous allodynia, trigger points, and reduced pain thresholds. The nonacute pain sample had 80% power to detect a difference of 0.5 standard deviation in average pain levels. Analysis included parametric and nonparametric comparisons of groups and univariate and linear regression analysis of clinically relevant variables.

RESULTS

In women who underwent tubal ligation, pain levels were low before and after the procedure. In women who underwent surgery for nonacute pain, pain levels at 6 months and all psychologic test scores were reduced significantly compared with baseline (P < .001 and P = .001, respectively). Among those women with positive results on the quantitative pain tests of sensitization at baseline, average postoperative pain was also significantly reduced (P < .001). Univariate analysis demonstrated only tests of sensitization that were correlated with change in average pain level (P = .01). Regression analysis suggested that baseline pain, catastrophizing, and the presence of cutaneous allodynia significantly predicted pain levels 6 months after surgery (P < .001).

CONCLUSION

Pain after laparoscopic surgery for nonacute painful conditions can be predicted by baseline pain, catastrophizing, and the presence of allodynia, which is a simple swab test that indicates sensitization.

The Val158Met polymorphism of the COMT gene is associated with increased pain sensitivity in morphine-treated patients undergoing a painful procedure after cardiac surgery

AIMS

The catechol-O-methyltransferase (COMT) Val158Met polymorphism affected pain sensitivity of healthy volunteers upon application of experimental pain stimuli. The relevance of these findings in morphine-treated postoperative cardiac patients undergoing painful healthcare procedures is unknown; therefore, the aim of this study was to investigate whether the COMT Val158Met polymorphism increases pain sensitivity in morphine-treated patients undergoing an unavoidable painful routine procedure after cardiac surgery.

METHODS

One hundred and seventeen postoperative cardiac patients in the intensive care unit were genotyped for the COMT Val158Met polymorphism. All patients were treated with continuous morphine infusions for pain at rest, and received a bolus of morphine (2.5 or 7.5 mg) before a painful procedure (turning and/or chest drain removal) on the first postoperative day. Numerical rating scale (NRS) scores were evaluated at the following four time points: at baseline (at rest), and before, during and after the painful procedure.

RESULTS

Overall mean NRS scores were significantly higher in patients carrying the Met-variant allele. During the painful procedure, the mean NRS score was significantly higher for Met/Met patients compared with Val/Met and Val/Val patients (mean NRS 3.4 ± 2.8, 2.7 ± 2.4 and 1.7 ± 1.7, respectively; P = 0.04). In Met/Met patients, the increase in NRS scores during the painful procedure compared with the baseline NRS score was clinically relevant (ΔNRS ≥ 1.3) and statistically significant and appeared to be independent of sex and the morphine bolus dose.

CONCLUSIONS

Our results show that the COMT Val158Met polymorphism contributes to variability in pain sensitivity after cardiac surgery of morphine-treated patients in the intensive care unit, because Met-allele carriers were more sensitive to overall pain and procedure-related pain.

Development of the Stanford Expectations of Treatment Scale (SETS): A tool for measuring patient outcome expectancy in clinical trials

Background

A patient’s response to treatment may be influenced by the expectations that the patient has before initiating treatment. In the context of clinical trials, the influence of participant expectancy may blur the distinction between real and sham treatments, reducing statistical power to detect specific treatment effects. There is therefore a need for a tool that prospectively predicts expectancy effects on treatment outcomes across a wide range of treatment modalities.

Purpose

To help assess expectancy effects, we created the Stanford Expectations of Treatment Scale (SETS): an instrument for measuring positive and negative treatment expectancies. Internal reliability of the instrument was tested in Study 1. Criterion validity of the instrument (convergent, discriminant, and predictive) was assessed in Studies 2 and 3.

Methods

The instrument was developed using 200 participants in Study 1. Reliability and validity assessments were made with an additional 423 participants in Studies 2 and 3.

Results

The final six-item SETS contains two subscales: positive expectancy (α = 0.81–0.88) and negative expectancy (α = 0.81–0.86). The subscales predict a significant amount of outcome variance (between 12% and 18%) in patients receiving surgical and pain interventions. The SETS is simple to administer, score, and interpret.

Conclusion

The SETS may be used in clinical trials to improve statistical sensitivity for detecting treatment differences or in clinical settings to identify patients with poor treatment expectancies.

Environmental impact of minimally invasive surgery in the United States: an estimate of the carbon dioxide footprint

PURPOSE

To attempt to quantitate the carbon footprint of minimally invasive surgery (MIS) through approximated scope 1 to 3 CO(2) emissions to identify its potential role in global warming.

PATIENTS AND METHODS

To estimate national usage, we determined the number of inpatient and outpatient MIS procedures using International Classification of Diseases, ninth revision-clinical modification codes for all MIS procedures in a 2009 sample collected in national databases. Need for surgery was considered essential, and therefore traditional open surgery was used as the comparator. Scope 1 (direct) CO(2) emissions resulting from CO(2) gas used for insufflation were based on both escaping procedural CO(2) and metabolic CO(2) eliminated via respiration. Scopes 2 and 3 (indirect) emissions related to capture, compression, and transportation of CO(2) to hospitals and the disposal of single-use equipment not used in open surgery were calculated.

RESULTS

The total CO(2) emissions were calculated to be 355,924 tonnes/year. For perspective, if MIS in the United States was considered a country, it would rank 189 th on the United Nations 2008 list of countries' carbon emissions per year. Limitations include the inability to account for uncertainty using the various models and tools for approximating CO(2) emissions.

CONCLUSION

CO(2) emission of MIS in the United States may have a significant environmental impact. This is the first attempt to quantify CO(2) emissions related to MIS in the United States. Strategies for reduction, while maintaining high quality medical care, should be considered.

Prediction of pain sensitivity in healthy volunteers

PURPOSE

The primary objective of the present study was to evaluate predictive parameters of the acute pain score during induction of an inflammatory heat injury.

PATIENTS AND METHODS

Healthy volunteers (50 females/50 males) were included in the study. The predictive potential of gender, anthropometric (body surface area, body mass index), psychological (anxiety, depression, vulnerability), and psychophysical (quantitative sensory testing, conditioned pain modulation) variables in estimating the pain response to a validated heat injury (47°C, 7 minutes, area 12.5 cm(2)) were investigated. All assessments were made in duplicate sessions separated by 21 days (median).

RESULTS

There were three main findings in this study. First, a predictive model of pain sensitivity during the heat injury, including both genders and using multiple regression technique, could account for 28% of the variance (P < 0.0001), but gender-related differences in the final model could not be demonstrated. Second, the results confirmed significant gender-related differences in perception of electrical, pressure, and cold pressor stimuli (P < 0.002). Third, positive correlations between anthropometric data and pain perception during electrical and pressure stimuli were demonstrated (P < 0.001 and P < 0.005, respectively).

CONCLUSION

The study demonstrated predictability of acute pain sensitivity, and although gender-related differences in pain perception were demonstrated, no gender-related differences in pain sensitivity could be shown. Interestingly, positive correlations between anthropometric data and pain perception were shown for the first time.

Predictors of postoperative movement and resting pain following total knee replacement

This study determined preoperative predictors of movement and resting pain following total knee replacement (TKR). We hypothesized that younger patients with higher preoperative pain intensity, pain sensitivity, trait anxiety, pain catastrophizing, and depression would be more likely to experience higher postoperative movement pain than older patients with lower scores on these variables prior to surgery, and that predictors would be similar for resting pain. Demographics, analgesic intake, anxiety, depression, pain catastrophizing, resting pain, movement pain (ie, during active knee range of motion), and quantitative sensory tests were performed preoperatively on 215 participants scheduled for a unilateral TKR. On postoperative day 2, analgesic intake, resting pain, and movement pain were again assessed. Significant predictors of moderate or severe movement pain were higher preoperative movement pain, von Frey pain intensity, and heat pain threshold. People with severe movement pain preoperatively were 20 times more likely to have severe movement pain postoperatively. When the influence of preoperative movement pain was removed, depression became a predictor. Significant predictors of moderate to severe resting pain were higher preoperative resting pain, depression, and younger age. These results suggest that patients with higher preoperative pain and depression are more likely to have higher pain following TKR, and younger patients may have higher resting pain. Cutaneous pain sensitivity predicted movement pain but not resting pain, suggesting that mechanisms underlying movement pain are different from resting pain. Aggressive management of preoperative pain, pain sensitivity, and depression prior to surgery may facilitate postoperative recovery.

The Transition from Acute to Chronic Post Surgical Pain

All chronic pain was once acute, but not all acute pain becomes chronic. The transition of acute postoperative pain to chronic post surgical pain is a complex and poorly understood developmental process. The manuscript describes the various factors associated with the transition from acute to chronic pain. The preoperative, intraoperative and postoperative surgical, psychosocial, socio-environmental and patient-related factors and the mechanisms involved are discussed and preventive (or limitation) strategies are suggested. In future, the increasing understanding of genetic factors and the transitional mechanisms involved may reveal important clues to predict which patients will go on to develop chronic pain. This may assist the development of appropriate interventions affecting not only the individual concerned, but also ultimately the community at large.

[Predictive factors and prevention of chronic postoperative pelvic and perineal pain]

INTRODUCTION

Chronic postoperative pain has been defined as pain arising after a surgical operation, present for at least 2 months, with no organic (active cancer or chronic infection) or preexisting cause. The purpose of this article is to review the risk factors and prevention of chronic postoperative pelvic and perineal pain.

MATERIAL AND METHODS

A review of the literature was performed by searching PubMed for articles on risk factors and prevention of chronic postoperative pelvic and perineal pain.

RESULTS

Chronic postoperative pain is frequent, disabling and represent a high cost to the community. This pain is generated by variable and complex interactions between the surgical procedure (the operated zone, perioperative management, the disease requiring the operative procedure) and the patient (age, gender, genetics, concomitant diseases, personal history). The multifactorial nature of chronic postoperative pain suggests the need for multidisciplinary management with prevention and reduction of the main risk factors. Similarly, appropriate management of acute postoperative pain has a major impact on the risk of chronic pain.

CONCLUSION

A good knowledge of the risk factors and appropriate prevention can decrease the incidence and consequences of chronic postoperative pain.