Incidence and risk factors for chronic pain after caesarean section under spinal anaesthesia

Brief Assessment of Patient Phenotype to Explain Variability in Postsurgical Pain and Opioid Consumption after Cesarean Delivery: Performance of a Novel Brief Questionnaire Compared to Long Questionnaires

BACKGROUND

Understanding factors that explain why some women experience greater postoperative pain and consume more opioids after cesarean delivery is crucial to building an evidence base for personalized prevention. Comprehensive psychosocial assessment with validated questionnaires in the preoperative period can be time-consuming. A three-item questionnaire has shown promise as a simpler tool to be integrated into clinical practice, but its brevity may limit the ability to explain heterogeneity in psychosocial pain modulators among individuals. This study compared the explanatory ability of three models: (1) the 3-item questionnaire, (2) a 58-item questionnaire (long) including validated questionnaires (e.g., Brief Pain Inventory, Patient Reported Outcome Measurement Information System [PROMIS]) plus the 3-item questionnaire, and (3) a novel 19-item questionnaire (brief) assessing several psychosocial factors plus the 3-item questionnaire. Additionally, this study explored the utility of adding a pragmatic quantitative sensory test to models.

METHODS

In this prospective, observational study, 545 women undergoing cesarean delivery completed questionnaires presurgery. Pain during local anesthetic skin wheal before spinal placement served as a pragmatic quantitative sensory test. Postoperatively, pain and opioid consumption were assessed. Linear regression analysis assessed model fit and the association of model items with pain and opioid consumption during the 48 h after surgery.

RESULTS

A modest amount of variability was explained by each of the three models for postoperative pain and opioid consumption. Both the brief and long questionnaire models performed better than the three-item questionnaire but were themselves statistically indistinguishable. Items that were independently associated with pain and opioid consumption included anticipated postsurgical pain medication requirement, surgical anxiety, poor sleep, pre-existing pain, and catastrophic thinking about pain. The quantitative sensory test was itself independently associated with pain across models but only modestly improved models for postoperative pain.

CONCLUSIONS

The brief questionnaire may be more clinically feasible than longer validated questionnaires, while still performing better and integrating a more comprehensive psychosocial assessment than the three-item questionnaire.

EDITOR’S PERSPECTIVE

Outcomes and outcome measures utilised in randomised controlled trials of postoperative caesarean delivery pain: a scoping review

BACKGROUND

Inadequately treated postoperative pain following caesarean delivery can delay recovery and the ability to care for a newborn. Effectiveness studies of interventions to treat postoperative caesarean delivery pain measure different outcomes, limiting data pooling for meta-analysis. We performed a comprehensive review of existing outcomes with the aim of recommending core outcomes for future research.

METHODS

A scoping review to identify all outcomes reported in randomised controlled trials (RCTs) and clinical trial registries of interventions to treat or prevent postoperative caesarean delivery pain, with postoperative pain as a primary outcome measure. We searched PubMed, Web of Science, CINAHL, LILACS, Embase, CDSR and CRCT for studies from May 2016 to 2021. Outcomes were extracted and frequencies tabulated.

RESULTS

Ninety RCTs and 11 trial registries were included. In total, 392 outcomes (375 inpatient and 17 outpatient) were identified and categorised. The most reported outcome domain was analgesia (n = 242/375, 64.5%), reported in 96% of inpatient studies, with analgesic consumption accounting for 108/375, 28.8% of analgesia outcomes. The second most common domain was pain intensity (n = 120/375, 32%), reported in 97% of inpatient studies, using the visual analogue scale (68/120, 59%) and the numerical reporting scale (37/120, 25%). Maternal and neonatal adverse effects accounted for 65/375 (17.3%) and 19/375 (5.1%) of inpatient outcomes, respectively.

CONCLUSIONS

Outcomes reported in RCTs for postoperative caesarean delivery pain vary widely. The results of this review suggest that standardisation is needed to promote research efficiency and aid future meta-analyses to identify optimal postoperative caesarean delivery pain management.

Persistent Postpartum Pain - A Somatic and Psychologic Perfect Storm

Persistent postpartum pain is common and has a complex etiology. It has both somatic and psychosocial provoking factors and has both functional and psychological ramifications following childbirth. Pain that limits the functional capacity of a person who has the daunting task to take care of all the demands of managing a growing newborn and infant can have debilitating consequences for several people simultaneously. We will review the incidence of persistent postpartum pain, analyze the risk factors, and discuss obstetric, anesthetic, and psychological tools for prevention and management. Based on the current knowledge, early antenatal screening and management is described as the most likely measure to identify patients at risk for persistent postpartum pain. Such antenatal management should be based on the close collaboration between obstetricians, anesthesiologists, and psychologists to tailor peripartum pain management and psychological support-based individual needs.

Cognitive-Affective-Behavioral Pathways Linking Adversity and Discrimination to Daily Pain in African-American Adults

The tendency to ruminate, magnify, and experience helplessness in the face of pain - known as pain catastrophizing - is a strong predictor of pain outcomes and is associated with adversity. The ability to maintain functioning despite adversity - referred to as resilience - also influences pain outcomes. Understanding the extent to which pain catastrophizing and resilience influence relations between adversity and daily pain in healthy African-American adults could improve pain risk assessment and mitigate racial disparities in the transition from acute to chronic pain. This study included 160 African-American adults (98 women). Outcome measures included daily pain intensity (sensory, affective) and pain impact on daily function (pain interference). Adversity measures included childhood trauma exposure, family adversity, chronic burden from recent stressors, and ongoing perceived stress. A measure of lifetime racial discrimination was also included. Composite scores were created to capture early-life adversity (childhood trauma, family adversity) versus recent-life adversity (perceived stress, chronic burden). Increased pain catastrophizing was correlated with increased adversity (early and recent), racial discrimination, pain intensity, and pain interference. Decreased pain resilience was correlated with increased recent-life adversity (not early-life adversity or racial discrimination) and correlated with increased pain intensity (not pain-related interference). Bootstrapped multiple mediation models revealed that relationships between all adversity/discrimination and pain outcomes were mediated by pain catastrophizing. Pain resilience, however, was not a significant mediator in these models. These findings highlight opportunities for early interventions to reduce cognitive-affective-behavioral risk factors for persisting daily pain among African-American adults with greater adversity exposure by targeting pain catastrophizing.

Inflammatory changes in the plasma and cerebrospinal fluid of patients with persistent pain and postpartum depression after elective Cesarean delivery: an exploratory prospective cohort study

PURPOSE

Severe acute pain after Cesarean delivery increases the risk of developing persistent pain (~20% incidence) and postpartum depression (PPD) (~15% incidence). Both conditions contribute to maternal morbidity and mortality, yet early risk stratification remains challenging. Neuroinflammation has emerged as a key mechanism of persistent pain and depression in nonobstetric populations. Nevertheless, most studies focus on plasma cytokines, and the relationship between plasma and cerebrospinal fluid (CSF) cytokine levels is unclear. Our primary aim was to compare inflammatory marker levels between patients who developed the composite outcome of persistent pain and/or PPD vs those who did not.

METHODS

We recruited term patients with singleton pregnancies undergoing elective Cesarean delivery under neuraxial anesthesia into an exploratory prospective cohort study. We collected baseline demographic, obstetric, and Edinburgh Postnatal Depression Scale information, and performed quantitative sensory tests. Plasma was collected preoperatively and 48 hr postoperatively. In the operating room, 10 mL of CSF was collected, followed by a standardized anesthetic. Intra- and postoperative management were according to standard practice. We obtained Edinburgh Postnatal Depression Scale and pain scores at six weeks and three months after delivery. The primary outcome was persistent pain and/or PPD at three months. We analyzed the difference in inflammatory marker levels between the groups (primary aim) using two-sided Mann-Whitney tests.

RESULTS

Eighty participants were enrolled, and 63 patients completed the study; 23 (37%) experienced the primary outcome at three months. Preoperative plasma transforming growth factor beta 1 (TGF-β1) concentration was higher in patients who developed the primary outcome compared with those who did not (median [interquartile range (IQR)], 2,879 [2,241-5,494] vs 2,292 [1,676-2,960] pg·mL-1; P = 0.04), while CSF IL-1β concentration was higher in patients who developed the primary outcome than in those who did not (median [IQR], 0.36 [0.29-0.39] vs 0.30 [0.25-0.35] pg·mL-1; P = 0.03).

CONCLUSIONS

We observed differential levels of plasma and CSF inflammatory biomarkers in patients who developed persistent pain and PPD compared with those who did not. We showed the feasibility of collecting plasma and CSF samples at Cesarean delivery, which may prove useful for future risk-stratification.

STUDY REGISTRATION

ClinicalTrials.gov (NCT04271072); registered 17 February 2020.

Impact of a Transitional Pain Service on postoperative opioid trajectories: a retrospective cohort study

INTRODUCTION

It has been well described that a small but significant proportion of patients continue to use opioids months after surgical discharge. We sought to evaluate postdischarge opioid use of patients who were seen by a Transitional Pain Service compared with controls.

METHODS

We conducted a retrospective cohort study using administrative data of individuals who underwent surgery in Ontario, Canada from 2014 to 2018. Matched cohort pairs were created by matching Transitional Pain Service patients to patients of other academic hospitals in Ontario who were not enrolled in a Transitional Pain Service. Segmented regression was performed to assess changes in monthly mean daily opioid dosage.

RESULTS

A total of 209 Transitional Pain Service patients were matched to 209 patients who underwent surgery at other academic centers. Over the 12 months after surgery, the mean daily dose decreased by an estimated 3.53 morphine milligram equivalents (95% CI 2.67 to 4.39, p<0.001) per month for the Transitional Pain Service group, compared with a decline of only 1.05 morphine milligram equivalents (95% CI 0.43 to 1.66, p<0.001) for the controls. The difference-in-difference change in opioid use for the Transitional Pain Service group versus the control group was -2.48 morphine milligram equivalents per month (95% CI -3.54 to -1.43, p=0.003).

DISCUSSION

Patients enrolled in the Transitional Pain Service were able to achieve opioid dose reduction faster than in the control cohorts. The difficulty in finding an appropriate control group for this retrospective study highlights the need for future randomized controlled trials to determine efficacy.

Integrating mechanistic-based and classification-based concepts into perioperative pain management: an educational guide for acute pain physicians

Chronic pain begins with acute pain. Physicians tend to classify pain by duration (acute vs chronic) and mechanism (nociceptive, neuropathic and nociplastic). Although this taxonomy may facilitate diagnosis and documentation, such categories are to some degree arbitrary constructs, with significant overlap in terms of mechanisms and treatments. In clinical practice, there are myriad different definitions for chronic pain and a substantial portion of chronic pain involves mixed phenotypes. Classification of pain based on acuity and mechanisms informs management at all levels and constitutes a critical part of guidelines and treatment for chronic pain care. Yet specialty care is often siloed, with advances in understanding lagging years behind in some areas in which these developments should be at the forefront of clinical practice. For example, in perioperative pain management, enhanced recovery protocols are not standardized and tend to drive treatment without consideration of mechanisms, which in many cases may be incongruent with personalized medicine and mechanism-based treatment. In this educational document, we discuss mechanisms and classification of pain as it pertains to commonly performed surgical procedures. Our goal is to provide a clinical reference for the acute pain physician to facilitate pain management decision-making (both diagnosis and therapy) in the perioperative period.

Association of pain, analgesic, psychological, and socioeconomic factors with sub-acute pain after childbirth: A prospective cohort study

STUDY OBJECTIVE

To determine if acute postpartum pain, psychological distress, socioeconomic factors, and labor analgesia were associated with sub-acute pain after childbirth (SAPC; pain starting after childbirth and lasting between four weeks to three months).

DESIGN

Prospective cohort study, from pre-conception to post-partum three months.

SETTING

Singapore's major public maternity institution.

PATIENTS

We included women planning to conceive within a year. We excluded women who were pregnant, taking chemotherapy or psychotropic medications, had diabetes mellitus, received assisted fertility interventions or contraception, did not conceive after 12 months, with multiple pregnancies, or who developed obstetric complications.

INTERVENTIONS

None.

MEASUREMENTS

We investigated the relationship between average pain score during the three days after childbirth (primary exposure) and incidence of SAPC at postpartum three months (primary outcome). Secondarily, psychological distress at pre-conception (Beck Depression Inventory (BDI), Edinburgh Postnatal Depression Scale (EPDS), State-Trait Anxiety Inventory (STAI), Perceived Stress Scale (PSS), General Health Questionnaire-12 (GHQ-12), Life Experiences Survey (LES)) and second trimester of pregnancy (BDI, EPDS, STAI, PSS, Pregnancy Experience Scale (PES)) were assessed. Baseline maternal and socioeconomic characteristics, labor analgesia, maternal and neonatal outcomes were also collected accordingly.

MAIN RESULTS

Of 317 women who met the study criteria, 30 (9.5%) developed SAPC. Higher average pain score during the three days after childbirth (adjusted odds ratio (aOR) 1.46, 95% CI 1.17 to 1.82, p = 0.001), use of meperidine for labor analgesia (aOR 4.23, 95% CI 1.03 to 17.43, p = 0.046), higher pre-conception GHQ-12 score (aOR 1.14, 95% CI 1.03 to 1.27, p = 0.013), and lack of employment with income during pregnancy (aOR 9.62, 95% CI 3.07 to 30.30, p < 0.001) were independently associated with SAPC, with area under the curve (AUC) of 0.837.

CONCLUSIONS

Higher acute postpartum pain scores, use of meperidine for labor analgesia, poorer pre-conception general psychological health, and lack of employment with income during pregnancy are associated with SAPC.

Is ABO Blood Group a Predictive Factor for the Amount of Opioid Consumption in the First 24 Hours After Cesarean Section?

Background

Cesarean section is the most common major surgery performed globally. Blood group O has been found as a factor affecting pain severity after cesarean section. We aimed to evaluate the predictive factors, including ABO blood group, for the amount of opioid consumption (measured as milligrams of morphine equivalent [MME]) within the first 24 hrs after cesarean section.

Methods

This retrospective study was done in 1530 pregnant women who had a cesarean section under the same regimen of spinal anesthesia (2.2 mL of 0.5% hyperbaric bupivacaine and morphine 0.2 mg). All were prescribed regular paracetamol and ibuprofen for postoperative pain control. Univariate and multinomial regression analyses were performed to identify the predictive factors for opioid consumption in the first 24 hrs postoperatively.

Results

About 2/5 of them (43.3%) received 0 mg MME, while 25.6%, 23.7% and 7.4% received 1–5, 6–10 and >10 mg MME, respectively. The majority have blood group O (40.6%), while 23.4%, 28% and 8% have blood group A, B and AB, respectively. After univariate and multinomial regression analyses, operation time, opioid consumption in PACU, maximum VNRS within the first 24 hrs and consumption of both paracetamol and ibuprofen were identified as predictive factors for postoperative opioid consumption. ABO blood group exhibited no correlation for opioid requirement postoperatively.

Conclusion

ABO blood group is not a predictive factor for opioid requirement within the first 24 hrs following cesarean section. Duration of operation, opioid given in PACU, maximum VNRS on ward and consumption of both paracetamol and ibuprofen have been found to be predictive factors for postcesarean opioid requirement.

The use of perineural dexamethasone and transverse abdominal plane block for postoperative analgesia in cesarean section operations under spinal anesthesia: an observational study

Background

During transverses abdominal plane block (TAP) procedure to provide analgesia in cesarean section (CS) operation, the use of perineural dexamethasone as an additive agent may improve pain relief and may cause a prolonged block duration. This study aims to investigate whether perineural dexamethasone, when added to bupivacaine local anesthetic agent during a TAP block, may provide adequate pain relief without adverse events.

Methods

This is a prospective cohort study of fifty-eight patients undergoing elective CS with spinal anesthesia. We hypothesized to perform bilateral TAP block using perineural dexamethasone as an additive agent. The patients were randomly divided into two groups using a systematic random sampling method. While one group of patients received perineural dexamethasone of 8 mg additive agent together with bupivacaine 0.25% 40 ml (Group TAPD), the other group received only bupivacaine 0.25% 40 ml in TAP block (Group TAPA). The primary outcomes are the period for the first request of postoperative pain relief medication and the numerical rating scale (NRS) pain intensity scores at 2, 6, 12, and 24 h after surgery. The secondary outcomes are comparing the 24-h tramadol and diclofenac analgesic requirements and the incidences of side effects on postoperative day one. A p-value of < 0.05 is statistically significant.

Results

The time to first analgesic request was 8.5 h (8.39–9.79) in the TAPD group versus 5.3 h (5.23–5.59) in the TAPA group, respectively. (p < 0.001) The median NRS scores were significantly reduced in the TAPD group compared to the TAPA group at 6, 12, and 24 h after surgery (p-values < 0.001). The total analgesics consumption over 24 h postoperatively was lower in Group TAPD compared to Group TAPA (p < 0.05).

Conclusion

An additive agent of perineural dexamethasone at a dose of 8 mg during bilateral TAP block for elective CS operation under spinal anesthesia provided better pain relief on postoperative day 1.

Neuropathic component of postoperative pain for predicting post-caesarean chronic pain at three months. A prospective observational study

BACKGROUND

Recent investigations have showed that caesarean section (CS) might be a cause of chronic pain, with a consequent decrease in quality of life.

METHODS

Prospective observational study in a Spanish tertiary hospital. Main Outcome measure was to assess early neuropathic characteristics of pain (DN2 score ≥ 3) one week after CS as a potential risk factor for post-caesarean section chronic pain (PCSCP) at three months. Secondary outcome was to identify other risk factors. 610 consecutive consenting patients undergoing CS were interviewed preoperatively, at discharge from recovery room and 24h postoperatively. Telephone follow-up interviews were conducted one week, three months and twelve months following surgery.

RESULTS

We analysed 597 consecutive patients. The incidence of PCSCP at three and twelve postoperative months were 6.2% and 1% respectively. Subjects with NRS score superior to five on movement one week after CS presented higher incidence of PCSCP (NRS superior to five: 19 (52,2%); NRS equal or lower to five: 172 (30,9%); p=0,009). On multivariate analysis neuropathic pain one week after CS was associated with a higher risk of PCSCP (AOR: 1.63 (95% CI: 1.26-2.11; p<0.001). Other identified risk factors for PCSCP were: uterine exteriorization during CS (AOR: 3.89 (95% CI 1.25-12.10; p=0.019) and a lower gestational age (AOR: 0.87 (95% CI: 0.78-0.96; p=0.008).

CONCLUSIONS

Incidence of PCSCP at three and twelve postoperative months was low, 6.2% and 1% respectively. Early neuropathic characteristics of pain after one week measured by neuropathic pain questionnaire, consisting of two questions (DN2) ≥ 3/7 could be used to identify patients at risk for chronic post-surgical pain and develop preventive strategies.

Predicting pain among female survivors of recent interpersonal violence: A proof-of-concept machine-learning approach

Interpersonal violence (IPV) is highly prevalent in the United States and is a major public health problem. The emergence and/or worsening of chronic pain are known sequelae of IPV; however, not all those who experience IPV develop chronic pain. To mitigate its development, it is critical to identify the factors that are associated with increased risk of pain after IPV. This proof-of-concept study used machine-learning strategies to predict pain severity and interference in 47 young women, ages 18 to 30, who experienced an incident of IPV (i.e., physical and/or sexual assault) within three months of their baseline assessment. Young women are more likely than men to experience IPV and to subsequently develop posttraumatic stress disorder (PTSD) and chronic pain. Women completed a comprehensive assessment of theory-driven cognitive and neurobiological predictors of pain severity and pain-related interference (e.g., pain, coping, disability, psychiatric diagnosis/symptoms, PTSD/trauma, executive function, neuroendocrine, and physiological stress response). Gradient boosting machine models were used to predict symptoms of pain severity and pain-related interference across time (Baseline, 1-,3-,6- follow-up assessments). Models showed excellent predictive performance for pain severity and adequate predictive performance for pain-related interference. This proof-of-concept study suggests that machine-learning approaches are a useful tool for identifying predictors of pain development in survivors of recent IPV. Baseline measures of pain, family life impairment, neuropsychological function, and trauma history were of greatest importance in predicting pain and pain-related interference across a 6-month follow-up period. Present findings support the use of machine-learning techniques in larger studies of post-IPV pain development and highlight theory-driven predictors that could inform the development of targeted early intervention programs. However, these results should be replicated in a larger dataset with lower levels of missing data.

Impact of a multimodal analgesic protocol modification on opioid consumption after cesarean delivery: a retrospective cohort study

INTRODUCTION

Adequate pain control is a mainstay in enhanced recovery after surgery (ERAS) protocols. ERAS protocols are widely accepted in colorectal and gynecologic surgeries and are increasingly implemented in the obstetric setting. Multimodal analgesia incorporating non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen is a mainstay of ERAS protocols for cesarean delivery, but little research has focused on the choice of NSAIDs or timing of initiation in women undergoing cesarean delivery. At our institution, patients undergoing cesarean delivery receive a standardized multimodal analgesic regimen consisting of neuraxial morphine with NSAIDs and acetaminophen. Our initial protocol involved starting the oral analgesics in the recovery room. There was variability in whether these medications were given in a timely manner or withheld in the setting of postoperative nausea and vomiting. We modified this protocol and performed a retrospective analysis to assess the impact of this change on postoperative opioid rescue requirements in women undergoing cesarean delivery under neuraxial anesthesia.

METHODS

This retrospective analysis included patients who underwent cesarean deliveries from 1 July 2014 to 22 August 2017. With the initial analgesic protocol, patients received neuraxial morphine, followed by naproxen 500 mg PO Q12 hours and acetaminophen 650-975 mg PO Q6 hours initiated in the recovery room. After protocol revision in January 2016, the same neuraxial morphine dose was used in addition to acetaminophen 975 mg PR at the start of the case and ketorolac 15-30 mg IV at the end of the case. Postoperatively, patients received acetaminophen PO 975 mg Q6 hours, ketorolac IV 15 mg Q6 hours for 3 doses, transitioning to ibuprofen 600 mg Q6 hours. Fentanyl, oxycodone, and intravenous hydromorphone were given for breakthrough pain with both protocols. The primary outcome of the study is the need for rescue opioid analgesia. Secondary outcomes are total opioid usage, time to first rescue opioid, maximum reported pain scores, and need for rescue antiemetics. Univariate and multivariate analyses were performed controlling for variables significantly different between the two cohorts.

RESULTS

3250 patients were included in our analysis (1574 in the old protocol and 1676 in the new protocol). There was no significant difference in patient demographics or intraoperative characteristics between the two cohorts except for more primiparous women (25% vs. 17%), more Pfannenstiel incision (98% vs. 96%), and less repeat cesarean deliveries (40% vs. 44%) in the new protocol cohort. Need for rescue opioids was reduced with the new protocol at 2, 24, and 48 h [(36.46% vs. 75.73%, p < .0001), (74.28% vs 91.99%, p < .0001), (87.53% vs 95.49% p < .0001), respectively]. Among those who received opioids, opioid consumption over 48 h was reduced (median [IQR]: 55 [30, 95] vs. 40 [20, 70] mg oxycodone equivalents) after protocol revision (GMR 0.75, 95% CI 0.7, 0.80, p < .0001). The time to first rescue opioid medication was significantly longer in the new protocol compared to the old protocol (175 [79, 1057] min vs 51 [28, 104] min, p < .001).

CONCLUSION

There was a significant decrease in the need for and the dose of rescue opioid medications with the new protocol. This highlights the importance of optimizing the choice of agents, as well as route and timing of administration of the components of the postoperative multimodal analgesic regimen.

Preoperative quantitative sensory testing and robot-assisted laparoscopic hysterectomy for endometrial cancer: can chronic postoperative pain be predicted?

Objectives Chronic postoperative pain is prevalent after robot-assisted laparoscopic hysterectomy for endometrial cancer. Preoperative Quantitative Sensory Testing (QST) has been utilized to identify patients at risk of developing chronic postoperative pain after a range of surgical procedures. The aim of this prospective, observational study was to (1) determine the prevalence of chronic postoperative pain, (2) assess selected preoperative risk factors for chronic postoperative pain, and (3) evaluate if preoperative QST profiling could predict the development of chronic postoperative pain following robot-assisted laparoscopic hysterectomy for endometrial cancer. Methods One-hundred and sixty consecutive patients were included and handheld pressure algometry, cuff pressure algometry, temporal summation of pain, conditioned pain modulation, and heat pain thresholds were assessed prior to surgery. Patients were asked to fill out a questionnaire concerning pain in the pre- and post-operative time period six months after surgery. Chronic postoperative pain was defined as persistent, moderate to severe pain (mean visual analogue scale (VAS)≥3) on a daily basis six months after surgery. Results The prevalence of chronic postoperative pain after robot-assisted laparoscopic hysterectomy for endometrial cancer was of 13.6% (95% CI 8.4-20.4%). Patients that would develop chronic postoperative pain had a lower BMI (p=0.032), a higher prevalence of preoperative pelvic pain (p<0.001), preoperative heat pain hyperalgesia (p=0.043) and a higher level of acute postoperative pain (p<0.001) when compared to patients that would not develop chronic postoperative pain. A logistic regression model demonstrated that the presence of preoperative pelvic pain was a significant, independent predictive risk factor for development of chronic postoperative pain (OR=6.62, 95% CI 2.26-19.44), whereas none of the QST parameters could predict postoperative pain. Conclusions Preoperative QST assessment could not predict the development of chronic postoperative pain despite preoperative heat pain hyperalgesia in patients that would develop chronic postoperative pain.

Risk Factors Associated with Development of Acute and Sub-Acute Post-Cesarean Pain: A Prospective Cohort Study

BACKGROUND

Although cesarean delivery is one of the most commonly performed surgical procedures, robust data regarding post-cesarean pain is still lacking. Recent studies showed an association between pain upon local anesthetic (LA) injection for spinal anesthesia, or the use of a "three simple questions", and acute post-cesarean pain. Nevertheless, these assessments have yet to be validated further, despite their relative ease of use. We aimed to assess the association between pain score upon LA injection with acute post-cesarean pain after 24 hours at rest (primary outcome) and sub-acute post-cesarean pain lasting for 4 weeks or more (secondary outcome).

METHODS

Women undergoing cesarean delivery under spinal anesthesia were given pre-operative questionnaires on pain and psychological vulnerability. We also assessed the pain score upon LA injection and mechanical temporal summation. Univariate and multivariable logistic regressions were performed.

RESULTS

The incidence of moderate-to-severe acute post-cesarean pain at 24 hours was 21.0% (95% CI=16.6-27.6%) (48 of 217 patients). Pain score upon LA injection was not significantly associated with acute post-cesarean pain after 24 hours at rest (unadjusted OR=1.10, 95% CI=0.95-1.27, P=0.21). However, pain score upon LA injection was significantly associated with sub-acute post-cesarean pain (adjusted OR=1.29, 95% CI=1.07-1.55, P=0.0089) with significant covariate of increased pre-operative central sensitization inventory (CSI) scores (adjusted OR=1.05, 95% CI=1.01-1.09, P=0.0111; area under the curve (AUC)=0.691).

CONCLUSION

There was no association between increased pain score upon LA injection and acute post-cesarean pain, but it was associated with sub-acute post-cesarean pain. Further work is needed to define pain score upon LA injection as a convenient pragmatic measure of risk stratifying patients predisposed to sub-acute post-cesarean pain.

The incidence of chronic pain following Cesarean section and associated risk factors: A cohort of women followed up for three months

BACKGROUND

Chronic post-surgical pain (CPSP) is one of the post-surgical complications of a Cesarean section. Despite the high rates of Cesarean section worldwide, the incidence of CPSP and the risk factors for this condition remain relatively unknown. The objective of this study was to calculate the incidence of CPSP in women submitted to Cesarean section and to analyze the associated risk factors.

MATERIALS AND METHODS

A prospective cohort of 621 women undergoing Cesarean section was recruited preoperatively. Potential presurgical (sociodemographic, clinical and lifestyle-related characteristics) and post-surgical risk factors (the presence and intensity of pain) risk factors were analyzed. Pain was measured at 24 hours and 7, 30, 60 and 90 days after surgery. Following discharge from hospital, data were collected by telephone. The outcome measure was self-reported pain three months after a Cesarean section. The risk factors for chronic pain were analyzed using the log-binomial regression model (a generalized linear model).

RESULTS

A total of 462 women were successfully contacted 90 days following surgery. The incidence of CPSP was 25.5% (95%CI: 21.8-29.7). Risk factors included presurgical anxiety (adjusted relative risk [RR] 1.03; 95%CI: 1.01-1.05), smoking (adjusted RR 2.22; 95%CI: 1.27-3.88) and severe pain in the early postoperative period (adjusted RR 2.79; 95%CI: 1.29-6.00).

CONCLUSION

One in four women submitted to Cesarean section may develop CPSP; however, the risk factors identified here are modifiable and preventable. Preventive strategies directed towards controlling anxiety, reducing smoking during pregnancy and managing pain soon after hospital discharge are recommended.

Factors associated with persistent pain after childbirth: a narrative review

A systematic literature search was performed to identify studies that reported risk factors for persistent pain after childbirth. Many studies have sought to identify risk factors for post-delivery pain in different populations, using different methodologies and different outcome variables. Studies of several different but interrelated post-partum pain syndromes have been conducted. Factors strongly and specifically associated with persistent incisional scar pain after Caesarean delivery include a coexisting persistent pain problem in another part of the body and severe acute postoperative pain. For persistent vaginal and perineal pain, operative vaginal delivery and the magnitude of perineal trauma have been consistently linked. History of pregnancy-related and pre-pregnancy back pain and heavier body weight are robust risk factors for persistent back pain after pregnancy. Unfortunately, limitations, particularly small samples and lack of a priori sample size calculation designed to detect specific effect sizes for risk of persistent pain outcomes, preclude definitive conclusions about many other predictors and the strength of outcome associations. In future studies, assessments of specific phenotypes using a rigorous analysis with appropriate predetermined sample sizes and validated instruments are needed to allow elucidation of stronger and reliable associations. Interventional studies targeting the most robustly associated, modifiable risk factors, such as acute post-partum pain, may lead to solutions for the prevention and treatment of these common problems that impact a large population.

Predicting Severity of Acute Pain After Cesarean Delivery: A Narrative Review

Cesarean delivery is one of the most common surgical procedures in the United States, with over 1.3 million performed annually. One-fifth of women who undergo cesarean delivery will experience severe pain in the acute postoperative period, increasing their risk of developing chronic pain and postpartum depression, and negatively impacting breastfeeding and newborn care. A growing body of research has investigated tools to predict which patients will experience more severe pain and have increased analgesic consumption after cesarean delivery. These include quantitative sensory testing, assessment of wound hyperalgesia, response to local anesthetic infiltration, and preoperative psychometric evaluations such as validated psychological questionnaires and simple screening tools. For this review, we searched MEDLINE, the Cochrane database, and Google Scholar to identify articles that evaluated the utility of various tools to predict severe pain and/or opioid consumption in the first 48 hours after cesarean delivery. Thirteen articles were included in the final review: 5 utilizing quantitative sensory testing, including patient responses to pressure, electrical, and thermal stimuli; 1 utilizing hyperalgesia testing; 1 using response to local anesthetic wound infiltration; 4 utilizing preoperative psychometric evaluations including the State-Trait Anxiety Inventory, the Pain Catastrophizing Scale, the Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale, and simple questionnaires; and 2 utilizing a combination of quantitative sensory tests and psychometric evaluations. A number of modalities demonstrated statistically significant correlations with pain outcomes after cesarean delivery, but most correlations were weak to modest, and many modalities might not be clinically feasible. Response to local anesthetic infiltration and a tool using 3 simple questions enquiring about anxiety and anticipated pain and analgesic needs show potential for clinical use, but further studies are needed to evaluate the utility of these predictive tests in clinical practice.

Persistent pain after cesarean delivery

The incidence of persistent pain after cesarean deliveries (CD) varies but is much lower than after comparable surgeries. However, with over four million deliveries annually and a rising CD rate, even a low prevalence of persistent pain after CD impacts many otherwise healthy young women. Consideration of the pathophysiology of persistent pain after surgery and the risk factors predisposing women to persistent and chronic pain after CD provides insights into the prevention and treatment of persistent pain; and improves the quality of care and recovery after CD. The findings that the peripartum state and oxytocin confer protection against persistent pain may provide new and interesting perspectives for the prevention and treatment of chronic pain caused by trauma or surgery. Predictive tools available to identify and target patients at high risk of acute and chronic pain have mostly weak to modest predictive correlations and many are either not clinically feasible or too time-consuming to apply. Persistent pain has been linked to the severity of acute postoperative pain and opioid exposure. Modified surgical techniques, neuraxial anesthesia and opioid-sparing analgesia may help limit the development of persistent and chronic pain. The goal of this narrative review is to examine the incidence of persistent pain after CD; review briefly the underlying pathophysiology of persistent pain and the transition from acute to chronic pain (with particular emphasis on the uniqueness after CD); and to review modifiable risk factors and prevention strategies that identify at-risk patients and allow tailored treatment.

Prevalence & correlates of chronic perinatal pain - a study from India

Objectives: To study the prevalence of chronic perinatal pain among mothers who had infants between the ages of 13-25 months in the State of Kerala, India and to report its correlates in the socio-demographic, obstetric and psychological domains. Methods: A total of 9305 mothers selected by cluster random sampling were assessed cross-sectionally for chronic perinatal pain using a questionnaire by Junior Public Health Nurses (JPHNs). In addition, information regarding socio-demographic profile, obstetric history, infant details and perinatal depression were collected. Results: Of the 8302 (89.3%) valid responses, 552 (6.6%) mothers reported chronic perinatal pain. Among those with pain, 142 (25.6%) reported pain during pregnancy, 314 (56.7%) during postpartum and 96 (17.7%) during both periods. The commonest sites of pain reported were back 280 (51%) and pelvic region 110 (19%). Mothers with chronic perinatal pain were more likely to be younger, less educated, employed and from an urban background. Chronic perinatal pain was associated with obstetric complications, delivery by instrumental/caesarean section, non-exclusive breast feeding and higher maternal depression scores. Conclusion: Chronic pain is common among mothers in India during the perinatal period and greater attention needs to be given for it to be recognised and treated early.

Local anesthetics and regional anesthesia versus conventional analgesia for preventing persistent postoperative pain in adults and children: A Cochrane systematic review and meta-analysis update

BACKGROUND

Regional anesthesia may mitigate the risk of persistent postoperative pain (PPP). This Cochrane review, published originally in 2012, was updated in 2017.

METHODS

We updated our search of Cochrane CENTRAL, PubMed, EMBASE and CINAHL to December 2017. Only RCTs investigating local anesthetics (by any route) or regional anesthesia versus any combination of systemic (opioid or non-opioid) analgesia in adults or children, reporting any pain outcomes beyond three months were included. Data were extracted independently by at least two authors, who also appraised methodological quality with Cochrane 'Risk of bias' assessment and pooled data in surgical subgroups. We pooled studies across different follow-up intervals. As summary statistic, we reported the odds ratio (OR) with 95% confidence intervals and calculated the number needed to benefit (NNTB). We considered classical, Bayesian alternatives to our evidence synthesis. We explored heterogeneity and methodological bias.

RESULTS

40 new and seven ongoing studies, identified in this update, brought the total included RCTs to 63. We were only able to synthesize data from 39 studies enrolling 3027 participants in a balanced design. Evidence synthesis favored regional anesthesia for thoracotomy (OR 0.52 [0.32 to 0.84], moderate-quality evidence), breast cancer surgery (OR 0.43 [0.28 to 0.68], low-quality evidence), and cesarean section (OR 0.46, [0.28 to 0.78], moderate-quality evidence). Evidence synthesis favored continuous infusion of local anesthetic after breast cancer surgery (OR 0.24 [0.08 to 0.69], moderate-quality evidence), but was inconclusive after iliac crest bone graft harvesting (OR 0.20, [0.04 to 1.09], low-quality evidence).

CONCLUSIONS

Regional anesthesia reduces the risk of PPP. Small study size, performance, null, and attrition bias considerably weakened our conclusions. We cannot extrapolate to other interventions or to children.

Prediction of outliers in pain, analgesia requirement, and recovery of function after childbirth: a prospective observational cohort study

BACKGROUND

Prediction models to identify parturients who experience protracted pain, prolonged opioid use, and delayed self-assessed functional recovery are currently inadequate.

METHODS

For this study, 213 nulliparous women who planned vaginal delivery were enrolled and assessed daily until they completed three outcomes: (1) pain resolution; (2) opioid cessation; and (3) self-assessed functional recovery to predelivery level. The primary composite endpoint, 'pain and opioid-free functional recovery' was the time required to reach all three endpoints. The subjects were divided into two categories (the worst (longest time) 20% and remaining 80%) for reaching the primary composite endpoint, and each individual component. Prediction models for prolonged recovery were constructed using multivariate logistic regression with demographic, obstetric, psychological, and health-related quality of life characteristics as candidate predictors.

RESULTS

Labour induction (vs spontaneous labour onset) predicted the worst 20% for the primary composite endpoint in the final multivariate model. Labour induction and higher postpartum day 1 numerical rating score for pain were predictors for being in the worst 20% for both functional recovery and pain burden. Labour type, delivery type, Patient-Reported Outcomes Measurement Information System (PROMIS) anxiety score, RAND 36 Item Health Survey 1.0 (SF-36) physical health composite score, and postpartum breastfeeding success were predictive of delayed opioid cessation.

CONCLUSIONS

Labour induction and elevated numerical rating score for pain are predictive of poor recovery after childbirth. Further research is necessary to determine whether modification would benefit mothers at risk for poor recovery.

The Effect of Spinal versus General Anesthesia on Quality of Life in Women Undergoing Cesarean Delivery on Maternal Request

Introduction

The proportion of women electing for cesarean delivery has increased in both developed and developing countries. Cesarean delivery on maternal request (CDMR) refers to a primary cesarean delivery performed because the mother requests this method of delivery in the absence of standard medical/obstetrical indications.

Several studies compared anesthesia modalities in cesarean section regarding clinical outcomes such as maternal mortality, post-operative pain and bleeding, but only a few compared health-related quality of life (HRQoL) of women undergoing general anesthesia versus spinal anesthesia. The aim of this study was to determine whether pregnant women who undergo general anesthesia (GA) for cesarean delivery compared with spinal anesthesia (SA) differ regarding their perceived HRQoL.

Methodology

We enrolled 160 pregnant women with American Society of Anesthesiologists (ASA) class II, scheduled for CDMR with GA or SA. Anesthesia modality was based on patient’s preference. Participants assessed their state of health with the EuroQoL-5 Dimensions-3 Levels (EQ-5D-3L) self-administered questionnaire at four time points: six hours before cesarean delivery, 24 hours after cesarean delivery, one week and one month after cesarean delivery. Patients also rated their health on the EQ visual analog scale (EQ-VAS) from 100 mm “best imaginable health state” to 0 mm “worst imaginable health state”.

Results

More women who underwent spinal anesthesia reported “no problem” with regards to “mobility’ (64% vs. 30%, p = 0.00), “usual activities” (90% vs. 38%, p = 0.00), and “pain/discomfort” (20% vs. 5%, p = 0.007). Repeated measurement analysis showed that the two groups started off with the same EQ-VAS score, however, both decreased over time with different slope resulting in different scores at 24 hours after CS. Then the scores increased in both groups over time and ended up being rather close at one month after CS.

Discussion

Unless there is a contraindication, neuraxial anesthesia is the anesthetic technique of choice for cesarean delivery in all parturient in general. This concept is based on more mortality and morbidity that have been seen with general anesthesia in this particular population. Our study demonstrated significant advantages of spinal anesthesia compared to general anesthesia in cesarean section regarding postoperatively perceived HRQoL. We showed that more pregnant women who chose spinal anesthesia as their anesthesia modality reported “no problem” with respect to “mobility” and “Self-care” 24 hours after cesarean section. On the top of that, more women in this group had “no problem” in their “usual activities” at one week and one month after cesarean delivery time points. Moreover, EQ-5D general health score was higher 24 hours after cesarean delivery with regional anesthesia comparing to general anesthesia.

Conclusion

We determined that compared to general anesthesia, spinal anesthesia is the technique of choice for cesarean section because not only it avoids a general anesthetic and the risk of failed intubation, but also because it provides effective pain control, mobility and fast return back to daily activities for new mothers and increase their quality of life.

Local anaesthetics and regional anaesthesia versus conventional analgesia for preventing persistent postoperative pain in adults and children

BACKGROUND

Regional anaesthesia may reduce the rate of persistent postoperative pain (PPP), a frequent and debilitating condition. This review was originally published in 2012 and updated in 2017.

OBJECTIVES

To compare local anaesthetics and regional anaesthesia versus conventional analgesia for the prevention of PPP beyond three months in adults and children undergoing elective surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase to December 2016 without any language restriction. We used a combination of free text search and controlled vocabulary search. We limited results to randomized controlled trials (RCTs). We updated this search in December 2017, but these results have not yet been incorporated in the review. We conducted a handsearch in reference lists of included studies, review articles and conference abstracts. We searched the PROSPERO systematic review registry for related systematic reviews.

SELECTION CRITERIA

We included RCTs comparing local or regional anaesthesia versus conventional analgesia with a pain outcome beyond three months after elective, non-orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial quality and extracted data and adverse events. We contacted study authors for additional information. We presented outcomes as pooled odds ratios (OR) with 95% confidence intervals (95% CI), based on random-effects models (inverse variance method). We analysed studies separately by surgical intervention, but pooled outcomes reported at different follow-up intervals. We compared our results to Bayesian and classical (frequentist) models. We investigated heterogeneity. We assessed the quality of evidence with GRADE.

MAIN RESULTS

In this updated review, we identified 40 new RCTs and seven ongoing studies. In total, we included 63 RCTs in the review, but we were only able to synthesize data on regional anaesthesia for the prevention of PPP beyond three months after surgery from 39 studies, enrolling a total of 3027 participants in our inclusive analysis.Evidence synthesis of seven RCTs favoured epidural anaesthesia for thoracotomy, suggesting the odds of having PPP three to 18 months following an epidural for thoracotomy were 0.52 compared to not having an epidural (OR 0.52 (95% CI 0.32 to 0.84, 499 participants, moderate-quality evidence). Simlarly, evidence synthesis of 18 RCTs favoured regional anaesthesia for the prevention of persistent pain three to 12 months after breast cancer surgery with an OR of 0.43 (95% CI 0.28 to 0.68, 1297 participants, low-quality evidence). Pooling data at three to 8 months after surgery from four RCTs favoured regional anaesthesia after caesarean section with an OR of 0.46, (95% CI 0.28 to 0.78; 551 participants, moderate-quality evidence). Evidence synthesis of three RCTs investigating continuous infusion with local anaesthetic for the prevention of PPP three to 55 months after iliac crest bone graft harvesting (ICBG) was inconclusive (OR 0.20, 95% CI 0.04 to 1.09; 123 participants, low-quality evidence). However, evidence synthesis of two RCTs also favoured the infusion of intravenous local anaesthetics for the prevention of PPP three to six months after breast cancer surgery with an OR of 0.24 (95% CI 0.08 to 0.69, 97 participants, moderate-quality evidence).We did not synthesize evidence for the surgical subgroups of limb amputation, hernia repair, cardiac surgery and laparotomy. We could not pool evidence for adverse effects because the included studies did not examine them systematically, and reported them sparsely. Clinical heterogeneity, attrition and sparse outcome data hampered evidence synthesis. High risk of bias from missing data and lack of blinding across a number of included studies reduced our confidence in the findings. Thus results must be interpreted with caution.

AUTHORS' CONCLUSIONS

We conclude that there is moderate-quality evidence that regional anaesthesia may reduce the risk of developing PPP after three to 18 months after thoracotomy and three to 12 months after caesarean section. There is low-quality evidence that regional anaesthesia may reduce the risk of developing PPP three to 12 months after breast cancer surgery. There is moderate evidence that intravenous infusion of local anaesthetics may reduce the risk of developing PPP three to six months after breast cancer surgery.Our conclusions are considerably weakened by the small size and number of studies, by performance bias, null bias, attrition and missing data. Larger, high-quality studies, including children, are needed. We caution that except for breast surgery, our evidence synthesis is based on only a few small studies. On a cautionary note, we cannot extend our conclusions to other surgical interventions or regional anaesthesia techniques, for example we cannot conclude that paravertebral block reduces the risk of PPP after thoracotomy. There are seven ongoing studies and 12 studies awaiting classification that may change the conclusions of the current review once they are published and incorporated.

Local anaesthetics and regional anaesthesia versus conventional analgesia for preventing persistent postoperative pain in adults and children

BACKGROUND

Regional anaesthesia may reduce the rate of persistent postoperative pain (PPP), a frequent and debilitating condition. This review was originally published in 2012 and updated in 2017.

OBJECTIVES

To compare local anaesthetics and regional anaesthesia versus conventional analgesia for the prevention of PPP beyond three months in adults and children undergoing elective surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase to December 2016 without any language restriction. We used a combination of free text search and controlled vocabulary search. We limited results to randomized controlled trials (RCTs). We updated this search in December 2017, but these results have not yet been incorporated in the review. We conducted a handsearch in reference lists of included studies, review articles and conference abstracts. We searched the PROSPERO systematic review registry for related systematic reviews.

SELECTION CRITERIA

We included RCTs comparing local or regional anaesthesia versus conventional analgesia with a pain outcome beyond three months after elective, non-orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial quality and extracted data and adverse events. We contacted study authors for additional information. We presented outcomes as pooled odds ratios (OR) with 95% confidence intervals (95% CI), based on random-effects models (inverse variance method). We analysed studies separately by surgical intervention, but pooled outcomes reported at different follow-up intervals. We compared our results to Bayesian and classical (frequentist) models. We investigated heterogeneity. We assessed the quality of evidence with GRADE.

MAIN RESULTS

In this updated review, we identified 40 new RCTs and seven ongoing studies. In total, we included 63 RCTs in the review, but we were only able to synthesize data on regional anaesthesia for the prevention of PPP beyond three months after surgery from 41 studies, enrolling a total of 3143 participants in our inclusive analysis.Evidence synthesis of seven RCTs favoured epidural anaesthesia for thoracotomy, suggesting the odds of having PPP three to 18 months following an epidural for thoracotomy were 0.52 compared to not having an epidural (OR 0.52 (95% CI 0.32 to 0.84, 499 participants, moderate-quality evidence). Simlarly, evidence synthesis of 18 RCTs favoured regional anaesthesia for the prevention of persistent pain three to 12 months after breast cancer surgery with an OR of 0.43 (95% CI 0.28 to 0.68, 1297 participants, low-quality evidence). Pooling data at three to 8 months after surgery from four RCTs favoured regional anaesthesia after caesarean section with an OR of 0.46, (95% CI 0.28 to 0.78; 551 participants, moderate-quality evidence). Evidence synthesis of three RCTs investigating continuous infusion with local anaesthetic for the prevention of PPP three to 55 months after iliac crest bone graft harvesting (ICBG) was inconclusive (OR 0.20, 95% CI 0.04 to 1.09; 123 participants, low-quality evidence). However, evidence synthesis of two RCTs also favoured the infusion of intravenous local anaesthetics for the prevention of PPP three to six months after breast cancer surgery with an OR of 0.24 (95% CI 0.08 to 0.69, 97 participants, moderate-quality evidence).We did not synthesize evidence for the surgical subgroups of limb amputation, hernia repair, cardiac surgery and laparotomy. We could not pool evidence for adverse effects because the included studies did not examine them systematically, and reported them sparsely. Clinical heterogeneity, attrition and sparse outcome data hampered evidence synthesis. High risk of bias from missing data and lack of blinding across a number of included studies reduced our confidence in the findings. Thus results must be interpreted with caution.

AUTHORS' CONCLUSIONS

We conclude that there is moderate-quality evidence that regional anaesthesia may reduce the risk of developing PPP after three to 18 months after thoracotomy and three to 12 months after caesarean section. There is low-quality evidence that regional anaesthesia may reduce the risk of developing PPP three to 12 months after breast cancer surgery. There is moderate evidence that intravenous infusion of local anaesthetics may reduce the risk of developing PPP three to six months after breast cancer surgery.Our conclusions are considerably weakened by the small size and number of studies, by performance bias, null bias, attrition and missing data. Larger, high-quality studies, including children, are needed. We caution that except for breast surgery, our evidence synthesis is based on only a few small studies. On a cautionary note, we cannot extend our conclusions to other surgical interventions or regional anaesthesia techniques, for example we cannot conclude that paravertebral block reduces the risk of PPP after thoracotomy. There are seven ongoing studies and 12 studies awaiting classification that may change the conclusions of the current review once they are published and incorporated.

Chronic pain during pregnancy: a review of the literature

BACKGROUND AND PURPOSE

The majority of the reviews and studies on chronic pain in pregnancy have primarily focused on the pharmacological and non-pharmacological treatment options. The purpose of our review was to identify evidence-based clinical research for the evaluation and management of preexisting chronic pain in pregnancy, chronic pain associated with pregnancy, and chronic pain in relation to mode of delivery.

METHODS

A literature search was undertaken using the search engines PubMed, CINAHL, EBSCOhost, and Web of Science. Search terms used included "chronic pain" AND "pregnant OR pregnancy" OR "pregnancy complications" from inception through August 2016.

RESULTS

The basis of this review was the 144 articles that met inclusion criteria for this review. Based on our review of the current literature, we recommend 7 guidelines for chronic pain management during and after pregnancy: 1) complete history and physical examination; 2) monitor patients for alcohol, nicotine, and substance use; 3) collaborate with patient to set treatment goals; 4) develop a management plan; 5) for opioids, use lowest effective dose; 6) formulate a pain management plan for labor and delivery; and 7) discuss reproductive health with women with chronic pain.

CONCLUSION

The management of chronic pain associated with pregnancy is understudied. Obstetrical providers primarily manage chronic pain during pregnancy. Some general guidelines are provided for those health care providers until more information is available.

Incidence and association factors for the development of chronic post-hysterectomy pain at 4- and 6-month follow-up: a prospective cohort study

Chronic pain has major adverse effects on health-related quality of life and contributes to significant socioeconomic burden. Hysterectomy is a very common gynecological surgery, resulting in chronic post-hysterectomy pain (CPHP), an important pain syndrome. We conducted a prospective cohort study in 216 Asian women who underwent abdominal or laparoscopic hysterectomy for benign conditions. Demographic, psychological, and perioperative data were recorded. Postoperative 4- and 6-month phone surveys were conducted to assess the presence of CPHP and functional impairment. The incidence rates of CPHP at 4 and 6 months were 32% (56/175) and 15.7% (25/159), respectively. Women with CPHP at 4 and 6 months had pain that interfered with their activities of daily living. Independent association factors for CPHP at 4 months were higher mechanical temporal summation score, higher intraoperative morphine consumption, higher pain score in the recovery room, higher pain score during coughing and itching at 24 hours postoperatively, and preoperative pain in the lower abdominal region. Independent association factors for CPHP at 6 months were preoperative pain during sexual intercourse, higher mechanical temporal summation score, and higher morphine consumption during postoperative 24 and 48 hours. In a majority of cases, CPHP resolved with time, but may have significant impact on activities of daily living.

Incidence and severity of chronic pain after caesarean section: A systematic review with meta-analysis

BACKGROUND

The frequency of caesarean section has increased dramatically in recent decades. Despite this, robust data regarding the consequences of caesarean section in terms of developing chronic postsurgical pain (CPSP) are still lacking.

OBJECTIVE

This systematic review analysed the incidence and severity of CPSP in women 3 to less than 6, 6 to less than 12, and at least 12 months after caesarean section.

DESIGN

Systematic review of prospective and retrospective observational studies and randomised controlled trials with meta-analysis.

DATA SOURCE

We searched MEDLINE to May 2015.

ELIGIBILITY CRITERIA

We included all studies investigating the incidence and/or severity of CPSP at least 3 months after caesarean section. The primary outcome was chronic postsurgical wound pain (CPSP 'wound'). Secondary outcomes were persistent pain in the back area, pelvic region or reported as residual pain, and severity of 'birth-related' chronic pain.

RESULTS

Meta-analysis using the random-effects model based on 15 studies (n = 4475) reporting CPSP 'wound' at 3 to less than 6 months after caesarean section revealed an incidence of 15.4% [95% confidence interval (CI): 9.9 to 20.9%]. For 6 to less than 12 and at least 12 months after caesarean section, the incidence of CPSP 'wound' was estimated at 11.5% (95% CI: 8.1 to 15.0%, n = 3345) and 11.2% (95% CI: 7.4 to 15.0%, n = 3451), respectively. Meta-regression analysis using the publication year as predictor revealed stable CPSP 'wound' incidences at each postoperative time slot from 2002 to the present. Of those patients who reported chronic pain, 9.6% (95% CI: 0.0 to 21.0%) had severe pain, 23.5% (95% CI: 10.0 to 37.0%) had moderate pain and 49.2% (95% CI: 18.9 to 79.4%) had mild pain at 6 months.

LIMITATIONS

Major limitations are high statistical heterogeneity of the meta-analyses and inconsistencies in reporting severity of chronic 'birth-related' pain.

CONCLUSION

This meta-analysis finds a clinically relevant incidence of CPSP 'wound' after caesarean section ranging from 15% at 3 months to 11% at 12 months or longer that has been largely stable in recent years.

[POSTOPERATIVE CHRONIC PAIN FOLLOWING MESH AND NON-MESH REPAIR OF PELPIC ORGAN PROLAPSE]

(Objective) A FDA alert in 2011 warned about postoperative chronic pain following transvaginal mesh (TVM) for pelvic organ prolapse (POP). We studied cases with chronic pain after TVM, natural tissue repair (NTR) and laparoscopic salcocopopexy (LSC). (Methods) We retrospectively reviewed medical charts of patients who underwent POP operations in our hospital or were referred to us after POP operations in other hospitals between 2006 and 2016. Postoperative chronic pain was defined as persistent pain for more than three months following the first three months from the time of POP operations.Patients' characteristics and treatments were analyzed. (Results) In patients who underwent POP operations in our hospital, the rates of chronic postoperative pain after TVM, NTR and LSC were 12/2,457 (0.49%), 1/402 (0.26%) and 0/29 (0%), respectively. Another 8 patients were referred to us after POP operations in other hospitals. Thus, a total of 21 patients (15: TVM, 6: NTR) had either medications, surgical treatment or were referred to other doctors due to postoperative chronic pain. All of them were parous women aged 53 to 81 years old. Preoperative chronic pelvic pain was found in seven patients (33%), and another four patients (19%) had orthopedic diseases with chronic pain. The main locations of pain were; vagina 11, vulva 2, urinary bladder 2, urethra 1, coccyx 1, buttocks 1, anus 1, perineum 1 and groin 1. Nineteen patients had pharmacological treatment using tricyclic antidepressants, Ca²⁺ channel α₂δ ligand and/or serotonin-noradrenalin reuptake inhibitor (SNRI); 9 (47%) of the patients showed a notable improvement. Three patients following TVM had surgical treatment; one with bladder mesh exposure was resolved with TURis, one with vaginal mesh exposure was resolved with mesh trimming, but one with tenderness on the mesh arm did not improve after a partial mesh removal. Four patients were referred to pain clinics. (Conclusions) Postoperative chronic pain can occur following both TVM and NTR therefore, attentive listening and proper medication are important as initial therapies. It is mandatory to examine the presence of mesh exposure in patients after using mesh. We should be careful about preoperative chronic pain, pelvic or elsewhere, as a risk factor for postoperative chronic pain.

Prevalence and Predictors of Chronic Pain in Pregnancy and Postpartum

OBJECTIVE

A clinically relevant number of patients report pain 1 year after vaginal delivery or Caesarean delivery. Study objectives were to identify the incidence of peripartum pain; determine whether pre-existing pain, pregnancy pain, or pain 2 weeks postpartum predicts pain at 3 months; and to identify whether delivery mode, epidural analgesia use, or delivery complications predict non-genito-pelvic pain postpartum.

METHODS

Primiparous women at 30 to 36 weeks GA with an uncomplicated singleton pregnancy were recruited from a large perinatal clinic. Participants completed questionnaires on sociodemographics and non-genito-pelvic pain. Questionnaires were completed in the perinatal clinic and then electronically 2 weeks and 3 months postpartum.

RESULTS

Of the 133 women included, 50 patients (38%) had a chronic pain condition or pain prior to pregnancy, whereas 73 patients (55%) reported pain in pregnancy. Pain was present 2 weeks postpartum in 57 patients (43%) and 3 months postpartum in 33 patients (25%). Patients with pre-existing pain were more likely to experience pain 2 weeks postpartum (P = 0.006), and patients with pain 2 weeks postpartum were more likely to have pain 3 months postpartum (P = 0.005). Women who had a Caesarean delivery (P < 0.001) were more likely to have non-genito-pelvic pain at 2 weeks but not 3 months postpartum.

CONCLUSIONS

Women with pain 2 weeks postpartum were significantly more likely to have pain at 3 months. Further investigation is required to determine whether pre-existing pain, pain in pregnancy, or pain at 2 weeks postpartum can adequately predict the likelihood of chronic pain.

[Ultrasound guided quadratus lumborum block for analgesia after cesarean delivery: case series]

INTRODUCTION

The majority of women having planned cesarean section receive spinal anesthesia for the procedure. Typically, spinal opioids are administered during the same time as a component of multimodal analgesia to provide pain relief in the 16-24h period postoperatively. The quadratus lumborum block is a regional analgesic technique that blocks T5-L1 nerve branches and has an evolving role in postoperative analgesia for lower abdominal surgeries and may be a potential alternative to spinal opioids. If found effective, it will have the advantage of a reduction in opioid associated adverse effects while providing similar quality of analgesia.

METHODS

We performed bilateral quadratus lumborum block in 3 women who received a spinal anesthetic for a cesarean delivery and evaluated their post-operative opioid consumption and patient satisfaction.

RESULTS

In all 3 patients, there was no additional opioid consumption during the first 24h after the block. Numeric Rating Scale (NRS) for pain was less than 6 for the first 24h. Women were all very satisfied with the quality of pain relief.

DISCUSSION

Quadratus lumborum block may be a promising anesthetic adjuvant for post-cesarean analgesia. Further randomized controlled trials are needed to compare the efficacy of the quadratus lumborum block with intrathecal opioids.

Effect of Topical Morphine on Acute and Chronic Postmastectomy Pain: What Is the Optimum Dose?

BACKGROUND AND OBJECTIVES

Poorly controlled postoperative pain is strongly associated with the development of chronic pain. We aimed to investigate the effect of topical morphine (in 1 of 3 doses: 5, 10, or 15 mg) on acute and chronic neuropathic pain after modified radical mastectomy for cancer breast.

METHODS

In this registered clinical trial (ClinicalTrials.gov identifier: NCT02462577), 90 patients were allocated to receive 10 mL plain bupivacaine 0.5% plus either 5, 10, or 15 mg morphine (designated by the group names Morphine5, Morphine10, and Morphine15, respectively). The combination was diluted by saline 0.9% to 20 mL and irrigated in the wound before skin closure. Groups were compared for the following: time to first postoperative analgesia; intravenous patient-controlled analgesia (PCA) morphine consumption; pain scores; hemodynamics; sedation; adverse events in first postoperative 48 hours; and Leeds Assessment of Neuropathic Symptoms and Signs scores in first and third postoperative months.

RESULTS

No patient in the Morphine15 group requested postoperative PCA morphine versus 19 and 8 in the Morphine5 and Morphine10 groups, respectively (P < 0.002). Time to first analgesic request and total consumption of PCA morphine analgesia were 7.31 ± 3.12 hours versus 14.00 ± 3.54 hours (P < 0.000) and 1.42 ± 0.50 mg versus 1.00 ± 0.00 mg (P = 0.371) in the Morphine5 and Morphine10 groups, respectively. Lowest scores on visual analog pain scale at rest (P < 0.001) and visual analog pain scale during movement (P < 0.01) were recorded in the Morphine15 group, followed by Morphine10 then Morphine5 group. Lowest Leeds Assessment of Neuropathic Symptoms and Signs scores were recorded in the Morphine15 group in the first month (1.10 ± 0.37 vs 5.76 ± 3.26 and 4.73 ± 2.87, P < 0.0001) and third postoperative month (4.40 ± 1.77 vs 6.33 ± 3.21 and 5.43 ± 2.67, P < 0.006) compared with Morphine5 and Morphine10 groups, respectively. No patient in the Morphine15 group developed chronic pain versus 4 and 2 in Morphine5 and Morphine10 groups, respectively.

CONCLUSIONS

Topical morphine controlled acute postmastectomy pain in a dose-dependent manner and reduced the incidence and severity of chronic postmastectomy pain syndrome.

Prevalence and risk factors for chronic pain following cesarean section: a prospective study

BACKGROUND

Chronic post-surgical pain (CPSP) remains a major clinical problem which may be associated with impaired activities of daily life and decreased health-related quality of life. Although cesarean section is one of the most commonly performed operations, chronic pain after cesarean delivery has not been well-studied. The purpose of this prospective study was to assess the incidence and risk factors of chronic pain at 3, 6 and 12 months after cesarean delivery.

METHODS

We prospectively investigated preoperative demographic and psychological factors, intraoperative clinical factors, and acute postoperative pain in a cohort of 527 women undergoing cesarean section. The women were interviewed and completed pain questionnaires after 3, 6 and 12 months. Questions were about pain intensity, frequency, and location, as well as medical treatment and impact on daily living.

RESULTS

The incidence of CPSP at 3, 6 and 12 months after cesarean section was 18.3 %, 11.3 % and 6.8 %, respectively. Most of the women with CPSP experienced mild pain at rest. The incidence of moderate and severe pain on movement was high at 3 month, and then has a significant decrease at 6 and 12 months. CPSP had a negative influence on the activities of daily living. Independent predictors of CPSP at 3 months included higher average pain intensity on movement within 24 h postoperatively, preoperative depression, and longer duration of surgery. At 6 months, more severe pain during movement within 24 h of surgery and preoperative depression were predictive of pain persistence. And 12 months after surgery, only higher average pain score on movement within 24 h following cesarean section was found to be significant associated with CPSP. The three models all showed moderate discrimination and good calibration for the prediction of CPSP at 3, 6 and 12 months postoperatively.

CONCLUSIONS

CPSP was not rare in women undergoing cesarean section. Patients with more intense of acute postoperative pain on movement, preoperative depression, and longer surgical time had greater risk for CPSP following surgery.

Effect of preoperative gabapentin on pain intensity and development of chronic pain after carpal tunnel syndrome surgical treatment in women: randomized, double-blind, placebo-controlled study

CONTEXT AND OBJECTIVES

Effective postoperative analgesia is important for reducing the incidence of chronic pain. This study evaluated the effect of preoperative gabapentin on postoperative analgesia and the incidence of chronic pain among patients undergoing carpal tunnel syndrome surgical treatment.

DESIGN AND SETTINGS

Randomized, double-blind controlled trial, Federal University of São Paulo Pain Clinic.

METHODS

Forty patients aged 18 years or over were randomized into two groups: Gabapentin Group received 600 mg of gabapentin preoperatively, one hour prior to surgery, and Control Group received placebo. All the patients received intravenous regional anesthesia comprising 1% lidocaine. Midazolam was used for sedation if needed. Paracetamol was administered for postoperative analgesia as needed. Codeine was used additionally if the paracetamol was insufficient. The following were evaluated: postoperative pain intensity (over a six-month period), incidence of postoperative neuropathic pain (over a six-month period), need for intraoperative sedation, and use of postoperative paracetamol and codeine. The presence of neuropathic pain was established using the DN4 (Douleur Neuropathique 4) questionnaire. Complex regional pain syndrome was diagnosed using the Budapest questionnaire.

RESULTS

No differences in the need for sedation, control over postoperative pain or incidence of chronic pain syndromes (neuropathic or complex regional pain syndrome) were observed. No differences in postoperative paracetamol and codeine consumption were observed.

CONCLUSIONS

Preoperative gabapentin (600 mg) did not improve postoperative pain control, and did not reduce the incidence of chronic pain among patients undergoing carpal tunnel syndrome surgery.

Chronic pain in the pelvic area or lower extremities after rectal cancer treatment and its impact on quality of life: a population-based cross-sectional study

The aim of this investigation was to examine the prevalence of and factors associated with chronic pain in the pelvic area or lower extremities after rectal cancer treatment and its impact on quality of life (QoL). This is a population-based cross-sectional study of chronic pain and QoL in patients treated for rectal cancer from 2001 to 2007. A modified version of the Brief Descriptive Danish Pain Questionnaire and the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire were mailed to 1713 Danish patients. Informative answers were obtained from 1369 patients (80%). A total of 426 patients (31%) reported chronic pain in the pelvic area or lower extremities, 173 (41%) of whom had daily pain. Pain in other parts of the body was associated with the presence of pain in the pelvic region (odds ratio [OR] 4.81 [3.63-6.38], P < 0.001). Multivariate logistic regression analysis showed an association with chronic pain in female patients (OR 1.91 [1.51-2.43], P < 0.001) and in those who received radio(chemo)therapy (OR 1.31 [1.01-1.7], P = 0.041) or underwent abdominoperineal excision (OR 1.71 [1.19-2.44], P = 0.003), total mesorectal excision (OR 1.39 [1.01-1.90], P = 0.041), and Hartmann procedure (OR 1.72 [1.04-2.84], P = 0.33) compared with partial mesorectal excision. Ordinal regression analysis showed a strong association between all QoL subgroups and pelvic pain. Chronic pain in the pelvic region or lower extremities after rectal cancer treatment is a common but largely neglected problem that is associated with female gender, type of surgery, radio(chemo)therapy, and young age, all of which impact the patient's QoL.

Intrathecal Administration of Morphine Decreases Persistent Pain after Cesarean Section: A Prospective Observational Study

PURPOSE

Chronic pain after cesarean section (CS) is a serious concern, as it can result in functional disability. We evaluated the prevalence of chronic pain after CS prospectively at a single institution in Japan. We also analyzed perioperative risk factors associated with chronic pain using logistic regression analyses with a backward-stepwise procedure.

MATERIALS AND METHODS

Patients who underwent elective or emergency CS between May 2012 and May 2014 were recruited. Maternal demographics as well as details of surgery and anesthesia were recorded. An anesthesiologist visited the patients on postoperative day (POD) 1 and 2, and assessed their pain with the Prince Henry Pain Scale. To evaluate the prevalence of chronic pain, we contacted patients by sending a questionnaire 3 months post-CS.

RESULTS

Among 225 patients who questionnaires, 69 (30.7%) of patients complained of persistent pain, although no patient required pain medication. Multivariate analyses identified lighter weight (p = 0.011) and non-intrathecal administration of morphine (p = 0.023) as determinant factors associated with persistent pain at 3 months. The adjusted odds ratio of intrathecal administration of morphine to reduce persistent pain was 0.424, suggesting that intrathecal administration of morphine could decrease chronic pain by 50%. In addition, 51.6% of patients had abnormal wound sensation, suggesting the development of neuropathic pain. Also, 6% of patients with abnormal wound sensation required medication, yet no patients with persistent pain required medication.

CONCLUSION

Although no effect on acute pain was observed, intrathecal administration of morphine significantly decreased chronic pain after CS.

The Role of Psychological Factors in Persistent Pain After Cesarean Delivery

This French multicenter prospective cohort study recruited 391 patients to investigate the risk factors for persistent pain after elective cesarean delivery, focusing on psychosocial aspects adjusted for other known medical factors. Perioperative data were collected and specialized questionnaires were completed to assess reports of pain at the site of surgery. Three dependent outcomes were considered: pain at the third month after surgery (M3, n = 268; risk = 28%), pain at the sixth month after surgery (M6, n = 239; risk = 19%), and the cumulative incidence (up to M6) of neuropathic pain, as assessed using the Douleur Neuropathique 4 questionnaire (n = 218; risk = 24.5%). The neuropathic aspect of reported pain changed over time in more than 60% of cases, pain being more intense if associated with neuropathic features. Whatever the dependent outcome, a high mental component of quality of life (SF-36) was protective. Pain at M3 was also predicted by pain reported during current pregnancy and a history of miscarriage. Pain at M6 was also predicted by report of a postoperative complication. Incident neuropathic pain was predicted by pain reported during current pregnancy, a previous history of a peripheral neuropathic event, and preoperative anxiety.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00812734.

PERSPECTIVE

Persistent pain after cesarean delivery has a relatively frequent neuropathic aspect but this is less stable than that after other surgeries. When comparing the risk factor analyses with published data for hysterectomy, the influence of preoperative psychological factors seems less important, possibly because of the different context and environment.