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OBJECTIVE The purpose of this study was to describe factors that influence nurses' time from pain assessment to intervention for acute postsurgical pain. BACKGROUND Nurses' time is a limited resource that must be optimized to manage patients' pain within budget constraints. Little is known about processes and activities nurses negotiate to manage pain. METHODS Human factors engineering and ethnography were used to quantify factors influencing time from pain assessment to intervention. RESULTS On the basis of 175.5 observation hours, nurses spent 11% of shifts (mean, 83 minutes) on pain care activities. Time from alert to intervention with PRN analgesics or biobehavioral strategies for 58 cases ranged from 0 to 48 minutes (mean

Purpose of review Thoracic myofascial plane blocks have gained popularity because of their ease of performance and relative safety. This review highlights current research demonstrating the efficacy of these blocks for specific surgical procedures and provides a brief description of how these techniques are performed. Recent findings Fascial plane blocks of the thorax and chest wall have been shown to be beneficial in providing perioperative analgesia for a variety of surgical procedures. Studies discussed in this review compare thoracic fascial plane blocks to systemic analgesia alone, contrast these novel methods of pain control to more traditional techniques, such as paravertebral nerve blocks and epidural anesthesia, and attempt to determine, which fascial plane blocks provide optimal postsurgical analgesia. Summary Thoracic fascial plane blocks provide the anesthesiologist a number of techniques to address postsurgical pain. The relative ease of performance and safety profile of these blocks make them an appealing option for pain control for many patients undergoing thoracic or chest wall surgery. Further research is needed to not only define additional indications for each of these blocks, but also explore optimal dosing including the use of continuous catheter techniques.

BACKGROUND Chronic pain is a common postoperative complication in patients undergoing major surgery and may significantly affect their quality of life (QOL). Whether patient-controlled analgesia (PCA) can reduce the risk of chronic postsurgical pain and promote long-term QOL is still unclear. METHODS In this prospective cohort study, we followed up patients undergoing major surgery, recorded changes in their postoperative QOL over time using the World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire and chronic pain events, evaluated the long-term effects of distinct PCA techniques (intravenous, epidural, or none) on their QOL and risk of chronic pain, and explored relevant predictors. The patients' QOL and chronic pain events were collected preoperatively, 3, 6, and 12 months after surgery. Generalized linear mixed models were used to control for individual heterogeneity and adjust for potential confounding factors. RESULTS We included 328 patients undergoing major surgery from September 22, 2015, to December 31, 2016, in this study. Multivariate regression models showed that patients using intravenous PCA had a better QOL in physical health (adjusted coefficient 3.7, 95% CI, 0.5-8.0) compared with those receiving non-PCA treatments. Distinct PCA techniques did not significantly affect QOL in psychological, social relationship, or environmental domains of the WHOQOL-BREF scale or the risk of chronic postsurgical pain. CONCLUSION Patients using intravenous PCA had a better QOL in physical health over time after major surgery, which may have been due to factors other than pain-relieving effects.

Although chronic postsurgical pain (CPSP) is a major health care problem, pain-related functional interference has rarely been investigated. Using the PAIN OUT registry, we evaluated patients' pain-related outcomes on the first postoperative day, and their pain-related interference with daily living (Brief Pain Inventory) and neuropathic symptoms (DN4: douleur neuropathique en 4 questions) at 6 months after surgery. Endpoints were pain interference total scores (PITS) and their association with pain and DN4 scores. Furthermore, possible risk factors associated with impaired function at M6 were analyzed by ordinal regression analysis with PITS groups (no to mild, moderate, and severe interference) as a dependent three-stage factor. Odds ratios with 95% confidence intervals were calculated. Of 2322 patients, 15.3% reported CPSP with an average pain score ≥3 (numeric rating scale 0-10). Risk for a higher PITS group increased by 190% (odds ratio [95% confidence interval]: 2.9 [2.7-3.2]; P0.001) in patients with CPSP, compared to without CPSP. A positive DN4 independently increased risk by 29% (1.3 [1.12-1.45]; P0.001). Preexisting chronic pain (3.6 [2.6-5.1]; P0.001), time spent in severe acute pain (2.9 [1.3-6.4]; P = 0.008), neurosurgical back surgery in males (3.6 [1.7-7.6]; P0.001), and orthopedic surgery in females (1.7 [1.0-3.0]; P = 0.036) were the variables with strongest association with PITS. Pain interference total scores might provide more precise information about patients' outcomes than pain scores only. Because neuropathic symptoms increase PITS, a suitable instrument for their routine assessment should be defined.

Editor’s PerspectiveWhat We Already Know about This TopicWhat This Article Tells Us That Is NewBackgroundEmerging evidence suggests that opioid use immediately after surgery and trauma may worsen outcomes. In these studies, the authors aimed to determine whether morphine administered for a clinically relevant time period (7 days) in a tibia fracture orthopedic surgery model had adverse effects on postoperative recovery.MethodsMice were given morphine twice daily for 7 days after unilateral tibial fracture and intramedullary pin fixation to model orthopedic surgery and limb trauma. Mechanical allodynia, limb-specific weight bearing, gait changes, memory, and anxiety were measured after injury. In addition, spinal cord gene expression changes as well as glial activation were measured. Finally, the authors assessed the effects of a selective Toll-like receptor 4 antagonist, TAK-242, on nociceptive and functional changes after injury.ResultsTibial fracture caused several weeks of mechanical nociceptive sensitization (F(1, 216) = 573.38, P < 0.001, fracture + vehicle vs. sham + vehicle, n = 10 per group), and this change was exacerbated by the perioperative administration of morphine (F(1, 216) = 71.61, P < 0.001, fracture + morphine vs. fracture + vehicle, n = 10 per group). In additional testing, injured limb weight bearing, gait, and object location memory were worse in morphine-treated fracture mice than in untreated fracture mice. Postfracture expression levels of several genes previously associated with opioid-induced hyperalgesia, including brain-derived neurotrophic factor and prodynorphin, were unchanged, but neuroinflammation involving Toll-like receptor 4 receptor–expressing microglia was observed (6.8 ± 1.5 [mean ± SD] cells per high-power field for fracture + vehicle vs. 12 ± 2.8 fracture + morphine, P < 0.001, n = 8 per /group). Treatment with a Toll-like receptor 4 antagonist TAK242 improved nociceptive sensitization for about 2 weeks in morphine-treated fracture mice (F(1, 198) = 73.36, P < 0.001, fracture + morphine + TAK242 vs. fracture + morphine, n = 10 per group).ConclusionsMorphine treatment beginning at the time of injury impairs nociceptive recovery and other outcomes. Measures preventing glial activation through Toll-like receptor 4 signaling may reduce the adverse consequences of postoperative opioid administration.

Purpose of review The increasing number of procedures done in the ambulatory surgical setting necessitates the need for analgesic modalities that enable the management of postsurgical pain with fast onset, predictable duration of action, and minimal need for management of undesirable side-effects. Recent findings The novel strategies for administration of local anesthetics in the ambulatory setting include prolonging their analgesic action at the site of surgical trauma while reducing systemic effects that result from their metabolism. Development of opioids aims to address receptor sites that provide for modulation of pain perception while reducing systemic, central effects of μ-receptor agonism. Other, more titratable agents with analgesic properties are also addressed. Summary Local anesthetics, opioids, and NSAIDS are the mainstay of multimodal analgesic management, and as such, improving their efficacy in the ambulatory surgical setting remains the primary focus. However, as knowledge of the modulating pathways involved in transduction of pain increases, newer agents that utilize this knowledge are also becoming more widely available.

Chronic postmastectomy pain (PMP) imposes a major burden on the quality of life of the ever-increasing number of long-term survivors of breast cancer. An earlier report by Nissenbaum et al. claimed that particular polymorphisms in the gene CACNG2 are associated with the risk of developing ch

Hysterectomy is a common surgical procedure with a low risk of major complications. However, some women experience long-lasting complications, including chronic postsurgical pain, which can have a negative impact on their quality of life. This review aims to present the recent literature on chronic pain following hysterectomy for benign indications.Chronic pain following hysterectomy is reported in 10-50% of women. Risk factors include preoperative pelvic pain, pain elsewhere, acute postoperative pain, surgical procedure, and psychological factors such as anxiety and depression. The pain may be neuropathic in 5-50% of cases.Chronic pain may occur after hysterectomy. Preoperative screening tools, including psychological screening for depression and anxiety, may identify women at risk of developing chronic postsurgical pain, and future studies should examine perioperative interventions aimed at preventing the development of chronic pain after hysterectomy.

Chronic postsurgical pain (CPSP) is an important and well recognized cause of much long-term suffering, which in some cases may be preventable and affects many people living with cancer. Unfortunately, general consensus is lacking as to how best reduce the risk of developing CPSP.Cancer is now not always a short-lived, fatal disease and is now moving towards a chronic illness. Poorly managed perioperative pain is the greatest risk factor for CPSP. Recent trials have examined preventive strategies for CPSP associated with breast surgery and thoracotomy, two operations used in cancer treatment. Standard antinociceptive drugs, 5% lidocaine patches and ketamine do not prevent CPSP. The evidence for gabapentinoids is conflicting. Intravenous lidocaine and, separately, regional anaesthesia appear beneficial.Well-managed pain, irrespective of technique, reduces the risk of CPSP. The literature is inconclusive regarding an 'optimal approach.' Regional anaesthesia, intravenous lidocaine and the aggressive management of perioperative pain using multimodal analgesia including antineuropathic pain agents such as gabapentinoids and certain antidepressants are recommended. Clinicians should not rely on general anaesthesia, opioids, NSAIDs and ketamine to prevent CPSP. A blanket approach using gabapentinoids for all patients undergoing major surgery is not indicated. Instead, the presence of perioperative neuropathic pain should be checked for regularly.

Background Effective pain management is an essential component in the perioperative care of surgical patients. However, postoperative pain after maxillofacial fracture repair and its optimal therapy has not been described in detail. Materials and methods In a prospective cohort study, 95 adults rated their pain on the first postoperative day after maxillofacial fracture repair using the questionnaire of the Quality Improvement in Postoperative Pain Management (QUIPS) project. Quality Improvement in Postoperative Pain Management allowed for a standardized assessment of patients' characteristics and pain-related parameters. Results Overall, the mean maximal pain and pain on activity (numeric rating scales) were significantly higher in patients with mandibular fractures than in patients with midface fractures (P = 0.002 and P = 0.045, respectively). In patients with mandibular fractures, a longer duration of surgery was significantly associated with higher satisfaction with pain intensity (P = 0.015), but was more frequently associated with postoperative vomiting (P = 0.023). A shorter duration of surgery and an absence of preoperative pain counseling in these patients were significantly correlated to desire for more pain medication (P = 0.049 and P = 0.004, respectively). Patients with mandibular fractures that received opioids in the recovery room had significantly higher strain-related pain (P = 0.017). In patients with midface fractures, a longer duration of surgery showed significantly higher levels of decreased mobility (P = 0.003). Patients receiving midazolam for premedication had significantly less minimal pain (P = 0.021). Conclusions Patients with mandibular fractures seem to have more postoperative pain than patients with midface fractures. Monitoring of postsurgical pain and a procedure-specific pain-treatment protocol should be performed in clinical routine.

Caudal anesthesia has been used for postoperative pain control in pediatric surgical patients, but the duration of the analgesic effect is occasionally unsatisfactory. Intravenous steroids have been shown to be effective for postsurgical pain management after certain surgeries. The aim of this meta-analysis with trial sequential analysis (TSA) was to evaluate the analgesic effect of steroids in patients administered with caudal anesthesia.This study was a systematic review and meta-analysis. A search of published literature was conducted in the MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases and in trial registration sites. Randomized controlled trials that compared intravenous steroids with a placebo in pediatric patients who had received caudal anesthesia for surgery were included in the study. The primary outcomes from the present meta-analysis were the analgesic duration and the number of patients who required rescue analgesics. The analgesic duration and incidence of rescue use were summarized using mean difference or risk ratio with a 97.5% confidence interval (CI), respectively. If the 97.5% CI of the mean difference or risk ratio included a value of 0 or 1, respectively, we considered the difference not to be significant. We used the random effects model to combine the results. Heterogeneity was quantified with the I statistic. The quality of the trials was evaluated using the Cochrane methodology. Moreover, a TSA with a risk of type 1 error of 2.5% and power of 90% was performed. We established the minimum clinically meaningful difference of analgesic duration as 3 hours. The target sample size for meta-analysis was also calculated in the TSA. We also assessed adverse events.Six trials with 424 patients were included; 211 patients received intravenous steroids. All trials compared dexamethasone of at least 0.5 mg/kg dose with a placebo. Dexamethasone prolonged the duration of caudal analgesia (mean difference, 244 minutes; 97.5% CI, 188-300). Heterogeneity was considerable with an I value of 94.8%. Quality of evidence was very low. The TSA suggested that only 17.0% of the target sample size had been reached, but the cumulative Z score crossed the trial sequential monitoring boundary to indicate a benefit. Rescue use was reported in 4 studies with 260 patients. Rescue use was not significantly reduced in the dexamethasone group (risk ratio, 0.53; 97.5% CI, 0.09-3.30; I, 98.7%). No increase in adverse events was reported.Intravenous dexamethasone prolongs the analgesic duration of caudal anesthesia. Trials to investigate the effectiveness of a lower dose of the dexamethasone in prolonging analgesic effects would be of interest. Further trials with a low risk of bias are necessary.

Supplemental Digital Content is Available in the Text. Examining the divergence of prevalence and predictors of postsurgical numbness vs positive neuropathic symptoms gives insights into variation in clinical postoperative pain experienced by patients., Introduction: Both positive (burning, stabbing, and allodynia) and negative (numbness) neuropathic symptoms may arise after surgery but likely contribute differently to patients' postoperative pain experience. Numbness has been identified as divergent from positive neuropathic symptoms and therefore excluded from some neuropathic assessment tools (Neuropathic Pain Scale for PostSurgical patients [NeuPPS]). Objectives: In this prospective longitudinal study of patients undergoing breast surgery, we aimed to delineate the time course of numbness and its coincidence with NeuPPS and to contrast the association of surgical, psychosocial, and psychophysical predictors with the development of negative vs positive neuropathic symptoms. Methods: Patients reported surgical area sensory disturbances at 2 weeks and 3, 6, and 12 months postoperatively. Association of baseline demographic, surgical, psychosocial, and psychophysical factors with NeuPPS and numbness across time was investigated using generalized estimating equation linear and logistic regression. Results: Numbness was consistently reported by 65% of patients; positive neuropathic symptoms were less common, often decreasing over time. Neuropathic Pain scale for PostSurgical patients and numbness co-occurred in half of patients and were both associated with greater clinical pain severity and impact, younger age, axillary surgery, and psychosocial factors. More extensive surgery and chemotherapy were only associated with numbness. Conversely, other chronic pain, lower physical activity, perioperative opioid use, negative affect, and lower baseline pressure pain threshold and tolerance were only associated with NeuPPS. Patients reporting numbness alone did not endorse substantial clinical pain. Conclusions: Differentiation of predictors, prevalence, and time course of numbness vs NeuPPS in breast surgical patients revealed important distinctions, suggesting that their independent assessment is worthwhile in future studies of postsurgical pain.

Erector spinae plane (ESP) continuous catheters are used for the management of postsurgical pain. The use of these catheters for acute nonsurgical abdominal pain is not well defined. This case describes a patient with refractory abdominal pain secondary to necrotizing pancreatitis despite escalating doses of opioids, ketamine, and dexmedetomidine. Our patient declined epidural analgesia. Bilateral ESP continuous catheters successfully controlled her pain, and she was weaned off of all analgesics during the week following catheter placement. This case demonstrates that ESP continuous catheters can be considered for patients with acute nonsurgical abdominal pain especially when thoracic epidural analgesia is contraindicated.

BACKGROUNDPerioperative regional anaesthesia may protect from persistent postsurgical pain (PPSP) and improve outcome after total knee arthroplasty (TKA).OBJECTIVESAim of this study was to evaluate the impact of regional anaesthesia on PPSP and long-term functional outcome after TKA.DESIGNA web-base

To evaluate the efficacy of pulsed electromagnetic field (PEMF) in relation to reducing postoperative pain, analgesic use, and wound healing in patients undergoing Cesarean section (C-section).This randomized, double-blind, placebo-controlled trial evaluated 72 women who underwent elective C-section. Thirty-six patients were assigned to the active-PEMF and 36 to the sham-PEMF groups. The participants were asked to report their pain intensity on a Visual Analog Scale (VAS) at 2, 4, 6, 12, and 24 hours and 2, 4, and 7 days after surgery. The amount of analgesics used was recorded. The surgical site was evaluated to assess the wound-healing process on the seventh postoperative day.Postoperative pain VAS scores were significantly lower in the active-PEMF group in all the measured periods within the early and the late postoperative periods. Fewer women in the active-PEMF group experienced severe postoperative pain within 24 hours postoperatively (36% vs. 72%, P=0.002). Analgesic use during the first 24 hours after C-section was 1.9-times lower in the active-PEMF group (1.6±0.7 vs. 3.1±1.2, P0.001). The total analgesic use during the seventh postoperative days was 2.1-times lower in the active-PEMF group than in the sham group (1.7±0.7 vs. 3.7±1.1, P0.001). Seven days postoperatively, patients in the active-PEMF group had better wound healing with no exudate, erythema, or edema (P=0.02).PEMF treatment after C-section decreases postsurgical pain, analgesic use, and surgical wound exudate and edema significantly, and is associated with a high level of patient satisfaction.

Tonsillectomy is a frequently performed surgical procedure in children; however, few multimodal analgesic strategies have been shown to improve postsurgical pain in this patient population. Systemic magnesium infusions have been shown to reliably improve postoperative pain in adults, but their effects in pediatric surgical patients remain to be determined. In the current investigation, our main objective was to evaluate the use of systemic magnesium to improve postoperative pain in pediatric patients undergoing tonsillectomy. We hypothesized that children who received systemic magnesium infusions would have less post-tonsillectomy pain than the children who received saline infusions.The study was a prospective, randomized, double-blinded, clinical trial. Subjects were randomly assigned using a computer-generated table of random numbers to 1 of the 2 intervention groups: systemic magnesium infusion (initial loading dose 30 mg/kg given over 15 minutes followed by a continuous magnesium infusion 10 mg/kg/h) and the same volume of saline. The primary outcome was pain scores in the postanesthesia care unit (PACU) measured by FLACC (Face, Legs, Activity, Cry, Consolability) pain scores. Pain reduction was measured by the decrement in the area under the pain scale versus 90-minute postoperative time curve using the trapezoidal method. Secondary outcomes included opioid consumption in the PACU, emergence delirium scores (measured by the pediatric anesthesia emergence delirium scale), and parent satisfaction.Sixty subjects were randomly assigned and 60 completed the study. The area under pain scores (up to 90 minutes) was not different between the study groups, median (interquartile range [IQR]) of 30 (0-120) score × min and 45 (0-135) score × min for the magnesium and control groups, respectively (P = 0.74). Similarly, there was no clinically significant difference in the morphine consumption in the PACU between the magnesium group, median (IQR) of 2.0 (0-4.44) mg IV morphine, compared with the control, median (IQR) of 2.5 (0-4.99) mg IV morphine (P = 0.25). The serum level of magnesium was significantly lower in the control group than in the treatment group at the end of the surgery (P0.001).Despite a large number of studies demonstrating the efficacy of systemic magnesium for preventing postsurgical pain in adults, we could not find evidence for a significant clinical benefit of systemic magnesium infusion in children undergoing tonsillectomies. Our findings reiterate the importance of validating multimodal analgesic strategies in children that have been demonstrated to be effective in the adult population.

Pain and physical activity are tightly intertwined. Although their relationship has been explored in chronic pain conditions, we know little about the pattern of recovery in activity and its short- and long-term relationship with pain after surgery. We recruited 103 women undergoing elective cesarean delivery and acquired daily pain assessments and hourly steps in 98 of them for 2 months after surgery. Compliance was good, with 78% of subjects missing less than 7 days of activity. Study personnel required daily checking for compliance and 20 minutes per subject per week in study. Activity increased over the first 2 postoperative months in a log(time) manner. The slope of each modeled individual curve for activity was inversely correlated (r = -0.54; P < 0.0001) with worst daily pain. After removing these 2-month trends, pain and activity within an individual day were negatively associated with each point increase in pain being inversely associated with -119 steps (95% confidence interval [CI] = -214 to -25; P = 0.013). A patient's previous experience of pain was not associated with current activity as well as current activity was not associated with future pain scores. These data, although limited by the study of a single operation in a unique social circumstance with low risk of chronic postsurgical pain, demonstrate feasibility of measuring hourly activity for 2 months after surgery. Recovery from pain and inactivity are tightly correlated, and the negative relationship between within-day pain and activity without interday carryover relationships is in stark contrast to findings in chronic pain conditions.

Background: Chronic postsurgical pain (CPSP) has been linked to many surgical settings. The authors aimed to analyze functional genetic polymorphisms and clinical factors that might identify CPSP risk after inguinal hernia repair, hysterectomy, and thoracotomy. Methods: This prospective multicenter cohort study enrolled 2,929 patients scheduled for inguinal hernia repair, hysterectomy (vaginal or abdominal), or thoracotomy. The main outcome was the incidence of CPSP confirmed by physical examination 4 months after surgery. The secondary outcome was CPSP incidences at 12 and 24 months. The authors also tested the associations between CPSP and 90 genetic markers plus a series of clinical factors and built a CPSP risk model. Results: Within a median of 4.4 months, CPSP had developed in 527 patients (18.0%), in 13.6% after hernia repair, 11.8% after vaginal hysterectomy, 25.1% after abdominal hysterectomy, and 37.6% after thoracotomy. CPSP persisted after a median of 14.6 months and 26.3 months in 6.2% and 4.1%, respectively, after hernia repair, 4.1% and 2.2% after vaginal hysterectomy, 9.9% and 6.7% after abdominal hysterectomy, and 19.1% and 13.2% after thoracotomy. No significant genetic differences between cases and controls were identified. The risk model included six clinical predictors: (1) surgical procedure, (2) age, (3) physical health (Short Form Health Survey-12), (4) mental health (Short Form Health Survey-12), (5) preoperative pain in the surgical field, and (6) preoperative pain in another area. Discrimination was moderate (c-statistic, 0.731; 95% CI, 0.705 to 0.755). Conclusions: Until unequivocal genetic predictors of CPSP are understood, the authors encourage systematic use of clinical factors for predicting and managing CPSP risk.

This article summarizes the current evidence for the use of gabapentinoids in the perioperative setting and provides useful clinical recommendations regarding dosing, timing, and choice of agent.

Purpose of review The aim of the present review is to describe how regional anaesthesia might oppose neuronal changes that surgery and opioids cause in the central nervous system to block both pain sensitization and chronicization following surgery. This might help anaesthesiologists to better understand the impact of their practice on the development of postoperative chronic pain. Recent findings Even though there are more evidences from animals and clinical trials showing that regional anaesthesia might impact the acute pain/hyperalgesia and chronic postsurgical pain, the controversy on how and when to use regional anesthesia to avoid chronic pain persists. Animal studies brought only a very partial answer on what to do in our daily clinical practice. Clinical studies were performed in different types of surgery with various protocols so that a strong conclusion on whether or not using regional anesthesia might benefit the patient to decrease the risk of postoperative chronic pain remains unclear. Studies performed with neuraxial anaesthesia seem to bring better evidences than those with nerve blocks. Future studies will have to specifically evaluate acute hyperalgesia and postoperative chronic pain and not only the classical pain scores and analgesic consumption to bring us the answer we all need. Summary Regional anaesthesia is able to reduce postoperative acute hyperalgesia and long-term chronic pain by decreasing pain sensitization induced by the surgery itself, and intraoperative use and opioid-induced hyperalgesia. Nevertheless, clinical studies on neuraxial anaesthesia and nerve blocks did not bring so far a strong conclusion to this question, and further better designed studies are necessary.

Persistent postsurgical pain (PPP) is an important cause of pain morbidity following surgery for almost any cause, but there is a greater evidence base for pain after cancer surgery. Historically, both patients and practitioners have struggled to recognize and accept this growing problem. This review will seek to highlight the awareness of this increasing epidemic and will discuss evidence base for diagnosis, risk factors and current strategies for prevention and treatment, especially after cancer surgery.Given the potential size of the problems of PPP, there is a relative paucity of recent data, especially as regards effective treatments. The review will synthesize current and existing evidence to give a balanced up-to-date view. There is a clear need for more high-quality randomized trials.An estimated 40,000 patients in the UK will develop PPP, of whom at least 5-10% will have severe pain. Lack of clear definition and lack of awareness have been barriers to diagnosis and access to treatment. Several risk factors associated with PPP have been identified and reduction of these factors may prevent its development. At present, there are large gaps in the evidence base and more large controlled trials are warranted.

The aim of this study was to examine the joint role of demographic, clinical, and psychological variables 30 as predictors of acute postsurgical pain in women undergoing hysterectomy due to benign disorders. A 31 consecutive sample of 203 women was assessed 24 hours before (T1) and 48 hours after (T2) surgery. 32 Baseline pain and predictors were assessed at T1 and postsurgical pain and analgesic consumption at 33 T2. Several factors distinguished women who had no or mild pain after surgery from those who had mod- 34 erate to severe pain, with the latter being younger, having more presurgical pain, and showing a less 35 favorable psychological profile. Younger age (odds ratio [OR] = 0.90, P < .001), presurgical pain 36 (OR = 2.50, P, Fundação para a Ciência e a Tecnologia (FCT), The authors gratefully acknowledge the contributions of Falko Sniehotta, PhD, and Justin Presseau, PhD, for suggestions. The authors also thank all of the women who agreed to participate in this study.

Quantitative testing of a patient's basal pain perception before surgery has the potential to be of clinical value if it can accurately predict the magnitude of pain and requirement of analgesics after surgery. This review includes 14 studies that have investigated the correlation between preoperative responses to experimental pain stimuli and clinical postoperative pain and demonstrates that the preoperative pain tests may predict 4-54% of the variance in postoperative pain experience depending on the stimulation methods and the test paradigm used. The predictive strength is much higher than previously reported for single factor analyses of demographics and psychologic factors. In addition, some of these studies indicate that an increase in preoperative pain sensitivity is associated with a high probability of development of sustained postsurgical pain.

Review Objective The objective of this systematic review is to synthesise the best available evidence on children’s experiences of the management of their postoperative pain at the hospital or home within a fortnight after a surgical procedure. Review question What are children’s experiences of the management of their postoperative pain at home and/or in the hospital within a fortnight after a surgical procedure? Inclusion Criteria Types of participants The review will consider publications that include the postoperative management of children aged between four to 18 years old,55 who have undergone surgery in the hospital and stayed in surgical, day surgery wards or ambulatory care units. The age group of four to 18 years was chosen as children younger than four have different linguistic abilities and have postoperative needs, which are beyond the scope of this systematic review. Phenomena of interest The review will consider studies that include the following phenomena of interest: children’s experiences in the management of their own postoperative pain. Context Context may include, but is not limited to, paediatric surgical wards in acute care hospital settings or in home settings within half a month after the surgery. Outcomes of interest The outcomes of interest include, but are not restricted to the following: • Strategies used by children for the management of their own post-operative pain. • Strategies used by children’s parents and nurses for the management of children’s post-operative pain based on children’s experiences. • Needs or suggestions provided by children for better management of their post-operative pain.

Background The authors have demonstrated a decrease in pH in the incisional wound environment, suggesting a possible contribution of low pH to postsurgical pain. In this study, the authors characterized the acid-responsiveness of nociceptors innervating the plantar aspect of the rat hind paw 1 day after plantar incision and compared this to plantar skin from unincised control rats. Methods Using the rat glabrous in vitro skin-tibial nerve preparation, afferent nerve activities from single mechanosensitive nociceptors were recorded. Differences in mechanosensitivity, spontaneous activity, and chemosensitivity of units were evaluated. For chemosensitivity, acid-responsiveness of nociceptors to lactic acid (pH 5.5 to 6.5) was studied. Results C-fibers showed dose-dependent, sustained responses to lactic acid. A greater proportion of C-fibers from 2 mm or less from the incision was activated by pH 6.0 lactic acid (52.9%) compared to control (14.3%). Total evoked potentials during acid exposure were greater in C-fibers innervating 2 mm or less from the incision compared to those in unincised skin. The prevalence of acid responses and total evoked potentials during acid exposure in C-fibers innervating more than 2 mm from the incision were not different from control. Few A-fibers responded to lactic acid, with a range of pH 5.5 to 6.5 in both incision and control groups. Increased spontaneous activity and mechanosensitivity were also evident. Conclusions C-fibers in the vicinity of the incision showed qualitatively and quantitatively greater chemosensitivity to pH 6.0 lactic acid compared to control. This change was localized to 2 mm or less from the incision, suggesting increased chemosensitivity of nociceptive C-fibers 1 day after plantar incision.

Gabapentin and pregabalin bind to the alpha-2-delta calcium channel subunit and represent a novel analgesic drug class. The evidence base supporting their use for chronic neuropathic and early postsurgical pain is reviewed.Multiple, large, high-quality trials have demonstrated the safety and efficacy of gabapentin and pregabalin in neuropathic pain. Treatment-related improvement of pain and sleep positively impact upon quality of life. Sedation, dizziness and ataxia are important and relatively common adverse effects, however. Accumulating evidence indicates that gabapentin, and possibly pregabalin, also exert important effects following surgery. Multiple high-quality trials have demonstrated analgesic and opioid-sparing efficacy with gabapentin following various surgical procedures. Gabapentin and pregabalin reduce movement-evoked pain and this can lead to enhanced functional postoperative recovery. Postoperative opioid sparing is of questionable relevance since few trials have shown reduced opioid-related adverse effects. Sedation, dizziness and ataxia have been reported in only a few trials. Future larger-scale perioperative trials focused on safety assessment are needed, however.Gabapentin and pregabalin are efficacious treatments for neuropathic and postsurgical pain. Future research addressing several specific questions would serve to better delineate their optimal roles in treating these and other pain conditions.

Background Treatment of postsurgical pain is a major use of analgesics, particularly after abdominal surgery. Analgesics display a number of limiting side effects, including sedation, cognitive impairment, and ileus. Although several postoperative rodent models have been developed, these models do not address these concerns. Methods A model is presented in the rat in which a subcostal incision is performed, penetrating into the peritoneal cavity. The behavioral effects of this surgical procedure are assessed using exploratory locomotor activity and conditioned operant responding. The effects of morphine and ketorolac were assessed in both behavioral paradigms. Results Laparotomy decreased ambulation and rearing by approximately 50% 24 h after surgery, and stereotypy (small confined movements) was affected to a lesser degree. The effects of laparotomy on conditioned operant responding were more complex. Total number of sucrose pellets earned was decreased for 2-3 days after laparotomy; however, the amount of time required was increased for up to 2 weeks. Morphine reversed the effects of surgery on ambulation and stereotypy but not rearing, and the dose-effect curve for morphine was shifted to the left by 5 mg/kg ketorolac. Ketorolac produced significant improvement in operant responding after laparotomy, and coadministration of ineffective doses of morphine and ketorolac produced a positive response. Conclusion The current model is consistent with behavioral aspects of postoperative pain seen clinically. The effects of morphine and ketorolac alone and in combination were consistent with the reported analgesic efficacy and occurrence of side effects found with these agents clinically.

The aim of this study was to document the level of pain and functionality in the 12 months following orthopedic surgery and identify if high pain levels following discharge were associated with pain persisting at 12 months. An observational prospective cohort study was undertaken, following 87 patients (mean age 62.4 years [18–92]; 47.1% male) who required orthopedic surgery at the Royal Hobart Hospital, Australia. Following an initial survey, patients were telephoned at 10 days, 6 weeks, 3 months, and 12 months after discharge. Postdischarge pain levels were high with 97.4% of patients suffering pain at 10 days, 81.2% at 6 weeks and 79.5% at 3 months. Pain affected the ability to undertake activities of daily living (ADLs) for 32.7% and 20.0% of patients at 10 days and 6 weeks, respectively. Twelve months after discharge, 65.5% of patients reported pain persisting at the surgical site, with 29.9% of all patients suffering moderate–severe incidental pain; and nearly one quarter of patients reported pain affected their sleep or ADLs. Average pain levels rated as moderate–severe at 10 days (P = 0.01) and 6 weeks (P = 0.02) and pain of neuropathic origin at 3 months (30.2% vs 10.3% P = 0.03) and 12 months (30.4% vs 4.9% P = 0.01) were associated with persistent pain at 12 months. Pain in the period following discharge from hospital is significant and undermanaged. Previous studies has shown that that acute pain, particularly in the first 48 hours following surgery is a predictor for long-term pain after surgery. This study adds to the current literature by showing that pain in the subacute period, following discharge from hospital is also associated with the pain persisting at 12 months. These findings have important implications for improving quality of life as well as potentially preventing persistent pain with increased follow-up and more intensive management of post-discharge pain.

Background: Chronic postsurgical pain (CPSP) has been linked to many surgical settings. The authors aimed to analyze functional genetic polymorphisms and clinical factors that might identify CPSP risk after inguinal hernia repair, hysterectomy, and thoracotomy. Methods: This prospective multicenter cohort study enrolled 2,929 patients scheduled for inguinal hernia repair, hysterectomy (vaginal or abdominal), or thoracotomy. The main outcome was the incidence of CPSP confirmed by physical examination 4 months after surgery. The secondary outcome was CPSP incidences at 12 and 24 months. The authors also tested the associations between CPSP and 90 genetic markers plus a series of clinical factors and built a CPSP risk model. Results: Within a median of 4.4 months, CPSP had developed in 527 patients (18.0%), in 13.6% after hernia repair, 11.8% after vaginal hysterectomy, 25.1% after abdominal hysterectomy, and 37.6% after thoracotomy. CPSP persisted after a median of 14.6 months and 26.3 months in 6.2% and 4.1%, respectively, after hernia repair, 4.1% and 2.2% after vaginal hysterectomy, 9.9% and 6.7% after abdominal hysterectomy, and 19.1% and 13.2% after thoracotomy. No significant genetic differences between cases and controls were identified. The risk model included six clinical predictors: (1) surgical procedure, (2) age, (3) physical health (Short Form Health Survey-12), (4) mental health (Short Form Health Survey-12), (5) preoperative pain in the surgical field, and (6) preoperative pain in another area. Discrimination was moderate (c-statistic, 0.731; 95% CI, 0.705 to 0.755). Conclusions: Until unequivocal genetic predictors of CPSP are understood, the authors encourage systematic use of clinical factors for predicting and managing CPSP risk.

Background Although several patient characteristic, clinical, and psychological risk factors for chronic postsurgical pain (CPSP) have been identified, genetic variants including single nucleotide polymorphisms have also become of interest as potential risk factors for the development of CPSP. The aim of this review is to summarize the current evidence on genetic polymorphisms associated with the prevalence and severity of CPSP in adult patients. Methods A systematic review of the literature was performed, and additional literature was obtained by reference tracking. The primary outcome was CPSP, defined as pain at least 2 months after the surgery. Studies performed exclusively in animals were excluded. Results Out of the 1001 identified studies, 14 studies were selected for inclusion. These studies described 5269 participants in 17 cohorts. A meta-analysis was not possible because of heterogeneity of data and data analysis. Associations with the prevalence or severity of CPSP were reported for genetic variants in the COMT gene, OPRM1, potassium channel genes, GCH1, CACNG, CHRNA6, P2X7R, cytokine-associated genes, human leucocyte antigens, DRD2, and ATXN1. Conclusions Research on the topic of genetic variants associated with CPSP is still in its initial phase. Hypothesis-free, genome-wide association studies on large cohorts are needed in this field. In addition, future studies may also integrate genetic risk factors and patient characteristic, clinical, and psychological predictors for CPSP.

Purpose of review Paravertebral blocks are becoming increasingly popular, especially as an anesthetic adjunct for breast procedures. New reports suggest additional reasons for adding this block to the anesthetic armamentarium. Recent findings Recent studies demonstrate a benefit from preoperative placement of a paravertebral block, not only in reducing acute postoperative pain, but also statistically significant reductions in the percentage of patients that develop chronic postsurgical pain 1 year after surgery. Another study found that the breast-cancer recurrence rate at 36 months after surgery was lower in the paravertebral group compared with the general anesthesia-only group of patients. Summary Paravertebral blocks are a well established option to provide anesthesia and postoperative analgesia during breast surgery. Recent studies suggest additional benefits to this procedure. Not only is acute pain better controlled, but the development of chronic mastectomy pain syndrome and recurrence of cancer may be reduced by preoperative placement of paravertebral block. These studies provide additional reasons why this block should be considered as part of the anesthetic for breast surgery.

A middle-range theory for Chronotherapeutic Intervention in Postsurgical Pain (CIPP) is presented. This theory supports time-dependent approaches to pain assessment and intervention that may be implemented by nurses in the clinical setting. CIPP was inductively derived from chronobiologic literature and validated through investigations in three separate chronobiologic studies. A circadian rhythm in pain was identified in Study I, with 19 postsurgical gynecologic oncology patients, and validated in Study II, with 45 postsurgical patients. Study III, a randomized clinical trial of 71 gynecologic oncology patients, compared the efficacy of chronotherapeutic versus continuous fixed-rate basal and demand-only PCA therapy for postoperative pain relief.