Risk Factors For Persistent Pain Research Articles

Association of Pain, Analgesic, Psychological, and Socioeconomic Factors With Subacute Pain After Childbirth: A Prospective Cohort Study

(J Clin Anesth. 2022;83:110978 | https://doi.org/10.1016/j.jclinane.2022.110978|) Persistent postpartum pain poses significant societal and health care challenges. It is defined by the International Association for the Study of Pain as pain lasting beyond 3 months after tissue injury, affecting up to 30% of postpartum women. Research primarily focuses on risk factors for persistent pain, including severe acute postpartum pain, psychological factors, and social deprivation. However, there is a lack of investigation into subacute pain after childbirth (lasting 4 wk to 3 mo). A previous study identified some risk factors for subacute pain, but the relationship between acute postpartum pain and subacute pain remains unexplored. This study aims to investigate these associations and explore potential interventions by anesthesiologists.

Neuropathic pain after surgery - A clinical validation study and assessment of accuracy measures of the 5-item NeuPPS scale.

The aim of this study was to validate the Neuropathic Pain for Post-Surgical Patients (NeuPPS) scale against clinically verified neuropathic pain (NP) by quantitative sensory testing (QST) as well as evaluation of other psychometric properties. The NeuPPS is a validated 5-item scale designed to evaluate NP in surgical populations. Data from 537 women aged >18 years scheduled for primary breast cancer surgery enrolled in a previous study for assessing risk factors for persistent pain after breast cancer treatment were used. Exclusion criteria were any other breast surgery or relevant comorbidity. A total of 448 eligible questionnaires were available at 6 months and 455 at 12 months. At 12 months, 290 patients completed a clinical examination and QST. NeuPPS and PainDETECT were analyzed against patients with and without clinically verified NP. NP was assessed using a standardized QST protocol including a clinical assessment. Furthermore, the NeuPPS and PainDETECT scores were psychometrically tested with an item response theory method, the Rasch analysis, to assess construct validity. Primary outcomes were the diagnostic accuracy measures for the NeuPPS, and secondary measures were psychometric analyses of the NeuPPS after 6 and 12 months. PainDETECT was also compared to clinically verified NP as well as NeuPPS comparing the stability of the estimates. Comparing the NeuPPS scores with verified NP using a receiver operating characteristic curve, the NeuPPS had an area under the curve of 0.80. Using a cutoff of 1, the NeuPPS had a sensitivity of 88% and a specificity of 59%, and using a cutoff of 3, the values were 35 and 96%, respectively. Analysis of the PainDETECT indicated that the used cutoffs may be inappropriate in a surgical population. The present study supports the validity of the NeuPPS as a screening tool for NP in a surgical population.

Neuropathic pain of the superficial branch of the radial nerve — Factors influencing surgical outcome and patient satisfaction

BackgroundDue to its partially superficial course, the superficial branch of the radial nerve is vulnerable to injury by trauma or surgery, potentially leading to painful neuroma. Surgical treatment is difficult. Among other factors, smoking and duration of pain before revision surgery have been suggested as risk factors for persistent pain after surgical revision, without concrete evidence. The aim of this study was therefore to identify factors influencing the outcome of revision surgery in SBRN neuropathic pain in our department. MethodsAll 51 patients receiving revision surgery of the superficial branch of the radial nerve for neuropathic pain from 2010 to 2020 were contacted; 19 agreed to return for assessment. A medical chart review was performed to collect patient-, pain- and treatment-specific factors. Outcomes were recorded. In an outpatient consultation, clinical follow-up was performed and patients filled out the DASH, MHQ and painDETECT questionnaires. ResultsAfter revision surgery, all patients experienced persistent pain. On multivariate logistic regression evaluating the risk of persistent pain, only smoking emerged as an independent risk factor. Age, gender, dominant side, location, time between trigger and surgery or diagnosis did not emerge as risk factors. No predictor for successful return to work could be identified. ConclusionsTreatment of painful neuroma of the superficial branch of the radial nerve is a challenge. Patients with neuropathic pain should be coached toward smoking cessation before neuroma surgery. Surgery can show benefit even after long symptom duration. No correlations between study clinical variables or test results and return to work could be identified, suggesting that other factors play a role in return to work.

Characteristics and Perioperative Risk Factors for Persistent Pain after Breast Cancer Surgery: A Prospective Cohort Study

Objective: Persistent pain is a common complication after breast cancer surgery. We sought to determine the characteristics of persistent pain after breast cancer surgery and identify perioperative risk factors associated with its development. Methods: This prospective cohort study uses data from a prior randomized controlled trial of 100 patients undergoing breast cancer surgery. Patients were assessed on the presence and characteristics of pain at 3 months after surgery. Baseline and perioperative data were explored for potential associations with persistent pain in univariate and multivariate logistic regression models. Results: Fifty-three percent of patients reported persistent pain 3-months after surgery. Pain was primarily located in the axilla, chest, and shoulder, with the vast majority of patients with pain (96.2%) reporting a neuropathic pain feature. The mean intensity of pain was 2.5 (standard deviation [SD] 2.4, on a 0 to 10 pain scale) and persistent pain was associated with worse quality of life scores (p = 0.004) and increased use of analgesics (p = 0.015). Variables found to be associated with persistent pain in our univariable and multivariable-adjusted analyses were preoperative employment (OR 2.70, 95% CI 1.04–9.66, p = 0.042), acute postoperative pain during movement (OR 1.63, 95% CI 1.06–2.51, p = 0.027), and adjuvant chemotherapy (OR 3.30, 95% CI 1.19 to 9.15, p = 0.022). Conclusions: Persistent pain after breast cancer surgery is neuropathic and is associated with reduced quality of life and increased analgesic need. Future research should focus on perioperative interventions to reduce acute postoperative pain and consideration of modified adjuvant chemotherapy regimens to address modifiable risk factors and potentially reduce the incidence of persistent pain after breast cancer surgery.

Treatment of borderline hip dysplasia with triple pelvic osteotomy: preoperative values of acetabular index and lateral center edge angle can indicate overcorrection

IntroductionAfter pelvic osteotomy for the treatment of symptomatic hip dysplasia, the longevity of the hip joint can be compromised by acetabular overcorrection. This iatrogenic pincer-type deformity is considered to be one of the major risk factors for persistent pain and progressing osteoarthritis. There is evidence that acetabula in the borderline range, defined by a lateral center edge angle (LCEA) between 18° and 25°, are more delicate to be orientated physiologically. The aim of this study was to assess the quality of acetabular orientation by triple pelvic osteotomy (TPO), established by Tönnis and Kalchschmidt, especially with respect to acetabular overcorrection.Materials and methodsA retrospective examination on 368 consecutive hips treated with TPOs was conducted. On the preoperative pelvic radiograph and the radiographic control 5 days after surgery, LCEA, acetabular index (AI), and anterior (AWI) and posterior wall index (PWI) were measured. According to the above-mentioned definition, the hips were divided into a borderline (n = 196) and a dysplastic (n = 172) group. Acetabular overcorrection was defined as when LCEA exceeded 35°, AI was below 0° and AWI exceeded 0.60, postoperatively. The postoperative occurrence of a relevant femoroacetabular impingement was correlated to these thresholds. Statistics comprised a priori power analysis, correlation analyses and receiver operating characteristics (ROC).ResultsIn the borderline group, in 64 hips (32.7%), LCEA and AI indicated lateral overcorrection. In the dysplastic group, in 14 hips (8.1%), solely AI indicated overcorrection. In none of the hips, relevant anterior overcorrection was detected since AWI never exceeded 0.60. Chi-square test demonstrated a significant correlation between the occurrence of a postoperative femoroacetabular impingement and LCEA exceeding 35°, as well as AI below 0° (p < 0.001, resp.). Bravais–Pearson’s analysis showed a significant correlation between the pre- and postoperative values of all parameters in the borderline and the dysplasia group (p < 0.001). Thus, ROC analysis could be performed and provided preoperative cutoff values for LCEA (23°) and AI (12.5°), hinting at postoperative overcorrection.ConclusionThe comparison of radiographic parameters after TPO showed a considerably greater percentage of laterally overcorrected acetabula in the borderline hips than in the dysplastic hips. According to the wall indices, anterior overcorrection was not observed. ROC analysis anticipated unfavorable lateral overcorrection when preoperative LCEA was above 23° and AI below 12.5°. These findings should sensitize the surgeon to the delicate acetabular correction in borderline dysplastic hips.

Prevalence and risk factors of significant persistent pain symptoms after critical care illness: a prospective multicentric study

BackgroundPrevalence, risk factors and medical management of persistent pain symptoms after critical care illness have not been thoroughly investigated.MethodsWe performed a prospective multicentric study in patients with an intensive care unit (ICU) length of stay ≥ 48 h. The primary outcome was the prevalence of significant persistent pain, defined as a numeric rating scale (NRS) ≥ 3, 3 months after admission. Secondary outcomes were the prevalence of symptoms compatible with neuropathic pain (ID-pain score > 3) and the risk factors of persistent pain.ResultsEight hundred fourteen patients were included over a 10-month period in 26 centers. Patients had a mean age of 57 (± 17) years with a SAPS 2 score of 32 (± 16) (mean ± SD). The median ICU length of stay was 6 [4–12] days (median [interquartile]). At 3 months, the median intensity of pain symptoms was 2 [1–5] in the entire population, and 388 (47.7%) patients had significant pain. In this group, 34 (8.7%) patients had symptoms compatible with neuropathic pain. Female (Odds Ratio 1.5 95% CI [1.1–2.1]), prior use of anti-depressive agents (OR 2.2 95% CI [1.3–4]), prone positioning (OR 3 95% CI [1.4–6.4]) and the presence of pain symptoms on ICU discharge (NRS ≥ 3) (OR 2.4 95% CI [1.7–3.4]) were risk factors of persistent pain. Compared with sepsis, patients admitted for trauma (non neuro) (OR 3.5 95% CI [2.1–6]) were particularly at risk of persistent pain. Only 35 (11.3%) patients had specialist pain management by 3 months.ConclusionsPersistent pain symptoms were frequent in critical illness survivors and specialized management remained infrequent. Innovative approaches must be developed in the ICU to minimize the consequences of pain.Trial registration. NCT04817696. Registered March 26, 2021.

Pain and Associated Factors in Nursing Home Residents

BackgroundUnderstanding factors associated with risk of pain allows residents and clinicians to plan care and set priorities, however, factors associated with pain in nursing home residents has not been conclusively studied. AimTo evaluate the association between pain and nursing home (NH) resident demographic and clinical characteristics. DesignRetrospective analysis of Minimum Data Set 3.0 records of nursing home residents residing in 44 Indiana NHs between September 27, 2011 and December 27, 2019 (N = 9,060). ResultsPain prevalence in this sample of NH residents was 23.7%. Of those with pain, 28.0% experienced moderate to severe/frequent pain and 54.6% experienced persistent pain. Risk factors for moderate to severe/frequent pain include female sex; living in a rural setting; intact, mildly, or moderately impaired cognition; arthritis; contracture; anxiety; and depression. In contrast, stroke and Alzheimer's disease and Alzheimer's-disease related dementias (AD/ADRD) were associated with decreased risk of reporting moderate to severe/frequent pain, likely representing both the under-assessment and under-reporting of pain among cognitively impaired NH residents. Risk factors for persistent pain included age <70, Black race, living in a rural location, intact cognition, contracture, and depression. ConclusionsPain remains a pressing problem for NH residents. In this study, we identified demographic and clinical factors associated with moderate to severe frequent pain and persistent pain. Residents with a diagnosis of AD/ADRD were less likely to report pain, likely representing the difficulty of evaluating pain in these residents. It is important to note that those with cognitive impairment may not experience any less pain, but assessment and reporting difficulties may make them appear to have less pain. Knowledge of factors associated with pain for NH residents has the potential for improving the ability to predict, prevent, and provide better pain care in NH residents.

Risk factors for persistent pain after breast cancer surgery: a multicentre prospective cohort study.

Identifying factors associated with persistent pain after breast cancer surgery may facilitate risk stratification and individualised management. Single-population studies have limited generalisability as socio-economic and genetic factors contribute to persistent pain development. Therefore, this prospective multicentre cohort study aimed to develop a predictive model from a sample of Asian and American women. We enrolled women undergoing elective breast cancer surgery at KK Women's and Children's Hospital and Duke University Medical Center. Pre-operative patient and clinical characteristics and EQ-5D-3L health status were recorded. Pain catastrophising scale; central sensitisation inventory; coping strategies questionnaire-revised; brief symptom inventory-18; perceived stress scale; mechanical temporal summation; and pressure-pain threshold assessments were performed. Persistent pain was defined as pain score ≥ 3 or pain affecting activities of daily living 4months after surgery. Univariate associations were generated using generalised estimating equations. Enrolment site was forced into the multivariable model, and risk factors with p < 0.2 in univariate analyses were considered for backwards selection. Of 210 patients, 135 (64.3%) developed persistent pain. The multivariable model attained AUC=0.807, with five independent associations: age (OR 0.85 95%CI 0.74-0.98 per 5 years); diabetes (OR 4.68, 95%CI 1.03-21.22); pre-operative pain score at sites other than the breast (OR 1.48, 95%CI 1.11-1.96); previous mastitis (OR 4.90, 95%CI 1.31-18.34); and perceived stress scale (OR 1.35, 95%CI 1.01-1.80 per 5 points), after adjusting for: enrolment site; pre-operative pain score at the breast; pre-operative overall pain score at rest; postoperative non-steroidal anti-inflammatory drug use; and pain catastrophising scale. Future research should validate this model and evaluate pre-emptive interventions to reduce persistent pain risk.

Preoperative Risk Factors of Persistent Pain following Total Knee Arthroplasty.

Despite good results of total knee arthroplasty (TKA) as a treatment of idiopathic osteoarthritis (OA) of the knee, significant number of patients (16-33%) complain of persistent pain of unknown origin. This phenomenon is the major cause of patient's dissatisfaction. It has been theorized that certain preoperative factors may increase the risk of persistent pain; hence, their identification should enable proper preoperative education and development of realistic expectations regarding results of TKA. This study is aimed at identifying the preoperative chronic pain predictors in patients undergoing TKA. In this prospective cohort study, patients scheduled for TKA were examined one day prior to surgery. Demographics, comorbidities, pressure pain thresholds, pain intensity and duration, radiographic OA grade, and range of motion were recorded. Questionnaires such as Beck Depression Inventory (BDI) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were collected. Study cohort was evaluated approximately 6 months following surgery. Patients were assigned to group A if they had no pain and to group B if they complained of any pain. Collected data was analyzed by biostatistician. 64 patients were included in final analysis, 49 (76,6%) females and 15 (23,4%) males. Mean age was 67,6 yrs (48-84, ±7,42). Group A consisted of 21 patients (33%) while group B consisted of 43 patients (67%). There were no statistically significant differences regarding preoperative factors except for duration of preoperative pain, which was shorter in group A (36 (12-180) vs. 72 (24-180), p = 0,011). Every 12 months of preoperative pain were found to increase risk of persistent pain by 1,27 (p = 0,009). Preoperative duration of pain is a risk factor for chronic pain following TKA. Therefore, patients should be operated on as soon as indications arise. Should the surgical treatment of knee arthritis be postponed, intensive and individualized pain management is highly recommended.

Childbirth Pain, Labor Epidural Analgesia, and Postpartum Depression: Recent Evidence and Future Directions.

Pregnancy and childbirth are major life events for women and their families, characterized by physical, psychological, and emotional changes that can trigger anxiety, depression, and mental disorders in susceptible individuals. Acute labor pain is an independent risk factor for persistent pain in the postpartum period and is associated with depressive disorders. Epidural analgesia is a well-established technique that has commonly been regarded as the gold standard in pain management during labor. Although the relationships between labor pain, labor epidural analgesia, and postpartum depression have been studied by many investigators, the results of these studies are conflicting. Some literature suggest that labor epidural analgesia is associated with a reduction in the incidence of postpartum depression; however, other studies have failed to demonstrate this association. Unmet analgesic needs expectations, unmet birth expectations, and/or the quality of social support during labor may contribute to postpartum depression. The limitations of the published studies included differential misclassification of study variables and residual confounding, variations in the diagnosis of depression, and incomplete history data. Thus, future studies should include information on sociodemographic and patient-level variables and assessments of pain during labor or in the postpartum period. Better management of labor pain should be provided to prevent long-term morbidity and improve maternal and neonatal outcomes. Anesthesiologists could collaboratively work with obstetricians and perinatal psychiatrists to ensure that hospitals prioritize screening and treatment for postpartum depression.

Predictive risk factors for persistent pain following total prosthetic temporomandibular joint replacement

The aim of this study was to determine the rate of persistent pain following total TMJ replacement and to identify potential predictive risk factors. A retrospective review of case notes treated by a single surgeon in a tertiary unit was performed. For each patient a number of variables were recorded including visual analogue pain scores (0 to 10) and opioid usage pre surgery and at 12 months or last follow up beyond 12 months. Persistent pain scores of 5 to 7 were regarded as moderate and 8 to 10 as severe. The mean pain score at last follow-up was significantly lower than preoperatively (2.1 vs. 6.3, p < 0.001) with a mean follow-up time of 40.1 months (range 12–44). 16.4% of the patients reported moderate to severe pain and 13.7% were still on regular opioids at the last follow-up. Therefore 15 patients (20.5%) suffered from chronic postoperative pain after TMJ replacement surgery. Patients reporting severe preoperative pain scores (p = 0.04), regular opioid use (p = 0.001) or multiple previous open TMJ surgeries (p = 0.03) were more likely to suffer from chronic persistent pain and these should be regarded as predictive risk factors. The identification of these factors allows for better risk stratification of patients, informed consent and the agreement of expected outcomes. Patients with true articular disease and a single failed surgery should be considered for early total TMJ replacement to minimise multifactorial persistent pain.

Risk factors for persistent pain after breast and thoracic surgeries: a systematic literature review and meta-analysis.

Persistent postsurgical pain (PPSP) is common after breast and thoracic surgeries. Understanding which risk factors consistently contribute to PPSP will allow clinicians to apply preventive strategies, as they emerge, to high-risk patients. The objective of this work was to systematically review and meta-analyze the literature on risk factors of PPSP after breast and thoracic surgeries. A systematic literature search using Ovid Medline, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Embase, PsycINFO, and Scopus databases was conducted. Study screening with inclusion and exclusion criteria, data extraction, and risk of bias assessment was performed independently by 2 authors. The data for each surgical group were analyzed separately and meta-analyzed where possible. The literature search yielded 5584 articles, and data from 126 breast surgery and 143 thoracic surgery articles were considered for meta-analysis. In breast surgery, younger age, higher body mass index, anxiety, depression, diabetes, smoking, preoperative pain, moderate to severe acute postoperative pain, reoperation, radiotherapy, and axillary lymph node dissection were the main factors associated with higher risk of PPSP. In thoracic surgery, younger age, female sex, hypertension, preoperative pain, moderate to severe acute postoperative pain, surgical approach, major procedure, and wound complications were associated with PPSP. This systematic review demonstrated certain consistent risk factors of PPSP after breast and thoracic surgeries, as well as identified research gaps. Understanding the factors that increase susceptibility to PPSP can help selectively allocate resources to optimize perioperative care in high-risk patients and help develop targeted, risk-stratified interventions for PPSP prevention.

Risk Factors for Persistent Pain Requiring Surgical Treatment in Adult Symptomatic Accessory Navicular.

Identifying the risk factors for persistent pain despite proper conservative treatment in adult symptomatic accessory navicular may reduce the need for surgical treatment. The aim of this study was to identify any such risk factors. Cohort study. University hospital foot and ankle clinic. A retrospective review of 313 patients who presented with adult symptomatic accessory navicular was performed. Potential risk factors were identified via medical records and foot radiographs. The possible risk factors included age, gender, body mass index, smoking status, occurrence/cause of symptoms, occupation, type of accessory navicular, and radiographic foot parameters. Predictors that relate to persistent pain requiring surgical treatment in adult accessory navicular were analyzed using logistic regression analysis. Of the 313 patients included, 30 (9.6%) underwent surgical treatment due to failure of conservative treatment. The odds of needing surgical treatment decreased by 0.96 per year of age at symptom onset (P = 0.030), but those odds were 8.52 times higher in patients who had a type IIB accessory navicular (P = 0.001). Other variables did not reach statistical significance. Younger age at symptom onset and type IIB were the risk factors for persistent pain requiring surgical treatment in adult symptomatic accessory navicular.

Efficacy of erector spinae plane block with opioid-sparing analgesic technique in breast-conserving surgery.

PurposeBreast-conserving surgery (BCS) is a surgical method designed to minimize intraoperative tissue injury. Although this technique is minimally invasive, it can cause significant postoperative pain and may be a risk factor for persistent pain. Erector spinae plane block (ESPB) is an easy interfascial plane block for analgesia in patients undergoing breast surgery. The primary outcome was the numeric rating scale scores measured separately on the breast and axilla. Secondary outcomes included correlation between pain score and skin sensitivity test.MethodsForty patients were divided into 2 groups (ESPB group and control group). Patients in the ESPB group received an ESPB 30 minutes before the induction of general anesthesia, whereas patients in the control group did not receive any regional analgesia during the perioperative period.ResultsMedian pain scores of the breast were significantly lower in the ESPB group than that in the control group at 12, 24, and 48 hours after surgery. However, the median pain scores of the axilla were not significantly different between the groups, and the pain score was unrelated to skin sensitivity.ConclusionESPB can effectively alleviate acute postoperative pain with an opioid-sparing analgesic technique in patients undergoing BCS, and a strong correlation is lacking between pain scores and skin sensitivity test.

How Does Preoperative Central Sensitization Affect Quality of Life Following Total Knee Arthroplasty?

BackgroundCentral sensitization (CS) has been recently identified as a significant risk factor for persistent pain and patient dissatisfaction following total knee arthroplasty (TKA). However, it remains unclear as to whether the preoperative CS persists after the elimination of a nociceptive pain source by TKA, or how CS affects the quality of life after TKA. MethodsA total of 222 consecutive patients undergoing primary TKA were enrolled in the study. All patients were preoperatively screened for CS using the Central Sensitization Inventory (CSI) and categorized into either a CS (n = 55; CSI ≥ 40) or non-CS group (n = 167; CSI < 40). CSI, pain visual analog scale (VAS), Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index score, and satisfaction were recorded at postoperative 2 years. ResultsTwo years after TKA, preoperative CS remained unchanged; there was no difference between preoperative and postoperative CSI scores, and both preoperative and postoperative CSI severity levels were similar (P > .1). The CS group showed worse pain VAS, KSS, and Western Ontario and McMaster Universities Osteoarthritis Index scores than did the non-CS group (P < .01) and more patients in the CS group were dissatisfied with all activities (P < .01). However, a similar percentage of the CS group achieved the previously documented minimal clinically important difference in pain VAS and KSS, compared with the non-CS group. Multivariate regression analysis revealed that preoperative CSI scores were associated with dissatisfaction at postoperative 2 years. ConclusionPreoperative CS was persistent at 2 years after TKA. Although CS patients achieved comparable clinical improvement following TKA, CS patients had worse quality of life, functional disability, and dissatisfaction than non-CS patients.

High Prevalence of Degenerative Changes at the Metatarsal Head Sesamoid Articulation Found During Hallux Valgus Correction Surgery.

Background. Despite the absence of complications and a restoration of normal hallux alignment, some patients have suboptimal outcomes from hallux valgus correction surgery. One risk factor for persistent pain may be the presence of arthritic changes at the metatarsal head articulation with the sesamoids, an area not easily assessed with standard radiographs unless dedicated sesamoid views are obtained. In this study, we prospectively evaluated the metatarsal head for degenerative changes during hallux valgus correction surgery and identified preoperative risk factors associated with these changes. Methods. We prospectively evaluated 200 feet in 196 patients who underwent hallux valgus surgery intraoperatively for the pattern and severity of arthritic changes at the metatarsal head. Mann-Whitney U testing was implemented to compare differences in arthritic scores between preoperative deformity groups. The Spearman correlation test was used to determine the association between age and preoperative deformity with the severity of degenerative changes. Results. More than half of all feet assessed had severe arthritic changes at the plantar medial aspect of the metatarsal head and 40% of feet at the plantar lateral aspect. Age and intermetatarsal angle were found to be positively correlated with arthritis in this area. Conclusion. Our prospective study has demonstrated the high prevalence of arthritic changes at the metatarsal head sesamoid articulation and the positive influence of age and severity of deformity on metatarsal head arthritic changes seen during hallux valgus correction surgery. Furthermore, these arthritic changes were found to have no significant influence on preoperative functional and pain levels.Levels of Evidence: Level IV: Case series.

Sleep deprivation of rats increases postsurgical expression and activity of L-type calcium channel in the dorsal root ganglion and slows recovery from postsurgical pain

Perioperative sleep disturbance is a risk factor for persistent pain after surgery. Clinical studies have shown that patients with insufficient sleep before and after surgery experience more intense and long-lasting postoperative pain. We hypothesize that sleep deprivation alters L-type calcium channels in the dorsal root ganglia (DRG), thus delaying the recovery from post-surgical pain. To verify this hypothesis, and to identify new predictors and therapeutic targets for persistent postoperative pain, we first established a model of postsurgical pain with perioperative sleep deprivation (SD) by administering hind paw plantar incision to sleep deprivation rats. Then we conducted behavioral tests, including tests with von Frey filaments and a laser heat test, to verify sensory pain, measured the expression of L-type calcium channels using western blotting and immunofluorescence of dorsal root ganglia (an important neural target for peripheral nociception), and examined the activity of L-type calcium channels and neuron excitability using electrophysiological measurements. We validated the findings by performing intraperitoneal injections of calcium channel blockers and microinjections of dorsal root ganglion cells with adeno-associated virus. We found that short-term sleep deprivation before and after surgery increased expression and activity of L-type calcium channels in the lumbar dorsal root ganglia, and delayed recovery from postsurgical pain. Blocking these channels reduced impact of sleep deprivation. We conclude that the increased expression and activity of L-type calcium channels is associated with the sleep deprivation-mediated prolongation of postoperative pain. L-type calcium channels are thus a potential target for management of postoperative pain.

High Prevalence of Degenerative Changes at the Metatarsal Head Sesamoid Articulation Found During Hallux Valgus Correction Surgery

Category:BunionIntroduction/Purpose:Despite absence of complications and a restoration of normal hallux alignment, some patients have suboptimal outcomes from hallux valgus correction surgery. One risk factor for persistent pain may be the presence of arthritic changes at the metatarsal head articulation with the sesamoids, an area not easily assessed with standard preoperative radiographs. In this study, we prospectively evaluated the metatarsal head for degenerative changes during hallux valgus correction surgery and identified preoperative risk factors associated with these changes.Methods:We prospectively evaluated 200 feet in 196 patients who underwent hallux valgus surgery intraoperatively for the pattern and severity of arthritic changes at the metatarsal head. Intraoperatively, the first metatarsophalangeal and sesamoid metatarsal joint were assessed for arthritic changes. The articular surface of the metatarsal head was divided into zones 1-6 (Figure 1). Cartilage loss in each zone was graded from 0-2 based on a novel grading system, with a score of 0 representing the absence of arthritis. A score of 1 indicated fissures without exposed bone, and a score of 2 represented degenerative changes to the level of exposed bone. Mann-Whitney U testing was implemented to compare differences in arthritic scores between preoperative deformity groups. Spearman’s correlation test was used to determine the association between age and preoperative deformity with the severity of degenerative changes.Results:One-hundred two out of 200 feet (51%) assessed had severe arthritic changes at the plantar medial aspect of the metatarsal head, and 40% (80/200) at the plantar lateral aspect. The mean preoperative hallux valgus and intermetatarsal angles were 29.6 ± 8.5 (range, 9.8-55.3) and 14.2 ± 3.3 (range, 6.6-25.9), respectively. Those presenting with an intermetatarsal angle (IMA) >/= 14 degrees had a significantly higher level of arthritis when compared to those presenting with an IMA < 14 degrees (p < 0.001). No difference in arthritis scores was found for HVA. Age was found to have a strong and significant (p < 0.001) correlation with zone 5, zone 6, total plantar zone, and total arthritis scores.Conclusion:The high prevalence of arthritic changes at the metatarsal head articulation with the sesamoids may be partially responsible for suboptimal outcome following hallux valgus correction surgery. Since these changes were associated with greater age and preoperative deformity, operating earlier in the pathology of hallux valgus may be of benefit.

Machine-learning-based knowledge discovery in rheumatoid arthritis-related registry data to identify predictors of persistent pain.

Early detection of patients with chronic diseases at risk of developing persistent pain is clinically desirable for timely initiation of multimodal therapies. Quality follow-up registries may provide the necessary clinical data; however, their design is not focused on a specific research aim, which poses challenges on the data analysis strategy. Here, machine-learning was used to identify early parameters that provide information about a future development of persistent pain in rheumatoid arthritis (RA). Data of 288 patients were queried from a registry based on the Swedish Epidemiological Investigation of RA. Unsupervised data analyses identified the following 3 distinct patient subgroups: low-, median-, and high-persistent pain intensity. Next, supervised machine-learning, implemented as random forests followed by computed ABC analysis-based item categorization, was used to select predictive parameters among 21 different demographic, patient-rated, and objective clinical factors. The selected parameters were used to train machine-learned algorithms to assign patients pain-related subgroups (1000 random resamplings, 2/3 training, and 1/3 test data). Algorithms trained with 3-month data of the patient global assessment and health assessment questionnaire provided pain group assignment at a balanced accuracy of 70%. When restricting the predictors to objective clinical parameters of disease severity, swollen joint count and tender joint count acquired at 3 months provided a balanced accuracy of RA of 59%. Results indicate that machine-learning is suited to extract knowledge from data queried from pain- and disease-related registries. Early functional parameters of RA are informative for the development and degree of persistent pain.

P109. Tobacco use is associated with worse patient-reported outcomes following elective cervical spine surgery

BACKGROUND CONTEXT Tobacco use has been shown to be a major modifiable risk factor for the development of postoperative complications in elective orthopedic surgeries. Numerous studies have described the adverse health effects of tobacco use and the associations between tobacco use and poor surgical outcomes, as well as increased post-operative health care utilization. PURPOSE The purpose of this study was to investigate the effect of preoperative tobacco use on (1) pre- and postoperative patient-reported outcomes, (2) complications, and (3) pre- and postoperative opioid consumption in patients undergoing elective cervical spine surgery. STUDY DESIGN/SETTING Retrospective chart review. PATIENT SAMPLE A total of 179 consecutive patients who underwent elective cervical spine surgery at a single academic institution from 2014-2016 with 2-year follow up data. OUTCOME MEASURES Perioperative variables, pre- and postoperative, opiod consumption, Neck Disabiity Index (NDI) score, VAS (visual analog scale) pain scores and Distressed Communities Index (DCI) METHODS Patient tobacco use, baseline characteristics, medical comorbidities, operative variables, and surgical complications (superficial and deep infection, wound complication, emergency department [ED] visits, readmissions, and repeat operations) were recorded. Additionally, preoperative ED visits, pre- and postoperative opioid use, total postoperative opioid prescription quantities, and most recent date of opioid prescription were collected. Quantitative measurements of pain (VAS) and disease specific disability score (NDI) were recorded preoperatively and 3 months after surgery. In addition, the Economic Innovation Group's 2017 Distressed Communities Index (DCI) was recorded for each patient's home zip code. DCI Scores are based on percentages of adults without a high school education, percentage living under the poverty line, unemployment rates, and the overall housing and business climate in a given area. DCI Scores range from 0 to 100, with higher scores indicative of greater economic distress, and DCI Scores ≥80 are considered to be highly distressed regions. Continuous variables were compared between patients that did vs did not use tobacco using two-tailed independent t-test, and categorical variables were compared using chi-square or Fisher Exact tests. RESULTS Of the 179 patients involved in this study, 98 (54.7%) were current tobacco users. Compared to non-users, current tobacco users were more likely to have COPD (p=0.001), illicit drug abuse (p=0.002), and worse distressed community index scores (p=0.02). Tobacco users had less pain relief than non-smokers at 3 months postoperatively (4.9±2.7 vs. 2.7±2.3, respectively), as they experienced significantly less improvement in VAS pain score (p 0.05). There were no other between-group differences. CONCLUSIONS Tobacco users undergoing elective cervical spine surgery may experience significantly worse pain during the early postoperative period compared to non-smokers. Tobacco use may represent a modifiable risk factor for persistent pain in this population. Surgeons should counsel patients about reducing tobacco use before cervical spine surgery, and socioeconomic status should be considered when developing patient education materials and smoking cessation programs for this at risk subset. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.