Bilateral versus unilateral erector spinae plane block for postoperative analgesia in laparoscopic cholecystectomy: a randomized controlled study

Abstract Introduction Laparoscopic cholecystectomy (LC) is the common surgical intervention for benign biliary diseases. Postoperative pain after LC remains as an important problem, with two components: somatic and visceral. Trocar entry incisions lead to somatic pain, while peritoneal distension with diaphragm irritation leads to visceral pain. Following its description by Forero et al., the erector spinae plane (ESP) block acquired considerable popularity among clinicians. This led to the use of ESP block for postoperative pain management for various operations. Materials and methods This study was conducted between January and June 2019. Patients aged between 18 and 65 years with an American Society of Anesthesiologists (ASA) physical status I-II, scheduled for elective laparoscopic cholecystectomy were included in the study. All the patients received bilateral or unilateral ESP block at the T8 level preoperatively according to their groups. Results There was no significant difference between the groups in terms NRS scores either at rest or while coughing at any time interval except for postoperative 6th hour (p = 0.023). Morphine consumption was similar between the groups but was significantly lower in group B at 12 and 24 hours (p = 0.044 and p = 0.022, respectively). Twelve patients in group A and three patients in group B had shoulder pain and this difference was statistically significant (p = 0.011). Discussion In conclusion, bilateral ESP block provided more effective analgesia than unilateral ESP block in patients undergoing elective LC. Bilateral ESP block reduced the amount of opioid consumption and the incidence of postoperative shoulder pain.

The impact of standard postoperative opioid prescribing guidelines on racial differences in opioid prescribing: A retrospective review.

BACKGROUND: Racial disparities in opioid prescribing are widely documented, though few studies assess racial differences in the postoperative setting specifically. We hypothesized standard opioid prescribing schedules reduce total opioids prescribed postoperatively and mitigate racial variation in postoperative opioid prescribing. METHODS: This is a retrospective review of adult general surgery cases at a large, public academic institution. Standard opioid prescribing schedules were implemented across general surgery services for common procedures in late 2018 at various timepoints. Interrupted time series analysis was used to compare mean biweekly discharge morphine milligram equivalents prescribed in the preintervention (Jan-Jun 2018) versus postintervention (Jan-Jun 2019) periods for Black and White patients. Linear regression was used to compare mean difference in discharge morphine milligram equivalents among White and Black patients in each study period, while controlling for demographics, chronic opioid use, and procedure/service. RESULTS: A total of 2,961 cases were analyzed: 1,441 preintervention and 1,520 postintervention. Procedural frequencies, proportion of Black patients (17% Black), and chronic opioid exposure (7% chronic users) were similar across time periods. Interrupted time series analysis showed significantly lower mean level of morphine milligram equivalents prescribed postintervention compared with the predicted nonintervention trend for both Black and White patients. Adjusted analysis showed on average in 2018 Black patients received significantly higher morphine milligram equivalents than White patients (+19 morphine milligram equivalents, 95% confidence interval 0.5-36.5). There was no significant difference in 2019 (-8 morphine milligram equivalents, 95% confidence interval -20.5 to 4.6). CONCLUSION: Standard opioid prescribing schedules were associated with the elimination of racial differences in postoperative opioid prescribing after common general surgery procedures, while also reducing total opioids prescribed. We hypothesize standard opioid prescribing schedules may mitigate the effect of implicit bias in prescribing.

Racial Differences in Pain and Function Following Knee Arthroplasty: A Secondary Analysis From a Multicenter Randomized Clinical Trial.

OBJECTIVE: The assessment of racial differences in pain and function outcome following knee arthroplasty (KA) has received little attention despite very substantial literature exploring a variety of other prognostic factors. The present study was undertaken to determine whether race was associated with KA outcome after accounting for potential confounding factors. METHODS: We conducted a secondary analysis of a randomized clinical trial of 384 participants with moderate-to-high pain catastrophizing who underwent KA. Preoperative measures included race/ethnicity status as well as a variety of potential confounders, including socioeconomic status, comorbidity, and bodily pain. Outcome measures were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scales as well as performance measures. Linear mixed-effects models compared outcomes over a 1-year follow-up period for African American versus non-African American participants. RESULTS: WOMAC pain scores differences for African American versus non-African American participants averaged ~2 points in unadjusted analyses and 1-1.5 points in adjusted analyses. In adjusted analyses, follow-up WOMAC function scores differed by 6 points for African Americans compared to non-African Americans (P = 0.002). CONCLUSION: African Americans generally had worse pain, function, and performance prior to KA and worse scores after surgery, but differences were small and attenuated by ~25-50% after adjustment for potential confounding. Only WOMAC function scores showed clinically important postsurgical differences in adjusted analyses. Clinicians should be aware that after adjustment for potential confounders, African Americans have approximately equivalent outcomes compared to others, with the exception of WOMAC function score.

Association Between Race and Ethnicity with Intraoperative Analgesic Administration and Initial Recovery Room Pain Scores in Pediatric Patients: a Single-Center Study of 21,229 Surgeries.

INTRODUCTION: Perioperative pain may have deleterious effects for all patients. We aim to examine disparities in pain management for children in the perioperative period to understand whether any racial and ethnic groups are at increased risk of poor pain control. METHODS: Medical records from children ≤ 18 years of age who underwent surgery from May 2014 to May 2018 were reviewed. The primary outcome was total intraoperative morphine equivalents. The secondary outcomes were intraoperative non-opioid analgesic administration and first conscious pain score. The exposure was race and ethnicity. The associations of race and ethnicity with outcomes of interest were modeled using linear or logistic regression, adjusted for preselected confounders and covariates. Bonferroni corrections were made for multiple comparisons. RESULTS: A total of 21,229 anesthetics were included in analyses. In the adjusted analysis, no racial and ethnic group received significantly more or less opioids intraoperatively than non-Hispanic (NH) whites. Asians, Hispanics, and Pacific Islanders were estimated to have significantly lower odds of receiving non-opioid analgesics than NH whites: odds ratio (OR) = 0.83 (95% confidence interval (CI): 0.70, 0.97); OR = 0.84 (95% CI: 0.74, 0.97), and OR = 0.53 (95% CI: 0.33, 0.84) respectively. Asians were estimated to have significantly lower odds of reporting moderate-to-severe pain on awakening than NH whites: OR = 0.80 (95% CI: 0.66, 0.99). CONCLUSIONS: Although children of all races and ethnicities investigated received similar total intraoperative opioid doses, some were less likely to receive non-opioid analgesics intraoperatively. Asians were less likely to report moderate-severe pain upon awakening. Further investigation may delineate how these differences lead to disparate patient outcomes and are influenced by patient, provider, and system factors.

Racial and Ethnic Inequities in Postpartum Pain Evaluation and Management.

OBJECTIVE: To evaluate whether the frequency of pain assessment and treatment differed by patient race and ethnicity for women after cesarean birth. METHODS: We performed a retrospective cohort study of all women who underwent cesarean birth resulting in a liveborn neonate at a single institution between July 1, 2014, and June 30, 2016. Pain scores documented and medications administered after delivery were grouped into 0-24 and 25-48 hours postpartum time periods. Number of pain scores recorded, whether any pain score was 7 of 10 or greater, and analgesic medication administered were calculated. Models were adjusted for propensity scores incorporating maternal age, body mass index, gestational age, nulliparity, primary compared with repeat cesarean delivery, classical hysterotomy, and admission to the neonatal intensive care unit. RESULTS: A total of 1,987 women were identified, and 1,701 met inclusion criteria. There were 30,984 pain scores documented. Severe pain (7/10 or greater) was more common among black (28%) and Hispanic (22%) women than among women who identified as white (20%) or Asian (15%). In the first 24 hours after cesarean birth, non-Hispanic white women had more documented pain assessments (adjusted mean 10.2) than, black, Asian, and Hispanic women (adjusted mean 8.4-9.5; P<.05). Results at 25-48 hours were similar, compared with non-Hispanic white women (adjusted mean 8.3). Black, Asian, and Hispanic women and women who were identified as other all received less narcotic medication at 0-24 hours postpartum (adjusted mean 5.1-7.5 oxycodone tablet equivalents; P<.001-.05), as well as at 25-28 hours postpartum. CONCLUSION: Racial and ethnic inequities in the experience, assessment and treatment of postpartum pain were identified. A limitation of our study is that we were unable to assess the role of patient beliefs about expression of pain, patient preferences with regards to pain medication, and beliefs and potential biases among health care providers.

Variables associated with pediatric emergency department visits for uncontrolled pain in postoperative adenotonsillectomy patients.

OBJECTIVE: Returns to the emergency department (ED) for pain or dehydration after adenotonsillectomy (T&A) are frequent. Attempts to associate the specific pain regimens with these visits have been unrevealing, suggesting a need to assess for other potential factors associated with readmission. METHODS: A review of a 2:1 cohort matched by age, gender and payer status compared post-T&A patients who did not return ED for pain or dehydration within 21 days to those who returned. Factors investigated included patient demographics, comorbidities, medication regimen and the presence of postoperative telephone encounters. Patients returning to the ED were further assessed for rates of medication adherence. RESULTS: 7493 patients underwent T&A during the period. Of these, 144 (1.9%) returned for pain/dehydration. Comparison to 285 matched patients revealed an association between ED returns and Hispanic ethnicity (p < 0.001), Spanish language (p = 0.0002), and comorbid Down syndrome and ADHD (p = 0.011 in both). The incidence of parent telephone calls to the office was associated with ED returns (58.7 in the ED cohort, 28.4% in non-ED cohort, p < 0.0001). On multivariable analysis, Hispanic ethnicity and phone calls were associated with ED returns (p < 0.0001 and p < 0.0001, respectively). Only 64.0% of patients returning to the ED were adherent with postoperative pain regimens. CONCLUSIONS: While demographic factors may be associated with rate of ED returns for pain and dehydration, post-operative phone calls were most highly associated with returns. The majority of patients returning to the ED were non-adherent with recommended pain regimens, suggesting an opportunity to investigate medication adherence in all post-tonsillectomy patients.

The Influence of Race, Ethnicity and Genetic Variants on Postoperative Pain Intensity: An Integrative Literature Review.

OBJECTIVES: Chronic postsurgical pain is pain that develops and persists for at least 3 months after a surgical procedure. The purpose of this review was to discover what evidence exists regarding the influence of race and ethnicity on postoperative pain intensity and what evidence exists regarding the influence of genetic polymorphisms on postoperative pain intensity. DESIGN: Integrative literature review. DATA SOURCES: CINAHL, PsychInfo, SCOPUS, and PubMed/Medline databases were searched for entries within the last 10 years. Sources included primary research investigating the relationship among race, ethnicity, and genetics in postoperative pain outcomes. REVIEW/ANALYSIS METHODS: Studies adhered to a strict inclusion and exclusion criteria. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized to evaluate and assess manuscripts for inclusion. RESULTS: Twelve manuscripts were included for final review. There are significantly higher preoperative and postoperative pain intensity scores reported between African American and Hispanic individuals compared with non-Hispanic whites. Although some studies identified that non-Hispanic whites consumed more opioids and reported increased pain, there were no significant differences in opioid requirements in Hispanic and non-Hispanic individuals. COMT and OPRM1 were the most identified genetic polymorphisms associated with postoperative pain intensity. CONCLUSIONS: The literature varies with respect to race, ethnicity, and postoperative pain perception. Perioperative pain intensity has been suggested as a significant predictor of chronic postsurgical pain. COMT and OPRM1 may be associated with higher pain perception after surgical procedures.

Postoperative Pain Management Among Native and Non-native Israeli Citizens-Data From the European PAIN-OUT Registry.

PURPOSE: It has been widely reported that minority groups receive inferior emergency pain management. We aimed to determine whether this is true in the postoperative setting, as effective postoperative analgesia is an essential component of high quality medical care. DESIGN: A retrospective case-control study of paired 248 postsurgical Israeli patients. METHODS: Data were gathered from the European Union's "PAIN-OUT" registry. Quality of care measures, composite pain score, composite side effect score, and composite emotional score were analyzed. FINDINGS: Composite pain, side effect, and emotional scores were significantly higher among natives compared with non-natives. Opioid consumption did not differ between the two groups. CONCLUSIONS: In this study, immigration status was not a predictor of inferior postoperative analgesia. In contrast, non-natives benefited more from analgesic care. We suggest this stems from differing patient expectations and attitudes toward pain management between the groups, with higher expectations for analgesia on the part of native patients accounting for these observations.

Effect of cultural background and healthcare environment on postoperative opioid requirement.

PURPOSE: The objective of this prospective observational study was to investigate the interactions between cultural background, healthcare environment, and postoperative pain experience. METHODS: We enrolled 128 Chinese patients living in rural mainland China and 134 patients in Hong Kong with a higher level of Western cultural influences (defined by educational attainment, place of residence, and ability to understand English). All patients had major abdominal surgery and received patient-controlled analgesia with intravenous morphine for postoperative pain relief. The primary endpoint was total opioid requirement up to 48 hr after surgery. Other measures included pain intensity, opioid-related side effects, and genetic markers for opioid responsiveness. RESULTS: The mean (95% confidence interval) cumulative opioid requirement, expressed as morphine equivalent, during the first 48 hr after surgery was significantly less in patients from mainland China (18.8 [15.7 to 22] mg) compared with patients from Hong Kong (42.0 [38.3 to 45.6] mg, P < 0.0001). In a multivariable analysis, opioid requirement was influenced by ethnicity, duration of surgery, and severity of pain upon admission to the postanesthetic care unit. CONCLUSIONS: These results suggest that postoperative pain behaviours and opioid requirement may be influenced by cultural background and healthcare environment in two populations of Chinese descent. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ACTRN12614000601639); registered 6 May, 2014.

RéSUMé: OBJECTIF: L'objectif de cette étude observationnelle prospective était d'étudier les interactions entre le contexte culturel, l'environnement de soins de santé et l'expérience de la douleur postopératoire. MéTHODES: Nous avons recruté 128 patients chinois vivant en zones rurales en Chine continentale et 134 patients vivant à Hong-Kong avec un haut niveau d'influences culturelles occidentales (définies par le niveau d'éducation atteint, le lieu de résidence et la capacité à comprendre l'anglais). Tous les patients avaient subi une chirurgie abdominale majeure et reçu une analgésie contrôlée par le patient par morphine intraveineuse pour le soulagement de la douleur postopératoire. Le critère d'évaluation principal était la demande totale en opioïdes pendant les 48 premières heures suivant la chirurgie. D'autres mesures ont inclus l'intensité de la douleur, les effets indésirables liés aux opioïdes et des marqueurs génétiques de sensibilité aux opioïdes. RéSULTATS: Le besoin cumulé moyen (intervalle de confiance à 95 %) cumulé en opioïdes, exprimé sous forme d'équivalent-morphine, au cours des 48 premières heures suivant la chirurgie était significativement inférieur pour les patients de Chine continentale (18,8 [15,7 à 22] mg) comparativement aux patients de Hong-Kong (42,0 [38,3 à 45,6] mg, P < 0,0001). Une analyse multifactorielle a montré que la demande en opioïdes était influencée par l'origine ethnique, la durée de l'intervention chirurgicale et l'intensité de la douleur au moment de l'arrivée dans l'unité de soins postanesthésiques. CONCLUSIONS: Ces résultats suggèrent que les comportements postopératoires envers la douleur et le besoin d'opioïdes peuvent être influencés par l'arrière-plan culturel et l'environnement des soins de santé dans deux populations différentes d'origine chinoise. ENREGISTREMENT DE L'ESSAI CLINIQUE: Registre des essais cliniques d'Australie et de Nouvelle-Zélande (ACTRN12614000601639); enregistré le 6 mai 2014.

Racial differences in opioid prescribing for children in the United States.

Racial differences exist in analgesic prescribing for children during emergency department and ambulatory surgery visits in the United States; however, it is unknown whether this is true in the outpatient setting. We examined racial and ethnic differences in outpatient analgesic prescribing using nationally representative data from 113,929 children from the Medical Expenditure Panel Survey. We also examined whether patient-provider race and ethnic concordance was associated with opioid prescription. White children were more commonly prescribed opioids as compared to minorities (3.0% vs 0.9%-1.7%), except for Native American children who had similar rates of opioid prescription (2.6%) as white children. Minorities were more likely to receive nonopioid analgesics than white children (2.0%-5.7% vs 1.3%). Although most white children had race-concordant providers (93.5%), only 34.3% of black children and 42.7% of Hispanic children had race-concordant providers. Among black children, having a race concordant usual source of care provider was associated with a decreased likelihood of receiving an opioid prescription as compared to having a white usual source of care provider (adjusted odds ratio [95% confidence interval] = 0.51 [0.30-0.87]). For all other racial groups, patient-provider race-concordance was not associated with likelihood of opioid prescription. Racial differences exist in analgesic prescriptions to children at outpatient health care visits in the United States, with white children more likely to receive opioids and minorities more likely to receive nonopioid analgesics. Health care providers' race and ethnicity may play a significant role in extant analgesic differences. Further work should focus on understanding the role of provider race and ethnicity in analgesic differences to children in the United States.

Cross-cultural adaptation, validity, and reliability of the Turkish version of revised American Pain Society patient outcome questionnaire for surgical patients.

OBJECTIVE: This study aims to investigate the validity and reliability of the Turkish Revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R-TR). METHODS: A methodological and cross-sectional design was used. This study included a total of 250 surgical patients (98 males, 152 females) between January 2015 and January 2016. Data were collected using a demographic questionnaire and the APSPOQ-R. Language equivalence, content and construct validity, and reliability of the scale were evaluated. RESULTS: The Pearson correlation coefficient of the scale for parallel test reliability was 0.362, and the Cronbach's alpha value was determined as 0.88 in the APS-POQ-R-TR. According to fit indexes of the confirmatory factor analysis [x2/SD=362.53/125=2.90; RMSEA=0.087 (90% CI: 0.077-0.098); CFI=0.95; IFI=0.95; NNFI=0.94], three factors were found to be appropriate for the APSPOQ-R-TR. CONCLUSION: The adaptation of the translated APS-POQ-R in Turkey is reliable and valid to measure and evaluate the quality of postoperative pain management in the Turkish population.

Simplified Chinese version of the Forgotten Joint Score (FJS) for patients who underwent joint arthroplasty: cross-cultural adaptation and validation.

BACKGROUND: The Forgotten Joint Score (FJS) is a newly developed health-related quality of life (HRQoL) questionnaire designed to evaluate the awareness after total knee arthroplasty (TKA). This study cross-culturally adapted and psychometrically validated a simplified Chinese version of the FJS (SC-FJS). METHODS: Cross-cultural adaptation was performed according to the internationally recognized guidelines. One-hundred and fifty participants who underwent primary TKA were recruited in this study. Cronbach's α and intra-class correlations were used to determine reliability. Construct validity was analyzed by evaluating the correlations between SC-FJS and the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the short form (36) health survey (SF-36). RESULTS: Each of the 12 items was properly responded and correlated with the total items. SC-FJS had excellent reliability [Cronbach's α = 0.907, intra-class correlation coefficient (ICC) = 0.970, 95% CI 0.959-0.978). Elimination of any one item in all did not result in a value of Cronbach's α of <0.80. SC-FJS had a high correlation with symptoms (0.67, p < 0.001) and pain (0.60, p < 0.001) domains of KOOS and social functioning (0.66, p < 0.001) domain of SF-36, and it also moderately correlated with function in daily living (0.53, p < 0.001) and function in sport and recreation (0.40, p < 0.001) domains of KOOS, and physical subscale of SF-36 (0.49-0.53, p < 0.001) but had a low (r = 0.20) or not significant (p > 0.05) correlation with mental subscale of SF-36. CONCLUSIONS: SC-FJS demonstrated excellent acceptability, internal consistency, reliability, and construct validity, which can be recommended for patients who underwent joint arthroplasty in Mainland China.

Impact of Race on 30-Day Complication Rates After Elective Complex Spinal Fusion (≥5 Levels): A Single Institutional Study of 446 Patients.

OBJECTIVE: Racial disparities have been shown to affect surgical outcomes. However, the effect of race on complex spinal fusion outcomes remains understudied. The aim of this study is to determine if patient race affects 30-day complication rates after elective complex spinal fusion (≥5 levels). METHODS: The medical records of 490 adult patients with spinal deformity undergoing elective complex spinal fusion (≥5 levels) at a major academic institution from 2005 to 2015 were reviewed. We identified 52 black patients (11.7%) and 438 white patients (88.3%). Patient demographics, comorbidities, and intraoperative and 30-day postoperative complication and readmission rates were collected. The primary outcome investigated in this study was the rate of 30-day postoperative complications. RESULTS: Patient demographics and comorbidities were similar between both groups, including age, gender, and body mass index. Median (interquartile range) number of fusion levels and operative time were similar between the cohorts (black, 6.5 [5-9] vs. white, 7 [5-9]; P = 0.55; and black, 307.3 ± 120.2 minutes vs. white, 321.3 ± 135.3 minutes; P = 0.45, respectively). Both cohorts had similar postoperative complications and lengths of hospital stay (black, 7.2 ± 5.4 days vs. white: 6.5 ± 4.9; P = 0.37). There was no significant difference in 30-day readmission between the cohorts (black, 9.6% vs. white, 12.8%; P = 0.66). There were no observed differences in 30-day complication rates, including: pain (P = 0.74), urinary tract infection (P = 0.68), hardware failure (P = 0.36), wound dehiscence (P = 0.29), and drainage (P = 0.86). CONCLUSIONS: Our study suggests that there is no difference between races in 30-day complication and readmission rates after complex spinal surgery requiring ≥5 levels of fusion.

Characterizations of Temporal Postoperative Pain Signatures With Symbolic Aggregate Approximations.

OBJECTIVES: The primary aim was to characterize the temporal dynamics of postoperative pain intensity using symbolic aggregate approximation (SAX). The secondary aim was to explore the effects of sociodemographic and clinical factors on the SAX representations of postoperative pain intensity. MATERIALS AND METHODS: We applied SAX to a large-scale time series database of 226,808 acute postoperative pain intensity ratings. Pain scores were stratified by patient age, sex, type of surgery, home opioid use, and postoperative day (POD), and costratified by age and sex. Cosine similarity, a metric that measures distance using vector angle, was applied to these motif data to compare pain behavior similarities across strata. RESULTS: Across age groups, SAX clusters revealed a shift from low-to-low pain score transitions in older patients to high-to-high pain score transitions in younger patients, whereas analyses stratified by sex showed that males had a greater focus of pain score transitions among lower-intensity pain scores compared with females. Surgical stratification, using cardiovascular surgery as a reference, demonstrated that pulmonary surgery had the highest cosine similarity at 0.855. With POD stratification, POD 7 carried the greatest cosine similarity to POD 0 (0.611) after POD 1 (0.765), with POD 3 (0.419) and POD 4 (0.441) carrying the lowest cosine similarities with POD 0. DISCUSSION: SAX offers a feasible and effective framework for characterizing large-scale postoperative pain within the time domain. Stratification of SAX representations demonstrate unique temporal dynamic profiles on the basis of age group, sex, type of surgery, preoperative opioid use, and across PODs 1 to 7.

Ethnicity-dependent influence of innate immune genetic markers on morphine PCA requirements and adverse effects in postoperative pain.

Although several genetic factors have been associated with postsurgical morphine requirements, those involving the innate immune system and cytokines have not been well investigated. The aim of this study was to investigate the contribution of genetic variability in innate immune signalling pathways to variability in morphine dosage after elective caesarean section under spinal anaesthesia in 133 Indian, 230 Malay, and 598 Han Chinese women previously studied. Twenty single nucleotide polymorphisms in 14 genes involved in glial activation (TLR2, TLR4, MYD88, MD2), inflammatory signalling (IL2, IL6, IL10, IL1B, IL6R, TNFA, TGFB1, CRP, CASP1), and neuronal regulation (BDNF) were newly investigated, in addition to OPRM1, COMT, and ABCB1 genetic variability identified previously. Postsurgical patient-controlled analgesia morphine use (mg/24 hours) was binned into 6 normally distributed groups and scored 0 to 5 to facilitate step-down multiple linear regression analysis of genetic predictors, controlling for ethnicity and nongenetic variables. Ethnicity, OPRM1 rs1799971 (increased), TLR2 rs3804100 (decreased), and an interaction between ethnicity and IL1B rs1143634 (increased), predicted 9.8% of variability in morphine use scores in the entire cohort. In the Indian cohort, 14.5% of the variance in morphine use score was explained by IL1B rs1143634 (increased) and TGFB1 rs1800469 (decreased). In Chinese patients, the incidence of postsurgical pain was significantly higher in variant COMT rs4680 genotypes (P = 0.0007) but not in the Malay or Indian cohorts. Innate immune genetics may contribute to variability in postsurgical opioid requirements in an ethnicity-dependent manner.

Disparities in TKA Outcomes: Census Tract Data Show Interactions Between Race and Poverty.

BACKGROUND: Race is an important predictor of TKA outcomes in the United States; however, analyses of race can be confounded by socioeconomic factors, which can result in difficulty determining the root cause of disparate outcomes after TKA. QUESTIONS/PURPOSES: We asked: (1) Are race and socioeconomic factors at the individual level associated with patient-reported pain and function 2 years after TKA? (2) What is the interaction between race and community poverty and patient-reported pain and function 2 years after TKA? METHODS: We identified all patients undergoing TKA enrolled in a hospital-based registry between 2007 and 2011 who provided 2-year outcomes and lived in New York, Connecticut, or New Jersey. Of patients approached to participate in the registry, more than 82% consented and provided baseline data, and of these patients, 72% provided 2-year data. Proportions of patients with complete followup at 2 years were lower among blacks (57%) than whites (74%), among patients with Medicaid insurance (51%) compared with patients without Medicaid insurance (72%), and among patients without a college education (67%) compared with those with a college education (71%). Our final study cohort consisted of 4035 patients, 3841 (95%) of whom were white and 194 (5%) of whom were black. Using geocoding, we linked individual-level registry data to US census tracts data through patient addresses. We constructed a multivariate linear mixed-effect model in multilevel frameworks to assess the interaction between race and census tract poverty on WOMAC pain and function scores 2 years after TKA. We defined a clinically important effect as 10 points on the WOMAC (which is scaled from 1 to 100 points, with higher scores being better). RESULTS: Race, education, patient expectations, and baseline WOMAC scores are all associated with 2-year WOMAC pain and function; however, the effect sizes were small, and below the threshold of clinical importance. Whites and blacks from census tracts with less than 10% poverty have similar levels of pain and function 2 years after TKA (WOMAC pain, 1.01 ± 1.59 points lower for blacks than for whites, p = 0.53; WOMAC function, 2.32 ± 1.56 lower for blacks than for whites, p = 0.14). WOMAC pain and function scores 2 years after TKA worsen with increasing levels of community poverty, but do so to a greater extent among blacks than whites. Disparities in pain and function between blacks and whites are evident only in the poorest communities; decreasing in a linear fashion as poverty increases. In census tracts with greater than 40% poverty, blacks score 6 ± 3 points lower (worse) than whites for WOMAC pain (p = 0.03) and 7 ± 3 points lower than whites for WOMAC function (p = 0.01). CONCLUSIONS: Blacks and whites living in communities with little poverty have similar patient-reported TKA outcomes, whereas in communities with high levels of poverty, there are important racial disparities. Efforts to improve TKA outcomes among blacks will need to address individual- and community-level socioeconomic factors. LEVEL OF EVIDENCE: Level III, therapeutic study.

Common variants of catechol-O-methyltransferase influence patient-controlled analgesia usage and postoperative pain in patients undergoing total hysterectomy.

Catechol-O-methyltransferase (COMT) gene polymorphisms and haplotypes have been associated with both experimental and clinical pain phenotypes. In this prospective study, we investigated the association of three common polymorphisms with experimentally induced pressure pain, postoperative pain and amount of self-administered morphine in 973 patients who underwent scheduled total hysterectomy. DNA extracted from peripheral blood was genotyped for three COMT polymorphisms by Taqman assay or a PCR-based method. In the overall sample, rs4633 and rs4680 were significantly associated with morphine use, whereas rs4818 was associated with time-averaged pain scores. Statistically significant associations were found between COMT rs4633 and rs4680 genotypes and the amount of morphine self-administered through a patient-controlled analgesia pump. For rs4818, the only statistically significant association was with time-averaged pain scores. Haplotype analysis showed statistically significant association of the low pain sensitivity haplotype with time-averaged pain scores; and average pain sensitivity haplotype with total morphine and weight-adjusted morphine.

Does Race Affect Outcomes in Total Joint Arthroplasty?

BACKGROUND: Several studies suggest worse surgical outcomes among racial/ethnic minorities. There is a paucity of research on preoperative and postoperative pain, general health, and disease-specific measures in which race is the main subject of investigation; furthermore, the results are not conclusive. QUESTIONS/PURPOSES: (1) Do black patients have more severe or more frequent preoperative pain, well-being, general health, and disease-specific scores when compared with white patients? (2) Are there differences between black patients and white patients after hip or knee arthroplasty on those same measures? METHODS: In this retrospective study, we used an institutional arthroplasty registry to analyze data on 2010 primary arthroplasties (1446 knees and 564 hips) performed by one surgeon at a single institution. Cases from patients self-identifying as black (n = 105) and white (n = 1905) were compared (controlling for confounders, including age and ethnicity) on the following preoperative and postoperative patient-oriented outcomes: pain intensity/frequency as measured by a visual analog scale (VAS), Quality of Well-Being (QWB-7), SF-36, and WOMAC scores. T-tests, chi square, and multivariate analysis of covariance were used. Alpha was set at 0.05. Postoperative analysis was performed only on those cases that had a minimum followup of 1 year (mean, 3.5 years; range, 1-9 years). Of the 2010 arthroplasties, 37% (39 of 105) of those cases performed in black patients and 64% (1219 of 1905) of those performed in white patients were included in the final postoperative model (multivariate analysis of covariance). RESULTS: Black patients had more severe preoperative pain intensity (VAS: 8 ± 1.8 versus 8 ± 2.0, mean difference = 0.76 [95% confidence interval {CI}, 0.34-1.1], p < 0.001). Black patients also had worse well-being scores (QWB-7: 0.527 ± 0.04 versus 0.532 ± 0.05, mean difference = -0.01 [CI, -0.02 to 0.00], p = 0.037). Postoperatively, pain intensity (VAS: 1 ± 3.1 versus 1 ± 1.8, mean difference= 0.8 [CI, 0.19-1.4], p= 0.010) and (QWB-7: 0.579 ± 0.09 versus 0.607 ± 0.11, mean difference= -0.049 [CI, -0.08 to -0.01], p = 0.008) were different but without clinical significance. CONCLUSIONS: Black patients underwent surgery earlier in life and with different preoperative diagnoses when compared with white patients. Black patients had worse preoperative baseline pain, well-being, general health, and disease-specific scores as well as worse postoperative scores. However, these differences were very narrow and without clinical significance. Notwithstanding, the relations of race with outcomes remain complex. Further investigations to recognize disparities and minimize or address them are warranted. LEVEL OF EVIDENCE: Level III, prognostic study.

An ethnographic exploration of postoperative pain experiences among Ghanaian surgical patients.

BACKGROUND: The experience of pain associated with surgery has been a challenge for health care professionals for many years, and culture is said to influence pain. PURPOSE: This study focused on patients' experiences of postoperative pain (POP) and factors that affect POP. DESIGN: The study employed qualitative ethnographic principles. METHOD: Data were collected through individual face-to-face interviews. Data were saturated after analyzing data from 13 patients from two hospitals in Ghana. FINDINGS: Themes that emerged were the subjective nature of pain, which described pain dimensions and communication; psycho-sociocultural factors, such as personal inclinations and sociocultural background; and health system factors, such as personnel attitudes and health financing. IMPLICATIONS FOR FUTURE RESEARCH AND PRACTICE: Health professionals need to understand the sociocultural effects of pain in order to give effective care. CONCLUSION: The study highlighted the need for patient education and the importance that health care professionals understand context-specific factors that influence POP management.

Acute postoperative pain relief with immediate-release tapentadol: randomized, double-blind, placebo-controlled study conducted in South Korea.

OBJECTIVE: To broaden the ethnic groups in which tapentadol IR is evaluated for treating acute postoperative pain to include Asians. METHODS: In this phase 3, multicenter, double-blind, randomized study, 352 Korean adults with moderate-to-severe pain following hallux valgus surgery received tapentadol IR 50 or 75 mg or placebo orally every 4-6 hours for 72 hours. Patients requesting other (rescue) analgesics during this period were discontinued for lack of efficacy. The primary endpoint, sum of pain intensity difference (SPID) over 48 hours, was evaluated based on the difference between tapentadol IR and placebo in least squares (LS) mean change from baseline using analysis of covariance (ANCOVA). Secondary endpoints included the time to first rescue medication use and the distribution of responder rates. RESULTS: A treatment effect, favoring tapentadol IR, was observed for SPID48 (p < 0.001 for both doses vs. placebo, ANCOVA). The between-group difference (vs. placebo) in LS means of SPID48 was 76.4 (95% CI: 51.0, 101.7) for tapentadol IR 50 mg and 90.6 (95% CI: 65.1, 116.1) for tapentadol IR 75 mg. Time to first rescue medication use was delayed for tapentadol IR (p < 0.001 for both doses vs. placebo; log-rank test). The distribution of responders at 12, 24, 48, and 72 hours favored tapentadol IR (p ≤ 0.001 for both doses vs. placebo; Cochran-Mantel-Haenszel test). Dizziness, nausea, and vomiting were each reported in ≥ 10% tapentadol-treated patients and at an incidence ≥ 2-fold higher vs. placebo. The study findings may be limited by study drug dosing every 4 to 6 hours and frequent monitoring during treatment, neither of which mimic pain treatment in clinical practice. However, any potential bias based on this systematic monitoring of patients would be mitigated by the randomized, double-blind nature of the study, with all treatment groups similarly affected by such biases, if any. CONCLUSIONS: Tapentadol IR reduced acute pain intensity, significantly more than placebo, after orthopedic surgery in Korean patients. CLINICAL TRIAL REGISTRATION: NCT01516008.