Gender affects report of pain and function after arthroscopic anterior cruciate ligament reconstruction

Pain perception during intravitreal injections is related to the timing of instilling anesthetic eyedrops

PURPOSE

To evaluate the correlation between the timing of instilling anesthetic eyedrops prior to intravitreal injection and the patient's perception of pain associated with the injection.

METHODS

A prospective observational study which included 192 eyes of 192 patients. Time interval between instillation of Oxybuprocaine-0.4% and Tetracaine-0.5% eyedrops upon checking-in and injection was measured and pain level was evaluated by the 101-point-Numeric Rating Scale.

RESULTS

We found significant correlation between time interval from the first eyedrops to injection and injection related pain. The lowest pain score (11 ± 18) was found in the 11-15 min group, while the highest was found in the 0-6 min (26 ± 25) and in the > 35 min (31 ± 28) groups. The highest percentage of patients without pain was found in the 11-15 min (64%), followed by the 7-10 min (56%) and 16-20 min (47%) groups. 10% or 17% of the 0-6 min or > 35 min. groups, respectively, reported no pain. No patients in 11-15 min group reported severe pain versus 10% in the 0-6 min and 17% in the > 35 min groups. The highest percentage of patients with 'absent-to-mild' pain was in the 11-15 min (89%) and the 7-10 min (87%) compared to all other groups.

CONCLUSIONS

Administration of first dose of anesthetic eyedrops within 11-15 min before intravitreal injection yields the lowest levels of injection-related pain, with 7-10 min being second best. Administration of eyedrops outside of this time-window results in higher pain levels avoidable with more attention to the timing issue.

Incidence and predictors of chronic pain after inguinal hernia surgery: a systematic review and meta-analysis

PURPOSE

The mesh is currently the preferred treatment option for hernia repair surgery. Chronic postoperative inguinal pain (CPIP), lasting more than 3 months after surgery, is a complication that significantly impacts patients' quality of life. Currently, there is a lack of evidence-based information describing the incidence and independent predictive factors of chronic pain, posing a serious challenge in clinical practice for devising personalized prevention strategies. Hence, we conducted this systematic review and meta-analysis to investigate the incidence and predictive factors, aiming to provide a reference for developing plans to prevent chronic pain.

METHODS

We conducted a systematic search of PubMed, Cochrane, Embase, and Web of Science, with the retrieval cutoff date set at December 17, 2022. The included studies underwent assessment using the NOS scale, and subgroup analysis for the incidence was carried out based on different regions.

RESULTS

Ultimately, 18 studies were included, involving 29,466 patients. Meta-analysis showed that the pooled incidence of chronic pain was 17.01% (95%CI 12.78% ~ 21.71%). The incidence was 18.65% (95%CI 13.59% ~ 24.29%) in Europe, 14.70% (95%CI 7.87% ~ 23.17%) in Asia, and 6.04%(95%CI 4.62 ~ 7.64) in North America. Furthermore, We also found that the risk factors for CPIP are younger age [OR = 2.261 (95%CI 1.126 ~ 4.549)], presence of other postoperative complications [OR = 1.849 (95%CI 1.034 ~ 3.305)], hernial sac defect < 3 cm [OR = 1.370 (95%CI 1.012 ~ 1.853)], being female [OR = 1.885 (95%CI 1.024 ~ 3.472)], postoperative pain [OR = 1.553 (95%CI 1.276 ~ 1.889)], preoperative pain [OR = 2.321 (95%CI 1.354 ~ 3.979)], and having a history of ipsilateral inguinal hernia repair [OR = 2.706 (95% CI 1.445 ~ 5.069)].

CONCLUSIONS

The incidence of persistent pain following hernia repair surgery is high in current clinical practice, a concern that should not be overlooked. Stratified assessment tools need to be established for patients experiencing early chronic pain, and personalized follow-up strategies and preventive interventions should be developed for those with potentially high risks. These measures aim to enhance the quality of life for patients after hernia repair.

Sex related difference in postoperative pain and opioid use following posterior spinal fusion for adolescent idiopathic scoliosis

PURPOSE

This project aims to evaluate the relationship between biological sex and postoperative pain and in patients receiving posterior spinal fusion for adolescent idiopathic scoliosis.

METHODS

This is a retrospective study of patients (n=137) aged 10-17 receiving posterior spinal fusion for adolescent idiopathic scoliosis between 01/2018 and 09/2022. Each patient received surgery by the same pediatric orthopedic surgeon with identical postoperative pain management regimen at a children's hospital or a tertiary referral center with a pediatric spine program.

RESULTS

There were no significant differences in any background characteristics between the male and female patients, including age, BMI, number of levels fused, preoperative degree of scoliosis, and length of surgery and anesthesia (p>0.05). There were no differences in amount given of any intraoperative medications, nor in amount of postoperative scheduled analgesics (p>0.05). Female patients demonstrated higher average pain scores on Visual Analogue Scale evaluations during the first 24 hours postoperatively (5.0 vs 3.6, p<0.0001), 24-48 hours postoperatively (4.9 vs 4.0, p=0.03), and at the first physical therapy evaluation (5.3 vs 3.8, p<0.001). These patients received significantly greater amounts of morphine milligram equivalents in the first 24 hours postoperatively (42.2 vs 31.5, p=0.01) and for the hospitalization in total (63.8 vs 51.3, p=0.048). There was no difference in hours until hospital discharge (44.3 vs 42.6, p=0.62) nor until first ambulation (20.1 vs 21.3, p=0.24) between the female and male patients.

CONCLUSION

The influence of biopsychosocial factors on postoperative pain in adolescents is complex. This study adds to the existing pool of literature suggesting differences in pain perception between adolescent female and male patients. Female patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis may benefit from increased preoperative counseling and more aggressive intra- and postoperative pain management regimens.

Preoperative factors affecting the quality of life after arthroscopic rotator cuff repair: a prospective study

Background

Rotator cuff tears are well known to cause significant pain and disability, having a marked impact on an individual's quality of life. This prospective study aimed to analyze the various patient factors and their impact on health-related quality of life (HrQoL) post arthroscopic rotator cuff repair (RCR).

Material and Methods

We prospectively analyzed 95 patients at one year and 81 patients at two years, with complete rotator cuff tear, who underwent arthroscopic repair of the same. The 36-Item Short Form Survey (physical and mental component score), visual analog scale (pain, function), and QuickDASH questionnaires were administered to all the patients preoperatively and at one- and two-year follow-ups. Relationships between various patient factors (age, gender, side, duration of symptoms, pseudoparalysis, diabetes mellitus [DM], type, and size of tear) and outcome measures were analyzed.

Results

All outcome parameters showed significant improvement at one- and two-year follow-ups. Patient factors, such as gender, tear type (traumatic vs degenerative), and DM, affected all outcome parameters and were significant even in the regression analysis model at a 2-year follow-up. Factors such as age and symptoms duration were significant only at 1-year follow-up, with older age and patients with symptoms > 6 weeks showing more disability. Side (dominant or nondominant), tear size, and pseudoparalysis do not affect outcomes.

Conclusions

This study showed that arthroscopic RCR significantly improved HrQoL post arthroscopic RCRs. Factors independently affecting HrQoL were noted as gender, tear type, and DM. On the other hand, age, side involved, duration of symptoms, pseudoparalysis, and tear size had no independent effect on HrQoL at a two-year follow-up.

Prospective paired crossover evaluation of potential impact of investigator gender on perceived pain intensity early after acute or scheduled surgery

BACKGROUND

Postoperative pain is common but often difficult to assess, and there are many potential confounders. Over the last decades, the gender of investigator as well as participant has been found to influence pain perception in both preclinical and clinical studies. However, to our knowledge this has not been studied in various postoperative patients. Objectives of this study were to test the hypotheses that pain intensity levels early after acute or scheduled in- or out-hospital surgery are lower when evaluated by a female investigator, and higher when reported by a female patient.

METHODS

In this prospective observational paired crossover study, two investigators of opposite genders independently obtained individually reported pain intensity levels with a visual analogue scale in a mixed cohort of adult postoperative study patients at Skåne University Hospital in Malmö, Sweden.

RESULTS

In total, 245 (129 female) study patients were included and then one female excluded. The study patients rated their intensity of postoperative pain lower when evaluated by a female than by a male investigator (P = 0.006), where the male patients constituted the significant difference (P < 0.001). Pain intensity levels did not differ between female and male study patients (P = 0.210).

CONCLUSIONS

Main findings of lower pain intensity reported by males to a female than to a male investigator early after surgery in this paired crossover study in mixed postoperative patients, indicate that potential impact of investigator gender on pain perception should be considered and further evaluated in clinical bedside practice. Trial registration Retrospectively registered in the ClinicalTrials.gov research database on 24th June 2019 with TRN number NCT03968497.

Sex Differences in Pain and Its Treatment

Pain is a highly personal experience. Pain is often considered to be a purely neurologic phenomenon, but in actuality, it is a combination of both sensory and emotional experiences. This has sometimes been translated clinically toward a more mechanistic approach to the assessment and treatment of pain instead of one that does not discount pain mechanisms, but also is more inclusive of the need for humanism - considering the individual. In today's medical environment, more than ever before there is a significant amount of attention being paid to educating clinicians to better understand that several physiological, neurophysiological, and psychosocial factors can significantly impact responses to pain. The composition of these factors will be unique to that individual's life narrative, context, sex, and prior life experiences. Thus, the concept that a templated approach to pain assessment and pharmacotherapeutic treatment planning should not be expected to provide optimal patient satisfaction and treatment outcomes in the majority. The hypotheses that there may be sex-based differences in the pain experience in a variety of ways including pain sensitivity, tolerance to pain, threshold at which something becomes painful, and the effectiveness of endogenous pain modulation systems are not new and have been well represented in the literature. This chapter reviews important key findings in the scientific literature with respect to sex-based differences in pain and pain responses to experimentally induced painful stimuli, pain experienced in commonly occurring painful medical conditions, and variations in responses to pain treatments. Possible explanations to account for observed differences or similarities will also be discussed.

Women Have Tendons… and Tendinopathy: Gender Bias is a "Gender Void" in Sports Medicine with a Lack of Women Data on Patellar Tendinopathy-A Systematic Review

INTRODUCTION

Patellar tendinopathy is one of the most common musculoskeletal problems associated with sport. While commonly perceived as a predominantly male problem, recent epidemiological studies revealed that it also affects a large number of sport-active women. The aim of this systematic review was to understand how the available treatments apply to women affected by patellar tendinopathy.

METHODS

We analysed the available literature with a systematic review on three databases (PubMed, Cochrane, Web of Science) on February 2021, retrieving a total of 136 studies published from 1983.

RESULTS

The overall scientific field offers an astonishingly low number of data on treatment results referring to only 78 women (2%) in the entire literature. Only 5% of the retrieved articles considered focusing only or mostly on men to be a limitation.

CONCLUSIONS

Women represent only a minority of patients studied for this topic. The few documented cases are further fragmented by being related to different treatments, thus basically offering no solid evidence for results and limitations of any therapeutic approach in women. This literature analysis showed a greater gender gap than what is recognized in science and general medicine; it showed a gender blindness in sports medicine when investigating a common problem like patellar tendinopathy.

Validation and Reliability of a Novel Vagus Nerve Neurodynamic Test and Its Effects on Heart Rate in Healthy Subjects: Little Differences Between Sexes

Background

The vagus nerve (VN), also called the pneumogastric nerve, connects the brainstem to organs contained in the chest and abdomen. Physiologically, VN stimulation can rapidly affect cardiac activity and heart rate (HR). VN neuropathy can increase the risk of arrhythmias and sudden death. Therefore, a selective test of VN function may be very useful. Since peripheral neurodynamic tests (NDT) are reliable for the assessment of neuropathies in somatic nerves, we aimed to validate a novel NDT to assess VN activity, namely, the VN-NTD.

Methods

In this cross-sectional double-blind, sex-balanced study, 30 participants (15 females) completed a checklist of autonomic dysfunction symptoms. During the VN-NDT administration, HR and symptoms (i.e., mechanical allodynia) were monitored in parallel to a real-time ultrasonography imaging (USI) and motion capture analysis of the neck. The VN-NDT impact on HR and its accuracy for autonomic symptoms reported in the last 7 days were tested.

Results

The VN-NDT induced a significant HR reduction of about 12 and 8 bpm in males and females [t(1, 119) = 2.425; p < 0.017; η_p² = 0.047, 95% confidence interval (CI): 0.93–9.18], respectively. No adverse events were observed during VN-NDT. A substantial interexaminer agreement between the evaluators in symptoms induction by VN-NDT was detected [F(1, 119) = 0.540; p = 0.464; η_p² = 0.005, low effect]. Notably, mechanical allodynia accuracy for gastrointestinal dysfunctions was excellent (p < 0.05; 95% CI: 0.52–0.73; p < 0.001; 95% CI: 0.81–0.96).

Conclusions

The novel VN-NDT is a valid and accurate test capable of detecting VN activation with high sensitivity. Data provided are suitable for both sexes as a hallmark of HR variation due to VN normal response. The proposed VN-NDT may be reliable as daily routine neurological examination tests for the evaluation of neuropathic signs related to neuroinflammation of the VN.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier NCT04192877.

Patients who have undergone rotator cuff repair experience around 75% functional recovery at 6 months after surgery

PURPOSE

The purposes of this study were to (1) evaluate changes in recovery patterns [i.e., clinical outcomes, range of motion (ROM)] in the first 12 months following surgery, (2) identify potential prognostic factors of early clinical outcomes after rotator cuff repair (RCR).

METHODS

The study cohort included 344 consecutive patients treated with RCR. Data were collected prospectively and included pre- and perioperative variables. Univariate and multivariate linear regression analyses for various parameters including demographics, pre- and perioperative variables were used to predict shoulder function at 12-month follow-up, as measured by clinical outcomes and ROM.

RESULTS

Significant improvement in all clinical scores and ROM were noted during serial follow-ups after RCR (all p < 0.001). Multivariate analysis revealed that female sex, older age, more anchors, diabetes mellitus, and preoperative stiffness were independently associated with worse shoulder function 3 months after RCR. Including the 3 months factors, heavy labor, use of the suture-bridge technique, and large tears were also independently associated with worse outcomes 6 months after surgery. Heavy labor, suture-bridge technique, diabetes mellitus, and preoperative stiffness were associated with significantly worse functional outcomes at 12 months after surgery (all p < 0.05).

CONCLUSION

Functional recovery based on clinical outcomes (i.e., UCLA, ASES scores) showed approximately 60% of ultimate recovery at 3 months and approximately 75% recovery at 6 months after RCR. Female sex, diabetes mellitus, preoperative stiffness, a larger number of anchors, suture bridge technique, heavy labor, old age and, larger tears were prognostic factors of poor clinical results or ROM in the short-term follow-up intervals. Knowledge of these prognostic factors may lead to improved insight for physicians to predict the pattern of the recovery and patient expectations accordingly.

LEVEL OF EVIDENCE

III, A cohort study.

Mesh in Elective Hernia Repair: 10-Year Experience with over 6,000 Patients

BACKGROUND

The use of mesh in hernia repair has faced intense scrutiny, leading patients to become fearful of its use, despite its benefits in reducing hernia recurrence. We report a single institutional experience in performing hernia repair with mesh in terms of hernia-specific outcomes, mesh-related complications, and patient-reported quality of life.

STUDY DESIGN

Patients who underwent abdominal wall hernia repair with mesh at a single institution were identified from a prospectively maintained quality database. Demographic, perioperative, and postoperative outcomes data were analyzed. Surgical Outcomes Measurements System (SOMS) and Carolinas Comfort Scale (CCS) surveys were administered pre- and postoperatively at 3 weeks, 6 months, 1, 2, and 5 years.

RESULTS

Between 2010 and 2020, a total of 6,387 patients underwent abdominal hernia repair with mesh. Inguinal hernia repairs made up the majority (65%) of the operations. Rates of mesh infection varied by hernia type, with lower rates after umbilical (0.0%) and inguinal (0.4%) repair, and highest after incisional repair (1.3%). Similarly, mesh explantation rates were low after umbilical and inguinal repair (0.0% and 0.4%, respectively) and highest after incisional repair (3.0%). Scores on all SOMS domains were significantly improved from baseline (all p < 0.05). On CCS, 2.9%, 3.3%, and 4.4% of patients reported severe or disabling symptoms postoperatively at 1, 2, and 5 years, respectively.

CONCLUSIONS

Rates of mesh-related complications vary by hernia type. A majority of patients report excellent long-term quality of life, although a relatively large percentage of patients experience severe or disabling symptoms at long-term follow-up.

The effect of age and gender on acute postoperative pain and function following lumbar spine surgeries

BACKGROUND AND PURPOSE

Understanding the factors contributing to the variability in postoperative pain and function following lumbar spine surgeries (LSS) is necessary to plan inpatient rehabilitation and optimize surgical outcomes. In particular, variability due to age and gender has not been studied. This study's aim was to evaluate the variability in postoperative pain and function, during hospital stay, due to age and gender following LSS.

METHODS

We conducted a retrospective analysis of 585 patients who underwent LSS during their hospital stay. Univariate ANCOVA was performed to study the differences in postoperative pain, and multivariate ANCOVA was performed to study the differences in postoperative function (gait distance, independency combined score, and balance combined score) between age groups (older adults [≥65 years of age] vs. younger adults) and gender.

RESULTS

Younger patients reported statistically, but not clinically, significant higher postoperative pain than older patients (β = 0.652 [95% CI (0.382-0.986)], p < 0.001), and males reported statistically, but not clinically, significant lower postoperative pain than female patients (β = -0.583 [95% CI (-0.825 to -0.252)], p < 0.001) with adjustment of covariates. Male patients walked significantly longer distance than female patients (β = 0.272 [95% CI (0.112-0.432)], p = 0.001) with adjustment of covariates. However, these were clinically insignificant. With adjustment of preoperative diagnosis, type of surgery, severity of illness, and prior level of function, there was no statistically significant difference between age groups in walking distance, and between age and gender groups in independency combined score and balance combined scores.

DISCUSSION

Following LSS, the difference in postoperative pain between age groups and gender are statistically but not clinically significant, suggesting patients require similar effective postoperative pain management regardless of age and gender. The apparent difference in age and gender in postoperative functional outcomes could be due to other factors.

Predictors of chronic pain after laparoscopic inguinal hernia repair

BACKGROUND

Multiple studies have analyzed predictors for chronic pain after open hernia repair. The purpose of this study is to determine which factors predict the development of chronic pain after a laparoscopic inguinal hernia repair.

METHODS

We identified patients who underwent laparoscopic inguinal hernia repair between 2008 and 2020 at a single institution. Quality of life was measured using the Surgical Outcomes Measurement System and Carolinas Comfort Scale. We categorized patients with chronic pain if their score on Carolinas Comfort Scale was greater than or equal to 3. Multivariable logistic regression analysis was used to identify predictors of chronic pain.

RESULTS

A total of 960 patients met inclusion criteria. Mean age was 59 (± 14, standard deviation) years, 89 (9.3%) of whom were female. Six percent of patients met criteria for chronic pain (Carolinas Comfort Scale ≥3). On multivariable analysis, predictors for chronic pain were age 45 (P < .001), female sex (P = .006), preoperative pain visual analog scale ≥1 (P = .025), prior inguinal hernia repair (P = .045), higher American Society of Anesthesiologists class (P = .041), use of multifilament polyester mesh (P = .0448), and intraoperative placement of a urinary catheter (P = .009).

CONCLUSION

Laparoscopic inguinal hernia repair results in 6.0% of patients experiencing chronic pain. We identified multiple predictors for chronic pain.

Predictive Modeling to Determine Functional Outcomes After Arthroscopic Rotator Cuff Repair

BACKGROUND

Arthroscopic rotator cuff repair (ARCR) is one of the most commonly performed orthopaedic surgical procedures; however, patient-reported outcomes have varied greatly in the literature.

PURPOSE

To identify preoperative factors that affect outcomes and to develop prognostic tools for predicting functional outcomes in future ARCR cases.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients were included who underwent ARCR for repairable full-thickness rotator cuff tears with at least 2 years of follow-up. Twelve predictors were entered as candidate predictors in each model: age, sex, workers' compensation (WC) status, previous cuff repair, tear size, tear shape, multiple-tendon involvement, tendon stump length, Goutallier classification, critical shoulder angle, length of follow-up, and baseline subjective outcomes score. Postoperative American Shoulder and Elbow Surgeons (ASES), 12-Item Short Form Health Survey Physical Component Summary (SF-12 PCS), QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand), and patient satisfaction were each modeled through proportional odds ordinal logistic regression. Model results were presented with marginal covariate effect plots and predictive nomograms.

RESULTS

Overall, 552 shoulders fit inclusion criteria. The mean age at surgery was 60.2 years (range, 23-81 years). Twenty-five (4.5%) shoulders underwent revision cuff repair or reverse arthroplasty at a mean 1.9 years (range, 0.1-7.9 years) postoperatively. Overall, 509 shoulders were eligible for follow-up, and minimum 2-year postoperative patient-reported outcomes were obtained for 449 (88.2%) at a mean 4.8 years (range, 2-11 years). The ASES score demonstrated significant improvement from pre- to postoperative median (interquartile range): 58 (44.9-71.6) to 98.3 (89.9-100; P < .001). Women demonstrated significantly higher 2-year reoperation rates than men (5.8% vs 1.6%; odds ratio, 2.8 [95% CI, 0.73-9.6]; P = .023). Independently significant predictors for lower postoperative ASES scores included previous ARCR (P < .001), female sex (P < .001), and a WC claim (P < .001). Significant predictors for worse QuickDASH scores included WC claim (P < .001), female sex (P < .001), previous ARCR (P = .007), and ≥7 years of follow-up time. Significant predictors for lower SF-12 PCS scores included WC claim (P < .001), female sex (P = .001), and lower baseline SF-12 PCS. Last, significant independent predictors of patient satisfaction included previous ARCR (P = .004), WC claim (P = .011), female sex (P = .041), and age (P = .041).

CONCLUSION

Excellent clinical outcomes and low failure rates were obtained after ARCR by using careful patient selection and modern surgical techniques for ARCR. Female sex, WC claim, and previous ARCR were significant predictors of poorer outcomes in at least 3 patient-reported outcome models. Prognostic nomograms were developed to aid in future patient selection, clinical decision making, and patient education.

The effect of intraoperative lidocaine versus esmolol infusion on postoperative analgesia in laparoscopic cholecystectomy: a randomized clinical trial

Background

As a part of multimodal analgesia for laparoscopic cholecystectomy, both intraoperative lidocaine and esmolol facilitate postoperative analgesia. Our objective was to compare these two emerging strategies that challenge the use of intraoperative opioids. We aimed to assess if intraoperative esmolol infusion is not inferior to lidocaine infusion for opioid consumption after laparoscopic cholecystectomy.

Methods

In this prospective, randomized, double-blind, non-inferiority clinical trial, 90 female patients scheduled for elective laparoscopic cholecystectomy received either intravenous (IV) lidocaine bolus 1.5 mg/kg at induction followed by an infusion (1.5 mg/ kg/h) or IV bolus of esmolol 0.5 mg/kg at induction followed by an infusion (5–15 μg/kg/min) till the end of surgery. Remaining aspect of anesthesia followed a standard protocol apart from no intraoperative opioid supplementation. Postoperatively, patients received either morphine or tramadol IV to maintain visual analogue scale (VAS) scores ≤3. The primary outcome was opioid consumption (in morphine equivalents) during the first 24 postoperative hours. Pain and sedation scores, time to first perception of pain and void, and occurrence of nausea/vomiting were secondary outcomes measured up to 24 h postoperatively.

Results

Two patients in each group were excluded from the analysis. The postoperative median (IQR) morphine equivalent consumption in patients receiving esmolol was 1 (0–1.5) mg compared to 1.5 (1–2) mg in lidocaine group (p = 0.27). The median pain scores at various time points were similar between the two groups (p > 0.05). More patients receiving lidocaine were sedated in the post-anesthesia care unit (PACU) than those receiving esmolol (p < 0.05); however, no difference was detected later.

Conclusion

Infusion of esmolol is not inferior to lidocaine in terms of opioid requirement and pain severity in the first 24 h after surgery. Patients receiving lidocaine were more sedated during their stay in PACU than those receiving esmolol.

Trial registration

ClinicalTrials.gov- NCT02327923. Date of registration: December 31, 2014.

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.

Designing a pain management protocol for craniotomy: A narrative review and consideration of promising practices

BACKGROUND

Craniotomy is a relatively common surgical procedure with a high incidence of postoperative pain. Development of standardized pain management and enhanced recovery after surgery (ERAS) protocols are necessary and crucial to optimize outcomes and patient satisfaction and reduce health care costs.

METHODS

This work is based upon a literature search of published manuscripts (between 1996 and 2017) from Pubmed, Cochrane Central Register, and Google Scholar. It seeks to both synthesize and review our current scientific understanding of postcraniotomy pain and its part in neurosurgical ERAS protocols.

RESULTS

Strategies to ameliorate craniotomy pain demand interventions during all phases of patient care: preoperative, intraoperative, and postoperative interventions. Pain management should begin in the perioperative period with risk assessment, patient education, and premedication. In the intraoperative period, modifications in anesthesia technique, choice of opioids, acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), regional techniques, dexmedetomidine, ketamine, lidocaine, corticosteroids, and interdisciplinary communication are all strategies to consider and possibly deploy. Opioids remain the mainstay for pain relief, but patient-controlled analgesia, NSAIDs, standardization of pain management, bio/behavioral interventions, modification of head dressings as well as patient-centric management are useful opportunities that potentially improve patient care.

CONCLUSIONS

Future research on mechanisms, predictors, treatments, and pain management pathways will help define the combinations of interventions that optimize pain outcomes.

Comparison of the Effects of Hegu Point Ice Massage and 2% Lidocaine Gel on Arteriovenous Fistula Puncture-Related Pain in Hemodialysis Patients: A Randomized Controlled Trial

Introduction: There is a paucity of information on the effects of Hegu point ice massage and 2% lidocaine gel on fistula puncture-related pain in hemodialysis patients. The aim of the present research was compare the two methods in terms of their effectiveness.

Methods: This study is a randomized controlled trial. Seventy hemodialysis patients were divided into two groups. The fistula puncture-related pain in the two groups was measured in the first session of hemodialysis without any intervention. During a hemodialysis session, 2% lidocaine gel was applied on the patient’s arteriovenous fistula site in one group. Also, for the other group, an ice cube was used to massage on the Hegu point in the hand without fistula in the other hemodialysis session. The pain score was recorded, using the Visual Analogue Scale. The data were analyzed using SPSS ver.13.

Results: No significant differences were observed in the mean pain scores of the two groups in the preintervention phase. The comparison of the pain score before and after interventions of the lidocaine gel and ice massage groups was found to bear significant differences. Moreover, the comparison of the mean changes of the pain score before and after the intervention of the Hegu point ice massage groups revealed a further reduction for Hegu point than of lidocaine gel groups.

Conclusion: Lidocaine gel and Hegu point ice massage affect the intensity of fistula puncture related pain in hemodialysis patients. Given the higher effectiveness of Hegu point ice massage, this method is recommended to be used for fast and safe pain reduction in hemodialysis patients.

Women report higher pain intensity at a lower level of inflammation after knee surgery compared with men

Women report more pain than men after arthroscopic surgery, but analyses of pro-inflammatory cytokines indicates higher male concentrations of pain biomarkers in synovial fluid.

Introduction and Objectives:

We previously found that women report more pain after knee arthroscopic procedures than men. It remains unclear whether this is due to different biochemical responses or nociceptive mechanisms.

Methods:

We analyzed acute pain-related inflammatory markers in a clinical model of patient self-reported pain immediately after knee surgery. To simultaneously measure 92 inflammatory biomarkers, we used the proximity extension assay with the Proseek Multiplex Inflammation I panel (Olink Bioscience, Uppsala, Sweden). Knee surgery was performed under general anesthesia with propofol and remifentanil. Analgesic drugs were only administered on patient request.

Results:

Women were 4.9 times more likely to report moderate or severe pain than men (95% confidence interval, 1.2–19.6, P = 0.024). Patient age, preoperative pain, and surgery duration were not significant factors. We analyzed synovial fluids from 44 patients (23 women, 21 men). After false discovery rate correction, MMP-10 was the only biomarker that was higher among men (P = 0.01). Linear discriminant analysis showed that 3 proteins (IL-8, CCL-4, and MCP-2) were expressed at higher levels in men, with differences of >1 normalized protein expression. No proteins were overexpressed by >1 normalized protein expression in women.

Conclusion:

Acute pain after knee arthroscopy was more intense in women, but pro-inflammatory biomarkers and MMP-10 were higher in men. Further knowledge of cytokine function is required before concluding that the disparities in biomarker expression are clinically unimportant. The similar biochemical signaling between sexes suggests that central mechanisms are of greater importance in sex-specific joint pain perception.

Time to Onset of Sustained Postoperative Pain Relief (SuPPR): Evaluation of a New Systems-level Metric for Acute Pain Management

OBJECTIVES

Prior work on postoperative pain trajectories has examined pain score changes over time using daily averages of pain scores. However, little is known about the time required until patients consistently report minimal postoperative pain.

MATERIALS AND METHODS

We conducted a retrospective cohort study of surgical case data from 7293 adult patients to examine the impact of age, sex, and the type of surgery on the time to sustained postoperative pain relief (SuPPR). We defined SuPPR as the time required until a patient reports the first of multiple (2, 3, 4, or 5 sequential measurements; eg, SuPPR-2, SuPPR-3), uninterrupted, mild pain scores (≤4/10).

RESULTS

Overall, SuPPR times ranged from 3 minutes for SuPPR-2 and 9 minutes for SuPPR-5 to 160.1 hours for SuPPR-2 and 183.1 hours for SuPPR-5. For the SuPPR-2 outcome, the median time to event was 10.9 hours (interquartile range, 3 to 26.1 h) after surgery. For the SuPPR-5 outcomes, the median time to event was 31.5 hours (interquartile range, 17.8 to 54.2 h) after surgery. The peak median difference between 2 sequential SuPPR definitions was between SuPPR-3 and SuPPR-2 at 9 hours, with subsequent decreases to 6.5 hours between SuPPR-4 and SuPPR-3, and 5.2 hours between SuPPR-5 and SuPPR-4. There were statistically different differences across SuPPR-2 through SuPPR-5 definitions by age, sex, and type of surgery.

DISCUSSION

Although additional analyses are necessary, SuPPR may represent a novel method for evaluating acute pain service performance.

The Impact of Evidence-Based Practices on Postoperative Pain in Patients undergoing Gastrointestinal Surgery in Amiralmomenin Hospital in Zabol During 2014-2015

INTRODUCTION

The Evidence-Based Practices (EBP), have gained considerable ground in treatment and care, increases the quality of nurses' clinical care. Yet EBP is less frequently employed despite its efficiency and importance. Pain management is an important component of nursing care and sufficient pain control has still remained as a challenge despite routine nursing practices that are already provided.

AIM

The present study intended to define the impact of evidence-based nursing practices on postoperative pain in patients undergoing gastrointestinal surgery.

MATERIALS AND METHODS

The present study was a single group quasi-experimental study with before/after design. The study was conducted in the General Surgery Departments of the Amiralmomenin Hospital in Zabol during 2014-2015. A purposive sampling method was used to study 55 patients undergoing abdominal surgery. The data collection tool was a questionnaire. The patients pain severity was defined before and after implementing evidence-based practices. The collected data were analysed in SPSS using descriptive statistics and inferential statistics.

RESULTS

The results showed that 61.8% of patients experienced severe postoperative pain. The mean perceived pain ratings in women and men were 7.88±1.78 and 9.42±0.81, respectively. The mean pain intensity was 8.48±1.66 before the intervention and reached 7.16±1.71 after the intervention, which was significant based on Kruskal-Wallis test (p=0.003). The mean postoperative pain experienced by the patients (p<0.01) and pain-relief following the intervention (p=0.002) was significant for gender.

CONCLUSION

This study suggests that a high percentage of patients experienced acute postoperative pain despite routine nursing care, while evidence-based nursing practices could significantly alleviate pain.

Short-Term Sleep Disturbance-Induced Stress Does not Affect Basal Pain Perception, but Does Delay Postsurgical Pain Recovery

Chronic sleep disturbance-induced stress is known to increase basal pain sensitivity. However, most surgical patients frequently report short-term sleep disturbance/deprivation during the pre- and postoperation periods and have normal pain perception presurgery. Whether this short-term sleep disturbance affects postsurgical pain is elusive. Here, we report that pre- or postexposure to rapid eye movement sleep disturbance (REMSD) for 6 hours daily for 3 consecutive days did not alter basal responses to mechanical, heat, and cold stimuli, but did delay recovery in incision-induced reductions in paw withdrawal threshold to mechanical stimulation and paw withdrawal latencies to heat and cold stimuli on the ipsilateral side of male or female rats. This short-term REMSD led to stress shown by an increase in swim immobility time, a decrease in sucrose consumption, and an increase in the level of corticosterone in serum. Blocking this stress via intrathecal RU38486 or bilateral adrenalectomy abolished REMSD-caused delay in recovery of incision-induced reductions in behavioral responses to mechanical, heat, and cold stimuli. Moreover, this short-term REMSD produced significant reductions in the levels of mu opioid receptor and kappa opioid receptor, but not Kv1.2, in the ipsilateral L4/5 spinal cord and dorsal root ganglia on day 9 after incision (but not after sham surgery).

PERSPECTIVE

Our findings show that short-term sleep disturbance either pre- or postsurgery does not alter basal pain perception, but does exacerbate postsurgical pain hypersensitivity. The latter may be related to the reductions of mu and kappa opioid receptors in the spinal cord and dorsal root ganglia caused by REMSD plus incision. Prevention of short-term sleep disturbance may help recovery from postsurgical pain in patients.

Gender Affects Early Postoperative Outcomes of Rotator Cuff Repair

BACKGROUND

The literature does not provide consistent information on the impact of patients' gender on recovery after rotator cuff repair. The purpose of this study was to determine whether gender affects pain and functional recovery in the early postoperative period after rotator cuff repair.

METHODS

Eighty patients (40 men and 40 women) were prospectively enrolled. Pain intensity and functional recovery were evaluated, using visual analog scale (VAS) pain score and range of motion on each of the first 5 postoperative days, at 2 and 6 weeks and at 3, 6, and 12 months after surgery. Perioperative medication-related adverse effects and postoperative complications were also assessed.

RESULTS

The mean VAS pain score was significantly higher for women than men at 2 weeks after surgery (p = 0.035). For all other periods, there was no significant difference between men and women in VAS pain scores, although women had higher scores than men. Mean forward flexion in women was significantly lower than men at 6 weeks after surgery (p = 0.033) and the mean degree of external rotation in women was significantly lower than men at 6 weeks (p = 0.007) and at 3 months (p = 0.017) after surgery. There was no significant difference in medication-related adverse effects or postoperative complications.

CONCLUSIONS

Women had more pain and slower recovery of shoulder motion than men during the first 3 months after rotator cuff repair. These findings can serve as guidelines for pain management and rehabilitation after surgery and can help explain postoperative recovery patterns to patients with scheduled rotator cuff repair.

Common risk factors for postoperative pain following the extraction of wisdom teeth

The extraction of third molars is a common task carried out at dental/surgery clinics. Postoperative pain is one of the two most common complications of this surgery, along with dry socket. Knowledge of the frequent risk factors of this complication is useful in determining high-risk patients, planning treatment, and preparing the patients mentally. Since the risk factors for postoperative pain have never been summarized before while the risk factors for dry socket have been highly debated, this report summarizes the literature regarding the common predictors of postextraction pain. Except for surgical difficulty and the surgeon's experience, the influences of other risk factors (age, gender and oral contraceptive use) were rather inconclusive. The case of a female gender or oral contraceptive effect might mainly be associated with estrogen levels (when it comes to dry socket), which can differ considerably from case to case. Improvement in and unification of statistical and diagnostic methods seem necessary. In addition, each risk factor was actually a combination of various independent variables, which should instead be targeted in more comprehensive studies.

Sex differences in the incidence of severe pain events following surgery: a review of 333,000 pain scores

OBJECTIVE/BACKGROUND

Prior work has not addressed sex differences in the incidence of severe postoperative pain episodes. The goal of this study was to examine sex differences in clinical postoperative pain scores across an array of surgical procedures using direct comparisons of numeric rating scale pain scores as well as using the incidence of severe pain events (SPEs).

DESIGN/SETTING

Retrospective cohort study of over 300,000 clinical pain score observations recorded from adult patients undergoing nonambulatory surgery at a tertiary care academic medical center over a 1-year period.

METHODS/PATIENTS

To test the hypothesis that the number of SPE on postoperative day (POD) 1 differed by sex after controlling for procedure, we calculated Cochran-Mantel-Haenszel statistics of sex by count of SPE, controlling for type of surgery.

ASSESSMENT TOOLS/OUTCOMES

Pain scores were collected from clinical nursing records where they were documented using the numeric rating scale.

RESULTS

In female patients, 10,989 (25.09%) of 43,806 POD 1 pain scores were considered SPE compared with 10,786 (22.45%) of 48,055 POD 1 pain scores in male patients. This produced an overall odds ratio of 1.16 (99% confidence interval 1.11-1.20) for females vs males to report an SPE for a pain score on POD 1. Estimates of the odds that a given pain observation represents an SPE for female vs male patients after controlling for type of surgery yielded an odds ratio of 1.14 (99% confidence interval, 1.10-1.19).

CONCLUSION

Female patients experience greater mean pain scores, as well as a higher incidence of SPE, on POD 1 for a variety of surgical procedures.

The effects of lavender aromatherapy on pain following needle insertion into a fistula in hemodialysis patients

OBJECTIVE

This study sought to determine the effects of lavender aromatherapy on pain following needle insertion into a fistula in patients undergoing hemodialysis.

METHOD

This is a randomized controlled clinical trial in which 92 patients undergoing hemodialysis with arteriovenous fistulas were randomly divided into two groups. The experimental-group patients inhaled lavender essence with a concentration of 10% for 5 min during 3 hemodialysis sessions, while the control-group patients received aromatherapy free of lavender essence.

RESULTS

The mean VAS pain intensity score in the experimental and control groups before the intervention was 3.78 ± 0.24 and 4.16 ± 0.32, respectively (p = 0.35). The mean VAS pain intensity score in the experimental and control groups after three aromatherapy sessions was 2.36 ± 0.25 and 3.43 ± 0.31, respectively (p = 0.009).

CONCLUSION

Lavender aromatherapy may be an effective technique to reduce pain following needle insertion into a fistula in hemodialysis patients.

Effect of gender on pain perception and analgesic consumption in laparoscopic cholecystectomy: An observational study

Background:

Evidence regarding gender affecting the response to pain and its treatment is inconsistent in literature. The objective of this prospective, observational study was to determine the effect of gender on pain perception and postoperative analgesic consumption in patients undergoing laparoscopic cholecystectomy.

Materials and Methods:

We recruited 60 male and 60 female patients undergoing elective laparoscopic cholecystectomy. Patients were observed for additional intraoperative and postoperative analgesia. Numerical rating scale was documented at 10 min interval for 1 h in post-anesthesia recovery room and at 4, 8, and 12 h postoperatively. Boluses of tramadol given as rescue analgesia were also noted. There were no dropouts.

Results:

The mean pain scores were significantly higher in female patients at 20 and 30 min following surgery. Mean dose of tramadol consumption was significantly higher in female patients for the first postoperative hour (P = 0.002), but not in the later period.

Conclusion:

Female patients exhibited greater intensity of pain and required higher doses of analgesics compared to males in in the immediate postoperative period in order to achieve a similar degree of analgesia.

Sex differences in pain: a brief review of clinical and experimental findings

Recent years have witnessed substantially increased research regarding sex differences in pain. The expansive body of literature in this area clearly suggests that men and women differ in their responses to pain, with increased pain sensitivity and risk for clinical pain commonly being observed among women. Also, differences in responsivity to pharmacological and non-pharmacological pain interventions have been observed; however, these effects are not always consistent and appear dependent on treatment type and characteristics of both the pain and the provider. Although the specific aetiological basis underlying these sex differences is unknown, it seems inevitable that multiple biological and psychosocial processes are contributing factors. For instance, emerging evidence suggests that genotype and endogenous opioid functioning play a causal role in these disparities, and considerable literature implicates sex hormones as factors influencing pain sensitivity. However, the specific modulatory effect of sex hormones on pain among men and women requires further exploration. Psychosocial processes such as pain coping and early-life exposure to stress may also explain sex differences in pain, in addition to stereotypical gender roles that may contribute to differences in pain expression. Therefore, this review will provide a brief overview of the extant literature examining sex-related differences in clinical and experimental pain, and highlights several biopsychosocial mechanisms implicated in these male-female differences. The future directions of this field of research are discussed with an emphasis aimed towards further elucidation of mechanisms which may inform future efforts to develop sex-specific treatments.

Pain assessment in brain tumor patients after elective craniotomy

Objective

This study was performed to assess the postoperative pain of brain tumor patients who underwent elective craniotomy and to evaluate the factors associated with pain intensity.

Methods

From January 2010 to December 2011, 47 patients with newly diagnosed brain tumors who underwent craniotomy were enrolled. The postoperative pain status was assessed daily until discharge using the visual analogue scale (VAS).

Results

The study participants comprised of 22 males and 25 females with ages ranging from 18-76 years (median age, 50 years). Patients were divided into two groups: the painful group included patients who had a VAS score of more than 3 during their hospital stay after the craniotomy, and the tolerable group included patients who had a VAS score of 1 to 3 during their hospital stay. There were no differences between the two groups in terms of age, sex, location of surgery, history of diabetes, hypertension and smoking, body mass index, and hospital stay. Univariate analysis revealed that operating time, length of wound, head fixation, and perioperative administration of opioid were not associated with the intensity of postoperative pain. Daily assessment of VAS revealed the two peaks of pain on the operation day and the 4th postoperative day. The intensity of pain during the ambulation period was higher than that during intensive care unit (ICU) stay.

Conclusion

Pain following elective craniotomy for brain tumor removal is insufficiently managed, especially after discharge from the ICU. More attention needs to be paid to patients' pain throughout the hospital stay.

Gender-specific differences in the central nervous system's response to anesthesia

Males and females are physiologically distinct in their responses to various anesthetic agents. The brain and central nervous system (CNS), the main target of anesthesia, are sexually dimorphic from birth and continue to differentiate throughout life. Accordingly, gender has a substantial impact on the influence of various anesthetic agents in the brain and CNS. Given the vast differences in the male and female CNS, it is surprising to find that females are often excluded from basic and clinical research studies of anesthesia. In animal research, males are typically studied to avoid the complication of breeding, pregnancy, and hormonal changes in females. In clinical studies, females are also excluded for the variations that occur in the reproductive cycle. Being that approximately half of the surgical population is female, the exclusion of females in anesthesia-related research studies leaves a huge knowledge gap in the literature. In this review, we examine the reported sex-specific differences in the central nervous system's response to anesthesia. Furthermore, we suggest that anesthesia researchers perform experiments on both sexes to further evaluate such differences. We believe a key goal of research studying the interaction of the brain and anesthesia should include the search for knowledge of sex-specific mechanisms that will improve anesthetic care and management in both sexes.

Validation of the activities assessment scale in women undergoing pelvic reconstructive surgery

OBJECTIVE

The Activities Assessment Scale (AAS) is a 13-item postoperative functional activity scale validated in men who underwent hernia surgery. We evaluated the psychometric characteristics of the AAS in women who underwent vaginal surgery for pelvic organ prolapse (POP) and stress urinary incontinence (SUI).

METHODS

Participants included 163 women with POP and SUI enrolled in a randomized trial comparing sacrospinous ligament fixation to uterosacral vault suspension with and without perioperative pelvic floor muscle training. Participants completed the AAS and SF-36 at baseline and 2 weeks and 6 months postoperatively. Internal reliability of the AAS was evaluated using Cronbach α. Construct validity and responsiveness were examined in cross-sectional and longitudinal data using Pearson correlation coefficient and analysis of variance. The AAS is scored from zero to 100 (higher scores=better function).

RESULTS

Mean (SD) baseline AAS score was 87 (17.3) (range, 25-100). Functional activity declined from baseline to 2 weeks postoperatively (mean change, -4.5; 95% confidence interval, -7.6 to -1.42) but improved above baseline at 6 months (mean change, +10.9; 95% confidence interval, 7.8-14.0). Internal reliability of the AAS was excellent (Cronbach α=0.93). Construct validity was demonstrated by a correlation of 0.59 to 0.60 between the AAS and SF-36 physical functioning scale (P<0.0001) and lower correlations between the AAS and other SF-36 scales. Patients who improved in physical functioning based on the SF-36 between 2 weeks and 6 months postoperatively showed an effect size of 0.86 for change in the AAS over the same period.

CONCLUSIONS

The AAS is a valid, reliable, and responsive measure for evaluation of physical function in women after pelvic reconstructive surgery.

Pain sensitivity and opioid analgesia: a pharmacogenomic twin study

Opioids are the cornerstone medication for the management of moderate to severe pain. Unfortunately, vast inter-individual differences in dose requirements complicate their effective and safe clinical use. Mechanisms underlying such differences are incompletely understood, are likely multifactorial, and include genetic and environmental contributions. While accumulating evidence suggests that variants of several genes account for some of the observed response variance, the relative contribution of these factors remains unknown. This study used a twin paradigm to provide a global estimate of the genetic and environmental contributions to inter-individual differences in pain sensitivity and analgesic opioid effects. Eighty one monozygotic and 31 dizygotic twin pairs successfully underwent a computer-controlled infusion with the μ-opioid agonist alfentanil in a single occasion, randomized, double-blind and placebo-controlled study design. Pain sensitivity and analgesic effects were assessed with experimental heat and cold pressor pain models along with important covariates including demographic factors, depression, anxiety, and sleep quality. Significant heritability was detected for cold pressor pain tolerance and opioid-mediated elevations in heat and cold pressor pain thresholds. Genetic effects accounted for 12-60% of the observed response variance. Significant familial effects accounting for 24-32% of observed variance were detected for heat and cold pressor pain thresholds and opioid-mediated elevation in cold pressor pain tolerance. Significant covariates included age, gender, race, education, and anxiety. Results provide a strong rationale for more detailed molecular genetic studies to elucidate mechanisms underlying inter-individual differences in pain sensitivity and analgesic opioid responses. Such studies will require careful consideration of the studied pain phenotype.

Opioid Pharmacogenomics Using a Twin Study Paradigm: Methods and Procedures for Determining Familial Aggregation and Heritability

Opioids are the cornerstone medication for the treatment of moderate to severe pain. However, analgesic opioid requirements and the propensity to suffer from aversive opioid effects, including fatal respiratory depression and addiction, vary widely among patients. The factors underlying the substantial response variance remain largely unknown and need clarification for using opioids more effectively in appropriately selected patients. This ongoing study takes advantage of the twin paradigm to estimate the genetic and environmental contributions to inter-individual differences in opioid responses. Evidence of significant heritability will justify more detailed and extensive genomic studies. The enrollment target is 80 monozygotic and 45 dizygotic twin pairs who undergo a target-controlled infusion of the opioid alfentanil and saline placebo in sequential but randomized order. In a laboratory-type setting, well-defined pharmacodynamic endpoints are measured to quantify pain sensitivity, analgesic opioid effects, and aversive opioid effects including respiratory depression, sedation and reinforcing affective responses. First results obtained in 159 participants provide evidence for the feasibility and utility of this interventional study paradigm to estimate familial aggregation and heritability components of relevant drug effects. Areas highlighted in this report include recruitment strategies, required infrastructure and personnel, selection of relevant outcome measures, drug infusion algorithm minimizing pharmacokinetic variability, and considerations for optimizing data quality and quantity without hampering feasibility. Applying the twin paradigm to complex and potentially harmful studies comprehensively characterizing pharmacological response profiles is without much precedent. Methods and first results including heritability estimates for heat and cold pain sensitivity should be of interest to investigators considering similar studies.

Sex-related differences of patient-controlled epidural analgesia for postoperative pain

Gender differences in pain modulation are evident but data are rare with regard to perioperative regional analgesia. The aim of the present analysis was to assess gender-related differences in pain ratings, analgesic consumption, and adverse events in a large group of patients treated with patient-controlled epidural analgesia (PCEA) after major surgery. Data from 14,988 adult patients (6506 women; 8482 men) receiving a PCEA between January 1998 and December 2009 were examined. Demographic data and postoperative measurements assessed by the Acute Pain Service, including total PCEA consumption, pain scores, and complications, were analyzed by using PASW Statistics (18.0; SPSS Inc, Chicago, IL, USA). Beyond standard descriptive analyses, gender-related differences were investigated using a stepwise multivariate analysis of variances. Postoperative pain scores during rest and movement were almost equal between men and women. However, women showed lower total PCEA consumption consistently throughout the 5-day observation period (relative reduction by 1.7%-10.2% compared to men; P=0.00). Total PCEA consumption did not interact with surgical site (abdomen, thorax, extremity) (P=0.379) or age (<50, 50-75, >75 years; P=0.330), but was influenced by body mass index (P=0.017) and vomiting (P=0.011). Furthermore, motor blockade was greater in females compared to males (P=0.000). In patients treated with PCEA, gender differences in numeric rating scale scores exist but are not clinically relevant. However, reduced total PCEA consumption in women might be a consequence of an increased incidence of motor blockade and vomiting; the latter point towards an opioid-free PCEA solution in female patients at high risk for vomiting.

Recovery after third-molar surgery: the effects of age and sex

INTRODUCTION

In this study, we assessed the effects of age and sex on quality-of-life recovery after third-molar surgery.

METHODS

Healthy subjects scheduled for removal of third molars were recruited at multiple sites for this study. Each patient was given a condition-specific instrument to be completed each postsurgery day for 14 days. Lifestyle and oral-function recovery were assessed by using a 5-point Likert-type scale. Recovery was defined as the number of days until the patient reported no or little trouble. Recovery from pain was defined as the number of days until no medications were taken. For each quality-of-life item, a Cox regression analysis was performed to assess the effects of age and sex on recovery after controlling for surgical-procedure variables.

RESULTS

Nine hundred fifty-eight subjects treated at 9 academic centers and 12 community practices were enrolled. Except for ability to open the mouth, recovery for all quality-of-life items for those 21 years or older significantly (P < 0.02) lagged behind recovery for younger subjects. Recovery for female subjects was significantly longer than for male subjects for all outcomes (P < 0.01).

CONCLUSIONS

Patients older than 21 and those who are female should be informed before removal of all 4 third molars that their oral function, lifestyle, and pain recovery will be prolonged compared with those who are younger and male.

Sex, gender, and pain: a review of recent clinical and experimental findings

Sex-related influences on pain and analgesia have become a topic of tremendous scientific and clinical interest, especially in the last 10 to 15 years. Members of our research group published reviews of this literature more than a decade ago, and the intervening time period has witnessed robust growth in research regarding sex, gender, and pain. Therefore, it seems timely to revisit this literature. Abundant evidence from recent epidemiologic studies clearly demonstrates that women are at substantially greater risk for many clinical pain conditions, and there is some suggestion that postoperative and procedural pain may be more severe among women than men. Consistent with our previous reviews, current human findings regarding sex differences in experimental pain indicate greater pain sensitivity among females compared with males for most pain modalities, including more recently implemented clinically relevant pain models such as temporal summation of pain and intramuscular injection of algesic substances. The evidence regarding sex differences in laboratory measures of endogenous pain modulation is mixed, as are findings from studies using functional brain imaging to ascertain sex differences in pain-related cerebral activation. Also inconsistent are findings regarding sex differences in responses to pharmacologic and non-pharmacologic pain treatments. The article concludes with a discussion of potential biopsychosocial mechanisms that may underlie sex differences in pain, and considerations for future research are discussed.

PERSPECTIVE

This article reviews the recent literature regarding sex, gender, and pain. The growing body of evidence that has accumulated in the past 10 to 15 years continues to indicate substantial sex differences in clinical and experimental pain responses, and some evidence suggests that pain treatment responses may differ for women versus men.

Patient Sex and its Influence on General Anaesthesia

Physiological and pharmacological differences exist between men and women. Women wake faster than men following general anaesthesia. Women also differ from men in their postoperative recovery as reflected by differences in postoperative pain, nausea and vomiting and overall quality of recovery. These gender differences seem to be more pronounced in premenopausal women, suggesting hormonal mechanisms are a major contributing factor.

Randomized double blind comparison between sciatic-femoral nerve block and propofol-remifentanil, propofol-alfentanil general anesthetics in out-patient knee arthroscopy

The aim of this study is the evaluation preparation and discharge times as well as the side-effects, patient satisfaction and costs after out-patient knee arthroscopy performed with a combined sciatic-femoral nerve block or a propofol-remifentanil, propofol-alfentanil general anesthetics. Sixty patients, (remifentanil group 1, n = 20), (alfentanil group 2, n = 20) and a combined sciatic-femoral nerve block (PNB group 3, n = 20). In group 1, anesthesia was induced with remifentanil (1 mic kg(-1) followed by 0.5 mic kg(-1) min(-1) i.v), in group 2 alfentanil (20 mic kg(-1) followed by 2 mic kg(-1) min(-1) i.v, in both groups (group 1, 2) propofol was given 2 mg kg(-1) i.v followed by 9 mg kg(-1) h(-1) i.v. Patients then received atracurium 0.6 mg kg(-1) i.v. to facilitate endotracheal intubation. In the PNB group (group 3), patients received a sciatic-femoral nerve block with ropivacaine 25 mL 0.75 mg using a multiple injection technique aided by a nerve stimulator and a short, bevelled, Teflon-coated stimulating needle. There was no significant difference in the duration of stay in the post anesthesia care unit and day surgery unit between groups, there was significant increase in the time to first urination in PNB group than the other two groups. Also there was no significant difference in the stay in delay surgery. The cost of disposal materials, preoperative and post operative times were higher in PNB group. The cost of drugs was higher in remifentanil and alfentanil groups than PNB group; the total cost was insignificant in the three groups. In conclusion, this prospective randomized study suggests that in patients undergoing out-patient arthroscopy, a combined sciatic-femoral nerve block (using a small volume of ropivacaine 0.75%) compared with a propofol-remifentanil or propofol-alfentanil general anesthetics techniques may provide similar intraoperative analgesic efficacy, a shorter length of stay in the PACU and an increased likelihood of bypassing the first phase of postoperative recovery.