Development and validation of a multivariable prediction model for early prediction of chronic postsurgical pain in adults: a prospective cohort study

Incidence and Risk Factors of Chronic Postoperative Pain in Same-day Surgery: A Prospective Cohort Study

BACKGROUND

The amount of same-day surgery has increased markedly worldwide in recent decades, but there remains limited evidence on chronic postsurgical pain in this setting.

METHODS

This study assessed pain 90 days after ambulatory surgery in an international, multicenter prospective cohort study of patients at least 45 yr old with comorbidities or at least 65 yr old. Pain was assessed using the Brief Pain Inventory. Chronic postsurgical pain was defined as a change of more than 1 point in self-rated average pain at the surgical site between baseline and 90 days, and moderate to severe chronic postsurgical pain was defined as a score greater than 4 in self-rated average pain at the surgical site at 90 days. Risk factors for chronic postsurgical pain were identified using multivariable logistic regression.

RESULTS

Between November 2021 and January 2023, a total of 2,054 participants were included, and chronic postsurgical pain occurred in 12% of participants, of whom 93.1% had new chronic pain at the surgical site (i.e., participants without pain before surgery). Moderate to severe chronic postsurgical pain occurred in 9% of overall participants. Factors associated with chronic postsurgical pain were active smoking (odds ratio, 1.82; 95% CI, 1.20 to 2.76), orthopedic surgery (odds ratio, 4.7; 95% CI, 2.24 to 9.7), plastic surgery (odds ratio, 4.3; 95% CI, 1.97 to 9.2), breast surgery (odds ratio, 2.74; 95% CI, 1.29 to 5.8), vascular surgery (odds ratio, 2.71; 95% CI, 1.09 to 6.7), and ethnicity (i.e., for Hispanic/Latino ethnicity, odds ratio, 3.41; 95% CI, 1.68 to 6.9 and for First Nations/native persons, odds ratio, 4.0; 95% CI, 1.05 to 15.4).

CONCLUSIONS

Persistent postsurgical pain after same-day surgery is common, is usually moderate to severe in nature, and occurs mostly in patients without chronic pain before surgery.

EDITOR’S PERSPECTIVE

Local Magnesium Sulfate Administration Ameliorates Nociception, Peripheral Inflammation, and Spinal Sensitization in a Rat Model of Incisional Pain

OBJECTIVE

Postoperative pain remains one of the most common complaints after surgery, and appropriate treatments are limited.

METHODS

We therefore investigated the effect of the anti-nociceptive properties of magnesium sulfate (MgSO4), an N-methyl-D-aspartate (NMDA) receptor antagonist, on incision-induced postoperative pain and peripheral and central nervous system inflammation.

RESULTS

We found that local MgSO4 administration dose-dependently increases paw withdrawal latency, indicating reduced peripheral postoperative pain. Furthermore, MgSO4 inhibited the expression of interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) and phosphorylation of the NMDA receptor NR1 subunit in injured paw tissue and significantly attenuated microglial and astrocytic activation in the ipsilateral lumbar spinal cord dorsal horn.

CONCLUSION

Locally administered MgSO4 has potential for development as an adjunctive therapy for preventing central nociceptive sensitization.

A nomogram prediction of implant apical non-coverage on bone-added transcrestal sinus floor elevation: A retrospective cohort study

OBJECTIVES

To identify the risk indicators and develop and validate a nomogram prediction model of implant apical non-coverage by comprehensively analyzing clinical and radiographic factors in bone-added transcrestal sinus floor elevation (TSFE).

MATERIAL AND METHODS

A total of 260 implants in 195 patients receiving bone-added TSFE were included in the study. The population was divided into a development (180 implants) and a validation (80 implants) cohort. According to 6 months post-surgery radiographic images, implants were categorized as "apical non-coverage" or "apical covered." The association of risk factors including clinical and radiographic parameters with implant apical non-coverage was assessed using regression analyses. A nomogram prediction model was developed, and its validation and discriminatory ability were analyzed.

RESULTS

The nomogram predicting bone-added TSFE's simultaneously placed implant's apex non-coverage after 6 months. This study revealed that sinus angle, endo-sinus bone gain, implant protrusion length, graft contact walls, and distal angle were predictors of implant apical non-coverage. The generated nomogram showed a strong predictive capability (area under the curve [AUC] = 0.845), confirmed by internal validation using 10-fold cross-validation (Median AUC of 0.870) and temporal validation (AUC = 0.854). The calibration curve and decision curve analysis demonstrated good performance and high net benefit of the nomogram, respectively.

CONCLUSIONS

The clinical implementation of the present nomogram is suitable for predicting the apex non-coverage of implants placed simultaneously with bone-added TSFE after 6 months.

Preoperative psychological symptoms and chronic postsurgical pain: analysis of the prospective China Surgery and Anaesthesia Cohort study

BACKGROUND

Both preoperative psychological symptoms and chronic postsurgical pain (CPSP) are prevalent conditions and major concerns among surgery patients, with inconclusive associations.

METHODS

Based on the China Surgery and Anaesthesia Cohort (CSAC), we recruited 8350 surgery patients (40-65 yr old) from two medical centres between July 2020 and March 2023. Patients with preoperative psychological symptoms (i.e. anxiety, depression, stress reaction, and poor sleep quality) were identified using corresponding well-established scales. We then examined the associations of individual preoperative psychological symptoms and major patterns of preoperative psychological symptoms (identified by k-means clustering analysis) with CPSP, and different pain trajectories within 3 months. Lastly, mediation analyses were conducted to elucidate the mediating role of surgery/anaesthesia-related factors and the presence of 1-month postoperative psychological symptoms on the studied associations.

RESULTS

We included 1302 (1302/8350, 15.6%) CPSP patients. When analysed separately, all studied preoperative psychological symptoms were associated with increased CPSP risk, with the most pronounced odds ratio noted for anxiety (1.52, 95% confidence interval [CI] 1.23-1.86). Compared with patients clustered in the minor symptom group, excess risk of CPSP and experiencing an increasing pain trajectory was increased among patients with preoperative psychological symptoms featured by sleep disturbances (odds ratio=1.46, 95% CI 1.25-1.70 for CPSP and 1.58, 95% CI 1.20-2.08 for increasing pain trajectory) and multiple psychological symptoms (1.84 [95% CI 1.48-2.28] and 4.34 [95% CI 3.20-5.88]). Mediation analyses revealed acute/subacute postsurgical pain and psychological symptoms existing 1 month after surgery as notable mediators of the observed associations.

CONCLUSIONS

The presence of preoperative psychological symptoms might individually or jointly increase the risk of chronic postsurgical pain or experiencing deterioration in pain trajectory. Interventions for managing acute/subacute postsurgical pain and psychological symptoms at 1 month after surgery might help reduce such risk.

CLINICAL TRIAL REGISTRATION

ChiCTR2000034039.

How to Modulate Peripheral and Central Nervous System to Treat Acute Postoperative Pain and Prevent Pain Persistence

Chronic postoperative pain (CPSP) is a major issue after surgery, which may impact on patient's quality of life. Traditionally, CPSP is believed to rely on maladaptive hyperalgesia and risk factors have been identified that predispose to CPSP, including acute postoperative pain. Despite new models of prediction are emerging, acute pain is still a modifiable factor that can be challenged with perioperative analgesic strategies. In this review we present the issue of CPSP, focusing on molecular mechanism underlying the development of acute and chronic hyperalgesia. Also, we focus on how perioperative strategies can impact directly or indirectly (by reducing postoperative pain intensity) on the development of CPSP.

Liposomal bupivacaine for ultrasound-guided rectus sheath blocks after midline laparotomy

Optimal pain management after open abdominal surgery is essential but can be difficult to achieve. The effects of inadequate analgesia go beyond the first few postoperative days; severe acute postoperative pain may contribute to the development of chronic postsurgical pain. Thoracic epidural analgesia is a traditional approach to the management of acute pain after open abdominal surgery but has multiple possible contraindications and can be technically challenging. In our hospital, we typically offer ultrasound-guided rectus sheath blocks with catheters when epidural analgesia is not feasible. However, the recent registration of long-acting liposomal bupivacaine in the Netherlands as well as logistical and equipment-related issues have led us to consider liposomal bupivacaine as an alternative to the use of catheters. Here, we present a short case series to describe our first clinical experiences with the use of liposomal bupivacaine in ultrasound-guided rectus sheath blocks after midline laparotomy for three patients in whom epidural insertion was contraindicated.

Low-intensity pulsed ultrasound phonophoresis with diclofenac alleviated inflammation and pain via downregulation of M1 macrophages in rats with carrageenan-induced knee joint arthritis

Objective

This study aimed to investigate the effects of low-intensity pulsed ultrasound (LIPUS) phonophoresis with diclofenac on inflammation and pain in the acute phase of carrageenan-induced arthritis in rats.

Design

60 male Wistar rats were randomly divided into the arthritis, diclofenac, LIPUS, phonophoresis, and sham-arthritis control groups. LIPUS and transdermal diclofenac gel were applied to the lateral side of the inflamed knee for 7 days, initiated postinjection day 1. In the phonophoresis group, diclofenac gel was rubbed onto the skin, followed by LIPUS application over the medication. Knee joint transverse diameters, pressure pain thresholds (PPTs), and paw withdrawal thresholds (PWT) were evaluated. The number of CD68-, CD11c-, and CD206-positive cells, and IL-1β and COX-2 mRNA expression were analyzed 8 days after injection.

Results

In the phonophoresis group, the transverse diameter, PPT, PWT significantly recovered at the day 8 compared to those in the LIPUS and diclofenac groups. The number of CD68- and CD11c-positive cells in the phonophoresis group was significantly lower than that in the LIPUS and diclofenac groups, but no significant differences were observed among three groups in CD206-positive cells. IL-1β and COX-2 mRNA levels were lower in the phonophoresis group than in the arthritis group, although there were no differences among the LIPUS, diclofenac, and phonophoresis groups.

Conclusion

LIPUS phonophoresis with diclofenac is more effective to ameliorate inflammation and pain compared to diclofenac or LIPUS alone, and the mechanism involves the decrease of M1 macrophages.

Severe Postoperative Pain in Total Knee Arthroplasty Patients: Risk Factors, Insights and Implications for Pain Management via a Digital Health Approach

Up to 25% of patients undergoing knee arthroplasty report chronic pain postoperatively. Early identification of high-risk individuals can enhance pain management strategies. This retrospective analysis investigates the incidence of severe postoperative pain and its associated risk factors among 740 patients who underwent total knee arthroplasty. Utilizing a digital application, patients provided comprehensive data encompassing pre- and postoperative pain levels, analgesic usage, and completed a chronic pain risk assessment. Participants were categorized into two distinct groups based on their pain status at three months post-op: Group D+ (14%), characterized by pain scores exceeding 40/100 and/or the utilization of level 2 or 3 analgesics, and Group D- (86%), who did not meet these criteria. An analysis of pain trajectories within these groups revealed a non-linear progression, with specific patterns emerging amongst those predisposed to chronic pain. Notably, patients with a trajectory towards chronic pain exhibited a plateau in pain intensity approximately three weeks post-surgery. Significant preoperative risk factors were identified, including elevated initial pain levels, the presence of comorbidities, pain in other body areas, heightened joint sensitivity and stiffness. This study highlights the utility of digital platforms in enhancing patient care, particularly through the continuous monitoring of pain. Such an approach facilitates the early identification of potential complications and enables timely interventions.

Exploring the terminological validity of 'chronic pain' nursing diagnosis: A retrospective descriptive study using nursing diaries

AIM

The aim of this study is to generate empirical evidence, drawing from clinical records, with the goal of elevating the level of evidence supporting the nursing diagnosis (ND) of 'chronic pain'.

BACKGROUND

Chronic pain is a prevalent condition that affects all age groups. Patients often feel disbelieved about their pain perception, leading to adverse psychological effects, difficulty accessing healthcare and poor rehabilitation outcomes.

DESIGN

Retrospective descriptive study. Standards for Reporting Diagnostic Accuracy Studies guidelines were followed in this study.

METHODS

Data were extracted from Electronic Health Records (EHR) of patients admitted to the University Hospital of Perugia, Italy, between March 2016 and December 2022. The study sample comprised individuals without a specific medical diagnosis or high-risk population. Out of 1,048,565 EHR, 43,341 clinical-nursing diaries with the keyword 'pain' were identified, from which 283 clinical-nursing notes were selected based on a keyword-based retrieval technique and diagnostic definition for further analysis.

RESULTS

Our study findings support the diagnostic descriptors of the 'chronic pain' ND in clinical-nursing diaries. We observed the presence of 9 out of 11 defining characteristics, 7 out of 10 related factors, 4 out of 8 at-risk populations and 11 out of 17 associated conditions.

CONCLUSIONS

The study validated diagnostic criteria for chronic pain and proposed 'haematological pathology' as a new associated condition. The findings were presented to the Diagnosis Development Committee of NANDA-International for further review. However, limitations of the study prompted the need for further analysis using natural language processing and artificial neural network techniques. As a result, a new research direction using artificial intelligence (AI) tools was initiated.

RELEVANCE TO CLINICAL PRACTICE

The study validates diagnostic descriptors for chronic pain and proposes future directions in semantic analysis and AI tools, aiming to enhance clinical practice and decision-making in nursing care.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

Mechanisms inherent in acute-to-chronic pain after surgery - risk, diagnostic, predictive, and prognostic factors

PURPOSE OF REVIEW

Pain is an expected consequence of a surgery, but it is far from being well controlled. One major complication of acute pain is its risk of persistency beyond healing. This so-called chronic post-surgical pain (CPSP) is defined as new or increased pain due to surgery that lasts for at least 3 months after surgery. CPSP is frequent, underlies a complex bio-psycho-social process and constitutes an important socioeconomic challenge with significant impact on patients' quality of life. Its importance has been recognized by its inclusion in the eleventh version of the ICD (International Classification of Diseases).

RECENT FINDINGS

Evidence for most pharmacological and non-pharmacological interventions preventing CPSP is inconsistent. Identification of associated patient-related factors, such as psychosocial aspects, comorbidities, surgical factors, pain trajectories, or biomarkers may allow stratification and selection of treatment options based on underlying individual mechanisms. Consequently, the identification of patients at risk and implementation of individually tailored, preventive, multimodal treatment to reduce the risk of transition from acute to chronic pain is facilitated.

SUMMARY

This review will give an update on current knowledge on mechanism-based risk, prognostic and predictive factors for CPSP in adults, and preventive and therapeutic approaches, and how to use them for patient stratification in the future.

Development and prospective validation of postoperative pain prediction from preoperative EHR data using attention-based set embeddings

Preoperative knowledge of expected postoperative pain can help guide perioperative pain management and focus interventions on patients with the greatest risk of acute pain. However, current methods for predicting postoperative pain require patient and clinician input or laborious manual chart review and often do not achieve sufficient performance. We use routinely collected electronic health record data from a multicenter dataset of 234,274 adult non-cardiac surgical patients to develop a machine learning method which predicts maximum pain scores on the day of surgery and four subsequent days and validate this method in a prospective cohort. Our method, POPS, is fully automated and relies only on data available prior to surgery, allowing application in all patients scheduled for or considering surgery. Here we report that POPS achieves state-of-the-art performance and outperforms clinician predictions on all postoperative days when predicting maximum pain on the 0-10 NRS in prospective validation, though with degraded calibration. POPS is interpretable, identifying comorbidities that significantly contribute to postoperative pain based on patient-specific context, which can assist clinicians in mitigating cases of acute pain.

Development and expansion of a pediatric transitional pain service to prevent complex chronic pain

The prevention of chronic pain is a key priority in North America and around the world. A novel pediatric Transitional Pain Service (pTPS) at the Hospital for Sick Children was established to address four main areas of need, which the authors will describe in more detail: (1) provide comprehensive multi-modal pain management and prevention techniques to children at-risk for the development of chronic pain, (2) provide opioid stewardship for children at-risk for chronic pain and their families at home after discharge, (3) facilitate continuity of pain care for children across transitions between inpatient and outpatient care settings, and (4) support caregivers to manage their child's pain at home. The pTPS works with healthcare providers, patients, and their families to address these areas of need and improve quality of life. Furthermore the service fills the gap between inpatient acute pain services and outpatient chronic pain services (accessible only once pain has persisted for >3 months). In pediatric patients who experience pain in hospital and who have been prescribed opioids, discharge to home or rehabilitation may represent a vulnerable time in which pain may persist and during which analgesic requirements may change. This offers an important opportunity to address and prevent the development of chronic pain, and to monitor opioids while ensuring alternative pain therapy is available. The authors will outline risk factors for persistent postsurgical pain, the development and implementation of a pTPS, present initial clinical outcomes andsuggest areas for future research in this evolving area of care.

Prognostic models for chronic postsurgical pain-Current developments, trends, and challenges

PURPOSE OF REVIEW

Prognostic models for chronic postsurgical pain (CPSP) aim to predict the likelihood for development and severity of CPSP in individual patients undergoing surgical procedures. Such models might provide valuable information for healthcare providers, allowing them to identify patients at higher risk and implement targeted interventions to prevent or manage CPSP effectively. This review discusses the latest developments of prognostic models for CPSP, their challenges, limitations, and future directions.

RECENT FINDINGS

Numerous studies have been conducted aiming to develop prognostic models for CPSP using various perioperative factors. These include patient-related factors like demographic variables, preexisting pain conditions, psychosocial aspects, procedure-specific characteristics, perioperative analgesic strategies, postoperative complications and, as indicated most recently, biomarkers. Model generation, however, varies and performance and accuracy differ between prognostic models for several reasons and validation of models is rather scarce.

SUMMARY

Precise methodology of prognostic model development needs advancements in the field of CPSP. Development of more accurate, validated and refined models in large-scale cohorts is needed to improve reliability and applicability in clinical practice and validation studies are necessary to further refine and improve the performance of prognostic models for CPSP.

Personalized medicine: Somatosensory phenotyping in musculoskeletal pain conditions

BACKGROUND

Current clinical phenotyping of musculoskeletal pain provides very limited evidence- based support to personalized medicine. This paper discusses the potential of somatosensory phenotyping to contribute to personalized medicine for prognosis and prediction of treatment effects.

METHODS

Highlight of definitions and regulatory requirements for phenotypes and biomarkers. Appraisal of the literature on somatosensory phenotyping in musculoskeletal pain.

RESULTS

Somatosensory phenotyping can identify clinical conditions and manifestations that may affect treatment decisions. However, studies have shown inconsistent associations of phenotyping measures with clinical outcomes, and the strength of association is mostly weak. Most somatosensory measures have been developed for research, are too demanding to find large acceptance in clinical settings, and have uncertain clinical usefulness.

CONCLUSIONS

Current somatosensory measures will unlikely be validated as strong prognostic or predictive biomarkers. However, they still have the potential to support personalized medicine. Including somatosensory measures in biomarker signatures, that is, a set of measures that are collectively associated with outcomes, is potentially more useful than aiming to the identification of single biomarkers. Furthermore, somatosensory phenotyping may be introduced as part of patient's evaluation to contribute to better-informed and personalized treatment decisions. To this purpose, a change in the way research currently approaches somatosensory phenotyping is warranted. A pathway is proposed that involves: (1) the identification of clinically applicable measures that are specific to clinical conditions; (2) the association of somatosensory phenotypes with outcomes; (3) multi-site replication; and (4) the determination of clinical benefits in randomized controlled trials.

SIGNIFICANCE

Somatosensory phenotyping has the potential to support personalized medicine. However, current measures do not seem to meet the criteria for being strong prognostic or predictive biomarkers, most of them are too demanding to find large acceptance in clinical settings, and their clinical usefulness has not been proven. The value of somatosensory phenotyping can be more realistically determined by re-orienting research to the development of simplified testing protocols, applicable to large-scale clinical practice, and tested for clinical usefulness in randomized controlled trials.

[Application possibilities of digital tools in postoperative pain therapy]

BACKGROUND

Recently, digital tools, such as smartphone-based applications and the use of artificial intelligence have increasingly found their way into pain medicine. This could enable new treatment approaches in postoperative pain management. Therefore, this article provides an overview of various digital tools and their potential application options in postoperative pain management.

MATERIAL AND METHODS

An orienting literature search was carried out in the MEDLINE and Web of Science databases, and a targeted selection of essential key publications was made in order to provide a structured presentation of different current possible applications and a discussion based on the most recent knowledge.

RESULTS

Today, possible applications of digital tools, even if they mostly have only a model character, include pain documentation and assessment, patient self-management and education, pain prediction, decision support for medical staff, and supportive pain therapy, for example in the form of virtual reality and videos. These tools offer advantages such as individualized treatment concepts, addressing specific patient groups, reduction of pain and analgesics, and the potential for early warning or detection of postoperative pain. Furthermore, the challenges of the technical implementation and appropriate user training are highlighted.

CONCLUSION

The use of digital tools, although so far integrated in clinical routine in a relatively selective and exemplary manner, promises to be an innovative approach for personalized postoperative pain therapy in the future. Future studies and projects should help to integrate the promising research approaches into everyday clinical practice.

Protocol for Development and Validation of Multivariable Prediction Models for Chronic Postsurgical Pain Following Video-Assisted Thoracic Surgery

Purpose

Chronic postsurgical pain (CPSP) is a common complication after thoracic surgery and associated with long-term adverse outcomes. This study aims to develop two prediction models for CPSP after video-assisted thoracic surgery (VATS).

Methods and Analysis

This single-center prospective cohort study will include a total of 500 adult patients undergoing VATS lung resection (n = 350 for development and n = 150 for external validation). Patients will be enrolled continuously at The First Affiliated Hospital of Soochow University in Suzhou, China. The cohort for external validation will be recruited in another time period. The outcome is CPSP, which is defined as pain with the numerical rating scale score of 1 or higher 3 months after VATS. Univariate and multivariable logistic regression analyses will be performed to develop two CPSP prediction models based on patients' data of postoperative day 1 and day 14, respectively. For internal validation, we will use the bootstrapping validation technique. For external validation, the discrimination capability of the models will be assessed using the area under the receiver operating characteristic curve, and the calibration will be evaluated using the calibration curve and Hosmer-Lemeshow goodness-of-fit statistic. The results will be presented in model formulas and nomograms.

Conclusion

Based on the development and validation of the prediction models, our results contribute to early prediction and treatment of CPSP after VATS.

Trial Registration

Chinese Clinical Trial Register (ChiCTR2200066122).

What Do We Know about Nociplastic Pain?

Nociplastic pain is a recently distinguished type of pain, distinct from neuropathic and nociceptive pain, and is well described in the literature. It is often mistaken for central sensitization. Pathophysiology has not been clearly established with regard to alteration of the concentration of spinal fluid elements, the structure of the white and gray matter of the brain, and psychological aspects. Many different diagnostic tools, i.e., the painDETECT and Douleur Neuropathique 4 questionnaires, have been developed to diagnose neuropathic pain, but they can also be applied for nociplastic pain; however, more standardized instruments are still needed in order to assess its occurrence and clinical presentation. Numerous studies have shown that nociplastic pain is present in many different diseases such as fibromyalgia, complex regional pain syndrome type 1, and irritable bowel syndrome. Current pharmacological and nonpharmacological treatments for nociceptive and neuropathic pain are not entirely suitable for treating nociplastic pain. There is an ongoing effort to establish the most efficient way to manage it. The significance of this field has led to several clinical trials being carried out in a short time. The aim of this narrative review was to discuss the currently available evidence on pathophysiology, associated diseases, treatment possibilities, and clinical trials. It is important that physicians widely discuss and acknowledge this relatively new concept in order to provide optimized pain control for patients.

Cohort profile of PLUTO: a perioperative biobank focusing on prediction and early diagnosis of postoperative complications

PURPOSE

Although elective surgery is generally safe, some procedures remain associated with an increased risk of complications. Improved preoperative risk stratification and earlier recognition of these complications may ameliorate postoperative recovery and improve long-term outcomes. The perioperative longitudinal study of complications and long-term outcomes (PLUTO) cohort aims to establish a comprehensive biorepository that will facilitate research in this field. In this profile paper, we will discuss its design rationale and opportunities for future studies.

PARTICIPANTS

Patients undergoing elective intermediate to high-risk non-cardiac surgery are eligible for enrolment. For the first seven postoperative days, participants are subjected to daily bedside visits by dedicated observers, who adjudicate clinical events and perform non-invasive physiological measurements (including handheld spirometry and single-channel electroencephalography). Blood samples and microbiome specimens are collected at preselected time points. Primary study outcomes are the postoperative occurrence of nosocomial infections, major adverse cardiac events, pulmonary complications, acute kidney injury and delirium/acute encephalopathy. Secondary outcomes include mortality and quality of life, as well as the long-term occurrence of psychopathology, cognitive dysfunction and chronic pain.

FINDINGS TO DATE

Enrolment of the first participant occurred early 2020. During the inception phase of the project (first 2 years), 431 patients were eligible of whom 297 patients consented to participate (69%). Observed event rate was 42% overall, with the most frequent complication being infection.

FUTURE PLANS

The main purpose of the PLUTO biorepository is to provide a framework for research in the field of perioperative medicine and anaesthesiology, by storing high-quality clinical data and biomaterials for future studies. In addition, PLUTO aims to establish a logistical platform for conducting embedded clinical trials.

TRIAL REGISTRATION NUMBER

NCT05331118.

Development of a Machine-Learning Model for Prediction of Extubation Failure in Patients with Difficult Airways after General Anesthesia of Head, Neck, and Maxillofacial Surgeries

(1) Background: Extubation failure after general anesthesia is significantly associated with morbidity and mortality. The risk of a difficult airway after the general anesthesia of head, neck, and maxillofacial surgeries is significantly higher than that after general surgery, increasing the incidence of extubation failure. This study aimed to develop a multivariable prediction model based on a supervised machine-learning algorithm to predict extubation failure in adult patients after head, neck, and maxillofacial surgeries. (2) Methods: A single-center retrospective study was conducted in adult patients who underwent head, neck, and maxillofacial general anesthesia between July 2015 and July 2022 at the Shanghai Ninth People's Hospital. The primary outcome was extubation failure after general anesthesia. The dataset was divided into training (70%) and final test sets (30%). A five-fold cross-validation was conducted in the training set to reduce bias caused by the randomly divided dataset. Clinical data related to extubation failure were collected and a stepwise logistic regression was performed to screen out the key features. Six machine-learning methods were introduced for modeling, including random forest (RF), k-nearest neighbor (KNN), logistic regression (LOG), support vector machine (SVM), extreme gradient boosting (XGB), and optical gradient boosting machine (GBM). The best performance model in the first cross-validation dataset was further optimized and the final performance was assessed using the final test set. (3) Results: In total, 89,279 patients over seven years were reviewed. Extubation failure occurred in 77 patients. Next, 186 patients with a successful extubation were screened as the control group according to the surgery type for patients with extubation failure. Based on the stepwise regression, seven variables were screened for subsequent analysis. After training, SVM and LOG models showed better prediction ability. In the k-fold dataset, the area under the curve using SVM and LOG were 0.74 (95% confidence interval, 0.55-0.93) and 0.71 (95% confidence interval, 0.59-0.82), respectively, in the k-fold dataset. (4) Conclusion: Applying our machine-learning model to predict extubation failure after general anesthesia in clinical practice might help to reduce morbidity and mortality of patients with difficult airways after head, neck, and maxillofacial surgeries.

Change in perioperative neutrophil-lymphocyte ratio as a potential predictive biomarker for chronic postsurgical pain and quality of life: an ambispective observational cohort study

Introduction

Accurate and accessible predictors of chronic postsurgical pain (CPSP) to identify high-risk postsurgical patients are prerequisite for preventive and interventional strategies. We investigated the incidence and risk factors of CPSP after abdominal surgery, with a focus on plasma immunological markers.

Materials and methods

This was a retrospective analysis of patients who underwent abdominal surgery under general anesthesia at a tertiary center between January 2021 and January 2022. The preoperative demographics, laboratory test data, and surgical factors of the participants were collected from the electronic medical record system. Postoperative pain intensity and living conditions at 1 year after discharge from the hospital were assessed via a phone survey. Univariate and multivariate analyses were used to explore independent risk factors associated with CPSP.

Results

A total of 968 patients were included, and 13.53% (n = 131 of 968) of patients reported CPSP 1 year after surgery. Patients with older age, open surgery, higher American Association of Anesthesiologists classification, patient-controlled intravenous analgesia application, longer surgery duration, higher postoperative absolute neutrophil count, and neutrophil-lymphocyte ratio (NLR), lower postoperative absolute lymphocyte count, and higher white blood cell count, were more likely to suffer from CPSP. A changed ratio of NLR (postoperative to preoperative) ≥ 5 significantly correlated with CPSP, moderate to severe pain, maximum numeric rating score since discharge from the hospital, and affected quality of life.

Discussion

The changed ratio of NLR could be used for the early identification of patients at risk for CPSP and affect the quality of life to alert the clinician to undertake further assessment.

Chronic pain after surgery and trauma: current situation and future directions

Chronic post-surgical pain (CPSP) stands as a major health issue. The unchanged incidence over the last two decades underlines both the failure of predictive models developed until now and the lack of efficacy of common “preventive” strategies (pharmacotherapy and regional analgesic techniques) applied in current clinical practice. The recognition of CPSP as a disease and the release of a common definition of the condition is an important progress in the field. CPSP predictive scores exist but none has presently demonstrated an impact on patient care. New clinical directions based on the resolution of postoperative pain, a complex and highly dynamic process supported by individual pain trajectories, argue for predictive models and preventive strategies extended to the subacute pain period i.e. after hospital discharge.

Towards better predictive models of chronic post-surgical pain: fitting to the dynamic nature of the pain itself

Chronic post-surgical pain predictive scores exist, but none has yet demonstrated an impact on patient care. Van Driel and colleagues offer an additional perspective on early postoperative detection of patient at risk of chronic post-surgical pain to enable early interventions in prevention and treatment. The authors derived and validated a model based on four easily obtainable predictors that could help clinicians assess and treat patients at risk. Additional work is needed to prove reliability and clinical benefit of chronic post-surgical pain prediction and intervention.