Reporting and Methodology of Multivariable Analyses in Prognostic Observational Studies Published in 4 Anesthesiology Journals

Age-related changes in intraoperative mean values of nociceptive response in patients undergoing non-cardiac surgery under general anesthesia: A retrospective cohort study

Intraoperative nociception is affected by preoperative factors, surgical invasiveness, and anesthesia. Although age-related changes in nociception in conscious humans have been well examined, those in intraoperative nociception in unconscious patients under general anesthesia are unknown. To clarify associations between age and intraoperative nociception under general anesthesia, we performed a retrospective cohort study in consecutive patients of all ages undergoing non-cardiac surgery under general anesthesia from January 2019 to July 2023. The intraoperative nociception value in each surgery was assessed by the averaged value of nociceptive response (mean NR) index during surgery. Patient characteristics, including age, sex, body mass index (BMI), emergent surgery, preoperative serum C-reactive protein (CRP) level, and comorbidities were also collected. After excluding patients with missing data of CRP and mean NR index, 22,061 patients were enrolled, and were divided into low, intermediate, and high surgical risk groups. Multivariable regression analysis showed a significant association between age and mean NR index in all three surgical procedure risk groups. The preoperative variables of CRP levels, BMI, emergent surgery, atrial fibrillation, renal failure, and long-term steroid use also showed significant associations with mean NR index in all three groups. Sensitivity analysis showed that intraoperative mean NR index was higher in younger children than that in both older children and younger adults, and it gradually increased again in older adults to the same level as in younger children. In conclusion, there is likely an association between age and intraoperative mean NR index in patients under general anesthesia.

Intraoperative nociception and postoperative inflammation associated with the suppression of major complications due to thoracic epidural block after pleurectomy/decortication for malignant pleural mesothelioma under general anesthesia: A retrospective observational study

A recent study showed that thoracic epidural block (TEB) suppressed the occurrence of major complications after pleurectomy/decortication (P/D) for malignant pleural mesothelioma (MPM) under general anesthesia. To investigate the mechanisms underlying the correlation, both acute inflammatory status and intraoperative nociception were evaluated in the present study. In a single-institutional observational study, consecutive adult patients undergoing P/D were enrolled from March 2019 to April 2022. Perioperative acute inflammatory status was evaluated using differential White blood cell (WBC) counts and serum concentration of C-reactive protein (CRP) both before and after the surgery on postoperative day (POD) 1. The averaged value of nociceptive response index during surgery (mean NR) was obtained to evaluate the level of intraoperative nociception. Multivariable logistic regression analysis was performed to determine the association between perioperative variables and major complications Postoperative major postoperative complication was defined as Clavien-Dindo grades ≥ III. We conducted this study with 97 patients. After logistic regression analysis showed that general anesthesia without TEB was a sole risk factor for major complications, patients were divided into 2 groups: general anesthesia with and without TEB. The incidence of major complications was significantly lower in patients with TEB (33.3%, n = 33) than in those without TEB (64.1%, n = 64, P < .01). Although there was no significant difference in the CRP level between 2 groups, the lymphocyte-to-monocyte ratio (LMR) on POD 1 in patients with TEB was significantly higher than that in patients without TEB (P = .04). The mean NR was significantly lower in patients with TEB than that in those without TEB (P = .02). Both lower mean NR during surgery and higher LMR on POD 1 are likely associated the suppression of major complications due to TEB after P/D under general anesthesia. Decreases in the postoperative acute inflammatory response, caused by the reduction of intraoperative nociception due to TEB, may help suppress major complications after P/D.

Association between averaged intraoperative nociceptive response index and postoperative complications after lung resection surgery

OBJECTIVES

Since postoperative complications, defined as Clavien-Dindo grade ≥II, correlate with long-term survival after lung resection surgery in patients with primary lung cancer, identification of intraoperative risk factors for postoperative complications is crucial for better perioperative management. In the present study, we investigated the possible association between intraoperative variables for use in anaesthetic management and Clavien-Dindo grade ≥II.

METHODS

In this multi-institutional observational study, consecutive adult patients undergoing video-assisted thoracic surgery for primary lung cancer under general anaesthesia from March 2019 to April 2021 were enrolled. All patients were divided into 2 groups with Clavien-Dindo grade <II and ≥II. Uni- and multivariable analyses were performed to identify intraoperative risk factors.

RESULTS

After univariable analysis between patients with Clavien-Dindo grade <II (n = 415) and ≥II (n = 121), multivariable analysis revealed higher averaged nociceptive response (NR) index during surgery (mean NR), male sex, lower body mass index, longer duration of surgery, higher blood loss and lower urine volume, as independent risk factors for postoperative complications. In sensitivity analysis, based on the cut-off value of mean NR for postoperative complications, all patients were divided into high and low mean NR groups. The incidence of postoperative complications was significantly higher in patients with high mean NR (n = 332) than in patients with low mean NR (n = 204; P < 0.001).

CONCLUSIONS

Higher mean NR, as intraoperative variables for use in anaesthetic management, is associated with the higher incidence of postoperative complications after primary lung cancer surgery.

Associations between insomnia and central sensitization in cancer survivors undergoing opioid therapy for chronic cancer pain: A STROBE-compliant prospective cohort study

Several risk factors for insomnia in cancer patients have been recognized, including chronic pain and treatment with opioid. Although associations between insomnia and central sensitization were previously reported in patients with chronic non-cancer pain, those have not been elucidated among cancer survivors undergoing opioid therapy for chronic cancer pain. To investigate the associations between insomnia and central sensitization among cancer survivors undergoing opioid therapy for chronic cancer pain, consecutive patients undergoing chemotherapy with chronic cancer pain under opioid therapy on an outpatient basis were enrolled from September 2019 to August 2020 and answered questions from the Athens Insomnia Scale (AIS) for assessing insomnia. Pain characteristics, including pain intensity, neuropathic pain, central sensitization assessed using the central sensitization inventory (CSI), opioid use disorder, and pain-related psychological symptoms were also examined. Uni- and multivariate regression analyses were performed to elucidate correlations between the AIS score and these pain characteristics. Of 44 enrolled patients, 20 patients completed to answer all questions. Insomnia was identified in 9 patients (45%). Although AIS scores showed no significant associations with pain intensity, neuropathic pain, opioid use disorder, or psychological symptoms, multivariate regression analysis revealed that CSI scores showed a positive relationship with AIS scores (P = .004). Discrimination was assessed using linear regression analysis which confirmed a significant association between the AIS and CSI scores (P = .002). Insomnia appears to be associated with central sensitization in cancer survivors with chronic cancer pain under opioid therapy.

Association between thoracic epidural block and major complications after pleurectomy/decortication for malignant pleural mesothelioma under general anesthesia

Introduction

A curative-intent surgical procedure, pleurectomy/decortication, for malignant pleural mesothelioma is accompanied by a high incidence of major postoperative complications. Although epidural block, which suppresses nociception during and after surgery, reportedly has both benefits and disadvantages in terms of outcomes after thoracic surgery for other diseases, the effects of epidural block on major complications after pleurectomy/decortication have not been evaluated. The aim of this study was to evaluate the association between epidural block and major postoperative complications following pleurectomy/decortication.

Methods

In a single-institutional observational study, consecutive adult patients undergoing pleurectomy/decortication under general anesthesia were enrolled from March 2019 to December 2021. Multivariable logistic regression analysis was performed to determine the association between perioperative variables and major complications. Next, patients were divided into two groups: general anesthesia with and without epidural block. Incidences of major postoperative complications, defined as Clavien-Dindo grades≥III, were compared between groups.

Results

In all patients enrolled with American Society of Anesthesiologists (ASA) physical status II or III (n=99), general anesthesia without epidural block was identified as a sole risk factor for major complications among perioperative variables. The incidence of major complications was 32.3% (95% CI 19.1% to 49.2%) in patients with epidural block (n=34), which was significantly lower than 63.1% (95% CI 50.9% to 73.8%) in patients without epidural block (n=65). In sensitivity analysis in patients with ASA physical status II alone, the same results were obtained.

Conclusion

Epidural block is likely associated with reduction of the incidence of major complications after pleurectomy/decortication for malignant pleural mesothelioma under general anesthesia.

Intra-operative nociceptive responses and postoperative major complications after gastrointestinal surgery under general anaesthesia: A prospective cohort study

BACKGROUND

Surgical procedures stimulate nociception and induce physiological responses according to the balance between nociception and antinociception. The severity of surgical stimuli is associated with major postoperative complications. Although an intra-operative quantitative index representing surgical invasiveness would be useful for anaesthetic management to predict and prevent major complications, no such index is available.

OBJECTIVES

To identify associations between major complications after gastrointestinal surgery and intra-operative quantitative values from intra-operative nociception monitoring.

DESIGN

A multi-institutional observational study.

SETTING

Two university hospitals.

PATIENTS

Consecutive adult patients undergoing gastrointestinal surgery under general anaesthesia.

MAIN OUTCOME MEASURES

Averaged values of nociceptive response index from start to end of surgery (mean NR index) and risk scores of the Surgical Mortality Probability Model (S-MPM) were calculated. Pre and postoperative serum C-reactive protein (CRP) levels were obtained. After receiver-operating characteristic (ROC) curve analysis, all patients were divided into groups with high and low mean nociceptive response index. Associations between mean nociceptive response index and postoperative major complications, defined as Clavien-Dindo grade at least IIIa, were examined using logistic regression analysis.

RESULTS

ROC curve analysis showed a nociceptive response index cut-off value for major complications of 0.83, and we divided patients into two groups with mean nociceptive response index less than 0.83 and at least 0.83. The incidence of major complications was significantly higher in patients with mean nociceptive response index at least 0.83 (23.1%; n = 346) than in patients with mean nociceptive response index less than 0.83 (7.7%; n = 443; P < 0.001). Multivariate analysis revealed emergency surgery, S-MPM risk score, mean nociceptive response index and postoperative CRP levels as independent risk factors for major complications.

CONCLUSION

Mean nociceptive response index during surgery likely correlates with major complications after gastrointestinal surgery.

TRIAL REGISTRATION

The current observational study had no intervention, and was therefore, not registered.

A Systematic Review of Labor Pain Used as an Outcome Criterion in Clinical Research

OBJECTIVES

Research on labor pain currently uses standard scores such as numerical scales as clinical outcomes, but no clear guidelines for such an assessment have appeared since a review published in 1998. We aimed to describe and estimate the quality of the methods used to assess and analyze such outcomes in a systematic review of 215 comparative studies published since then in 27 influential journals.

METHODS

In addition to a complete description, we created for each study a composite "analysis quality score" (AQS) on the basis of the methods of both measurement of pain/analgesia, and statistical analysis. AQS was tested against various factors, including a "design quality score" (DQS), created to estimate methodological quality (regardless of the analysis of pain intensity).

RESULTS

Both the AQS and its "measurement" component increased with the year of publication, as well as the DQS. The impact factor correlated only with the statistical component of the AQS, and with the DQS. However, the mean AQS and DQS were, respectively, at 43% and 75% of their maximal possible value, and these 2 scores were not correlated. The intensity of labor pain (or pain relief) was the primary outcome in 19% of the studies. Although most of the studies actually used numerical scales, the methods of analysis were heterogeneous. When a cutoff point was determined to define analgesia, this was most often 30% of the maximal value.

DISCUSSION

This review points out the need for a better standardization of the methods in this field of research.

Methodological and Reporting Quality of Systematic Reviews Published in the Highest Ranking Journals in the Field of Pain

BACKGROUND

Systematic reviews (SRs) are important for making clinical recommendations and guidelines. We analyzed methodological and reporting quality of pain-related SRs published in the top-ranking anesthesiology journals.

METHODS

This was a cross-sectional meta-epidemiological study. SRs published from 2005 to 2015 in the first quartile journals within the Journal Citation Reports category Anesthesiology were analyzed based on the Journal Citation Reports impact factor for year 2014. Each SR was assessed by 2 independent authors using Assessment of Multiple Systematic Reviews (AMSTAR) and Preferred Reporting Items of Systematic reviews and Meta-Analyses (PRISMA) tools. Total score (median and interquartile range, IQR) on checklists, temporal trends in total score, correlation in total scores between the 2 checklists, and variability of those results between journals were analyzed.

RESULTS

A total of 446 SRs were included. Median total score of AMSTAR was 6/11 (IQR: 4-7) and of PRISMA 18.5/27 (IQR: 15-22). High compliance (reported in over 90% SRs) was found in only 1 of 11 AMSTAR and 5 of 27 PRISMA items. Low compliance was found for the majority of AMSTAR and PRISMA individual items. Linear regression indicated that there was no improvement in the methodological and reporting quality of SRs before and after the publication of the 2 checklists (AMSTAR: F(1,8) = 0.22; P = .65, PRISMA: F(1,7) = 0.22; P = .47). Total scores of AMSTAR and PRISMA had positive association (R = 0.71; P < .0001).

CONCLUSIONS

Endorsement of PRISMA in instructions for authors was not a guarantee of compliance. Methodological and reporting quality of pain-related SRs should be improved using relevant checklists. This can be remedied by a joint effort of authors, editors, and peer reviewers.

Retrospective study of intra-anesthetic predictors of prolonged hospitalization, increased cost of care and mortality for canine patients at a veterinary teaching hospital

OBJECTIVE

To determine the impact of intraoperative anesthetic variables on the length of hospitalization, cost of care and mortality in dogs.

STUDY DESIGN

Retrospective, observational study.

ANIMALS

A total of 235 dogs undergoing general anesthesia.

METHODS

Medical records of dogs undergoing general anesthesia between 2007 and 2014 at the University of Georgia Veterinary Teaching Hospital were reviewed. Data collected included demographic data, American Society of Anesthesiologists (ASA) physical status, type and duration of anesthesia, hemodynamic variables, temperature, ventilation, fluid therapy and adjunctive drugs administered. Outcome variables were length of hospitalization in the intensive care unit (ICU), hospital charges and survival to discharge.

RESULTS

The only factor significantly associated with duration of ICU care was higher ASA status (p<0.0001). Factors associated with increased cost of hospitalization were ICU duration (p<0.0001), anesthesia duration (p<0.0001), hemorrhage amount (p<0.0001), colloid use (p=0.0081), increased age (p=0.0253), increased weight (p = 0.0293) and presence of hypertension (p=0.0179). Overall mortality rate was 5.1%. The only factors negatively associated with survival were the administration of colloids (p<0.0008) and ASA status (p=0.0314).

CONCLUSIONS AND CLINICAL RELEVANCE

Several intrinsic patient factors and intraoperative hemodynamic variables were significantly associated with postoperative morbidity and mortality in dogs. These factors might have prognostic value in conjunction with preoperative risk assessment, and patient outcome may be improved by stricter intraoperative control of these variables.

Risk prediction models for delirium in the intensive care unit after cardiac surgery: a systematic review and independent external validation

Numerous risk prediction models are available for predicting delirium after cardiac surgery, but few have been directly compared with one another or been validated in an independent data set. We conducted a systematic review to identify validated risk prediction models of delirium (using the Confusion Assessment Method-Intensive Care Unit tool) after cardiac surgery and assessed the transportability of the risk prediction models on a prospective cohort of 600 consecutive patients undergoing cardiac surgery at a university hospital in Hong Kong from July 2013 to July 2015. The discrimination (c-statistic), calibration (GiViTI calibration belt), and clinical usefulness (decision curve analysis) of the risk prediction models were examined in a stepwise manner. Three published high-quality intensive care unit delirium risk prediction models (n=5939) were identified: Katznelson, the original PRE-DELIRIC, and the international recalibrated PRE-DELIRIC model. Delirium occurred in 83 patients (13.8%, 95% CI: 11.2-16.9%). After updating the intercept and regression coefficients in the Katznelson model, there was fair discrimination (0.62, 95% CI: 0.58-0.66) and good calibration. As the original PRE-DELIRIC model was already validated externally and recalibrated in six countries, we performed a logistic calibration on the recalibrated model and found acceptable discrimination (0.75, 95% CI: 0.72-0.79) and good calibration. Decision curve analysis demonstrated that the recalibrated PRE-DELIRIC risk model was marginally more clinically useful than the Katznelson model. Current models predict delirium risk in the intensive care unit after cardiac surgery with only fair to moderate accuracy and are insufficient for routine clinical use.

Gastric regurgitation in patients undergoing gynecological laparoscopy with a laryngeal mask airway: a prospective observational study

OBJECTIVE

The use of pneumoperitonium and the placement of patients in Trendelenburg position are commonly cited reasons for the potential development of intraoperative regurgitation of gastric contents and the need for an endotracheal tube in laparoscopic surgery. The main objective of the current investigation was to evaluate the presence of regurgitation of gastric contents in the oropharynx of patients having laparoscopic gynecological surgery with a laryngeal mask airway (LMA).

DESIGN

Prospective, observational clinical investigation.

INTERVENTIONS

Not applicable.

MEASUREMENTS

Healthy subjects having a laparoscopic gynecological surgery under general anesthesia with a ProSeal LMA were included in the study. An insufflation pressure of 15 mm Hg was established as the maximum intra-abdominal pressure for the pneumoperitonium, and patients were placed in Trendelenburg position at a 15° angle. The pH of secretions extracted from subjects' hypopharynx was measured at multiple time points during the surgical procedure. A pH of oropharynx secretions ≤4.1 indicated the regurgitation of gastric contents.

MAIN RESULTS

Eighty subjects were recruited and completed the study. The median (range) of pH measurements at any time (T3-T9) was 6.5 (5.5-7.0). The median (range) for the lowest pH for each subject was 6.0 (5.5-7.0). The lowest detected pH in the hypopharynx was not correlated (Spearman ρ) with total surgical time (P = .9), total pneumopertitonium time (P = .17), or total Trendelenburg position time (P = .47).

CONCLUSIONS

Our current results suggest that the use of an LMA in healthy patients undergoing laparoscopic gynecological surgery may be safe. Future studies to confirm or refute our findings are warranted.

Evaluation of observational research reports published in Turkish nursing journals

AIM

The aim of this literature-based descriptive study was to examine the reporting of the observational research studies published in peer-reviewed nursing journals in Turkey.

METHODS

Eleven peer-reviewed nursing journals printed on a regular basis in Turkey between 2007 and 2012 were selected. These journals were searched for observational research studies, and 502 studies were selected and examined by using the Strengthening the Reporting of Observational Studies in Epidemiology Statement.

RESULTS

Of the 502 studies, 495 were cross-sectional, 3 were cohort, and 4 were case controlled. Summary and introduction and aim sections were sufficient in most of the studies. The methods sections of the reports were mostly not reported: 64.3% of the reports did not indicate eligibility/inclusion criteria; sampling method, 67.0%; possible sources of bias, 99.2%; ways to reach sample size, 92.6%. In the results section, the number of individuals participating in each stage of the studies (44.0%) and in other analyses made (39.2%) was not reported. In the discussion section, a main comment about research findings was partly made (97.4%), and limitations of the studies and possible sources of bias were not written in 99.0% of the studies.

CONCLUSIONS

This study clearly revealed that the observational research studies published in nursing journals in Turkey did not fulfil the important criteria and needed to be improved.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Information obtained from this study can contribute to improvement of the quality of reporting observational studies in nursing and thus using obtained findings in practice.