Processed electroencephalography-guided general anesthesia and norepinephrine requirements: A randomized trial in patients having vascular surgery

STUDY OBJECTIVE

Processed electroencephalography (pEEG) may help clinicians optimize depth of general anesthesia. Avoiding excessive depth of anesthesia may reduce intraoperative hypotension and the need for vasopressors. We tested the hypothesis that pEEG-guided - compared to non-pEEG-guided - general anesthesia reduces the amount of norepinephrine needed to keep intraoperative mean arterial pressure above 65 mmHg in patients having vascular surgery.

DESIGN

Randomized controlled clinical trial.

SETTING

University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

PATIENTS

110 patients having vascular surgery.

INTERVENTIONS

pEEG-guided general anesthesia.

MEASUREMENTS

Our primary endpoint was the average norepinephrine infusion rate from the beginning of induction of anesthesia until the end of surgery.

MAIN RESULT

96 patients were analyzed. The mean ± standard deviation average norepinephrine infusion rate was 0.08 ± 0.04 μg kg-1 min-1 in patients assigned to pEEG-guided and 0.12 ± 0.09 μg kg-1 min-1 in patients assigned to non-pEEG-guided general anesthesia (mean difference 0.04 μg kg-1 min-1, 95% confidence interval 0.01 to 0.07 μg kg-1 min-1, p = 0.004). Patients assigned to pEEG-guided versus non-pEEG-guided general anesthesia, had a median time-weighted minimum alveolar concentration of 0.7 (0.6, 0.8) versus 0.8 (0.7, 0.8) (p = 0.006) and a median percentage of time Patient State Index was <25 of 12 (1, 41) % versus 23 (3, 49) % (p = 0.279).

CONCLUSION

pEEG-guided - compared to non-pEEG-guided - general anesthesia reduced the amount of norepinephrine needed to keep mean arterial pressure above 65 mmHg by about a third in patients having vascular surgery. Whether reduced intraoperative norepinephrine requirements resulting from pEEG-guided general anesthesia translate into improved patient-centered outcomes remains to be determined in larger trials.

[Preoperative evaluation of adult patients before elective, non-cardiothoracic surgery : A joint recommendation of the German Society for Anesthesiology and Intensive Care Medicine, the German Society for Surgery and the German Society for Internal Medicine]

The 70 recommendations summarize the current status of preoperative risk evaluation of adult patients prior to elective non-cardiothoracic surgery. Based on the joint publications of the German scientific societies for anesthesiology and intensive care medicine (DGAI), surgery (DGCH), and internal medicine (DGIM), which were first published in 2010 and updated in 2017, as well as the European guideline on preoperative cardiac risk evaluation published in 2022, a comprehensive re-evaluation of the recommendation takes place, taking into account new findings, the current literature, and current guidelines of international professional societies. The revised multidisciplinary recommendation is intended to facilitate a structured and common approach to the preoperative evaluation of patients. The aim is to ensure individualized preparation for the patient prior to surgery and thus to increase patient safety. Taking into account intervention- and patient-specific factors, which are indispensable in the preoperative risk evaluation, the perioperative risk for the patient should be minimized and safety increased. The recommendations for action are summarized under "General Principles (A)," "Advanced Diagnostics (B)," and the "Preoperative Management of Continuous Medication (C)." For the first time, a rating of the individual measures with regard to their clinical relevance has been given in the present recommendation. A joint and transparent agreement is intended to ensure a high level of patient orientation while avoiding unnecessary preliminary examinations, to shorten preoperative examination procedures, and ultimately to save costs. The joint recommendation of DGAI, DGCH and DGIM reflects the current state of knowledge as well as the opinion of experts. The recommendation does not replace the individualized decision between patient and physician about the best preoperative strategy and treatment.

Psychometric evaluation of the modified quality of recovery score for the postanaesthesia care unit (QoR-PACU2)-A prospective validation study

BACKGROUND

To date, there is no instrument to adequately assess self-reported quality of recovery (QoR) in the post-anesthesia care unit (PACU). We previously developed the QoR-PACU, a 13-item questionnaire specifically applicable to the PACU. The feasibility, acceptance, and validity of the QoR-PACU were promising. However, measures of reliability were slightly lower than expected.

METHODS

We modified the QoR-PACU and evaluated its psychometric properties in a cohort of adult patients scheduled for non-cardiac surgery with general anesthesia. The modified QoR-PACU (termed QoR-PACU2) was administered before surgery and postoperatively in the PACU at the time of the decision to discharge.

RESULTS

A total of 307 patients were included in the final analysis. Postoperative QoR-PACU2 sum scores differed across categories of sex, perioperative and surgical risk, and modes of airway management. The duration of anesthesia and surgery, maximum pain intensity and analgesic requirement in the PACU, and length of PACU stay were all inversely correlated with QoR in the PACU. Cronbach's alpha was 0.70 (95%CI: 0.66-0.75). The intra-class correlation coefficient was 0.86 (95%CI: 0.70-0.94, p < 0.001) for intra-rater reliability (n = 24) and 0.94 (95%CI 0.90 to 0.97, p < 0.001) for inter-rater reliability (n = 31). Cohen's effect size was 0.68 and the standardized response mean was 0.57.

CONCLUSION

The QoR-PACU2 assesses self-reported QoR after surgery in the PACU. Measures of feasibility, validity, and reliability were consistently high. Measures of responsiveness were moderate, which might be attributable to the heterogeneity of the study population. Future studies should include aspects of ethnicity and cross-cultural applicability.

Medical student´s motivational changes during the COVID-19 university lockdown: a mixed-method study

BACKGROUND

During the crucial stage of the COVID-19 pandemic, face-to-face undergraduate medical education was disrupted and replaced with online teaching activities. Based on its emphasized impact on several outcomes, a deeper insight into the pandemic related effects on medical students´ motivation is aspirational. Therefore, this study aimed to assess the motivational changes that took place during the pandemic in medical students and explored, how motivation of medical students is influenced.

METHODS

Using a mixed method inter-cohort study design, 4th year medical students´ motivation, assessed pre- and post-pandemic were compared. In subsequent qualitative analyses underlying variables that may have contributed to both- medical students´ motivation and pandemic related changes were identified. These variables were then systematically explored- both individually and in combination. In a final step, the results were embedded within the Self-Determination Theory.

RESULTS

Students who were affected by the university lockdown reported significantly higher levels of less self-determined motivation and amotivation. The qualitative analysis identified determinants that influence medical students´ motivation. The common core of these determinants is lacking social interaction and support, with a great emphasis on the interaction with the lecturer and patients.

CONCLUSION

This study emphasizes the crucial role of medical educators, patient contact, social interactions and personal support on students´ motivation. Students need to be strengthened in their beliefs about their abilities, the value of their task at hand and receive encouragement in their efforts. All this will result in an increased identification with the task and less detrimental outcomes.

Patient perception and satisfaction in awake burr hole trepanation under local anesthesia for evacuation of chronic subdural hematoma

Evacuation of chronic subdural hematoma (CSDH) will be one of the most common neurosurgical procedures in the future in the increasingly aging societies. Performing cranial surgery on awake patients may place a psychological burden on them. Aim of this study was to evaluate the psychological distress of patients during awake CSDH relief. Patients with awake evacuation of CSDH via burr hole trepanation were included in our monocentric prospective study. Patient perception and satisfaction were measured using standardized surveys 3-5 days and 6 months after surgery. Among other questionnaires, the Hospital Anxiety and Depression and the Impact of Event Scale, were used to quantify patients' stress. A total of 50 patients (mean age 72.9 years (range 51 - 92)) were included. During surgery, 28 patients reported pain (mean 4.1 (SD 3.3)). Postoperatively, 26 patients experienced pain (mean 2.7 (SD 2.6)). Patients' satisfaction with intraoperative communication was reported with a mean of 8.3 (SD 2.1). There was a significant negative correlation between intraoperatively perceived pain and satisfaction with intraoperative communication (p = 0.023). Good intraoperative communication during evacuation of CSDH in awake patients is associated with positive patient perception and correlates with pain reduction.

Hyperangulated blades or direct epiglottis lifting to optimize glottis visualization in difficult Macintosh videolaryngoscopy: a non-inferiority analysis of a prospective observational study

Purpose

It is unknown if direct epiglottis lifting or conversion to hyperangulated videolaryngoscopes, or even direct epiglottis lifting with hyperangulated videolaryngoscopes, may optimize glottis visualization in situations where Macintosh videolaryngoscopy turns out to be more difficult than expected. This study aims to determine if the percentage of glottic opening (POGO) improvement achieved by direct epiglottis lifting is non-inferior to the one accomplished by a conversion to hyperangulated videolaryngoscopy in these situations.

Methods

One or more optimization techniques were applied in 129 difficult Macintosh videolaryngoscopy cases in this secondary analysis of a prospective observational study. Stored videos were reviewed by at least three independent observers who assessed the POGO and six glottis view grades. A linear mixed regression and a linear regression model were fitted. Estimated marginal means were used to analyze differences between optimization maneuvers.

Results

In this study, 163 optimization maneuvers (77 direct epiglottis lifting, 57 hyperangulated videolaryngoscopy and 29 direct epiglottis lifting with a hyperangulated videolaryngoscope) were applied exclusively or sequentially. Vocal cords were not visible in 91.5% of the cases with Macintosh videolaryngoscopy, 24.7% with direct epiglottis lifting, 36.8% with hyperangulated videolaryngoscopy and 0% with direct lifting with a hyperangulated videolaryngoscope. Conversion to direct epiglottis lifting improved POGO (mean + 49.7%; 95% confidence interval [CI] 41.4 to 58.0; p < 0.001) and glottis view (mean + 2.2 grades; 95% CI 1.9 to 2.5; p < 0.001). Conversion to hyperangulated videolaryngoscopy improved POGO (mean + 43.7%; 95% CI 34.1 to 53.3; p < 0.001) and glottis view (mean + 1.9 grades; 95% CI 1.6 to 2.2; p < 0.001). The difference in POGO improvement between conversion to direct epiglottis lifting and conversion to hyperangulated videolaryngoscopy is: mean 6.0%; 95% CI -6.5-18.5%; hence non-inferiority was confirmed.

Conclusion

When Macintosh videolaryngoscopy turned out to be difficult, glottis exposure with direct epiglottis lifting was non-inferior to the one gathered by conversion to hyperangulated videolaryngoscopy. A combination of both maneuvers yields the best result.

Clinical trial registration

ClinicalTrials.gov, NCT03950934.

Impact of Intraoperative Fluctuations of Cardiac Output on Cerebrovascular Autoregulation: An Integrative Secondary Analysis of Individual-level Data

BACKGROUND

Intraoperative impairment of cerebral autoregulation (CA) has been associated with perioperative neurocognitive disorders. We investigated whether intraoperative fluctuations in cardiac index are associated with changes in CA.

METHODS

We conducted an integrative explorative secondary analysis of individual-level data from 2 prospective observational studies including patients scheduled for radical prostatectomy. We assessed cardiac index by pulse contour analysis and CA as the cerebral oxygenation index (COx) based on near-infrared spectroscopy. We analyzed (1) the cross-correlation between cardiac index and COx, (2) the correlation between the time-weighted average (TWA) of the cardiac index below 2.5 L min-1 m-2, and the TWA of COx above 0.3, and (3) the difference in areas between the cardiac index curve and the COx curve among various subgroups.

RESULTS

The final analysis included 155 patients. The median cardiac index was 3.16 [IQR: 2.65, 3.72] L min-1 m-2. Median COx was 0.23 [IQR: 0.12, 0.34]. (1) The median cross-correlation between cardiac index and COx was 0.230 [IQR: 0.186, 0.287]. (2) The correlation (Spearman ρ) between TWA of cardiac index below 2.5 L min-1 m-2 and TWA of COx above 0.3 was 0.095 (P=0.239). (3) Areas between the cardiac index curve and the COx curve did not differ significantly among subgroups (<65 vs. ≥65 y, P=0.903; 0 vs. ≥1 cardiovascular risk factors, P=0.518; arterial hypertension vs. none, P=0.822; open vs. robot-assisted radical prostatectomy, P=0.699).

CONCLUSIONS

We found no meaningful association between intraoperative fluctuations in cardiac index and CA. However, it is possible that a potential association was masked by the influence of anesthesia on CA.

Preoperative Spirometry in Patients With Known or Suspected Chronic Obstructive Pulmonary Disease Undergoing Major Surgery: The Prospective Observational PREDICT Study

BACKGROUND

Pulmonary function tests (PFTs) such as spirometry and blood gas analysis have been claimed to improve preoperative pulmonary risk assessment, but the scientific literature is conflicting. The Preoperative Diagnostic Tests for Pulmonary Risk Assessment in Chronic Obstructive Pulmonary Disease (PREDICT) study aimed to determine whether preoperative PFTs improve the prediction of postoperative pulmonary complications (PPCs) in patients with known or suspected chronic obstructive pulmonary disease (COPD) undergoing major surgery. A secondary aim was to determine whether the Global Initiative for Chronic Obstructive Lung Diseases (GOLD) classification of airflow limitation severity (grades I-IV) is associated with PPC.

METHODS

In this prospective, single-center study, patients with GOLD key indicators for COPD scheduled for major surgery received PFTs. Patients with confirmed COPD (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ≤0.7) were included in the COPD cohort and compared with a reference cohort without COPD. We developed 3 multivariable risk prediction models and compared their ability to predict PPC: the "standard model" (medical preconditions, and sociodemographic and surgical data), the "COPD assessment model" (additional GOLD key indicators, pack-years, and poor exercise capacity), and the "PFT model" (additional PFT parameters selected by adaptive least absolute shrinkage and selection operator [LASSO] regression). Multiple LASSO regressions were used for cross-validation.

RESULTS

A total of 31,714 patients were assessed for eligibility; 1271 individuals received PFTs. Three hundred twenty patients (240 with confirmed COPD: 78 GOLD I, 125 GOLD II, 28 GOLD III, 9 GOLD IV, and 80 without COPD) completed follow-up. The diagnostic performance was similar among the standard model (cross-validated area under the curve [cvAUC], 0.723; bias-corrected bootstrapped [bc-b] 95% confidence interval [CI], 0.663-0.775), COPD assessment model (cvAUC, 0.724; bc-b 95% CI, 0.662-0.777), and PFT model (cvAUC, 0.729; bc-b 95% CI, 0.668-0.782). Previously known COPD was an independent predictor in the standard and COPD assessment model. %FEV1 PRED was the only PFT parameter selected by LASSO regression and was an independent predictor in the PFT model (adjusted odds ratios [OR], 0.98; 95% CI, 0.967-.0.998; P = .030). The risk for PPC significantly increased with GOLD grades ( P < .001). COPD was newly diagnosed in 53.8% of the patients with confirmed COPD; however, these individuals were not at increased risk for PPC ( P = .338).

CONCLUSIONS

COPD is underdiagnosed in surgical patients. Patients with newly diagnosed COPD commonly presented with low GOLD severity grades and were not at higher risk for PPC. Neither a structured COPD-specific assessment nor preoperative PFTs added incremental diagnostic value to the standard clinical preassessment in patients with known or suspected COPD. Unnecessary postponement of surgery and undue health care costs can be avoided.

Psychometric evaluation of a quality of recovery score for the postanesthesia care unit-A preliminary validation study

INTRODUCTION

Patients' perception of postoperative recovery is a key aspect of perioperative care. Self-reported quality of recovery (QoR) has evolved as a relevant endpoint in perioperative research. Several psychometric instruments have been introduced to assess self-reported recovery 24 hours after surgery. However, there is no questionnaire suitable for use in the postanesthesia care unit (PACU). We aimed to develop and psychometrically evaluate a QoR questionnaire for the PACU (QoR-PACU).

METHODS

The QoR-PACU was developed in German language based on the 40-item QoR-40 questionnaire. Between March and November 2020, adult patients scheduled for elective urologic surgery completed the QoR-PACU preoperatively and during the PACU stay. We evaluated feasibility, validity, reliability, and responsiveness.

RESULTS

We included 375 patients. After two piloting phases including 72 and 48 patients, respectively, we administered the final version of the QoR-PACU to 255 patients, with a completion rate of 96.5%. Patients completed the QoR-PACU at a median of 125.0 (83.0; 156.8) min after arrival in the PACU. Construct validity was good with postoperative QoR-PACU sum scores correlating with age (r = 0.23, 95% CI: 0.11 to 0.35, p < 0.001), length of PACU stay (r = -0.15, 95%CI: -0.27 to -0.03, p = 0.02), pain in the PACU (r = -0.48, 95% CI: -0.57 to -0.37, p < 0.001) and piritramide dose administered (r = -0.29, 95% CI: -0.40 to -0.17, p < 0.001). Cronbach's alpha was 0.67 (95% CI: 0.61-0.73) with moderate test-retest reliability (ICC of 0.67, 95% CI: 0.38 to 0.83). Cohen's effect size was 3.08 and the standardized response mean was 1.65 indicating adequate responsiveness.

CONCLUSION

The assessment of QoR in the early postoperative period is feasible. We found high acceptability, good validity, adequate responsiveness, and moderate reliability. Future studies should evaluate the psychometric properties of the QoR-PACU in more heterogeneous patient populations including female and gender-diverse patients with varying degress of perioperative risk.

Glidescope Video Laryngoscopy in Patients with Severely Restricted Mouth Opening-A Pilot Study

BACKGROUND

An inter-incisor gap <3 cm is considered critical for videolaryngoscopy. It is unknown if new generation GlideScope Spectrum™ videolaryngoscopes with low-profile hyperangulated blades might facilitate safe tracheal intubation in these patients. This prospective pilot study aims to evaluate feasibility and safety of GlideScopeTM videolaryngoscopes in severely restricted mouth opening.

METHODS

Feasibility study in 30 adults with inter-incisor gaps between 1.0 and 3.0 cm scheduled for ENT or maxillofacial surgery. Individuals at risk for aspiration or rapid desaturation were excluded.

RESULTS

The mean mouth opening was 2.2 ± 0.5 cm (range 1.1-3.0 cm). First attempt success rate was 90% and overall success was 100%. A glottis view grade 1 or 2a was achieved in all patients. Nasotracheal intubation was particularly difficult if Magill forceps were required (n = 4). Intubation time differed between orotracheal (n = 9; 33 (25; 39) s) and nasotracheal (n = 21; 55 (38; 94) s); p = 0.049 intubations. The airway operator's subjective ratings on visual analogue scales (0-100) revealed that tube placement was more difficult in individuals with an inter-incisor gap <2.0 cm (n = 10; 35 (29; 54)) versus ≥2.0 cm (n = 20; 20 (10; 30)), p = 0.007, while quality of glottis exposure did not differ.

CONCLUSIONS

GlidescopeTM videolaryngoscopy is feasible and safe in patients with severely restricted mouth opening if given limitations are respected.

Impact of Introducing a PACU24 Concept on the Perioperative Outcome of Patients with Advanced Ovarian Cancer Treated with Cytoreductive Surgery

Introduction

Patients with ovarian cancer who undergo multivisceral surgery usually require intensive care monitoring postoperatively. In view of the ever-fewer numbers of high-care/intensive care beds and the introduction of fast-track treatment concepts, it is increasingly being suggested that these patients should be cared for postoperatively in 24-h Post Anesthesia Care Units (PACU24). No analyses have been carried out to date to investigate whether such a postoperative care concept might be associated with a potential increase in postoperative complications in this patient cohort.

Methods

A PACU24 unit was set up in our institution in 2015 and it has become the primary postoperative care pathway for patients with ovarian cancer who have undergone cytoreductive (debulking) surgery. A structured, retrospective analysis of data from patients treated before (control group) and after (PACU group) the introduction of this care concept was carried out, with a particular focus on postoperative complications and secondary admission to an intensive care unit where necessary.

Results

The data of 42 patients were analyzed for the PACU group and 45 patients for the control group. According to the analysis, the preoperative and surgical data of both groups were comparable (age, ASA, BMI, FIGO stage, duration of surgery, blood loss). The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM score) as a measure for the risk of postoperative complications was higher in the PACU group (11.1% vs. 9.7%, p = 0.001). Patients in the PACU group underwent bowel resection with anastomosis significantly more often (76.3% vs. 33.3%, p < 0.001), although the extent of surgery was otherwise comparable. The total number, type and severity of postoperative complications and the duration of the overall stay in hospital did not differ between the two groups. None of the patients required secondary transfer from the PACU or normal ward to an intensive care unit (ICU).

Summary

Our data support the assumption that the care concept of transferring patients to a PACU24 represents a safe and cost-saving care pathway for the postoperative care of patients even after complex gynecological-oncological procedures.

Association of the classification of intraoperative adverse events (ClassIntra) with complications and neurological outcome after neurosurgical procedures: a prospective cohort study

PURPOSE

To analyze the reliability of the classification of intraoperative adverse events (ClassIntra) to reflect intraoperative complications of neurosurgical procedures and the potential to predict the postoperative outcome including the neurological performance. The ClassIntra classification was recently introduced and found to be reliable for assessing intraoperative adverse events and predicting postoperative complications across different surgical disciplines. Nevertheless, its potential role for neurosurgical procedures remains elusive.

METHODS

This is a prospective, monocentric cohort study assessing the ClassIntra in 422 adult patients who underwent a neurosurgical procedure and were hospitalized between July 1, 2021, to December 31, 2021. The primary outcome was the occurrence of intraoperative complications graded according to ClassIntra and the association with postoperative outcome reflected by the Clavien-Dindo classification and comprehensive complication index (CCI). The ClassIntra is defined as intraoperative adverse events as any deviation from the ideal course on a grading scale from grade 0 (no deviation) to grade V (intraoperative death) and was set at sign-out in agreement between neurosurgeon and anesthesiologist. Secondary outcomes were the neurological outcome after surgery as defined by Glasgow Coma Scale (GCS), modified Rankin scale (mRS), Neurologic Assessment in Neuro-Oncology (NANO) scale, National Institute Health of Strokes Scale (NIHSS), and Karnofsky Performance Score (KPS), and need for unscheduled brain scan.

RESULTS

Of 442 patients (mean [SD] age, 56.1 [16.2]; 235 [55.7%] women and 187 [44.3%] men) who underwent a neurosurgical procedure, 169 (40.0%) patients had an intraoperative adverse event (iAE) classified as ClassIntra I or higher. The NIHSS score at admission (OR, 1.29; 95% CI, 1.03-1.63, female gender (OR, 0.44; 95% CI, 0.23-0.84), extracranial procedures (OR, 0.17; 95% CI, 0.08-0.61), and emergency cases (OR, 2.84; 95% CI, 1.53-3.78) were independent risk factors for a more severe iAE. A ClassIntra ≥ II was associated with increased odds of postoperative complications classified as Clavien-Dindo (p < 0.01), neurological deterioration at discharge (p < 0.01), prolonged hospital (p < 0.01), and ICU stay (p < 0.01). For elective craniotomies, severity of ClassIntra was associated with the CCI (p < 0.01) and need for unscheduled CT or MRI scan (p < 0.01). The proportion of a ClassIntra ≥ II was significantly higher for emergent craniotomies (56.2%) and associated with in-hospital mortality, and an unfavorable neurological outcome (p < 0.01).

CONCLUSION

Findings of this study suggest that the ClassIntra is sensitive for assessing intraoperative adverse events and sufficient to identify patients with a higher risk for developing postoperative complications after a neurosurgical procedure.

National consensus on entrustable professional activities for competency-based training in anaesthesiology

Entrustable Professional Activities (EPA) are specialty specific tasks or responsibilities, combining the clinical workplace and the long-demanded competency-based medical education. The first step to transform time-based into EPA-based training is to reach consensus on core EPAs that describe sufficiently the workplace. We aimed to present a nationally validated EPA-based curriculum for postgraduate training in anaesthesiology. Using a predefined and validated list of EPAs, we applied a Delphi consensus approach, involving all German chair directors of anaesthesiology. We then conducted a subsequent qualitative analysis. Thirty-four chair directors participated in the Delphi survey (77% response) and twenty-five completed all the questions (56% overall response). Reflected by the intra-class-correlation, the consensus on the importance (ICC: 0.781, 95% CI [0.671, 0.868]) and the year of entrustment (ICC: 0.973, 95% CI [0.959, 0.984]) of each EPA reached high levels of agreement among the chair directors. The comparison of data assessed in the preceding validation and present study showed excellent and good levels of agreement (ICC entrustment: 0.955, 95% CI [0.902, 0.978]; ICC importance: 0.671, 95% CI [-0.204, 0.888]). The adaptation process, based on the qualitative analysis, resulted in a final set of 34 EPAs. We present an elaborate, fully described and nationally validated EPA-based curriculum, reflecting a broad consensus among different stakeholders of anaesthesiology. We hereby provide a further step towards competency-based postgraduate anaesthesiology training.

Stair-Climbing Tests or Self-Reported Functional Capacity for Preoperative Pulmonary Risk Assessment in Patients with Known or Suspected COPD-A Prospective Observational Study

BACKGROUND

This prospective study aims to determine whether preoperative stair-climbing tests (SCT) predict postoperative pulmonary complications (PPC) better than self-reported poor functional capacity (SR_PFC) in patients with known or suspected COPD.

METHODS

A total of 320 patients undergoing scheduled for major non-cardiac surgery, 240 with verified COPD and 80 with GOLD key indicators but disproved COPD, underwent preoperative SR_PFC and SCT and were analyzed. Least absolute shrinkage and selection operator (LASSO) regression was used for variable selection. Two multivariable regression models were fitted, the SR_PFC model (baseline variables such as sociodemographic, surgical and procedural characteristics, medical preconditions, and GOLD key indicators plus SR_PFC) and the SCT model (baseline variables plus SCT_PFC).

RESULTS

Within all stair-climbing variables, LASSO exclusively selected self-reported poor functional capacity. The cross-validated area under the receiver operating characteristic curve with bias-corrected bootstrapping 95% confidence interval (95% CI) did not differ between the SR_PFC and SCT models (0.71; 0.65-0.77 for both models). SR_PFC was an independent risk factor (adjusted odds ratio (OR) 5.45; 95% CI 1.04-28.60; p = 0.045 in the SR_PFC model) but SCT_PFC was not (adjusted OR 3.78; 95% CI 0.87-16.34; p = 0.075 in the SCT model).

CONCLUSIONS

Our findings indicate that preoperative SR_PFC adequately predicts PPC while additional preoperative SCTs are dispensable in patients with known or suspected COPD.

Nasendoscopy to Predict Difficult Videolaryngoscopy: A Multivariable Model Development Study

BACKGROUND

Transnasal videoendoscopy (TVE) is the standard of care when staging pharyngolaryngeal lesions. This prospective study determined if preoperative TVE improves the prediction of difficult videolaryngoscopic intubation in adults with expected difficult airway management in addition to the Simplified Airway Risk Index (SARI).

METHODS

374 anesthetics were included (252 with preoperative TVE). The primary outcome was a difficult airway alert issued by the anesthetist after Macintosh videolaryngoscopy. SARI, clinical factors (dysphagia, dysphonia, cough, stridor, sex, age and height) and TVE findings were used to fit three multivariable mixed logistic regression models; least absolute shrinkage and selection operator (LASSO) regression was used to select co-variables.

RESULTS

SARI predicted the primary outcome (odds ratio [OR] 1.33; 95% confidence interval [CI] 1.13-1.58). The Akaike information criterion for SARI (327.1) improved when TVE parameters were added (311.0). The Likelihood ratio test for SARI plus TVE parameters was better than for SARI plus clinical factors (p < 0.001). Vestibular fold lesions (OR 1.82; 95% CI 0.40-8.29), epiglottic lesions (OR 3.37; 0.73-15.54), pharyngeal secretion retention (OR 3.01; 1.05-8.63), restricted view on rima glottidis <50% (OR 2.13; 0.51-8.89) and ≥50% (OR 2.52; 0.44-14.56) were concerning.

CONCLUSION

TVE improved prediction of difficult videolaryngoscopy in addition to traditional bedside airway examinations.

Transnasal Videoendoscopy for Preoperative Airway Risk Stratification: Development and Validation of a Multivariable Risk Prediction Model

BACKGROUND

Transnasal flexible videoendoscopy (TVE) of the larynx is a standard of care for the detection and staging of pharyngolaryngeal lesions in otorhinolaryngology. Patients frequently present with existing TVE examinations before anesthesia. Although these patients are considered high risk, the diagnostic value of TVE for airway risk stratification is currently unknown. How can captured images or videos be used for anesthesia planning, and which lesions are most concerning? This study aimed to develop and validate a multivariable risk prediction model for difficult airway management based on TVE findings and to determine whether the discrimination of the Mallampati score can be improved by adding this new TVE model.

METHODS

This retrospective single-center development and validation study assessed 4021 patients who underwent 4524 otorhinolaryngologic surgeries at the University Medical Centre Hamburg-Eppendorf between January 1, 2011, and April 30, 2018, with electronically stored TVE videos and included 1099 patients who underwent 1231 surgeries. TVE videos and anesthesia charts were systematically reviewed in a blinded fashion. The Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis was used for variable selection, model development, and cross validation.

RESULTS

The prevalence of difficult airway management was 24.7% (304/1231). Lesions at the vocal cords, epiglottis, or hypopharynx were not selected by the LASSO regression, while lesions at the vestibular folds (ß-coefficient 0.123), supraglottic region (ß-coefficient 0.161), arytenoids (ß-coefficient 0.063), and viewing restrictions on the rima glottidis that cover ≥50% of the glottis area (ß-coefficient 0.485) and pharyngeal secretion retention (ß-coefficient 0.372) were relevant risk factors for difficult airway management. The model was adjusted for sex, age, and body mass index. The area under the receiver operating characteristic curve (95% confidence interval) of the Mallampati score was 0.61 (0.57-0.65) and 0.74 (0.71-0.78) of the TVE model combined with Mallampati (P < .001).

CONCLUSIONS

Stored images and videos from TVE examinations can be reused for the purpose of predicting risk associated with airway management. Vestibular fold, supraglottic, and arytenoid lesions are most concerning, especially if they are accompanied by secretion retention or restrict the glottic view. Our data indicate that the TVE model improves discrimination of the Mallampati score and might, therefore, be a useful addition to traditional bedside airway risk examinations.

Oscillatory and aperiodic neuronal activity in working memory following anesthesia

OBJECTIVE

Anesthesia and surgery are associated with cognitive impairment, particularly memory deficits. So far, electroencephalography markers of perioperative memory function remain scarce.

METHODS

We included male patients >60 years scheduled for prostatectomy under general anesthesia. We obtained neuropsychological assessments and a visual match-to-sample working memory task with simultaneous 62-channel scalp electroencephalography 1 day before and 2 to 3 days after surgery.

RESULTS

Twenty-six patients completed both pre- and postoperative sessions. Compared with preoperative performance, verbal learning deteriorated after anesthesia (California Verbal Learning Test total recall; t₂₅ = -3.25, p = 0.015, d = -0.902), while visual working memory performance showed a dissociation between match and mismatch accuracy (match*session F_1,25 = 3.866, p = 0.060). Better verbal learning was associated with an increase of aperiodic brain activity (total recall r = 0.66, p = 0.029, learning slope r = 0.66, p = 0.015), whereas visual working memory accuracy was tracked by oscillatory theta/alpha (7 - 9 Hz), low beta (14 - 18 Hz) and high beta/gamma (34 - 38 Hz) activity (matches: p < 0.001, mismatches: p = 0.022).

CONCLUSIONS

Oscillatory and aperiodic brain activity in scalp electroencephalography track distinct features of perioperative memory function.

SIGNIFICANCE

Aperiodic activity provides a potential electroencephalographic biomarker to identify patients at risk for postoperative cognitive impairments.

A digital application and augmented physician rounds reduce postoperative pain and opioid consumption after primary total knee replacement (TKR): a randomized clinical trial

BACKGROUND

Severe postoperative pain not only is a considerable burden for patients but also leads to overprescription of opioids, resulting in considerable health concerns. The remarkable development of new technologies in the health care system provides novel treatment opportunities in this area and could exploit the additional placebo effect, provide added value for patients, and at the same time support hospital staff. We aimed to test the pain- and opioid intake-reducing effects of enhanced postoperative pain management by boosting pain medication by using a technical application and/or augmented physician rounds.

METHODS

In a four-arm, randomized clinical trial, 96 patients (24 patients per group) scheduled for a total knee replacement (TKR) were randomized into four groups for four postoperative days: an "application" group (APP) with information via an iPad-based application; a "doctor" group (DOC) with augmented physician rounds; a combination group (APP+DOC), which received both interventions; and a "treatment as usual" group (TAU) as a baseline with no additional intervention besides the standard care which consists of standardized medication, regular physician rounds, and physiotherapy. Postoperative pain and opioid requirements pre- and postoperatively until hospital discharge were recorded.

RESULTS

The difference between post- and preoperative pain was significantly different between the groups (P=.02, partial η²=.10). APP+DOC experienced greater postoperative pain relief than DOC (mean: 2.3 vs. 0.7, 95% CI: 0.08-3.09; P=.04) and TAU (mean 2.3 vs. 0.1; 95% CI: 0.69-3.71; P=.005), respectively, the difference compared to APP (mean 2.3 vs. 1.7; 95% CI -1.98-1.76) was not significant. Opioid consumption differed significantly between groups (P=.01, partial η²=.12). APP+DOC (72.9 mg) and DOC (75.4 mg) consumed less oxycodone than APP (83.3 mg) and TAU (87.9 mg; 95% CI: 2.9-22.1; P=.003). APP+DOC consumed significantly less oxycodone than DOC (d=0.2-0.4). There were no significant group differences in NSAID and Morphine sulfate consumption. Patients in APP+DOC were more satisfied with their treatment than patients in TAU (P=.03, partial η²=.09).

CONCLUSIONS

The combination of an innovative digital app, which implements open drug administration and augmented physician rounds that support the doctor-patient relationship can significantly improve postoperative pain management.

TRIAL REGISTRATION

The protocol was approved by the local ethics committee of the ethical commission of the German Psychological Society (Deutsche Gesellschaft für Psychologie; DGPs). The study was registered at DRKS.de (identifier: DRKS00009554).

A model to predict difficult airway alerts after videolaryngoscopy in adults with anticipated difficult airways - the VIDIAC score

A model to classify the difficulty of videolaryngoscopic tracheal intubation has yet to be established. The videolaryngoscopic intubation and difficult airway classification (VIDIAC) study aimed to develop one based on variables associated with difficult videolaryngoscopic tracheal intubation. We studied 374 videolaryngoscopic tracheal intubations in 320 adults scheduled for ear, nose and throat or oral and maxillofacial surgery, for whom airway management was expected to be difficult. The primary outcome was whether an anaesthetist issued a 'difficult airway alert' after videolaryngoscopy. An alert was issued after 183 (49%) intubations. Random forest and lasso regression analysis selected six intubation-related variables associated with issuing an alert: impaired epiglottic movement; increased lifting force; direct epiglottic lifting; vocal cords clearly visible; vocal cords not visible; and enlarged arytenoids. Internal validation was performed by a 10-fold cross-validation, repeated 20 times. The mean (SD or 95%CI) area under the receiver operating characteristic curve was 0.92 (0.05) for the cross validated coefficient model and 0.92 (0.89-0.95) for a simplified unitary score (VIDIAC score with component values of -1 or 1 only). The calibration belt for the coefficient model was consistent with observed alert probabilities, from 0% to 100%, while the unitary VIDIAC score overestimated probabilities < 20% and underestimated probabilities > 70%. Discrimination of the VIDIAC score for patients more or less likely to be issued an alert was better than discrimination by the Cormack-Lehane classification, with mean (95%CI) areas under the receiver operating characteristic curve of 0.92 (0.89-0.95) vs. 0.75 (0.70-0.80), respectively, p < 0.001. Our model and score can be used to calculate the probabilities of difficult airway alerts after videolaryngoscopy.

Continuous intra-arterial versus intermittent oscillometric arterial pressure monitoring and hypotension during induction of anaesthesia: the AWAKE randomised trial

BACKGROUND

Hypotension during induction of anaesthesia is associated with organ injury. Continuous arterial pressure monitoring might help reduce hypotension. We tested the hypothesis that continuous intra-arterial compared with intermittent oscillometric arterial pressure monitoring reduces hypotension during induction of anaesthesia in noncardiac surgery patients.

METHODS

In this single-centre randomised trial, 242 noncardiac surgery patients in whom intra-arterial arterial pressure monitoring was planned were randomised to unblinded continuous intra-arterial or to intermittent oscillometric arterial pressure monitoring (with blinded intra-arterial arterial pressure monitoring) during induction of anaesthesia. The primary endpoint was the area under a mean arterial pressure (MAP) of 65 mm Hg within the first 15 min of induction of anaesthesia. Secondary endpoints included areas under MAP values of 60, 50, and 40 mm Hg and durations of MAP values <65, <60, <50, and <40 mm Hg.

RESULTS

There were 224 subjects available for analysis. The median (25th-75th percentile) area under a MAP of 65 mm Hg was 15 (2-36) mm Hg • min in subjects assigned to continuous intra-arterial monitoring and 46 (7-111) mm Hg • min in subjects assigned to intermittent oscillometric monitoring (P<0.001). Subjects assigned to continuous intra-arterial monitoring had smaller areas under MAP values of 60, 50, and 40 mm Hg and shorter durations of MAP values <65, <60, <50, and <40 mm Hg than subjects assigned to intermittent oscillometric monitoring.

CONCLUSION

Continuous intra-arterial arterial pressure monitoring reduces hypotension during induction of anaesthesia compared with intermittent oscillometric arterial pressure monitoring in noncardiac surgery patients. In patients for whom an arterial catheter is planned, clinicians might therefore consider inserting the arterial catheter before rather than after induction of anaesthesia.

CLINICAL TRIALS REGISTRATION

NCT04894019.

Observing treatment outcomes in other patients can elicit augmented placebo effects on pain treatment: a double-blinded randomized clinical trial with patients with chronic low back pain

ABSTRACT

Clinical research on social observational learning (SoL) as an underlying mechanism for inducing expectancy and eliciting analgesic placebo effects is lacking. This double-blinded randomized controlled clinical trial investigated the influence of SoL on medication-augmenting placebo effects in 44 patients with chronic low back pain. Our hypothesis was that observing positive drug effects on pain and mobility in another patient could increase pain reduction and functional capacity. To test this, we compared the effects of observing positive treatment outcomes in a sham patient (the social learning group [SoLG]) vs hearing the same sham patient report neutral effects (the control group). In the SoLG, the sham patient told peers about pain reduction due to amitriptyline and demonstrated his improved mobility by bending forwards and sideways while he told the control group only that he was taking amitriptyline. The primary outcome was a reduction in clinical low back pain self-ratings. The secondary outcome was perceptions of pain-related disability. The exploratory outcome was mood and coping statements. Data collection occurred before and after the intervention and 2 weeks later. After the intervention, pain decreased in both groups (F [1, 41] = 7.16, P < 0.05, d = 0.83), with no difference between groups. However, the SoLG showed a significantly larger decrease in perceived disability (F [1, 41] = 5, P < 0.05, d = 0.63). The direct observation of patient with chronic low back pain of positive treatment outcomes in the sham patient seems to have enhanced the treatment effects while indirect verbal reports of reduced pain did not.

Left Ventricular Diastolic Dysfunction Is Not Associated With Pulmonary Edema in Septic Patients. A Prospective Observational Cohort Study

Purpose

We aimed to investigate whether left ventricular diastolic dysfunction (LVDD) is associated with pulmonary edema in septic patients.

Methods

We conducted a prospective cohort study in adult septic patients between October 2018 and May 2019. We performed repeated echocardiography and lung ultrasound examinations within the first 7 days after diagnosis of sepsis. We defined LVDD according to the 2016 recommendations of the American Society of Echocardiography and—for sensitivity analysis—according to an algorithm which has been validated in septic patients. We quantified pulmonary edema using the lung ultrasound score (LUSS), counting B-lines in four intercostal spaces.

Results

We included 54 patients. LVDD was present in 51 (42%) of 122 echocardiography examinations. The mean (±SD) LUSS was 11 ± 6. There was no clinically meaningful association of LVDD with LUSS (B = 0.55 [95%CI: −1.38; 2.47]; p = 0.571). Pneumonia was significantly associated with higher LUSS (B = 4.42 [95%CI: 0.38; 8.5]; p = 0.033).

Conclusion

The lack of a clinically meaningful association of LVDD with LUSS suggests that LVDD is not a major contributor to pulmonary edema in septic patients.

Trial Registration

NCT03768752, ClinicalTrials.gov, November 30^th, 2018 - retrospectively registered.

Interdisciplinary and cross-sectoral perioperative care model in cardiac surgery: implementation in the setting of minimally invasive heart valve surgery (INCREASE)-study protocol for a randomized controlled trial

Background

Valvular heart diseases are frequent and increasing in prevalence. Minimally invasive heart valve surgery embedded in an interdisciplinary enhanced recovery after surgery (ERAS) program may have potential benefits with regard to reduced length of stay and improved patient reported outcomes. However, no prospective randomized data exist regarding the superiority of ERAS program for the patients’ outcome.

Methods

We aim to randomize (1:1) a total of 186 eligible patients with minimally invasive heart valve surgery to an ERAS program vs. standard treatment at two centers including the University Medical Center Hamburg-Eppendorf, Germany, and the University Hospital Augsburg, Germany. The intervention is composed out of pre-, peri-, and postoperative components. The preoperative protocol aims at better preparation for the operation with regard to physical activity, nutrition, and psychological preparedness. Intraoperative anesthesiologic and surgical management are trimmed to enable an early extubation. Patients will be transferred to a specialized postoperative anesthesia care unit, where first mobilization occurs 3 h after surgery. Transfer to low care ward will be at the next day and discharge at the fifth day. Participants in the control group will receive treatment as usual. Primary endpoints include functional discharge at discharge and duration of in-hospital care during the first 12 months after index surgery. Secondary outcomes include health-related quality of life, health literacy, and level of physical activity.

Discussion

This is the first randomized controlled trial evaluating the effectiveness of an ERAS process after minimally invasive heart valve surgery. Interprofessional approach is the key factor of the ERAS process and includes in particular surgical, anesthesiological, physiotherapeutic, advanced nursing, and psychosocial components. A clinical implication guideline will be developed facilitating the adoption of ERAS model in other heart teams.

Trial registration

The study has been registered in ClinicalTrials.gov (NCT04977362 assigned July 27, 2021).

Virtual reality as a teaching method for resuscitation training in undergraduate first year medical students during COVID-19 pandemic: a randomised controlled trial

BACKGROUND

Virtual reality (VR) is a computer-generated simulation technique which yields plenty of benefits and its application in medical education is growing. This study explored the effectiveness of a VR Basic Life Support (BLS) training compared to a web-based training during the COVID-19 pandemic, in which face-to-face trainings were disrupted or reduced.

METHODS

This randomised, double-blinded, controlled study, enrolled 1^st year medical students. The control group took part in web-based BLS training, the intervention group received an additional individual VR BLS training. The primary endpoint was the no-flow time-an indicator for the quality of BLS-, assessed during a structural clinical examination, in which also the overall quality of BLS (secondary outcome) was rated. The tertiary outcome was the learning gain of the undergraduates, assessed with a comparative self-assessment (CSA).

RESULTS

Data from 88 undergraduates (n = 46 intervention- and n = 42 control group) were analysed. The intervention group had a significant lower no-flow time (p = .009) with a difference between the two groups of 28% (95%-CI [8%;43%]). The overall BLS performance of the intervention group was also significantly better than the control group with a mean difference of 15.44 points (95%-CI [21.049.83]), p < .001. In the CSA the undergraduates of the intervention group reported a significant higher learning gain.

CONCLUSION

VR proved to be effective in enhancing process quality of BLS, therefore, the integration of VR into resuscitation trainings should be considered. Further research needs to explore which combination of instructional designs leads to deliberate practice and mastery learning of BLS.

Is Prehospital Assessment of qSOFA Parameters Associated with Earlier Targeted Sepsis Therapy? A Retrospective Cohort Study

BACKGROUND

This study aimed to determine whether prehospital qSOFA (quick sequential organ failure assessment) assessment was associated with a shortened 'time to antibiotics' and 'time to intravenous fluid resuscitation' compared with standard assessment.

METHODS

This retrospective study included patients who were referred to our Emergency Department between 2014 and 2018 by emergency medical services, in whom sepsis was diagnosed during hospitalization. Two multivariable regression models were fitted, with and without qSOFA parameters, for 'time to antibiotics' (primary endpoint) and 'time to intravenous fluid resuscitation'.

RESULTS

In total, 702 patients were included. Multiple linear regression analysis showed that antibiotics and intravenous fluids were initiated earlier if infections were suspected and emergency medical services involved emergency physicians. A heart rate above 90/min was associated with a shortened time to antibiotics. If qSOFA parameters were added to the models, a respiratory rate ≥ 22/min and altered mentation were independent predictors for earlier antibiotics. A systolic blood pressure ≤ 100 mmHg and altered mentation were independent predictors for earlier fluids. When qSOFA parameters were added, the explained variability of the model increased by 24% and 38%, respectively (adjusted R² 0.106 versus 0.131 for antibiotics and 0.117 versus 0.162 for fluids).

CONCLUSION

Prehospital assessment of qSOFA parameters was associated with a shortened time to a targeted sepsis therapy.

Effect of sedative premedication with oral midazolam on postanesthesia care unit delirium in older adults: a secondary analysis following an uncontrolled before-after design

BACKGROUND

Sedative premedication with benzodiazepines has been linked with prolonged recovery and inadequate emergence during the immediate postoperative period. We aimed to analyze the association between postanesthesia care unit (PACU) delirium and sedative premedication with oral midazolam.

METHODS

We performed a secondary analysis of prospectively collected data before (midazolam cohort) and after (non-midazolam cohort) implementation of a restrictive strategy for oral premedication with midazolam. From March 2015 until July 2018, we included patients 60 years and older, who underwent elective radical prostatectomy for prostate cancer. Exclusion criteria were contraindications to premedication with midazolam, preoperative anxiety, and a history of neurological disorders. Patients, who were scheduled for postoperative admission to the intensive care unit, were excluded. Between 2015 and 2016, patients received 7.5 mg oral midazolam preoperatively (midazolam cohort). Patients included between 2017 and 2018 did not receive any sedative medication preoperatively (non-midazolam cohort). The primary endpoint was the incidence of PACU delirium.

RESULTS

PACU delirium rates were 49% in the midazolam cohort (n = 214) and 33% in the non-midazolam cohort (n = 218). This difference was not statistically significant on multivariable logistic regression analysis (OR 0.847 [95% CI 0.164; 4.367]; P = 0.842). Age (OR 1.102 [95% CI 1.050; 1.156]; P < 0.001), the cumulative dose of sufentanil (OR 1.014 [95% CI 1.005; 1.024]; P = 0.005), and propofol-sufentanil for anesthesia maintenance (OR 2.805 [95% CI 1.497; 5.256]; P = 0.001) were significantly associated with PACU delirium.

CONCLUSION

Midazolam for sedative premedication was not significantly associated with PACU delirium. The reduction in the incidence of PACU delirium throughout the study period may be attributable to improvements in perioperative management other than a more restrictive preoperative benzodiazepine administration.

Pulmonary Function Tests for the Prediction of Postoperative Pulmonary Complications–a Systematic Review

BACKGROUND

Pulmonary function tests (PFTs) such as spirometry and blood gas analysis have been claimed to improve preoperative risk assessment. This systematic review summarizes the available scientific literature regarding the ability of PFTs to predict postoperative pulmonary complications (PPC) in nonthoracic surgery.

METHODS

We systematically searched MEDLINE, CINAHL, and the Cochrane Library for pertinent original research articles (PROSPERO CRD42020215502), framed by the PIT-criteria (PIT, participants, index test, target conditions), respecting the PRISMA-DTA recommendations (DTA, diagnostic test accuracy).

RESULTS

46 original research studies were identified that used PFT-findings as index tests and PPC as target condition. QUADAS-2 quality assessment revealed a high risk of bias regarding patient selection, blinding, and outcome definitions. Qualitative synthesis of prospective studies revealed inconclusive study findings: 65% argue for and 35% against preoperative spirometry, and 43% argue for blood gas analysis. A (post-hoc) subgroup analysis in prospective studies with low-risk of selection bias identified a possible benefit in upper abdominal surgery (three studies with 959 participants argued for and one study with 60 participants against spirometry).

CONCLUSION

As the existing literature is inconclusive it is currently unknown if PFTs improve risk assessment before nonthoracic surgery. Spirometry should be considered in individuals with key indicators for chronic obstructive pulmonary disease (COPD) scheduling for upper abdominal surgery.

Optimising treatment expectations in chronic lower back pain through observing others: a study protocol for a randomised clinical trial

INTRODUCTION

Chronic lower back pain (CLBP) is a frequent cause of medical consultations worldwide, and it results in decreased quality of life and disability. Current treatments for CLBP are often not effective, and alternatives are urgently needed. Three promising possibilities have emerged: (1) open-label placebo treatment reduces chronic pain, (2) placebo treatment is as efficacious as opioid treatment with a high correlation between patient expectation and treatment outcome, and (3) observing positive effects in another patient can improve functional capacity. We hypothesise that treatment expectations can be positively influenced through social observation and improve treatment outcome.

METHODS AND ANALYSIS

In our clinical trial, we will randomise patients with CLBP into five groups. Two groups receive either a 3 week course of treatment with an analgesic (ANA) (metamizole/dipyrone) or with open-label placebos (OLP). For one of each group, we will build treatment expectations through observational learning and assess its impact on the treatment. For this purpose, one group each will watch either a positive or a neutral video. The intervention groups will be compared with a control group that will not be given any medication or observational learning. Participants will be recruited via all institutions in the Hamburg metropolitan area that treat patients with CLBP. Patients are eligible for inclusion if they are at least 18 years or older, have CLBP (of at least 3 months duration), and agree to potentially receive an active ANA or an OLP. Patients with pain-related "red flags" will be excluded. The study requires 150 participants (30 participants per group) to assess the differences in the primary outcome, pain intensity. Secondary outcomes include changes in treatment expectations, anxiety, comorbid depression, stress-related neuroendocrine measures, functional and structural connectivity, functional capacity, and ANA consumption. All outcomes and treatment expectations will be measured before and after the intervention and 3 months post-intervention.

ETHICS AND DISSEMINATION

Ethical approval was obtained in January 2020 from the Hamburg Medical Ethics Council (ref number PV7067). Outcomes will be disseminated through publications in peer-reviewed journals and presentations at national and international conference meetings.

TRIAL REGISTRATION NUMBER

The approved trial protocol was registered at the German Clinical Trials Register (DRKS) and can be found at drks.de (Identifier: DRKS00024418).

The effects of simulation-based education on medical students' motivation

OBJECTIVES

To assess the effects of simulation-based education on medical students' motivation and to compare these effects with the motivational effects of a classical teaching approach (seminar).

METHODS

In this cross-sectional study, motivational qualities of 164 3rd year medical students, who participated in four mandatory simulation-based training and two seminars of the department of anaesthesiology, were assessed. Comparative analysis was made to determine differences and changes of motivation towards participating in each teaching unit and each teaching format, using a one-way analysis of variance and unpaired t-tests.

RESULTS

The different motivational qualities, as well as the computed levels of autonomous and controlled motivation of students towards participating in each of the six teaching units and each teaching format did not differ significantly (F _{(5, 839)} = 0.66, p = 0.657; F _{(5, 839)} = 0.29, p = 0.920; (t ₍₈₄₃₎ = - 0.72, p = 0.471; t ₍₈₄₃₎ = -0.17, p = 0.868). Students` motivation, particularly autonomous motivation, did not enhance after participating in the first SBME, (t ₍₂₆₄₎ = 1.035, p = 0.301), after participating in the second SBME, (t ₍₂₅₄₎ = -0.055, p = 0.956), or after participating in the third training (t ₍₂₅₀₎ = -0.881, p = 0.379).

CONCLUSIONS

Simulation-based medical education provides a valuable teaching approach but, in this study, this teaching approach did not enhance nor stimulate student motivation. Therefore, simulation-based medical education equals classical teaching approaches regarding student motivation. Further investigations are needed to identify how simulation-based medical education could enhance medical students' motivation.

Flipped learning enhances non-technical skill performance in simulation-based education: a randomised controlled trial

BACKGROUND

Many efforts of the past years aimed to build a safer health care system and hereby, non-technical skills (NTS) have been recognised to be responsible for over 70 % of preventable medical mishaps. In order to counteract those mishaps, several simulation-based trainings have been implemented in health care education to convey NTS. Still, the best and effective way to foster NTS in simulation-based training is not known. Due to the importance of NTS, this gap in knowledge needs to be filled. A possible approach to convey NTS effectively during simulation-based medical education (SBME), might be the use of the flipped learning approach. The benefits of flipped learning regarding the improvement of human factors (NTS), have not been investigated yet. Therefore, the authors introduced flipped learning as an experimental intervention into their SBME emergency trainings and aimed to analyse, whether flipped learning improved students´ NTS performance compared to lecture-based learning (LBL).

METHODS

In a randomized controlled trial, 3rd year medical students participated in a SBME training and then received either a further SBME training with integrated flipped learning on NTS (intervention), or a further SBME training and an accompanying lecture on NTS (control). NTS performance was assessed on three skill dimensions with a validated behavioural marker system.

RESULTS

The authors analysed NTS performance of 102 students, prior and after their allocation to each teaching method. The baseline NTS performance of both groups did not differ, whereas the intervention group enhanced significantly on all three skill dimensions (t (44) = 5.63, p < .001; t (44) = 4.47, p < .001; t (44) = 4.94, p < .001).

CONCLUSION

The integration of flipped learning into SBME yields a significant improvement of NTS performance and therefore medical educators should consider the application of flipped learning to convey complex human factors and skills.

Understanding how the motivational dimension of learning is influenced by clinical teaching in medical education: A prospective cohort study

Introduction

Many changes of medical curricula have been conducted in the past years. Based on learning psychology, three dimensions of learning have to be covered, in order to create the best possible curricula: Cognitive, metacognitive and motivational. The metacognitive and cognitive dimension (what/how to teach) have always been considered and the motivational dimension has been neglected, although the importance and benefits of motivation in learning have been emphasized repeatedly. One way to influence motivation in medical curricula are the teaching formats, as it has been shown that the construction of a curriculum can influence students' motivation. So far, evidence about the motivational effects of teaching formats are scarce.

Methods

In a prospective interventional cohort study, 145 3rd year medical students were sampled. The effects of a 3-day bedside teaching in the operating theatre and two simulation-based trainings on students' motivation (outcome measure) were analysed. It was hypothesized, that the simulation training and the bedside teaching enhance autonomous motivation and decrease controlled motivation.

Results

The bedside-teaching decreased external (controlled) motivation (-0.14, p = .013, 95% CI [-0.24, -0.03]), alongside with identified (autonomous) motivation (-0.22, p < .001, 95% CI [-0.34, -0.10]). The simulation-based trainings did not change students' motivation.

Conclusion

To prevent the unintended decrease of identified (autonomous) motivation, undergraduates should be supervised and introduced carefully, when attending bedside teaching in unknown medical fields. Simulation-based medical education certainly has plenty of benefits in medical education but its effects on the motivational dimension of learning needs further investigations.

Health-related quality of life and self-reported cognitive function in patients with delayed neurocognitive recovery after radical prostatectomy: a prospective follow-up study

Background

Delayed neurocognitive recovery (DNCR) is a common and serious complication after radical prostatectomy. We hypothesized that patients with DNCR in the early postoperative period would report reduced health-related quality of life (HRQoL) and more cognitive failures 12 months after surgery, compared with patients without DNCR.

Methods

We performed a 12-month follow-up on 367 patients who had been enrolled in a prospective observational trial to study the incidence of DNCR after radical prostatectomy. Patients were screened for preoperative cognitive impairment and depression. We defined DNCR as a decline in cognitive function between days 3 and 5 after surgery, compared with baseline assessments. We evaluated HRQoL and cognitive failures 12 months after surgery with the 36-item Short Form Health Survey and the Cognitive Failures Questionnaire. General linear models were used to analyze associations of DNCR with HRQoL and cognitive failures.

Results

Delayed neurocognitive recovery in the early postoperative period was significantly associated with self-reported cognitive failures (B for no DNCR =  − 0.411 [95% CI: − 0.798;0.024], p = 0.038), but not with physical (B = 0.082 [95% CI: − 0.021;0.186], p = 0.118) or mental HRQoL (B =  − 0.044 [95% CI: − 0.149;0.062], p = 0.417) 12 months after surgery. Preoperative depression screening scores were significantly associated with self-reported cognitive failures and both physical and mental HRQoL 12 months after surgery.

Conclusions

Delayed neurocognitive recovery in the early period after radical prostatectomy has a long-term impact on patients’ daily lives by impairing memory, attention, action, and perception. Therefore, prevention of DNCR must be a priority for physicians and researchers. Consequent preoperative screening for depressive symptoms may facilitate early psycho-oncological intervention to improve postoperative HRQoL.

Trials registrationDRKS00010014, date of registration: 21.03.2016, retrospectively registered.

Do Elderly Patients With Diastolic Dysfunction Require Higher Doses of Norepinephrine During General Anesthesia for Noncardiac Surgeries? A Prospective Observational Study

BACKGROUND

Diastolic dysfunction is a risk factor for postoperative major cardiovascular events. During anesthesia, patients with diastolic dysfunction might experience impaired hemodynamic function and worsening of diastolic function, which in turn, might be associated with a higher incidence of postoperative complications.We aimed to investigate whether patients with diastolic dysfunction require higher doses of norepinephrine during general anesthesia. Furthermore, we aimed to examine the association between the grade of diastolic dysfunction and the E/e' ratio during anesthesia. A high E/e' ratio corresponds to elevated filling pressures and is an important measure of impaired diastolic function.

METHODS

We conducted a prospective observational cohort study at a German university hospital from February 2017 to September 2018. Patients aged ≥60 years and undergoing general anesthesia (ie, propofol and sevoflurane) for elective noncardiac surgery were enrolled. Exclusion: mitral valve disease, atrial fibrillation, and implanted mechanical device.The primary outcome parameter was the administered dose of norepinephrine within 30 minutes after anesthesia induction (μg·kg-1 30 min-1). The secondary outcome parameter was the change of Doppler echocardiographic E/e' from ECHO1 (baseline) to ECHO2 (anesthesia). Linear models and linear mixed models were used for statistical evaluation.

RESULTS

A total of 247 patients were enrolled, and 200 patients (75 female) were included in the final analysis. Diastolic dysfunction at baseline was not associated with a higher dose of norepinephrine during anesthesia (P = .6953). The grade of diastolic dysfunction at baseline was associated with a decrease of the E/e' ratio during anesthesia (P < .001).

CONCLUSIONS

We did not find evidence for an association between diastolic dysfunction and impaired hemodynamic function, as expressed by high vasopressor support during anesthesia. Additionally, our findings suggest that diastolic function, as expressed by the E/e' ratio, does not worsen during anesthesia.

Correlation of medical students' situational motivation and performance of non-technical skills during simulation-based emergency training

BACKGROUND

Non-technical skills (NTS) are an indispensable element of emergency care and need to be prevalent alongside with good technical skills. Though, questions of how to teach (instructional design) and improve NTS effectively remain unresolved. One adjustment screw to enhance performance of NTS, which is detached from instructional designs and learning efforts might be motivation. Theoretical models and observational studies suggest that high levels of intrinsic (situational) motivation result in better performance and better learning. Therefore, this study analyzed the influence of motivation on performance of NTS, by exploring if high levels of intrinsic motivation lead to better performance of NTS in medical students.

METHODS

In this prospective cross-sectional cohort study, the authors assessed the correlation of situational motivation and performance of NTS within a cohort of 449 undergraduates in their 1st to 4th year of medical studies, in a total of 101 emergency simulation trainings. Situational motivation was measured with the validated Situational Motivation Scale (SIMS), which was completed by every undergraduate directly before each simulation training. The NTS were evaluated with the Anesthesiology Students´ Non-Technical skills (AS-NTS) rating tool, a validated taxonomy, especially developed to rate NTS of undergraduates.

RESULTS

Student situational motivation was weakly correlated with their performance of NTS in simulation-based emergency trainings.

CONCLUSION

Although motivation has been emphasized as a determining factor, enhancing performance in different fields and in medicine in particular, in our study, student situational motivation was independent from their performance of NTS in simulation-based emergency trainings (SBET).

Development and validation of a postgraduate anaesthesiology core curriculum based on Entrustable Professional Activities: a Delphi study

Background: Postgraduate training curricula should not be based on time-spans or predefined numbers of performed procedures. One approach to link competencies to clinical tasks is the concept of Entrustable Professional Activities (EPA). The goal of this study was the definition, ranking and validation of EPAs for anaesthesiology postgraduate training and the creation of an anaesthesiologic core curriculum. Methods: Anaesthesiologists of different levels of training participated in the study (single-center, cross-sectional) . First, an expert group defined a preliminary list of EPAs. Then a first Delphi round (n= 47 participants) was applied to identify daily anaesthesiology tasks with the goal to define EPAs. From the first Delphi round a new set of EPAs was defined, using the template and mapping method. Through an alignment process, conducted by the expert group, the preliminary EPAs and the new set of EPAs from the first Delphi round were summarised into a new list of EPAs. This list was presented to the study participants in a second Delphi round (n=80 participants), with the goal to validate and rank each EPA and to define the year of entrustment. For this purpose, participants were asked in the second Delphi round if each EPA should be included into an anaesthesiology core curriculum and in which year of training entrustment should take place. Furthermore, they were asked to rank each EPA on a numeric scale, defining its importance. From this numeric scale, the content validity index (CVI) for each EPA was calculated. Consensus of the results from the second Delphi round was calculated, using the one-way random effects model to calculate Intra-Class-Correlations (ICC). Percentages of agreement among the whole set of EPAs of this study and a previously published set of EPAs were computed. Results: A core-curriculum comprising of 39 EPAs was developed. The EPAs were subdivided into superior/high and inferior/low scoring EPAs, reflecting their importance and were mapped to the year of entrustment. The results reached high consensus among the different participating anaesthesiologist groups (overall agreement was 0.96 for the CVI of each EPA and 0.83 for the year in which the EPAs should be entrusted). Agreement with the previously defined set of EPAs was 73.3%. Conclusion: This study provides a further step in transforming postgraduate anaesthesiology training into a more contemporary approach. Other studies are necessary to complete and amend the presented core curriculum of EPA based postgraduate anaesthesiology training.

Comparing the effect of positioning on cerebral autoregulation during radical prostatectomy: a prospective observational study

Purpose

Surgery in the prolonged extreme Trendelenburg position may lead to elevated intracranial pressure and compromise cerebral hemodynamic regulation. We hypothesized that robot-assisted radical prostatectomy with head-down tilt causes impairment of cerebral autoregulation compared with open retropubic radical prostatectomy in the supine position.

Methods

Patients scheduled for elective radical prostatectomy were included at a tertiary care prostate cancer clinic. Continuous monitoring of the cerebral autoregulation was performed using the correlation method. Based on measurements of cerebral oxygenation with near-infrared spectroscopy and invasive mean arterial blood pressure (MAP), a moving correlation coefficient was calculated to obtain the cerebral oxygenation index as an indicator of cerebral autoregulation. Cerebral autoregulation was measured continuously from induction until recovery from anesthesia.

Results

There was no significant difference in cerebral autoregulation between robot-assisted and open retropubic radical prostatectomy during induction (p = 0.089), intraoperatively (p = 0.162), and during recovery from anesthesia (p = 0.620). Age (B = 0.311 [95% CI 0.039; 0.583], p = 0.025) and a higher difference between baseline MAP and intraoperative MAP (B = 0.200 [95% CI 0.073; 0.327], p = 0.002) were associated with impaired cerebral autoregulation, whereas surgical technique was not (B = 3.339 [95% CI  1.275; 7.952], p = 0.155).

Conclusion

Compared with open radical prostatectomy in the supine position, robot-assisted surgery in the extreme Trendelenburg position with capnoperitoneum did not lead to an impairment of cerebral autoregulation during the perioperative period in our study population.

Trial registration number: DRKS00010014, date of registration: 21.03.2016, retrospectively registered.

Electronic supplementary material

The online version of this article (10.1007/s10877-020-00549-0) contains supplementary material, which is available to authorized users.

Positive Treatment Expectancies Reduce Clinical Pain and Perceived Limitations in Movement Ability Despite Increased Experimental Pain: A Randomized Controlled Trial on Sham Opioid Infusion in Patients with Chronic Back Pain

BACKGROUND

Increasing evidence for the efficacy of analgesic placebo effects in laboratory studies with healthy persons raises the question whether placebos could be used to improve the treatment of pain patients. Expectancies play a central role in shaping analgesic placebo but also nocebo effects.

OBJECTIVES

We investigated to what extent a sham opioid infusion (saline solution) produces sustained clinically relevant placebo and nocebo effects in chronic back pain patients.

METHODS

Fifty-nine patients received the sham opioid infusion applied via a large drain dressing and were compared to 14 control patients without intervention (natural history, NH) while experimental pain stimuli were applied. All subjects were told that the infusion would decrease pain although in rare cases pain increase would be possible (induction of expectancy). In addition, conditioning was introduced where the participants either experienced a decrease in experimental pain (n = 17; placebo conditioning), an increase (n = 21; nocebo conditioning), or no change (n = 21, no conditioning).

RESULTS

Compared to the NH group, all infusion groups showed positive treatment expectancies and significantly (p < 0.001) reduced clinical back pain (primary outcome) and pain-related disability (secondary outcome, assessed by self-reported functional capacity and perceived impairment of mobility). Even the nocebo conditioned group experiencing increased experimental pain developed positive treatment expectancies followed by reduced pain experience. Positive treatment expectancies and relief in clinical back pain were significantly positively correlated (r = 0.72, p < 0.01).

CONCLUSIONS

These findings suggest that it may be beneficial to explicitly shape and integrate treatment expectancies into clinical pain management.

Postanesthesia care unit delirium following robot-assisted vs open retropubic radical prostatectomy: A prospective observational study

BACKGROUND

The aim of this study was to compare the incidence of early postoperative delirium in the postanesthesia care unit (PACU) between robot-assisted radical prostatectomy (RARP) in the extreme Trendelenburg position and open retropubic radical prostatectomy (ORP) in supine position.

METHODS

Patients were screened for delirium signs 15, 30, 45, and 60 minutes following extubation.

RESULTS

PACU delirium was present in 39.3% of RARP (64/163) patients and 41.8% of ORP (77/184) patients. Higher age (OR 1.072, 95%CI: 1.034-1.111, P < .001), total intravenous anesthesia (OR 2.001, 95%CI: 1.243-3.221, P = .004), and anesthesia duration (OR 1.255, 95%CI: 1.067-1.476, P = .006) were associated with PACU delirium, but no association was found between surgical technique and PACU delirium.

CONCLUSION

Compared with inhalational anesthesia, total intravenous anesthesia using propofol-sufentanil, higher age, and longer duration of anesthesia were associated with PACU delirium. Based on these findings, adverse effects on postoperative recovery and delirium signs do not have to be considered in the choice of surgical approach for radical prostatectomy.

TRIAL REGISTRATION

https://www.drks.de/, identifier: DRKS00010014.

Comparison of Cognitive Function After Robot-Assisted Prostatectomy and Open Retropubic Radical Prostatectomy: A Prospective Observational Single-Center Study

OBJECTIVE

To assess the effects of robot-assisted radical prostatectomy in the Trendelenburg position on postoperative neurocognitive outcomes this study compared cognitive function between patients who underwent robot-assisted radical prostatectomy and those who underwent open retropubic radical prostatectomy.

METHODS

Objective evaluations of pre- and postoperative cognitive function were performed upon admission and before hospital discharge, by using a neuropsychological test battery. We collected self-reported data on cognitive failures at 3 months postoperatively. Binary logistic regression analysis was used to assess the effects of surgical technique on postoperative cognitive performance.

RESULTS

The pre- and postoperative neuropsychological assessments were completed by 367 patients with a median age of 64 years (range 44-76). The incidence of postoperative cognitive dysfunction was 23.9% after robot-assisted (39/165) and 22.3% after open radical prostatectomy (45/202). There was no significant difference in postoperative cognitive function during the early postoperative period (P = 0.758) and self-reported cognitive failures at 3 months (P = 0.303) between robot-assisted and open surgery. Surgical technique was not associated with early postoperative cognitive dysfunction in multivariable analysis (OR 1.012, 95%CI: 0.608-1.685, P = 0.962).

CONCLUSION

Compared with open surgery in supine position postoperative neurocognitive disorders do not occur more frequently after robot-assisted radical prostatectomy in the extreme Trendelenburg position. Based on these findings potential adverse effects on cognitive function do not have to be considered in the choice of surgical approach for radical prostatectomy.

Airway management and perioperative adverse events in children with mucopolysaccharidoses and mucolipidoses: A retrospective cohort study

BACKGROUND

Children suffering from mucopolysaccharidoses (subtypes I, II, III, IV, VI, and VII) or mucolipidoses often require anesthesia, but are at high risk for perioperative adverse events. However, the impact of the disease subtype and the standard of care for airway management are still unclear.

AIMS

This study aimed to assess independent risk factors for perioperative adverse events in individuals with mucopolysaccharidoses/mucolipidoses and to analyze the interaction with the primary airway technique implemented.

METHODS

This retrospective study included individuals with mucopolysaccharidoses/mucolipidoses who underwent anesthesia at two high-volume centers from 2002 to 2016. The data were analyzed in a multivariate hierarchical model, accounting for repeated anesthesia procedures within the same patient and for multiple events within a single anesthesia.

RESULTS

Of 141 identified inpatients, 67 (63 mucopolysaccharidoses and 4 mucolipidoses) underwent 269 anesthesia procedures (study cases) for 353 surgical or diagnostic interventions. At least one perioperative adverse event occurred in 25.6% of the cases. The risk for perioperative adverse events was higher in mucopolysaccharidoses type I (OR 8.0 [1.5-42.7]; P = .014) or type II (OR 8.8 [1.3-58.6]; P = .025) than in type III. Fiberoptic intubation through a supraglottic airway was associated with the lowest risk for perioperative adverse events and lowest conversion rate. Direct laryngoscopy was associated with a significantly higher risk for airway management problems than indirect techniques (estimated event rates 47.8% vs 10.1%, OR 24.05 [5.20-111.24]; P < .001). The risk for respiratory adverse events was significantly higher for supraglottic airway (22.6%; OR 31.53 [2.79-355.88]; P = .001) and direct laryngoscopy (14.8%; OR 14.70 [1.32-163.44]; P = .029) than for fiberoptic intubation through a supraglottic airway (2.1%).

CONCLUSIONS

The disease subtype and primary airway technique were the most important independent risk factors for perioperative adverse events. Our findings indicate that in MPS/ML children with predicted difficult airway indirect techniques should be favored for the first tracheal intubation attempt.

A Simulator for Probabilistic Timed Graph Transformation Systems with Complex Large-Scale Topologies

Future cyber-physical systems, like networks of autonomous vehicles, will result in a huge number of collaborating systems acting together on large-scale topologies. Modeling them requires capturing timed and probabilistic behavior as well as structure dynamics. In [9], we introduced Probabilistic Timed Graph Transformation Systems (PTGTSs) as a means of modeling a high-level view of these systems of systems and provided model checking support. However, given the scale of emerging systems of systems and their often complex topologies, analyzing only small or medium size models using model checking is insufficient. To close this gap, we developed a simulator for PTGTSs that can import real-world topologies, automatically detect violations of state properties, and handle the graph pattern matching as well as time and probabilities efficiently so that complex large-scale topologies can be considered.

Improvement of perioperative care of the elderly patient (PeriAge): protocol of a controlled interventional feasibility study

INTRODUCTION

Geriatric patients have a pronounced risk to suffer from postoperative complications. While effective risk-specific perioperative measures have been studied in controlled experimental settings, they are rarely found in routine healthcare. This study aims (1) to implement a multicomponent preoperative and intraoperative intervention, and investigate its feasibility, and (2) exploratorily assess the effectiveness of the intervention in routine healthcare.

METHODS AND ANALYSIS

Feasibility and exploratory effectiveness of the intervention will be investigated in a monocentric, prospective, non-randomised, controlled trial. The intervention includes systematic information for patients and family about measures to prevent postoperative complications; preoperative screening for frailty, malnutrition, strength and mobility with nutrient supplementation and physical exercise (prehabilitation) as needed. Further components focus on potentially inadequate medication, patient blood-management and carbohydrate loading prior to surgery, retainment of orientation aids in the operating room and a geriatric anaesthesia concept. Data will successively be collected from control, implementation and intervention groups. Patients aged 65+ with impending surgery will be included. A sample size of 240, n=80 per group, is planned. Assessments will take place at inclusion and 2, 30 and 180 days after surgery. Mixed-methods analyses will be performed. Exploratory effectiveness will be assessed using mixed segmented regressions. The primary endpoint is functional status. Secondary endpoints include cognitive performance, health-related quality of life, length of inpatient stay and occurrence of postoperative complications. Feasibility will be assessed through semi-structured interviews with staff and patients and quantitative analyses of the data quality, focussing on practicability, acceptance, adoption and fidelity to protocol.

ETHICS AND DISSEMINATION

The study will be carried out in accordance with the Helsinki Declaration and to principles of good scientific practice. The Ethics Committee of the Medical Association Hamburg, Germany, approved the protocol (study ID: PV5596). Results will be disseminated in scientific journals and healthcare conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT03325413.

Basic life support training using shared mental models improves team performance of first responders on normal wards: A randomised controlled simulation trial

INTRODUCTION

Survival of in-hospital cardiac arrest (IHCA) depends on fast and effective action of the first responding team. Not only technical skills, but professional teamwork is required. Observational studies and theoretical models suggest that shared mental models of members improve teamwork. This study investigated if a training on shared mental models, improves team performance in simulated in-hospital cardiac arrest.

METHODS

On the background of an introduction of mandatory Basic Life Support (BLS) training for clinical staff a randomized controlled trial was performed to compare two training methods. Staff from clinical departments was randomised to receive either a conventional instructor led training (control group) or an interventional training (intervention group). The interventional training was based on self-directed learning of the group in order to develop shared mental models. Primary outcome were mean scores of the team assessment scale (TAS) and the hands-off time. Secondary outcome were mean scores for quality of BLS.

RESULTS

Performance of 75 teams of the interventional and 66 of the control group was analysed. The hands-off time was significantly lower in the interventional group (5.42% vs. 8.85%, p = 0.029). Scores of the TAS and the overall BLS score were high and not significantly different between the groups. Hands-off time correlated significantly negative with all TAS items.

CONCLUSION

BLS training for clinical staff which creates shared mental models reduces hands-off time in a simulated cardiac arrest scenario. Training methods establishing shared mental models of team members can be considered for effective team trainings without adding additional training time.

Reduced auditory evoked gamma-band response and schizophrenia-like clinical symptoms under subanesthetic ketamine

Abnormal gamma-band oscillations (GBO) have been frequently associated with the pathophysiology of schizophrenia. GBO are modulated by glutamate, a neurotransmitter, which is continuously discussed to shape the complex symptom spectrum in schizophrenia. The current study examined the effects of ketamine, a glutamate N-methyl-D-aspartate receptor (NMDAR) antagonist, on the auditory-evoked gamma-band response (aeGBR) and psychopathological outcomes in healthy volunteers to investigate neuronal mechanisms of psychotic behavior. In a placebo-controlled, randomized crossover design, the aeGBR power, phase-locking factor (PLF) during a choice reaction task, the Positive and Negative Syndrome Scale (PANSS) and the Altered State of Consciousness (5D-ASC) Rating Scale were assessed in 25 healthy subjects. Ketamine was applied in a subanaesthetic dose. Low-resolution brain electromagnetic tomography was used for EEG source localization. Significant reductions of the aeGBR power and PLF were identified under ketamine administration compared to placebo (p < 0.01). Source-space analysis of aeGBR generators revealed significantly reduced current source density (CSD) within the anterior cingulate cortex during ketamine administration. Ketamine induced an increase in all PANSS (p < 0.001) as well as 5D-ASC scores (p < 0.01) and increased response times (p < 0.001) and error rates (p < 0.01). Only negative symptoms were significantly associated with an aeGBR power decrease (p = 0.033) as revealed by multiple linear regression. These findings argue for a substantial role of the glutamate system in the mediation of dysfunctional gamma band responses and negative symptomatology of schizophrenia and are compatible with the NMDAR hypofunction hypothesis of schizophrenia.