Discrepancy in Reporting of Perioperative Complications: A Retrospective Observational Study

OBJECTIVE

To assess the discrepancy between perioperative complications, prospectively recorded during a cohort study versus retrospectively from health records.

BACKGROUND

Perioperative adverse events are relevant for patient outcome, but incomplete reporting is common.

METHODS

Two physicians independently recorded all intraoperative adverse events according to ClassIntra and all postoperative complications according to the Clavien-Dindo classification based on all available health records. These retrospective assessments were compared with the number and severity of those prospectively assessed in the same patients during their inclusion in 1 center of a prospective multicenter cohort study.

RESULTS

Interrater agreement between both physicians for retrospective recording was high [intraclass correlation coefficient: 0.89 (95% CI, 0.86, 0.91) for intraoperative and 0.88 (95% CI, 0.85, 0.90) for postoperative complications]. In 320 patients, the incidence rate was higher retrospectively than prospectively for any intraoperative complication (incidence rate ratio: 1.79; 95% CI, 1.50, 2.13) and for any postoperative complication (incidence rate ratio: 2.21; 95% CI, 1.90, 2.56). In 71 patients, the severity of the most severe intraoperative complication was higher in the retrospective than in the prospective data collection, whereas in 69 the grading was lower. In 106 patients, the severity of the most severe postoperative complication was higher in the retrospective than in the prospective data collection, whereas in 19 the grading was lower.

CONCLUSIONS

There is a noticeable discrepancy in the number and severity of reported perioperative complications between these 2 data collection methods. On the basis of the double-blinded assessment of 2 independent raters, our study renders prospective underreporting more likely than retrospective overreporting.

Bibliometric analysis of academic journal recommendations and requirements for surgical and anesthesiologic adverse events reporting

BACKGROUND

Standards for reporting surgical adverse events (AEs) vary widely within the scientific literature. Failure to adequately capture AEs hinders efforts to measure the safety of healthcare delivery and improve the quality of care. The aim of the present study is to assess the prevalence and typology of perioperative AE reporting guidelines among surgery and anesthesiology journals.

MATERIALS AND METHODS

In November 2021, three independent reviewers queried journal lists from the SCImago Journal & Country Rank (SJR) portal (www.scimagojr.com), a bibliometric indicator database for surgery and anesthesiology academic journals. Journal characteristics were summarized using SCImago, a bibliometric indicator database extracted from Scopus journal data. Quartile 1 (Q1) was considered the top quartile and Q4 bottom quartile based on the journal impact factor. Journal author guidelines were collected to determine whether AE reporting recommendations were included and, if so, the preferred reporting procedures.

RESULTS

Of 1409 journals queried, 655 (46.5%) recommended surgical AE reporting. Journals most likely to recommend AE reporting were: by category surgery (59.1%), urology (53.3%), and anesthesia (52.3%); in top SJR quartiles (i.e. more influential); by region, based in Western Europe (49.8%), North America (49.3%), and the Middle East (48.3%).

CONCLUSIONS

Surgery and anesthesiology journals do not consistently require or provide recommendations on perioperative AE reporting. Journal guidelines regarding AE reporting should be standardized and are needed to improve the quality of surgical AE reporting with the ultimate goal of improving patient morbidity and mortality.

Appraisal of Intraoperative Adverse Events to Improve Postoperative Care

Background: Intraoperative adverse events (iAEs) are associated with adverse postoperative outcomes and cause a significant healthcare burden. However, a critical appraisal of iAEs is lacking. Considering the details of iAEs could benefit postoperative care. We comprehensively analyzed iAEs in a large series including all types of operations and their relation to postoperative complications. Methods: All patients enrolled in the multicenter ClassIntra® validation study (NCT03009929) were included in this analysis. The surgical and anesthesia team prospectively recorded all iAEs. Two researchers, blinded to each other’s ratings, appraised all recorded iAEs according to their origin into four categories: surgery, anesthesia, organization, or other, including subcategories such as organ injury, arrhythmia, or instrument failure. They further descriptively analyzed subcategories of all iAEs. Postoperative complications were assessed using the Comprehensive Complication Index (CCI®), a weighted sum of all postoperative complications according to the Clavien–Dindo classification. The association of iAE origins in addition to the severity grade of ClassIntra® on CCI® was assessed with a multivariable mixed-effects generalized linear regression analysis. Results: Of 2520 included patients, 778 iAEs were recorded in 610 patients. The origin was surgical in 420 (54%), anesthesia in 283 (36%), organizational in 34 (4%), and other in 41 (5%) events. Bleeding (n = 217, 28%), hypotension (n = 118, 15%), and organ injury (n = 98, 13%) were the three most frequent subcategories in surgery and anesthesia, respectively. In the multivariable mixed-effect analysis, no significant association between the origin and CCI® was observed. Conclusion: Analyzing the type and origin of an iAE offers individualized and contextualized information. This detailed descriptive information can be used for targeted surveillance of intra- and postoperative care, even though the overall predictive value for postoperative events was not improved by adding the origin in addition to the severity grade.

Comparing propofol anaesthesia guided by Bispectral Index monitoring and frontal EEG wave analysis with standard monitoring in laparoscopic surgery: protocol for the 'EEG in General Anaesthesia - More Than Only a Bispectral Index' Trial, a multicentre, double-blind, randomised controlled trial

INTRODUCTION

The use of Bispectral Index (BIS) monitors for assessing depth of sedation has led to a reduction in both the incidence of awareness and anaesthetic consumption in total intravenous anaesthesia. However, these monitors are vulnerable to artefacts. In addition to the processed number, the raw frontal electroencephalogram (EEG) can be displayed as a curve on the same monitor. Anaesthesia practitioners can learn to interpret the EEG in a short tutorial and may be quicker and more accurate thanBIS in assessing anaesthesia depth by recognising EEG patterns. We hypothesise that quality of recovery (QoR) in patients undergoing laparoscopic surgery is better, if propofol is titrated by anaesthesia practitioners able to interpret the EEG.

METHODS AND ANALYSIS

This is a multicentre, double-blind (patients and outcome assessors) randomised controlled trial taking place in four Swiss hospitals. Patients aged 18 years or older undergoing laparoscopic procedures with general anaesthesia using propofol and anaesthesia practitioners with more than 2 years experience will be eligible. The primary study outcome is the difference in QoR 24 hours after surgery. Secondary outcomes are propofol consumption, incidence of postoperative nausea and vomiting (PONV) and postoperative delirium.QoR and propofol consumption are compared between both groups using a two-sample t-test. Fisher's exact test is used to compare the incidences of PONV and delirium. A total of 200 anaesthesia practitioners (and 200 patients) are required to have an 80% chance of detecting the minimum relevant difference for the QoR-15 as significant at the 5% level assuming a SD of 20.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from all responsible ethics committees (lead committee: Ethikkommission Nordwest- und Zentralschweiz, 16 January 2021). The findings of the trial will be published in a peer-reviewed journal, presented at international conferences, and may lead to a change in titrating propofol in clinical practice.

TRIAL REGISTRATION NUMBER

www.

CLINICALTRIALS

gov:NCT04105660.

Who can do this procedure? Using entrustable professional activities to determine curriculum and entrustment in anesthesiology - An international survey

INTRODUCTION

As competency-based curricula get increasing attention in postgraduate medical education, Entrustable Professional Activities (EPAs) are gaining in popularity. The aim of this survey was to determine the use of EPAs in anesthesiology training programs across Europe and North America.

METHODS

A survey was developed and distributed to anesthesiology residency training program directors in Switzerland, Germany, Austria, Netherlands, USA and Canada. A convergent design mixed-methods approach was used to analyze both quantitative and qualitative data.

RESULTS

The survey response rate was 38% (108 of 284). Seven percent of respondents used EPAs for making entrustment decisions. Fifty-three percent of institutions have not implemented any specific system to make such decisions. The majority of respondents agree that EPAs should become an integral part of the training of residents in anesthesiology as they are universal and easy to use.

CONCLUSION

Although recommended by several national societies, EPAs are used in few anesthesiology training programs. Over half of responding programs have no specific system for making entrustment decisions. Although several countries are adopting or planning to adopt EPAs and national societies are recommending the use of EPAs as a framework in their competency-based programs, few are yet using these to make "competence" decisions.

Classification of intraoperative adverse events in visceral surgery

BACKGROUND

Intraoperative adverse events (iAEs) are frequent in visceral surgery, but severity and related postoperative outcome are poorly investigated. A novel classification of intraoperative adverse events, ClassIntra, includes surgical and anesthesiologic intraoperative adverse events using 5 severity grades and showed a high criterion and construct validity across all surgical disciplines. ClassIntra was studied for reproducibility in a prespecified group of patients undergoing visceral surgery.

METHODS

iAEs were recorded in all patients enrolled in the ClassIntra validation study (NCT03009929). Postoperative complications were assessed daily according to the Clavien-Dindo classification. Results of the visceral group were compared with those of the non-visceral group and the full cohort. The risk-adjusted association between most severe intra and postoperative complications was investigated in a multivariable proportional odds model. Second, risk-adjusted association between ClassIntra grade and Comprehensive Complication Index, and postoperative length of stay was investigated.

RESULTS

In total, 1,270 out of 2,520 patients (50%) underwent visceral surgery. Compared with the nonvisceral group and full cohort, more intraoperative (337/1270 [27%] vs 273/1250 [22%] vs 610/2520 [24%] patients) and postoperative complications (457/1270 [36%] vs 381/1250 [30%] vs 838/2520 [33%] patients) occurred. The risk for a more severe postoperative complication increased with each ClassIntra grade (odds ratio [95% confidence interval] I vs 0 1.10 [0.73 to 1.66], II vs 0 1.69 [1.10 to 2.60], III vs 0 2.31 [1.21 to 4.41], IV vs 0 2.35 [0.69 to 8.06]). Accordingly, CCI and postoperative length of stay increased with each ClassIntra grade in the visceral group, comparable with the nonvisceral and full cohort.

CONCLUSION

Consistent results for the association of intraoperative adverse events and patient outcomes render ClassIntra a valuable instrument in visceral surgery.

The impact of deep versus standard neuromuscular block on intraoperative safety during laparoscopic surgery: an international multicenter randomized controlled double-blind strategy trial - EURO-RELAX TRIAL

Background

Muscle relaxants are routinely used during anesthesia to facilitate endotracheal intubation and to optimize surgical conditions. However, controversy remains about the required depth of neuromuscular block (NMB) needed for optimal surgical working conditions and how this relates to other outcomes. For instance, a deep neuromuscular block yields superior surgical working conditions compared to a standard NMB in laparoscopic surgery, however, a robust association to other (safety) outcomes has not yet been established.

Methods

Trial design: an international multicenter randomized controlled double-blind strategy trial.

Trial population: 922 patients planned for elective, laparoscopic or robotic, abdominal surgery.

Intervention: Patients will be randomized to a deep NMB (post-tetanic count 1–2 twitches) or standard care (single-dose muscle relaxant administration at induction and repeated only if warranted by surgical team).

Main trial endpoints: Primary endpoint is the difference in incidence of intraoperative adverse events during laparoscopic surgery graded according to ClassIntra® classification (i.e., ClassIntra® grade ≥ 2) between both groups. Secondary endpoints include the surgical working conditions, 30-day postoperative complications, and patients’ quality of recovery.

Discussion

This trial was designed to analyze the effect of deep neuromuscular block compared to standard neuromuscular block on intra- and postoperative adverse events in patients undergoing laparoscopic surgery.

Trial registration

ClinicalTrials.gov NCT04124757(EURO-RELAX); registration URL: https://clinicaltrials.gov/ct2/show/NCT04124757, registered on October 11th, 2019. 

Ninety-day outcome of patients with severe COVID-19 treated with tocilizumab - a single centre cohort study

OBJECTIVES

Patients with severe COVID-19 may be at risk of longer term sequelae. Long-term clinical, immunological, pulmonary and radiological outcomes of patients treated with anti-inflammatory drugs are lacking.

METHODS

In this single-centre prospective cohort study, we assessed 90-day clinical, immunological, pulmonary and radiological outcomes of hospitalised patients with severe COVID-19 treated with tocilizumab from March 2020 to May 2020. Criteria for tocilizumab administration were oxygen saturation <93%, respiratory rate >30/min, C-reactive protein levels >75 mg/l, extensive area of ground-glass opacities or progression on computed tomography (CT). Descriptive analyses were performed using StataIC 16.

RESULTS

Between March 2020 and May 2020, 50 (27%) of 186 hospitalised patients had severe COVID-19 and were treated with tocilizumab. Of these, 52% were hospitalised on the intensive care unit (ICU) and 12% died. Eleven (22%) patients developed at least one microbiologically confirmed super-infection, of which 91% occurred on ICU. Median duration of hospitalisation was 15 days (interquartile range [IQR] 10–24) with 24 days (IQR 14–32) in ICU patients and 10 days (IQR 7–15) in non-ICU patients. At day 90, 41 of 44 survivors (93%) were outpatients. No long-term adverse events or late-onset infections were identified after acute hospital care. High SARS-CoV-2 antibody titres were found in all but one patient, who was pretreated with rituximab. Pulmonary function tests showed no obstructive patterns, but restrictive patterns in two (5.7%) and impaired diffusion capacities for carbon monoxide in 11 (31%) of 35 patients, which predominated in prior ICU patients. Twenty-one of 35 (60%) CT-scans at day 90 showed residual abnormalities, with similar distributions between prior ICU and non-ICU patients.

CONCLUSIONS

In this cohort of severe COVID-19 patients, no tocilizumab-related long-term adverse events or late-onset infections were identified. Although chest CT abnormalities were highly prevalent at day 90, the majority of patients showed normal lung function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04351503.

BMI and malignant hyperthermia pathogenic ryanodine receptor type 1 sequence variants in Switzerland: A retrospective cohort analysis

BACKGROUND

Ryanodine receptor type 1 (RYR1) sequence variants are pathogenic for malignant hyperthermia. Variant carriers have a subtle increase in resting myoplasmic calcium concentration compared with nonaffected individuals, but whether this has metabolic effects in daily life is unknown.

OBJECTIVES

We analysed the potential effect of malignant hyperthermia-pathogenic RYR1 sequence variants on BMI as a single factor. Due to the heterogeneity of genetic variants predisposing to malignant hyperthermia, and to incomplete information about their regional distribution, we describe the prevalence of RYR1 variants in our population.

DESIGN

A retrospective cohort study.

SETTING

A single University hospital.

PATIENTS

Patients from malignant hyperthermia families with pathogenic RYR1 sequence variants were selected if BMI was available.

OUTCOME MEASURES

BMI values were compared amongst malignant hyperthermia susceptible (MHS) and malignant hyperthermia-negative individuals using hierarchical multivariable analyses adjusted for age and sex and considering family clustering. Variant prevalence was calculated.

RESULTS

The study included 281 individuals from 42 unrelated malignant hyperthermia families, 109 of whom were MHS and carriers of the familial RYR1 sequence variants. Median [IQR] BMI in MHS individuals with pathogenic RYR1 variants was 22.5 kg m-2 [21.3 to 25.6 kg m-2]. In malignant hyperthermia-negative individuals without variants, median BMI was 23.4 kg m-2 [21.0 to 26.3 kg m-2]. Using multivariable regression adjusted for age and sex, the mean difference was -0.73 (95% CI -1.51 to 0.05). No carrier of a pathogenic RYR1 sequence variant was found to have BMI higher than 30 kg m-2. Only 10 RYR1 variants from the list of the European MH Group were found in our cohort, the most common being p.Val2168Met (39% of families), p.Arg2336His (24%) and p.Arg614Cys (12%).

CONCLUSION

The observed tendency towards lower BMI values in carriers of malignant hyperthermia-pathogenic RYR1 sequence variants points to a possible protective effect on obesity. This study confirms regional differences of the prevalence of malignant hyperthermia-pathogenic RYR1 sequence variants, with just three variants covering 75% of Swiss MHS families.

TRIAL REGISTRATION

This manuscript is based on a retrospective analysis.

[Prospective Cohort Study of In-Hospital Patients Undergoing Ophthalmic Surgery for the Validation of ClassIntra: Classification of Intraoperative Adverse Events]

BACKGROUND

To the best of our knowledge, there is no validated classification to assess intraoperative adverse events (iAEs) in ophthalmic surgery. ClassIntra is a newly developed classification for surgery- and anaesthesia-related iAEs that has been recently validated in various surgical disciplines, but not in ophthalmic surgery. We aim to assess the validity and practicability of ClassIntra in patients undergoing ophthalmic surgery.

METHODS

A consecutive sample of in-hospital patients undergoing any type of ophthalmic surgery was included in this single-centre prospective cohort study. iAEs were classified using ClassIntra, consisting of 5 severity grades according to the symptoms of the patient and the required treatment. All patients were followed for two weeks to record all postoperative adverse events according to Clavien-Dindo. The primary endpoint was the risk-adjusted association between the most severe iAE and the weighted sum of all postoperative adverse events within the two-week follow-up using the Comprehensive Complication Index (CCI). In addition, ophthalmologists and anaesthesiologists were asked to complete an online survey assessing the severity of iAEs for 10 fictitious clinical case scenarios. Reliability was assessed by comparing the clinicians' ratings to the prespecified benchmark rating of the study team.

RESULTS

In this study, 100 in-hospital patients with an average age of 64 years (SD 15) were included. The majority of all patients were ASA II (n = 53, 53%) or III (n = 42, 42%). Thirty-two iAEs were recorded in 22 patients (17 grade I, 12 grade II, 3 grade III). Ninety-four postoperative adverse events occurred in 50 patients (44 grade I, 36 grade II, 14 grade IIIa). We found a mean difference in CCI of 2,1 (95% confidence interval [CI] - 2,5 to 6,8) per one unit increase in severity grades of ClassIntra. Fifty ophthalmologists and anaesthesiologists completed the online survey (response rate 54%). The intraclass correlation coefficient was 0,79 (95% CI 0,64 to 0,94).

CONCLUSIONS

The application of ClassIntra during daily routine in ophthalmic surgery showed the usefulness and practicability of this classification for the standardised assessment of intraoperative adverse events. Although construct validity could not be demonstrated, the good reliability in the survey's rating underlines the criterion validity of this newly developed classification in ophthalmic surgery.

Prospective validation of classification of intraoperative adverse events (ClassIntra): international, multicentre cohort study

OBJECTIVE

To prospectively assess the construct and criterion validity of ClassIntra version 1.0, a newly developed classification for assessing intraoperative adverse events.

DESIGN

International, multicentre cohort study.

SETTING

18 secondary and tertiary centres from 12 countries in Europe, Oceania, and North America.

PARTICIPANTS

The cohort study included a representative sample of 2520 patients in hospital having any type of surgery, followed up until discharge. A follow-up to assess mortality at 30 days was performed in 2372 patients (94%). A survey was sent to a representative sample of 163 surgeons and anaesthetists from participating centres.

MAIN OUTCOME MEASURES

Intraoperative complications were assessed according to ClassIntra. Postoperative complications were assessed daily until discharge from hospital with the Clavien-Dindo classification. The primary endpoint was construct validity by investigating the risk adjusted association between the most severe intraoperative and postoperative complications, measured in a multivariable hierarchical proportional odds model. For criterion validity, inter-rater reliability was evaluated in a survey of 10 fictitious case scenarios describing intraoperative complications.

RESULTS

Of 2520 patients enrolled, 610 (24%) experienced at least one intraoperative adverse event and 838 (33%) at least one postoperative complication. Multivariable analysis showed a gradual increase in risk for a more severe postoperative complication with increasing grade of ClassIntra: ClassIntra grade I versus grade 0, odds ratio 0.99 (95% confidence interval 0.69 to 1.42); grade II versus grade 0, 1.39 (0.97 to 2.00); grade III versus grade 0, 2.62 (1.31 to 5.26); and grade IV versus grade 0, 3.81 (1.19 to 12.2). ClassIntra showed high criterion validity with an intraclass correlation coefficient of 0.76 (95% confidence interval 0.59 to 0.91) in the survey (response rate 83%).

CONCLUSIONS

ClassIntra is the first prospectively validated classification for assessing intraoperative adverse events in a standardised way, linking them to postoperative complications with the well established Clavien-Dindo classification. ClassIntra can be incorporated into routine practice in perioperative surgical safety checklists, or used as a monitoring and outcome reporting tool for different surgical disciplines. Future studies should investigate whether the tool is useful to stratify patients to the appropriate postoperative care, to enhance the quality of surgical interventions, and to improve long term outcomes of surgical patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03009929.

Generalisability of randomised trials of the programmed intermittent epidural bolus technique for maintenance of labour analgesia: a prospective single centre cohort study

BACKGROUND

Several randomised controlled trials show that maintenance of labour epidural analgesia with programmed intermittent epidural bolus reduces the maternal motor block compared with maintenance with a continuous infusion. However, these trials were usually restricted to healthy nulliparous parturients. To assess the generalisability of these randomised controlled trials to 'real-world' conditions, we compared maternal motor function (modified Bromage score) over time between healthy nulliparous and parous women using routinely collected quality-control data.

METHODS

After ethical approval, all parturients receiving programmed intermittent epidural bolus labour analgesia between June 2013 and October 2014 were included in this prospective cohort study. Bupivacaine 0.1% with fentanyl 2 μg ml^-1 was used allowing for patient-controlled bolus every 20 min. The maternal motor function (primary outcome) was regularly assessed from insertion of the epidural catheter until delivery.

RESULTS

Of the 839 parturients included, 553 (66%) were nulliparous and 286 (34%) were parous. The parous women had a shorter median duration of epidural analgesia (3 h 59 min vs 5 h 45 min) and a higher incidence of spontaneous delivery (66% vs 37%). The probability of being in a certain Bromage category at birth was similar in nulliparous and parous women in a general additive model adjusting for duration of epidural analgesia, number of rescue top-ups, and number of catheter manipulations (cumulative odds ratio: 1.18; 95% confidence interval: 0.98-1.41). Parous women required a higher time-weighted number and volume of rescue top-ups.

CONCLUSIONS

The results of the randomised controlled trials on a reduced motor block with programmed intermittent epidural bolus seem generalisable to parturients typically not included in these trials.

Efficacy and safety of carbetocin given as an intravenous bolus compared with short infusion for Caesarean section - double-blind, double-dummy, randomized controlled non-inferiority trial

Background

Carbetocin is a synthetic oxytocin-analogue, which should be administered as bolus according to manufacturer's recommendations. A higher speed of oxytocin administration leads to increased cardiovascular side-effects. It is unclear whether carbetocin administration as short infusion has the same efficacy on uterine tone compared with bolus administration and whether haemodynamic parameters differ.

Methods

In this randomized, double-blind, non-inferiority trial, women undergoing planned or unplanned Caesarean section (CS) under regional anaesthesia received a bolus and a short infusion, only one of which contained carbetocin 100 mcg (double dummy). Obstetricians quantified uterine tone two, three, five and 10 min after cord-clamping by manual palpation using a linear analogue scale from 0 to 100. We evaluated whether the lower limit of the 95% CI of the difference in maximum uterine tone within the first five min after cord-clamping did not include the pre-specified non-inferiority limit of -10.

Results

Between December 2014 and November 2015, 69 patients were randomized to receive carbetocin as bolus and 71 to receive it as short infusion. Maximal uterine tone was 89 in the bolus and 88 in the short infusion group (mean difference -1.3, 95% CI -5.7 to 3.1). Bp, calculated blood loss, use of additional uterotonics, and side-effects were comparable.

Conclusions

Administration of carbetocin as short infusion does not compromise uterine tone and has similar cardiovascular side-effects as a slow i.v. bolus. In accordance with current recommendations for oxytocin, carbetocin can safely be administered as short -infusion during planned or unplanned CS.

Clinical trial registration

ClinicalTrials.gov NCT02221531 and www.kofam.ch SNCTP000001197.

Minimally invasive anterior muscle-sparing versus a transgluteal approach for hemiarthroplasty in femoral neck fractures-a prospective randomised controlled trial including 190 elderly patients

BACKGROUND

The relevance of femoral neck fractures (FNFs) increases with the ageing of numerous societies, injury-related decline is observed in many patients. Treatment strategies have evolved towards primary joint replacement, but the impact of different approaches remains a matter of debate. The aim of this trial was to evaluate the benefit of an anterior minimally-invasive (AMIS) compared to a lateral Hardinge (LAT) approach for hemiarthroplasty in these oftentimes frail patients.

METHODS

Four hundred thirty-nine patients were screened during the 44-months trial, aiming at the evaluation of 150 patients > 60 yrs. of age. Eligible patients were randomised using an online-tool with completely random assignment. As primary endpoint, early mobility, a predictor for long-term outcomes, was evaluated at 3 weeks via the "Timed up and go" test (TUG). Secondary endpoints included the Functional Independence Measure (FIM), pain, complications, one-year mobility and mortality.

RESULTS

A total of 190 patients were randomised; both groups were comparable at baseline, with a predominance for frailty-associated factors in the AMIS-group. At 3 weeks, 146 patients were assessed for the primary outcome. There was a reduction in the median duration of TUG performance of 21.5% (CI [- 41.2,4.7], p = 0.104) in the AMIS-arm (i.e., improved mobility). This reduction was more pronounced in patients with signs of frailty or cognitive impairment. FIM scores increased on average by 6.7 points (CI [0.5-12.8], p = 0.037), pain measured on a 10-point visual analogue scale decreased on average by 0.7 points (CI: [- 1.4,0.0], p = 0.064). The requirement for blood transfusion was lower in the AMIS- group, the rate of complications comparable, with a higher rate of soft tissue complications in the LAT-group. The mortality was higher in the AMIS-group.

CONCLUSION

These results, similar to previous reports, support the concept that in elderly patients at risk of frailty, the AMIS approach for hemiarthroplasty can be beneficial, since early mobilisation and pain reduction potentially reduce deconditioning, morbidity and loss of independence. The results are, however, influenced by a plethora of factors. Only improvements in every aspect of the therapeutic chain can lead to optimisation of treatment and improve outcomes in this growing patient population.

TRIAL REGISTRATION

www.clinicaltrials.gov : NCT01408693 (registered August 3rd 2011).

Systematic review and simulation study of ignoring clustered data in surgical trials

BACKGROUND

Multiple surgical procedures in a single patient are relatively common and lead to dependent (clustered) data. This dependency needs to be accounted for in study design and data analysis. A systematic review was performed to assess how clustered data were handled in inguinal hernia trials. The impact of ignoring clustered data was estimated using simulations.

METHODS

PubMed, Embase and the Cochrane Library were reviewed systematically for RCTs published between 2004 and 2013, including patients undergoing unilateral or bilateral inguinal hernia repair. Study characteristics determining the appropriateness of handling clustered data were extracted. Using simulations, various statistical methods accounting for clustered data were compared with an analysis ignoring clustering by assuming 100 hernias, with a varying percentage of patients having bilateral hernias.

RESULTS

Of the 50 eligible trials including patients with bilateral hernias, 20 (40 per cent) did not provide information on how they dealt with clustered data and 18 (36 per cent) avoided clustering by assessing the outcome by patient and not by hernia. None of the remaining 12 trials (24 per cent) considered clustering in the design or analysis. In the simulations, ignoring clustering led to an increased type I error rate of up to 12 per cent and to a loss in power of up to 15 per cent, depending on whether the patient or the hernia was the randomization unit.

CONCLUSION

Clustering was rarely considered in inguinal hernia trials. The simulations underline the importance of considering clustering as part of the statistical analysis to avoid false-positive and false-negative results, and hence inappropriate study conclusions.

Right retroperitoneoscopic living donor nephrectomy does not increase surgical complications in the recipient and leads to excellent long-term outcome

BACKGROUND

Right-sided retroperitoneoscopic living donor nephrectomy (LDN) has been shown to be safe for the donor but it is unknown whether the short renal vein is associated with complications or an impaired long-term outcome in the recipient.

METHODS

In this retrospective cohort study, consecutive transplant recipients after retroperitoneoscopic LDN were enrolled. Complications occurring within 1 year were classified according to the Clavien-Dindo Classification for Surgical Complications and analysed using multivariable logistic regression. Predictors of 1-year creatinine clearance were analysed with multivariable linear regression. Cox proportional hazard models were used to analyse graft survival.

RESULTS

Of the 251 recipients, 193 (77%) received a left kidney and 58 (23%) a right kidney. Surgical complications of Clavien-Dindo grade 3 or higher were comparable in recipients of right and left kidneys (33% vs 29%, odds ratio 0.98, 95% confidence interval [CI] 0.50, 1.94). The occurrence of a surgical complication had a significant impact on creatinine clearance at 1 year (decrease of 6 ml/min/m2, p = 0.016). Vascular complications in right kidneys were more common but were all corrected without impact on graft survival. One-year graft-survival was similar in recipients of right (98.3%) and left (96.9%) kidneys, as was creatinine clearance one year after transplantation (mean difference 3.3 ml/min/m2, 95% CI -1.5, 8.1; p = 0.175). After a median follow-up of 5 years, neither the side (hazard ratio 1.56, 95% CI 0.67, 3.63) nor surgical complications (hazard ratio 1.44, 95% CI 0.65, 3.19) were associated with graft failure.

CONCLUSION

Right retroperitoneoscopic LDN does not compromise the outcome of transplantation. Surgical complications, long-term graft function and graft survival were comparable in right and left kidneys.

Surgical treatment of uncomplicated diverticulitis in Switzerland: comparison of population-based data over two time periods

AIM

The standard of care for acute uncomplicated diverticulitis used to be an elective colon resection after the second or third episode. This practice was replaced by a more conservative and individualized approach. This study investigates current surgical practice in the treatment of acute uncomplicated diverticulitis in Switzerland.

METHOD

Retrospective cross-sectional analysis of all hospital admissions due to uncomplicated diverticulitis in Switzerland using prospectively collected data from the Swiss Federal Statistical Office in two periods: 2004/2005 and 2010/2011. Treatment options were compared between the two periods with adjustment for baseline characteristics of patients and treating institutions.

RESULTS

A total of 24 497 patients (11 835 in 2004/2005; 12 662 in 2010/2011) were admitted to Swiss hospitals for uncomplicated diverticulitis. Between periods, the incidence increased from 81 to 85 admissions per 10⁵ inhabitants per year. Elective admissions decreased from 46% (n = 5490) to 34% (n = 4294). The unadjusted resection rate decreased from 40% (n = 4730) to 34% (n = 4308). In the adjusted analysis, inpatients were more likely to have a resection in 2010/2011 than in 2004/2005 [odds ratio of 1.38 (95% confidence interval 1.25-1.54)]. In addition, private insurance, elective mode of admission and younger age increased the odds for resection while there was no evidence of an association between resection and either gender or comorbidities.

CONCLUSION

The probability of colon resection for patients hospitalized with acute uncomplicated diverticulitis increased between periods while the overall number of colon resections declined. A change of practice expected given the paradigm shift towards conservative treatment could not be confirmed in this analysis.

Presence of bone marrow micro-metastases in stage I-III colon cancer patients is associated with worse disease-free and overall survival

The prognostic significance of bone marrow micro‐metastases (BMM) in colon cancer patients remains unclear. We conducted a prospective cohort study with long‐term follow‐up to evaluate the relevance of BMM as a prognostic factor for disease free (DFS) and overall survival (OS) in stage I‐III colon cancer patients. In this prospective multicenter cohort study 144 stage I‐III colon cancer patients underwent bone marrow aspiration from both iliac crests prior to open oncologic resection. The bone marrow aspirates were stained with the pancytokeratin antibody A45‐B/B3 and analyzed for the presence of epithelial tumor cells. DFS and OS were analyzed using a Cox proportional hazard model and robust standard errors to account for clustering in the multicenter setting. Median overall follow‐up was 6.2 years with no losses to follow‐up, and 7.3 years in patients who survived. BMM were found in 55 (38%) patients. In total, 30 (21%) patients had disease recurrence and 56 (39%) patients died. After adjusting for known prognostic factors, BMM positive patients had a significantly worse DFS (hazard ratio [HR] 1.33; 95% confidence interval [95% CI]: 1.02‐1.73; P = 0.037) and OS (HR 1.30; 95% CI: 1.09‐1.55; P = 0.003) compared to BMM negative patients. Bone marrow micro‐metastases occur in over one third of stage I‐III colon cancer patients and are a significant, independent negative prognostic factor for DFS and OS. Future trials should evaluate whether node‐negative colon cancer patients with BMM benefit from adjuvant chemotherapy.

Comparison of Canadian and Swiss Surgical Training Curricula: Moving on Toward Competency-Based Surgical Education

OBJECTIVE

Quality of surgical training in the era of resident duty-hour restrictions (RDHR) is part of an ongoing debate. Most training elements are provided during surgical service. As exposure to surgical procedures is important but time-consuming, RDHR may affect quality of surgical training. Providing structured training elements may help to compensate for this shortcoming.

DESIGN

This binational anonymous questionnaire-based study evaluates frequency, time, and structure of surgical training programs at 2 typical academic teaching hospitals with different RDHR.

SETTING

Departments of Surgery of University of Basel (Basel, Switzerland) and the Queen's University (Kingston, Ontario, Canada).

PARTICIPANTS

Surgical consultants and residents of the Queen's University Hospital (Kingston, Ontario, Canada) and the University Hospital Basel (Basel, Switzerland) were eligible for this study.

RESULTS

Questionnaire response rate was 37% (105/284). Queen's residents work 80 hours per week, receiving 7 hours of formal training (8.8% of workweek). Basel residents work 60 hours per week, including 1 hour of formal training (1.7% of working time). Queen's faculty and residents rated their program as "structured" or "rather structured" in contrast to Basel faculty and residents who rated their programs as "neutral" in structure or "unstructured." Respondents identified specific structured training elements more frequently at Queen's than in Basel. Two-thirds of residents responded that they seek out additional surgical experiences through voluntary extra work. Basel participants articulated a stronger need for improvement of current surgical training. Although Basel residents and consultants in both institutions fear negative influence of RDHR on the training program, this was not the case in Queen's residents.

CONCLUSIONS

Providing more structured surgical training elements may be advantageous in providing optimal-quality surgical education in an era of work-hour restrictions.

Efficacy and safety of carbetocin applied as an intravenous bolus compared to as a short-infusion for caesarean section: study protocol for a randomised controlled trial

BACKGROUND

The two most commonly used uterotonic drugs in caesarean section are oxytocin and carbetocin, a synthetic oxytocin analogue. Carbetocin has a longer half-life when compared to oxytocin, resulting in a reduced use of additional uterotonics. Oxytocin is known to cause fewer cardiovascular side effects when administered as a short-infusion compared to as an intravenous bolus. Based on these findings, we aim at comparing carbetocin 100 mcg given as a slow intravenous bolus with carbetocin 100 mcg applied as a short-infusion in 100 ml 0.9 % sodium chloride in women undergoing a planned or unplanned caesarean delivery. We hypothesise uterine contraction not to be inferior to a bolus application (primary efficacy endpoint) and greater haemodynamic stability to be achieved after a short-infusion than after a bolus administration, as measured by heart rate and mean arterial blood pressure (primary safety endpoint).

METHODS/DESIGN

This is a prospective, double-blind, randomised controlled, investigator-initiated, non-inferiority trial taking place at the University Hospital Basel, Switzerland. Uterine tone is quantified by manual palpation by the obstetrician using a linear analogue scale from 0 to 100 at 2, 3, 5 and 10 minutes after cord clamping. We will evaluate whether the lower limit of the confidence interval for the difference of the maximal uterine tone within the first 5 minutes after cord clamping between both groups does not include the pre-specified non-inferiority limit of -10. Both haemodynamic secondary endpoints will be analysed using a linear regression model, adjusting for the baseline value and the dosage of vasoactive drug given between cord clamping and 1 minute thereafter, in order to investigate superiority of a short-infusion as compared to a bolus application. We will follow the extension of CONSORT guidelines for reporting the results of non-inferiority trials.

DISCUSSION

Haemodynamic stability and adequate uterine tone are important outcomes in caesarean sections. The results of this trial may be used to optimise these factors and thereby increase patient safety due to a reduction in cardiovascular side effects.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02221531 on 19 August 2014 and www.kofam.ch SNCTP000001197 on 15 November 2014.

Definition and Classification of Intraoperative Complications (CLASSIC): Delphi Study and Pilot Evaluation

BACKGROUND

Standardized reporting of intraoperative adverse events is important to enhance transparency. To the best of our knowledge, there is no validated definition and classification of intraoperative complications.

METHODS

We conducted a two-round Delphi study to develop a definition and classification of intraoperative complications. Experts were contacted by email and sent a link to the online questionnaire. In a pilot study, two independent raters applied the definition and classification in a sample of 60 surgical interventions of low, intermediate, and high complexity and evaluated practicability. Interrater agreement of the classification was determined (raw categorical agreement, weighted kappa, and intraclass correlation).

RESULTS

In the Delphi study, 40 of 52 experts (77 % return rate) from 14 countries took part in each round. The Delphi study resulted in a comprehensive definition of intraoperative complications as any deviation from the ideal intraoperative course occurring between skin incision and skin closure. The classification foresees four grades depending on the need for treatment (no need, grade I; need for treatment, grade II) and the severity of the complication (life-threatening/permanent disability, grade III; death, grade IV). The pilot study showed good practicability (6 on a 7-point scale) and a high raw agreement of 87 %, a weighted kappa of 0.83 [95 % confidence interval (CI) 0.73-0.94] and an intraclass correlation coefficient of 0.83 (95 % CI 0.73-0.90).

CONCLUSIONS

While the Delphi process enabled to develop definitions and classification of intraoperative complications by severity, further research including a multicentre international full-scale validation needs to be conducted with the ultimate goal to contribute to standardized reporting in surgical practice and research.

Surgical complications in kidney transplantation: no evidence for a learning curve

OBJECTIVE

To evaluate whether surgical complications after kidney transplantation correlate with surgeon's experience and whether individual surgeons' complication rates improve during their learning process.

STUDY DESIGN

Retrospective analysis: A generalized linear mixed-effects model was used to identify risk factors for surgical complications. Plots of cumulative sums of complications were used to evaluate the individual surgeons' performance.

SETTING

Single-center experience of a teaching hospital in Switzerland.

PARTICIPANTS

Consecutive kidney transplant recipients operated from 1962 until 2003.

RESULTS

A total of 1496 kidney transplants were analyzed; 73% were from deceased donors and 27% from living donors. At least 1 surgical complication occurred in 352 patients (24%). Male gender (odds ratio [OR] = 1.35, 95% CI: 1.04-1.74), donor's age (OR = 1.14, 95% CI: 1.06-1.24 per decade increment), and third or fourth vs. first or second transplant in a recipient (OR = 2.90, 95% CI: 1.02-8.24) were significantly associated with surgical complications. The surgeon's transplant experience was not found to be associated with surgical complications. Even surgeons with an experience of less than 10 kidney transplants did not have higher complication rates, 30-day mortality, or 1-year graft survival. Individual surgeons' complication rates analyzed by cumulative sum plots did not improve with increasing experience.

CONCLUSIONS

We present the largest single-center study on surgical complications after kidney transplantation, with unique data on the surgeon's experience for every single procedure. We found no evidence for a learning curve during training for kidney transplantation. We conclude that carefully selected experienced general and vascular surgeons can achieve good results in kidney transplantation after a relatively short training period.

Designing questionnaires: healthcare survey to compare two different response scales

BACKGROUND

A widely discussed design issue in patient satisfaction questionnaires is the optimal length and labelling of the answering scale. The aim of the present study was to compare intra-individually the answers on two response scales to five general questions evaluating patients' perception of hospital care.

METHODS

Between November 2011 and January 2012, all in-hospital patients at a Swiss University Hospital received a patient satisfaction questionnaire on an adjectival scale with three to four labelled categories (LS) and five redundant questions displayed on an 11-point end-anchored numeric scale (NS). The scales were compared concerning ceiling effect, internal consistency (Cronbach's alpha), individual item answers (Spearman's rank correlation), and concerning overall satisfaction by calculating an overall percentage score (sum of all answers related to the maximum possible sum).

RESULTS

The response rate was 41% (2957/7158), of which 2400 (81%) completely filled out all questions. Baseline characteristics of the responders and non-responders were similar. Floor and ceiling effect were high on both response scales, but more pronounced on the LS than on the NS. Cronbach's alpha was higher on the NS than on the LS. There was a strong individual item correlation between both answering scales in questions regarding the intent to return, quality of treatment and the judgement whether the patient was treated with respect and dignity, but a lower correlation concerning satisfactory information transfer by physicians or nurses, where only three categories were available in the LS. The overall percentage score showed a comparable distribution, but with a wider spread of lower satisfaction in the NS.

CONCLUSIONS

Since the longer scale did not substantially reduce the ceiling effect, the type of questions rather than the type of answering scale could be addressed with a focus on specific questions about concrete situations instead of general questions. Moreover, the low correlation in questions about information provision suggests that only three possible response choices are insufficient. Further investigations are needed to find a more sensitive scale discriminating high-end ratings. Otherwise, a longitudinal within-hospital or a cross-sectional between-hospital comparison of patient care is questionable.

Medical students' career expectations and interest in opting for a surgical career

BACKGROUND

Whilst surgery will face an imminent workforce shortage, an increasing majority of students decide against a surgical career. This study evaluated the current career expectations of medical students and tested a hands-on virtual reality (VR) intervention as a tool to increase their interest in surgery.

METHODS

Randomly selected medical students of the University of Basel received a short questionnaire to rank their interest in five different postgraduate working environments prior to a lecture. After the lecture they participated in a hands-on VR demonstration. Thereafter an online questionnaire regarding workplace expectations, surgery and VR was sent to the students.

RESULTS

The online questionnaire response rate was 87% (225/258). Before using the VR intervention, a nonsurgical career was preferred by the majority of students, followed by a surgical career, cross-disciplinary specialties, research and, finally, nonclinical work. Surgery (n = 99, 44%) and emergency medicine (n = 111, 49%) were rated as incompatible with a good work-life balance. Further drawbacks to surgery were apprehension of competitive mentality, unclear career perspectives and longer working hours. The VR intervention had limited impact on re-ranking the five working sectors and slightly increased the students' interest in surgery.

CONCLUSION

Students' work environment expectations, their declining interest in a surgical career and the increasing need for surgeons represent challenges for surgical societies to address, in order to improve the attractiveness of surgery amongst students. VR sessions may be integrated as part of the actions required to improve students' interest in a surgical career and should be further evaluated within controlled study designs.

Impact of tutorial assistance in laparoscopic sigmoidectomy for acute recurrent diverticulitis

PURPOSE

Adequate training and close supervision by an experienced surgeon are crucial to assure the patient safety during laparoscopic training. This study evaluated the impact of tutorial assistance on the duration of surgery and postoperative complications after laparoscopic sigmoidectomy.

METHODS

The data from 235 patients undergoing laparoscopic sigmoidectomy were collected. Operating surgeons were classified as either residents/registrars (group A, tutorial assistance) or consultants operating autonomously (group B). Groups were compared concerning the duration of surgery and in-hospital complications using a multivariable regression model accounting for the most relevant confounders.

RESULTS

The median duration of the operation in group A (n = 75) was 221 min, and that in group B (n = 160) 189 min (p < 0.001). The risk of developing any in-hospital complication (Clavien-Dindo classification I-V) was 36.0 % in Group A and 32.5 % in group B (95 % CI -16.6, 9.6 %). The risk of developing moderate to severe surgical complications (Clavien-Dindo classification II-V) was 16.0 % in group A and 12.5 % in group B (95 % CI -13.3, 6.3 %).

CONCLUSIONS

We were unable to demonstrate a clear impact of tutorial assistance on the risk of postoperative complications. Although associated with a longer duration of surgery, laparoscopic sigmoidectomy for acute recurrent sigmoid diverticulitis conducted by a junior supervised surgeon appears to be a safe surgical modality.

Histomorphometric, CT arthrographic, and biomechanical mapping of the human ankle

BACKGROUND

The specific morphological and biomechanical characteristics of the osteochondral unit of the ankle joint are not yet fully understood. This anatomical study aimed to map regional thickness of the articular hyaline uncalcified cartilage and its adjacent layers of mineralized cartilage and subchondral bone as well as to measure the regional indentation stiffness of human ankle joint cartilage.

MATERIALS AND METHODS

A total of 20 pairs of human cadaver ankle joints (median age: 78 years) were evaluated by histomorphometry and multidetector row double-contrast CT arthrography for cartilage thickness in 17 distinct anatomical regions. In addition, regional distribution of the subchondral bone plate and of the mineralized cartilage was scrutinized histologically. Cartilage indentation stiffness was measured using an arthroscopic handheld device (Artscan200), especially validated for use in thin cartilage. The correlation between the thickness of different components of the osteochondral unit and the cartilage indentation stiffness was evaluated.

RESULTS

The thinnest uncalcified cartilage was measured at the anterior talar dome and the distal fibula. The thickest uncalcified cartilage was found in the mid and posterior talar dome, as well as in the tibial plafond. Mineralized cartilage and subchondral bone showed highest values at the anteromedial talar dome. Cartilage indentation stiffness showed a bicentric distribution pattern in 14/20 ankle pairs and was highest in regions with thin cartilage. Positive correlation between the thickness of the mineralized cartilage and the subchondral bone plate was found. No correlation between the thickness of the uncalcified and the mineralized cartilage could be identified.

CONCLUSION

This anatomical study provides a comprehensive mapping of the osteochondral unit of the human ankle joint in elderly people. Articular hyaline uncalcified cartilage and the subchondral bone plate showed clear regional differences and were reciprocally distributed. Cartilage indentation stiffness was inversely correlated to cartilage thickness in elderly people.

CLINICAL RELEVANCE

Thorough understanding of the osteochondral unit of the ankle joint could be helpful for clinicians and researchers in the development of improved operative repair techniques for osteochondral defects in the ankle joint, for example, in constructing specific tissue-engineered osteochondral plugs.

Impact of loss of high-molecular-weight von Willebrand factor multimers on blood loss after aortic valve replacement

BACKGROUND

Severe aortic stenosis is associated with loss of the largest von Willebrand factor (vWF) multimers, which could affect primary haemostasis. We hypothesized that the altered multimer structure with the loss of the largest multimers increases postoperative bleeding in patients undergoing aortic valve replacement.

METHODS

We prospectively included 60 subjects with severe aortic stenosis. Before and after aortic valve replacement, vWF antigen, activity, and multimer structure were determined and platelet function was measured by impedance aggregometry. Blood loss from mediastinal drainage and the use of blood and haemostatic products were evaluated perioperatively.

RESULTS

Before operation, the altered multimer structure was present in 48 subjects (80%). Baseline characteristics and laboratory data were similar in all subjects. The median blood loss after 6 h was 250 (105-400) and 145 (85-240) ml in the groups with the altered and normal multimer structures, respectively (P=0.182). After 24 h, the cumulative loss was 495 (270-650) and 375 (310-600) ml in the groups with the altered and normal multimer structures, respectively (P=0.713). Multivariable analysis revealed no significant influence of multimer structure and platelet function on bleeding volumes after 6 and 24 h. After 24 h, there was no obvious difference in vWF antigen, activity, and multimer structure in subjects with and without the altered multimer structure before operation or in subjects with and without perioperative plasma transfusion.

CONCLUSIONS

The altered vWF multimer structure before operation was not associated with increased bleeding after aortic valve replacement. Our findings might be explained by perioperative release of vWF and rapid recovery of the largest vWF multimers.

Propofol sedation alone or in combination with pharyngeal lidocaine anesthesia for routine upper GI endoscopy: a randomized, double-blind, placebo-controlled, non-inferiority trial

BACKGROUND

In patients undergoing routine upper EGD, propofol is increasingly used without pharyngeal anesthesia because of its excellent sedative properties. It is unclear whether this practice is non-inferior in regard to ease of endoscopic intubation and patient comfort.

OBJECTIVE

To assess the relevance of local pharyngeal anesthesia regarding the ease of EGD performance in patients sedated with propofol as monotherapy.

DESIGN

Randomized, double-blind, placebo-controlled, non-inferiority trial.

SETTING

One community hospital and one university hospital in Switzerland.

PATIENTS

We enrolled 300 consecutive adult patients undergoing elective EGD.

INTERVENTION

Pharyngeal anesthesia with 4 squirts of lidocaine spray versus placebo spray immediately before propofol sedation.

MAIN OUTCOME MEASUREMENTS

Number of gag reflexes (primary endpoint), number of intubation attempts, and degree of salivation during intubation (secondary endpoints) assessed by the endoscopists and staff.

RESULTS

In the lidocaine group, 122 patients (82%) had no gag events, and 25 patients had a total of 39 gag events, whereas in the placebo group 104 patients (71%) had no gag events, and 43 patients had a total of 111 gag events. The rate ratio of gagging with quasi-likelihood estimation of placebo compared with lidocaine was 2.85 (95% confidence interval [CI], 1.42-6.19; P = .005). In adjusted logistic regression analysis, the odds ratio for gagging for placebo pharyngeal anesthesia compared with lidocaine was 1.9 (95% CI, 1.03-3.54). The number of intubation attempts and the degree of salivation were similar in both groups. Two patients in the placebo group experienced oxygen desaturation and needed short-term mask ventilation.

LIMITATIONS

The level of sedation and possible long-term side effects of pharyngeal anesthesia were not assessed.

CONCLUSION

Topical pharyngeal anesthesia reduces the gag reflex in patients sedated with propofol even though it does not seem to have an influence on the ease of the procedure and on patient or endoscopist satisfaction in adequately sedated patients.

Effect of age on intraoperative cerebrovascular autoregulation and near-infrared spectroscopy-derived cerebral oxygenation

BACKGROUND

Age is an important risk factor for perioperative cerebral complications such as stroke, postoperative cognitive dysfunction, and delirium. We explored the hypothesis that intraoperative cerebrovascular autoregulation is less efficient and brain tissue oxygenation lower in elderly patients, thus, increasing the vulnerability of elderly brains to systemic insults such as hypotension.

METHODS

We monitored intraoperative cerebral perfusion in 50 patients aged 18-40 and 77 patients >65 yr at two Swiss university hospitals. Mean arterial pressure (MAP) was measured continuously using a plethysmographic method. An index of cerebrovascular autoregulation (Mx) was calculated based on changes in transcranial Doppler flow velocity due to changes in MAP. Cerebral oxygenation was assessed by the tissue oxygenation index (TOI) using near-infrared spectroscopy. End-tidal CO₂, O₂, and sevoflurane concentrations and peripheral oxygen saturation were recorded continuously. Standardized anaesthesia was administered in all patients (thiopental, sevoflurane, fentanyl, atracurium).

RESULTS

Autoregulation was less efficient in patients aged >65 yr [by 0.10 (se 0.04; P=0.020)] in a multivariable linear regression analysis. This difference was not attributable to differences in MAP, end-tidal CO₂, or higher doses of sevoflurane. TOI was not significantly associated with age, sevoflurane dose, or Mx but increased with increasing flow velocity [by 0.09 (se 0.04; P=0.028)] and increasing MAP [by 0.11 (se 0.05; P=0.043)].

CONCLUSIONS

Our results do not support the hypothesis that older patients' brains are more vulnerable to systemic insults. The difference of autoregulation between the two groups was small and most likely clinically insignificant.

Lipid and lipoprotein profile in HIV-infected patients treated with lopinavir/ritonavir as a component of the first combination antiretroviral therapy

We characterized lipid and lipoprotein changes associated with a lopinavir/ritonavir-containing regimen. We enrolled previously antiretroviral-naive patients participating in the Swiss HIV Cohort Study. Fasting blood samples (baseline) were retrieved retrospectively from stored frozen plasma and posttreatment (follow-up) samples were collected prospectively at two separate visits. Lipids and lipoproteins were analyzed at a single reference laboratory. Sixty-five patients had two posttreatment lipid profile measurements and nine had only one. Most of the measured lipids and lipoprotein plasma concentrations increased on lopinavir/ritonavir-based treatment. The percentage of patients with hypertriglyceridemia (TG >150 mg/dl) increased from 28/74 (38%) at baseline to 37/65 (57%) at the second follow-up. We did not find any correlation between lopinavir plasma levels and the concentration of triglycerides. There was weak evidence of an increase in small dense LDL-apoB during the first year of treatment but not beyond 1 year (odds ratio 4.5, 90% CI 0.7 to 29 and 0.9, 90% CI 0.5 to 1.5, respectively). However, 69% of our patients still had undetectable small dense LDL-apoB levels while on treatment. LDL-cholesterol increased by a mean of 17 mg/dl (90% CI -3 to 37) during the first year of treatment, but mean values remained below the cut-off for therapeutic intervention. Despite an increase in the majority of measured lipids and lipoproteins particularly in the first year after initiation, we could not detect an obvious increase of cardiovascular risk resulting from the observed lipid changes.

Video gaming in children improves performance on a virtual reality trainer but does not yet make a laparoscopic surgeon

BACKGROUND

In children, video game experience improves spatial performance, a predictor of surgical performance. This study aims at comparing laparoscopic virtual reality (VR) task performance of children with different levels of experience in video games and residents.

PARTICIPANTS AND METHODS

A total of 32 children (8.4 to 12.1 years), 20 residents, and 14 board-certified surgeons (total n = 66) performed several VR and 2 conventional tasks (cube/spatial and pegboard/fine motor). Performance between the groups was compared (primary outcome). VR performance was correlated with conventional task performance (secondary outcome).

RESULTS

Lowest VR performance was found in children with low video game experience, followed by those with high video game experience, residents, and board-certified surgeons. VR performance correlated well with the spatial test and moderately with the fine motor test.

CONCLUSIONS

The use of computer games can be considered not only as pure entertainment but may also contribute to the development of skills relevant for adequate performance in VR laparoscopic tasks. Spatial skills are relevant for VR laparoscopic task performance.

Modifiable and nonmodifiable risk factors for postoperative delirium after cardiac surgery with cardiopulmonary bypass

OBJECTIVES

Postoperative delirium after cardiac surgery is associated with increased morbidity and mortality as well as prolonged stay in both the intensive care unit and the hospital. The authors sought to identify modifiable risk factors associated with the development of postoperative delirium in elderly patients after elective cardiac surgery in order to be able to design follow-up studies aimed at the prevention of delirium by optimizing perioperative management.

DESIGN

A post hoc analysis of data from patients enrolled in a randomized controlled trial was performed.

SETTING

A single university hospital.

PARTICIPANTS

One hundred thirteen patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

None. MEASUREMENTS AND MAINS RESULTS: Screening for delirium was performed using the Confusion Assessment Method (CAM) on the first 6 postoperative days. A multivariable logistic regression model was developed to identify significant risk factors and to control for confounders. Delirium developed in 35 of 113 patients (30%). The multivariable model showed the maximum value of C-reactive protein measured postoperatively, the dose of fentanyl per kilogram of body weight administered intraoperatively, and the duration of mechanical ventilation to be independently associated with delirium.

CONCLUSIONS

In this post hoc analysis, larger doses of fentanyl administered intraoperatively and longer duration of mechanical ventilation were associated with postoperative delirium in the elderly after cardiac surgery. Prospective randomized trials should be performed to test the hypotheses that a reduced dose of fentanyl administered intraoperatively, the use of a different opioid, or weaning protocols aimed at early extubation prevent delirium in these patients.

Cerebral perfusion in sepsis-associated delirium

Introduction

The pathophysiology of sepsis-associated delirium is not completely understood and the data on cerebral perfusion in sepsis are conflicting. We tested the hypothesis that cerebral perfusion and selected serum markers of inflammation and delirium differ in septic patients with and without sepsis-associated delirium.

Methods

We investigated 23 adult patients with sepsis, severe sepsis, or septic shock with an extracranial focus of infection and no history of intracranial pathology. Patients were investigated after stabilisation within 48 hours after admission to the intensive care unit. Sepsis-associated delirium was diagnosed using the confusion assessment method for the intensive care unit. Mean arterial pressure (MAP), blood flow velocity (FV) in the middle cerebral artery using transcranial Doppler, and cerebral tissue oxygenation using near-infrared spectroscopy were monitored for 1 hour. An index of cerebrovascular autoregulation was calculated from MAP and FV data. C-reactive protein (CRP), interleukin-6 (IL-6), S-100β, and cortisol were measured during each data acquisition.

Results

Data from 16 patients, of whom 12 had sepsis-associated delirium, were analysed. There were no significant correlations or associations between MAP, cerebral blood FV, or tissue oxygenation and sepsis-associated delirium. However, we found a significant association between sepsis-associated delirium and disturbed autoregulation (P = 0.015). IL-6 did not differ between patients with and without sepsis-associated delirium, but we found a significant association between elevated CRP (P = 0.008), S-100β (P = 0.029), and cortisol (P = 0.011) and sepsis-associated delirium. Elevated CRP was significantly correlated with disturbed autoregulation (Spearman rho = 0.62, P = 0.010).

Conclusion

In this small group of patients, cerebral perfusion assessed with transcranial Doppler and near-infrared spectroscopy did not differ between patients with and without sepsis-associated delirium. However, the state of autoregulation differed between the two groups. This may be due to inflammation impeding cerebrovascular endothelial function. Further investigations defining the role of S-100β and cortisol in the diagnosis of sepsis-associated delirium are warranted.

Trial registration

ClinicalTrials.gov NCT00410111.