Postoperative troponin surveillance to detect myocardial infarction: an observational cohort modelling study

BACKGROUND

Clinical presentation of postoperative myocardial infarction (POMI) is often silent. Several international guidelines recommend routine troponin surveillance in patients at risk. We compared how these different guidelines select patients for surveillance after noncardiac surgery with our established risk stratification model.

METHODS

We used outcome data from two prospective studies: Measurement of Exercise Tolerance before Surgery (METS) and Troponin Elevation After Major non-cardiac Surgery (TEAMS). We compared the major American, Canadian, and European guideline recommendations for troponin surveillance with our established risk stratification model. For each guideline and model, we quantified the number of patients requiring monitoring, % POMI detected, sensitivity, specificity, diagnostic odds ratio, and number needed to screen (NNS).

RESULTS

METS and TEAMS contributed 2350 patients, of whom 319 (14%) had myocardial injury, 61 (2.5%) developed POMI, and 14 (0.6%) died. Our risk stratification model selected fewer patients for troponin monitoring (20%), compared with the Canadian (78%) and European (79%) guidelines. The sensitivity to detect POMI was highest with the Canadian and European guidelines (0.85; 95% confidence interval [CI] 0.74-0.92). Specificity was highest using the American guidelines (0.91; 95% CI 0.90-0.92). Our risk stratification model had the best diagnostic odds ratio (2.5; 95% CI 1.4-4.2) and a lower NNS (21 vs 35) compared with the guidelines.

CONCLUSIONS

Most postoperative myocardial infarctions were detected by the Canadian and European guidelines but at the cost of low specificity and a higher number of patients undergoing screening. Patient selection based on our risk stratification model was optimal.

The effect of proactive versus reactive treatment of hypotension on postoperative disability and outcome in surgical patients under anaesthesia (PRETREAT): clinical trial protocol and considerations

Background

Intraoperative hypotension has been extensively studied for its association with adverse outcomes. However, small sample sizes and methodological issues limit the causal inference that can be drawn.

Methods

In this multicentre, adaptive, randomised controlled trial, we will include 5000 adult inpatients scheduled for elective non-cardiac surgery under general or central neuraxial anaesthesia. Patients will be either randomly allocated to the intervention or care-as-usual group using computer-generated blocks of four, six, or eight, with an allocation ratio of 1:1. In the intervention arm patients will be divided into low-, intermediate-, and high-risk groups based on their likelihood to experience intraoperative hypotension, with resulting mean blood pressure targets of 70, 80, and 90 mm Hg, respectively. Anaesthesia teams will be provided with a clinical guideline on how to keep patients at their target blood pressure. During the first 6 months of the trial the intervention strategy will be evaluated and further revised in adaptation cycles of 3 weeks if necessary, to improve successful impact on the clinical process. The primary outcome is postoperative disability after 6 months measured with the World Health Organization Disability Assessment Score (WHODAS) 2.0 questionnaire.

Ethics and dissemination

This study protocol has been approved by the Medical Ethics Committee of the University Medical Centre Utrecht (20-749) and all protocol amendments will be communicated to the Medical Ethics Committee. The study protocol is in adherence with the Declaration of Helsinki and the guideline of Good Clinical Practice. Dissemination plans include publication in a peer-reviewed journal.

Clinical trial registration

The Dutch Trial Register, NL9391. Registered on 22 March 2021.

Effect of a national guideline on postoperative troponin surveillance: a retrospective cohort study

PURPOSE

We aimed to evaluate the effect of the 2017 Canadian Cardiovascular Society (CCS) guidelines on troponin surveillance after noncardiac surgery.

METHODS

This was a single-centre, retrospective, observational study. Patients aged 40 yr or older undergoing intermediate- to high-risk elective noncardiac surgery between 2016 and 2021 were included. We compared the number and percentage of troponin tests ordered before and after the guidelines were published and compared patient characteristics, specifically cardiovascular comorbidity, using odds ratio's (OR) with 95% confidence intervals (CIs). Outcomes were myocardial injury, myocardial infarction (MI), and in-hospital mortality.

RESULTS

The cohort included 36,386 patients and the median age was 63 yr. Between 2016 and 2018, troponin surveillance was done in 2,461 (13%) of the 19,046 patients, compared with 2,398 (14%) of the 17,340 patients who had surgery between 2019 and 2021 (OR, 1.08; 95% CI, 1.02 to 1.15). Patients who had surgery in the second period had less cardiovascular comorbidity; the adjusted OR for troponin surveillance was 1.14 (95% CI, 1.07 to 1.21). In the two periods, troponin was elevated in 561 (2.9%) and 470 (2.7%) patients, an MI was documented in 54 (0.3%) and 36 (0.2%) patients, and 95 (0.5%) and 73 (0.4%) patients died, respectively. After adjustment for baseline differences in the two periods, the ORs for MI and mortality were 0.83 (95% CI, 0.54 to 1.27) and 0.88 (95% CI, 0.64 to 1.19), respectively.

CONCLUSION

Although the odds of troponin ordering were slightly but significantly higher after publication of the CCS guidelines, the odds for detecting an MI and for mortality did not change.

Postoperative myocardial injury phenotypes and self-reported disability in patients undergoing noncardiac surgery: a multicentre observational study

BACKGROUND

Postoperative myocardial injury (PMI) comprises a spectrum of mechanisms resulting in troponin release. The impact of different PMI phenotypes on postoperative disability remains unknown.

METHODS

This was a multicentre prospective cohort study including patients aged ≥50 yr undergoing elective major noncardiac surgery. Patients were stratified in five groups based on the occurrence of PMI and clinical information on postoperative adverse events: PMI classified as myocardial infarction (MI; according to fourth definition), PMI plus adverse event other than MI, clinically silent PMI (PMI without adverse events), adverse events without PMI, and neither PMI nor an adverse event (reference). The primary endpoint was 6-month self-reported disability (assessed by WHO Disability Assessment Schedule 2.0 [WHODAS]). Disability-free survival was defined as WHODAS ≤16%.

RESULTS

We included 888 patients of mean age 69 (range 53-91) yr, of which 356 (40%) were women; 151 (17%) patients experienced PMI, and 625 (71%) experienced 6-month disability-free survival. Patients with PMI, regardless of its phenotype, had higher preoperative disability scores than patients without PMI (difference in WHODAS; β: 3.3, 95% confidence interval [CI]: 0.5-6.2), but scores remained stable after surgery (β: 1.2, 95% CI: -3.2-5.6). Before surgery, patients with MI (n=36, 4%) were more disabled compared with patients without PMI and no adverse events (β: 5.5, 95% CI: 0.3-10.8). At 6 months, patients with MI and patients without PMI but with adverse events worsened in disability score (β: 11.2, 95% CI: 2.3-20.2; β: 8.1, 95% CI: 3.0-13.2, respectively). Patients with clinically silent PMI did not change in disability score at 6 months (β: 1.39, 95% CI: -4.50-7.29, P=0.642).

CONCLUSIONS

Although patients with postoperative myocardial injury had higher preoperative self-reported disability, disability scores did not change at 6 months after surgery. However, patients experiencing myocardial infarction worsened in disability score after surgery.

Preoperative frailty and one-year functional recovery in elderly cardiac surgery patients

OBJECTIVE

Frailty increases risk for morbidity and mortality after cardiac surgery. Its influence on functional outcome is largely unknown. We studied the association of frailty with health-related quality of life and disability after cardiac surgery.

METHODS

A prospective 2-center observational cohort of 555 patients aged 70 years or more undergoing cardiac surgery. A comprehensive frailty assessment was performed before surgery based on 11 individual assessments in physical, mental, and social domains. Frailty was defined as at least 1 positive test in each domain. The primary outcome was health-related quality of life over 1 year, and the secondary outcomes were severe in-hospital complications and disability over 1 year. Adverse functional outcome was defined as the composite of a decreased health-related quality of life and disability.

RESULTS

Physical frailty was most common (91%) compared with mental (39%) or social frailty (42%). Adverse functional outcome occurred in 257 patients (46%) and consisted of decreased physical health-related quality of life in 134 (24%), decreased mental health-related quality of life in 141 (25%), and disability in 120 (22%). Frailty was more common in patients with adverse functional outcome (29%) compared with patients without adverse functional outcome (16%, P < .001). Poor mobility, malnutrition, and polypharmacy were associated with a decreased health-related quality of life over time, whereas impaired physical functioning and higher self-rated health were related to increased health-related quality of life. Disability after cardiac surgery was associated with poor mobility, polypharmacy, dependent living, living alone, and lower self-rated mental health before surgery.

CONCLUSIONS

Mobility, nutrition, medication use, physical functioning, and self-rated health before surgery are associated with health-related quality of life in elderly patients 1 year after cardiac surgery.

Complications of Factor V Leiden in Adults Undergoing Noncardiac Surgical Procedures: A Systematic Review

Factor V Leiden is the commonest hereditary prothrombotic allele, affecting 1% to 5% of the world's population. The objective of this study was to characterize the perioperative and postoperative outcomes of patients with Factor V Leiden compared to patients without a diagnosis of hereditary thrombophilia. This was a focused systematic review of studies including adult (>18 years) patients with Factor V Leiden (heterozygous or homozygous) undergoing noncardiac surgery. Included studies were either randomized controlled trials or observational. The primary clinical outcomes of interest were thromboembolic events occurring from the perioperative period up to 1 year postoperatively, defined as deep venous thrombosis, pulmonary embolism, or other clinically significant thrombosis occurring during or after a surgical procedure. Secondary outcomes included cerebrovascular events, cardiac events, death, transplant-related outcomes, and surgery-specific morbidity. Pediatric and obstetrical patients were excluded, as were case reports and case series. Databases searched included MEDLINE and EMBASE from inception until August 2021. Study bias was assessed through the CLARITY (Collaboration of McMaster University researchers) Risk of Bias tools, and heterogeneity through analysis of study design and end points, as well as the I 2 statistic with its confidence interval and the Q statistic. A total of 5275 potentially relevant studies were identified, with 115 having full text assessed for eligibility and 32 included in the systematic review. On the whole, the literature suggests that patients with Factor V Leiden have an increased risk of perioperative and postoperative thromboembolic events compared to patients without the diagnosis. Increased risk was also seen in relation to surgery-specific morbidity and transplant-related outcomes, particularly arterial thrombotic events. The literature did not support an increased risk for mortality, cerebrovascular, or cardiac complications. Limitations of the data include predisposition toward bias due in many study designs and small sample sizes across the majority of published studies. Variable outcome definitions and durations of patient follow-up across different surgical procedures resulted in high study heterogeneity precluding the effective use of meta-analysis. Factor V Leiden status may confer additional risk for surgery-related adverse outcomes. Large, adequately powered studies are required to accurately estimate the degree of this risk by zygosity.

Systematic reviews and consensus definitions for the Standardised Endpoints in Perioperative Medicine (StEP) initiative: mortality, morbidity, and organ failure

BACKGROUND

Mortality, morbidity, and organ failure are important and common serious harms after surgery. However, there are many candidate measures to describe these outcome domains. Definitions of these measures are highly variable, and validity is often unclear. As part of the International Standardised Endpoints in Perioperative Medicine (StEP) initiative, this study aimed to derive a set of standardised and valid measures of mortality, morbidity, and organ failure for use in perioperative clinical trials.

METHODS

Three domains of endpoints (mortality, morbidity, and organ failure) were explored through systematic literature review and a three-stage Delphi consensus process using methods consistently applied across the StEP initiative. Reliability, feasibility, and patient-centredness were assessed in round 3 of the consensus process.

RESULTS

A high level of consensus was achieved for two mortality time points, 30-day and 1-yr mortality, and these two measures are recommended. No organ failure endpoints achieved threshold criteria for consensus recommendation. The Clavien-Dindo classification of complications achieved threshold criteria for consensus in round 2 of the Delphi process but did not achieve the threshold criteria in round 3 where it scored equivalently to the Post Operative Morbidity Survey. Clavien-Dindo therefore received conditional endorsement as the most widely used measure. No composite measures of organ failure achieved an acceptable level of consensus.

CONCLUSIONS

Both 30-day and 1-yr mortality measures are recommended. No measure is recommended for organ failure. One measure (Clavien-Dindo) is conditionally endorsed for postoperative morbidity, but our findings suggest that no single endpoint offers a reliable and valid measure to describe perioperative morbidity that is not dependent on the quality of deli-vered care. Further refinement of current measures, or development of novel measures, of postoperative morbidity might improve consensus in this area.

Association of a Liberal Fasting Policy of Clear Fluids Before Surgery With Fasting Duration and Patient Well-being and Safety

Importance

Current fasting guidelines for procedures under anesthesia are poorly implemented, leading to negative metabolic sequelae. Recent studies in children showed support of liberal clear fluid intake; adult physiology can support clear fluid intake, but implementation studies are lacking.

Objective

To evaluate the successfulness of implementation of a liberal clear fluid policy with regard to fasting duration, well-being, and safety in adults scheduled for anesthesia.

Design, Setting, and Participants

This was a quality improvement study conducted from January 2016 to July 2021 at a tertiary referral hospital in the Netherlands. Adults scheduled for nonemergency procedures under anesthesia were included in the study. Patients undergoing obstetrics procedures or those who were intubated preoperatively were excluded.

Interventions

Stepwise introduction of a liberal fluid fasting policy, allowing for ingestion of clear fluids until arrival at the operating room.

Main Outcomes and Measures

The primary outcome was change in fasting duration. Secondary outcomes were patient well-being, measured as preoperative thirst, amount of fluid ingested, postoperative nausea and vomiting (PONV), and administration of antiemetics. Safety was measured as incidence of regurgitation and aspiration (pneumonia).

Results

Of the 76 451 patients (mean [SD] age, 56 [17] years; 39 530 male individuals [52%] 36 921) included in the study, 59 036 (78%) followed the standard policy, and 16 815 (22%) followed the liberal policy. Time series analysis showed an estimated fasting duration decrease of 3:07 hours (IQR, 1:36-7:22; P < .001) after implementation of the liberal policy. Postimplementation median (IQR) fasting duration was 1:20 (0:48-2:24) hours. The incidence of regurgitation changed from 18 (95% CI, 14-21) to 24 (95% CI, 17-32) in 10 000 patients, and the incidence of aspiration changed from 1.7 (95% CI, 0.6-2.7) to 2.4 (95% CI, 0.5-4.7) in 10 000 patients. In the liberal policy, thirst feelings decreased (37% [4982 of 8615] vs 46% [3373 of 7362]; P < .001). PONV incidence decreased from 10.6% (6339 of 59 636) to 9.4% (1587 of 16 815; P < .001) and antiemetic administration decreased from 11.0% (6538 of 59 636) to 9.5% (1592 of 16 815; P < .001).

Conclusions and Relevance

Results of this quality improvement study suggest that a liberal fasting policy was associated with a clinically relevant reduction in fasting duration and improved patient well-being with regard to preoperative thirst and PONV. Although a slightly higher incidence of regurgitation could not be ruled out, wider implementation of such a policy may be advocated as results are still within the clinically accepted risks margins. Results suggest that surgical procedures in patients who drink clear fluids within 2 hours before anticipated anesthesia should not be postponed or canceled.

Definitions of low cardiac output syndrome after cardiac surgery and their effect on the incidence of intraoperative LCOS: A literature review and cohort study

Objectives

Low cardiac output syndrome (LCOS) is a serious complication after cardiac surgery. Despite scientific interest in LCOS, there is no uniform definition used in current research and clinicians cannot properly compare different study findings. We aimed to collect the LCOS definitions used in literature and subsequently applied the definitions obtained to existing data to estimate their effect on the intraoperative LCOS incidences in adults, children and infants.

Design

This is a literature review, followed by a retrospective cohort study.

Setting

This is a single-institutional study from a university hospital in the Netherlands.

Participants

Patients from all ages undergoing cardiac surgery with cardiopulmonary bypass between June 2011 and August 2018.

Interventions

We obtained different definitions of LCOS used in the literature and applied these to data obtained from an anesthesia information management system to estimate intraoperative incidences of LCOS. We compared intraoperative incidences of LCOS in different populations based on age (infants, children and adults).

Measurements and main results

The literature search identified 262 LCOS definitions, that were applied to intraoperative data from 7,366 patients. Using the 10 most frequently published LCOS definitions, the obtained incidence estimates ranged from 0.4 to 82% in infants, from 0.6 to 56% in children and from 1.5 to 91% in adults.

Conclusion

There is an important variety in definitions used to describe LCOS. When applied to data obtained from clinical care, these different definitions resulted in large distribution of intraoperative LCOS incidence rates. We therefore advocate for standardization of the LCOS definition to improve clinical understanding and enable adequate comparison of outcomes and treatment effects both in daily care and in research.

Associations between intraoperative hypotension, duration of surgery and postoperative myocardial injury after noncardiac surgery: a retrospective single-centre cohort study

BACKGROUND

Studies of intraoperative hypotension typically specify a blood pressure threshold associated with adverse outcomes. Such thresholds are likely to be study-biased, investigator-biased, or both. We hypothesised that a newly developed modelling method without a threshold, which is biologically more plausible than a threshold-based approach, would reveal a continuous association between exposure to intraoperative hypotension and adverse outcomes.

METHODS

Single-centre, retrospective cohort study of subjects ≥60 yr old undergoing noncardiac surgery. We modelled intraoperative hypotension using three different approaches: (1) unweighted, (2) weighted for degree of hypotension (depth), and (3) weighted for duration of hypotension. The primary outcome was myocardial injury, defined as elevated troponin I (>60 ng L^-1) measured during the first 3 days after surgery. The associations between the three models, postoperative myocardial injury, and mortality (secondary outcome) were reported as penalised adjusted odds ratios (ORs) scaled between the 75th and 25th percentiles.

RESULTS

Myocardial injury occurred in 1812/15 452 (12%) procedures, with 554/15 452 (3.6%) procedures resulting in death before discharge from hospital. The unweighted lower blood pressure measure (OR: 0.26, 95% confidence interval [CI]: 0.12-0.53) and the depth-weighted measure (OR: 4.4, 95% CI: 2.6-7.4) were associated with myocardial injury. The duration-weighted measure was not associated with myocardial injury (OR: 0.89, 95% CI: 0.61-1.3). The unweighted measure (OR 0.08, 95% CI: 0.01-0.40) and the depth-weighted measure (OR: 12, 95% CI, 3.8-35) were associated with in-hospital mortality, but not the duration-weighted measure (OR: 1.3, 95% CI: 0.53-3.0).

CONCLUSIONS

Intraoperative hypotension appears to have a graded association with postoperative myocardial injury and mortality, with depth appearing to contribute more than duration.

Autonomous patient consent for anaesthesia without preoperative consultation: a qualitative feasibility study including low-risk procedures

Background

Informed consent for anaesthesia is mandatory and requires provision of information and subsequent consent during consultation between anaesthesiologist and patient. Although information can be provided in an electronic format, it is unknown whether this a valid substitute for a consultation. We explored whether provision of digital information is equivalent to oral consultation and whether it enables patients to give electronic informed consent (e-consent) for anaesthesia.

Methods

Qualitative feasibility study using semi-structured interviews in 20 low-risk adults scheduled for minor surgery under general anaesthesia or procedural sedation at a university hospital. Data were analysed using a thematic content analysis approach. During the interviews, patients followed an application that provides information and subsequent e-consenting.

Results

The mean age was 50 yr and patients had good digital skills. Fifteen patients (75%) had previous experience of anaesthesia. The digital application provided enough information for all patients, but eight (40%) preferred consultation with an anaesthesiologist, mainly for personal contact. Patients had different information needs, with previous experiences leading to lower information needs. Nineteen patients had sufficient information to consent autonomously. Most patients considered separate anaesthesia consent superfluous to the surgical consent.

Conclusion

The digital application provided sufficient information and patients valued the information offered and the advantage of processing information at their own pace. This information made patients feel empowered to autonomously consent to anaesthesia without consultation. Remarkably, consent for anaesthesia was considered unimportant, because patients felt they had 'no choice' if they wanted to undergo surgery.

Outlying End-Tidal Carbon Dioxide During General Anesthesia Is Associated With Postoperative Pulmonary Complications: A Multicenter Retrospective Observational Study From US Hospitals Between 2010 and 2017

BACKGROUND

Postoperative pulmonary complications (PPCs) occur in up to 33% of patients who undergo noncardiothoracic surgery. Emerging evidence suggests that permissive hypercapnia may reduce the risk of lung injury. We hypothesized that higher intraoperative end-tidal carbon dioxide (Etco2) concentrations would be associated with a decreased risk of PPCs.

METHODS

This retrospective, observational, multicenter study included patients undergoing general anesthesia for noncardiothoracic procedures (January 2010-December 2017). The primary outcome was PPC within 30 postoperative days. Secondary outcomes were PPC within 1 week, postoperative length of stay, and inhospital 30-day mortality. The association between these outcomes, median Etco2, and 4 time-weighted average area-under-the-curve (TWA-AUC) thresholds (<28, <35, <45, and >45 mm Hg) was explored using a multivariable mixed-effect model and by plotting associated risks.

RESULTS

Among 143,769 cases across 11 hospitals, 10,276 (7.1%) experienced a PPC. When compared to a baseline median Etco2 of 35 to 40 mm Hg, a median Etco2 >40 mm Hg was associated with an increase in PPCs within 30 days (median Etco2, 40-45 mm Hg; adjusted OR, 1.16 [99% confidence interval {CI}, 1.00-1.33]; P value = .008 and median Etco2, >45 mm Hg; OR, 1.64 [99% CI, 1.33-2.02]; P value < .001). The occurrence of any Etco2 value <28 mm Hg (ie, a positive TWA-AUC < 28 mm Hg) was associated with PPCs (OR, 1.40 [95% CI, 1.33-1.49]; P value < .001), mortality, and length of stay. Any Etco2 value >45 mm Hg (ie, a positive TWA-AUC >45 mm Hg) was also associated with PPCs (OR, 1.24 [95% CI, 1.17-1.31]; P < .001). The Etco2 range with the lowest incidence of PPCs was 35 to 38 mm Hg.

CONCLUSIONS

Both a very low (<28 mm Hg) and a high Etco2 (>45 mm Hg) were associated with PPCs within 30 days. The lowest PPC incidence was found in patients with an Etco2 of 35 to 38 mm Hg. Prospective studies are needed to clarify the relationship between postoperative PPCs and intraoperative Etco2.

The comparative and added prognostic value of biomarkers to the Revised Cardiac Risk Index for preoperative prediction of major adverse cardiac events and all-cause mortality in patients who undergo noncardiac surgery

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is a widely acknowledged prognostic model to estimate preoperatively the probability of developing in-hospital major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the RCRI does not always make accurate predictions, so various studies have investigated whether biomarkers added to or compared with the RCRI could improve this.

OBJECTIVES

Primary: To investigate the added predictive value of biomarkers to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Secondary: To investigate the prognostic value of biomarkers compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Tertiary: To investigate the prognostic value of other prediction models compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery.

SEARCH METHODS

We searched MEDLINE and Embase from 1 January 1999 (the year that the RCRI was published) until 25 June 2020. We also searched ISI Web of Science and SCOPUS for articles referring to the original RCRI development study in that period.

SELECTION CRITERIA

We included studies among adults who underwent noncardiac surgery, reporting on (external) validation of the RCRI and: - the addition of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of the RCRI to other models. Besides MACE, all other adverse outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form based on the CHARMS checklist. Independent pairs of authors screened references, extracted data and assessed risk of bias and concerns regarding applicability according to PROBAST. For biomarkers and prediction models that were added or compared to the RCRI in ≥ 3 different articles, we described study characteristics and findings in further detail. We did not apply GRADE as no guidance is available for prognostic model reviews.

MAIN RESULTS

We screened 3960 records and included 107 articles.   Over all objectives we rated risk of bias as high in ≥ 1 domain in 90% of included studies, particularly in the analysis domain. Statistical pooling or meta-analysis of reported results was impossible due to heterogeneity in various aspects: outcomes used, scale by which the biomarker was added/compared to the RCRI, prediction horizons and studied populations.  Added predictive value of biomarkers to the RCRI Fifty-one studies reported on the added value of biomarkers to the RCRI. Sixty-nine different predictors were identified derived from blood (29%), imaging (33%) or other sources (38%). Addition of NT-proBNP, troponin or their combination improved the RCRI for predicting MACE (median delta c-statistics: 0.08, 0.14 and 0.12 for NT-proBNP, troponin and their combination, respectively). The median total net reclassification index (NRI) was 0.16 and 0.74 after addition of troponin and NT-proBNP to the RCRI, respectively. Calibration was not reported. To predict myocardial infarction, the median delta c-statistic when NT-proBNP was added to the RCRI was 0.09, and 0.06 for prediction of all-cause mortality and MACE combined. For BNP and copeptin, data were not sufficient to provide results on their added predictive performance, for any of the outcomes. Comparison of the predictive value of biomarkers to the RCRI  Fifty-one studies assessed the predictive performance of biomarkers alone compared to the RCRI. We identified 60 unique predictors derived from blood (38%), imaging (30%) or other sources, such as the American Society of Anesthesiologists (ASA) classification (32%). Predictions were similar between the ASA classification and the RCRI for all studied outcomes. In studies different from those identified in objective 1, the median delta c-statistic was 0.15 and 0.12 in favour of  BNP and NT-proBNP alone, respectively, when compared to the RCRI, for the prediction of MACE. For C-reactive protein, the predictive performance was similar to the RCRI. For other biomarkers and outcomes, data were insufficient to provide summary results. One study reported on calibration and none on reclassification. Comparison of the predictive value of other prognostic models to the RCRI   Fifty-two articles compared the predictive ability of the RCRI to other prognostic models. Of these, 42% developed a new prediction model, 22% updated the RCRI, or another prediction model, and 37% validated an existing prediction model. None of the other prediction models showed better performance in predicting MACE than the RCRI. To predict myocardial infarction and cardiac arrest, ACS-NSQIP-MICA had a higher median delta c-statistic of 0.11 compared to the RCRI. To predict all-cause mortality, the median delta c-statistic was 0.15 higher in favour of ACS-NSQIP-SRS compared to the RCRI. Predictive performance was not better for CHADS₂, CHA₂DS₂-VASc, R₂CHADS₂, Goldman index, Detsky index or VSG-CRI compared to the RCRI for any of the outcomes. Calibration and reclassification were reported in only one and three studies, respectively.

AUTHORS' CONCLUSIONS

Studies included in this review suggest that the predictive performance of the RCRI in predicting MACE is improved when NT-proBNP, troponin or their combination are added. Other studies indicate that BNP and NT-proBNP, when used in isolation, may even have a higher discriminative performance than the RCRI. There was insufficient evidence of a difference between the predictive accuracy of the RCRI and other prediction models in predicting MACE. However, ACS-NSQIP-MICA and ACS-NSQIP-SRS outperformed the RCRI in predicting myocardial infarction and cardiac arrest combined, and all-cause mortality, respectively. Nevertheless, the results cannot be interpreted as conclusive due to high risks of bias in a majority of papers, and pooling was impossible due to heterogeneity in outcomes, prediction horizons, biomarkers and studied populations. Future research on the added prognostic value of biomarkers to existing prediction models should focus on biomarkers with good predictive accuracy in other settings (e.g. diagnosis of myocardial infarction) and identification of biomarkers from omics data. They should be compared to novel biomarkers with so far insufficient evidence compared to established ones, including NT-proBNP or troponins. Adherence to recent guidance for prediction model studies (e.g. TRIPOD; PROBAST) and use of standardised outcome definitions in primary studies is highly recommended to facilitate systematic review and meta-analyses in the future.

Intraoperative hypotension and delirium among older adults undergoing transcatheter aortic valve replacement

Background

Postoperative delirium (POD) is a frequently observed complication after transcatheter aortic valve replacement (TAVR). The effects of intraoperative hypotension (IOH) on POD occurrence are currently unclear.

Methods

A retrospective observational cohort study of patients who underwent TAVR was conducted. We predefined IOH as area under the threshold (AUT) of five mean arterial blood pressures (MBP), varying from <100 to <60 mmHg. The AUT consisted of the combination of duration and depth under the MBP thresholds, expressed in mmHg*min. All MBP AUTs were computed based on the complete procedure, independent of procedural phase or duration.

Results

This cohort included 675 patients who underwent TAVR under general anesthesia (n = 128, 19%) or procedural sedation (n = 547, 81%). Delirium occurred mostly during the first 2 days after TAVR, and was observed in n = 93 (14%) cases. Furthermore, 674, 672, 663, 630, and 518 patients had at least 1 min intraoperative MBP <100, <90, <80, <70, and <60 mmHg, respectively. Patients who developed POD had higher AUT based on all five MBP thresholds during TAVR. The penalized adjusted odds ratio varied between 1.08 (99% confidence interval [CI] 0.74–1.56) for the AUT based on MBP < 100 mmHg and OR 1.06 (99% CI 0.88–1.28) for the AUT based on MBP < 60 mmHg.

Conclusions

Intraoperative hypotension is frequently observed during TAVR, but not independently associated with POD after TAVR. Other potential factors than intraoperative hypotension may explain the occurrence of delirium after TAVR.

Critical oxygen delivery threshold during cardiopulmonary bypass in older cardiac surgery patients with increased frailty risk

OBJECTIVES

Older patients have a higher cardiac surgery-associated acute kidney injury (CSA-AKI) related mortality. Low oxygen delivery (DO2) during cardiopulmonary bypass (CPB) is a risk factor for CSA-AKI, but critical DO2 thresholds for older patients are unknown. This study investigated critical DO2 thresholds for CSA-AKI in patients ≥70 years undergoing on-pump cardiac surgery.

METHODS

Patients were enrolled from July 2015 until August 2017. CPB data from 432 patients were collected, and DO2 values were calculated per minute. The primary outcome was CSA-AKI. The association between DO2 and CSA-AKI was analysed with multivariable regression analysis. Multiple DO2 thresholds were analysed. The association between CSA-AKI and the area below the DO2 thresholds (DO2 deficit) was evaluated, as was the association between frailty and CSA-AKI.

RESULTS

CSA-AKI occurred in 63 (14.6%) patients. Mean and nadir (lowest) DO2 values were lower in patients with CSA-AKI (283 vs 312 ml/min/m2; P-value <0.001 and 238 vs 270 ml/min/m2; P-value <0.001, respectively). The adjusted relative risk for CSA-AKI was 1.006 [99% confidence interval (CI) 1.001-1.012] per ml/min/m2 nadir DO2 decrease. The critical DO2 threshold was 270 ml/min/m2 [adjusted relative risk 2.06 (99% CI 1.33-2.80)]. The DO2 deficit below 270 ml/min/m2 was associated with CSA-AKI [adjusted relative risk 2.84 (99% CI 1.87-3.81)]. No association between frailty and CSA-AKI was found (P = 0.82).

CONCLUSIONS

Low DO2 increased the risk for CSA-AKI in older patients who had cardiac surgery. A critical DO2 threshold of 270 ml/min/m2 was applicable for frail and non-frail patients. The efficacy of a DO2 >270 ml/min/m2 to reduce CSA-AKI in older patients needs further evaluation.

Emergency Airway Management in Patients with COVID-19: A Prospective International Multicenter Cohort Study

Background:

Tracheal intubation for patients with COVID-19 is required for invasive mechanical ventilation. The authors sought to describe practice for emergency intubation, estimate success rates and complications, and determine variation in practice and outcomes between high-income and low- and middle-income countries. The authors hypothesized that successful emergency airway management in patients with COVID-19 is associated with geographical and procedural factors.

Methods:

The authors performed a prospective observational cohort study between March 23, 2020, and October 24, 2020, which included 4,476 episodes of emergency tracheal intubation performed by 1,722 clinicians from 607 institutions across 32 countries in patients with suspected or confirmed COVID-19 requiring mechanical ventilation. The authors investigated associations between intubation and operator characteristics, and the primary outcome of first-attempt success.

Results:

Successful first-attempt tracheal intubation was achieved in 4,017/4,476 (89.7%) episodes, while 23 of 4,476 (0.5%) episodes required four or more attempts. Ten emergency surgical airways were reported—an approximate incidence of 1 in 450 (10 of 4,476). Failed intubation (defined as emergency surgical airway, four or more attempts, or a supraglottic airway as the final device) occurred in approximately 1 of 120 episodes (36 of 4,476). Successful first attempt was more likely during rapid sequence induction versus non–rapid sequence induction (adjusted odds ratio, 1.89 [95% CI, 1.49 to 2.39]; P < 0.001), when operators used powered air-purifying respirators versus nonpowered respirators (adjusted odds ratio, 1.60 [95% CI, 1.16 to 2.20]; P=0.006), and when performed by operators with more COVID-19 intubations recorded (adjusted odds ratio, 1.03 for each additional previous intubation [95% CI, 1.01 to 1.06]; P=0.015). Intubations performed in low- or middle-income countries were less likely to be successful at first attempt than in high-income countries (adjusted odds ratio, 0.57 [95% CI, 0.41 to 0.79]; P=0.001).

Conclusions:

The authors report rates of failed tracheal intubation and emergency surgical airway in patients with COVID-19 requiring emergency airway management, and identified factors associated with increased success. Risks of tracheal intubation failure and success should be considered when managing COVID-19.

The authors report a secondary analysis of associations of intubation and operator characteristics related to the primary outcome of first-attempt intubation success in 4,476 intubations among 1,722 clinicians at 607 institutions across 32 countries, also considering differential rates of success between high-income and low- and middle-income countries. Although successful first-attempt intubation was noted in 89.7% of intubations, 0.5% required four or more attempts, an emergency surgical airway was required in 0.2%, and a composite variable of failed intubation occurred in 0.8%. Multivariable analysis demonstrated that successful first attempts were more likely with rapid sequence intubations, when operators used powered air-purifying respirators, and with increasing operator experience. Intubations performed in low- and middle-income countries were nearly half as likely to be successful on first attempt than in high-income countries. These results provide potentially useful information for global and local policy-making related to this and future pandemics. However, the observational nature, along with lack of patient level characteristics, leave room for substantial residual confounding of these associations.

Supplemental Digital Content is available in the text.

Patient Selection for Routine Troponin Monitoring After Noncardiac Surgery

Background

Myocardial infarction is an important complication after noncardiac surgery. Therefore, perioperative troponin surveillance is recommended for patients at risk. The aim of this study was to identify patients at high risk of perioperative myocardial infarction (POMI), in order to aid appropriate selection and to omit redundant laboratory measurements in patients at low risk.

Methods and Results

This observational cohort study included patients ≥60 years of age who underwent intermediate to high risk noncardiac surgery. Routine postoperative troponin I monitoring was performed. The primary outcome was POMI. Classification and regression tree analysis was used to identify patient groups with varying risks of POMI. In each subgroup, the number needed to screen to identify 1 patient with POMI was calculated. POMI occurred in 216 (4%) patients and other myocardial injury in 842 (15%) of the 5590 included patients. Classification and regression tree analysis divided patients into 14 subgroups in which the risk of POMI ranged from 1.7% to 42%. Using a risk of POMI ≥2% to select patients for routine troponin I monitoring, this monitoring would be advocated in patients ≥60 years of age undergoing emergency surgery, or those undergoing elective surgery with a Revised Cardiac Risk Index class >2 (ie >1 risk factor). The number needed to screen to detect a patient with POMI would be 14 (95% CI 14–14) and 26% of patients with POMI would be missed.

Conclusions

To improve selection of high‐risk patients ≥60 years of age, routine postoperative troponin I monitoring could be considered in patients undergoing emergency surgery, or in patients undergoing elective surgery classified as having a revised cardiac risk index class >2.

Postoperative visits by dedicated anesthesiologists in patients with elevated troponin: a retrospective cohort study evaluating postoperative care utility and early detection of complications

Background

An elevated cardiac troponin level after noncardiac surgery is associated with both morbidity and mortality. Guidelines suggest routine troponin monitoring in high-risk patients. We implemented a dedicated anesthesia team to conduct follow-up on patients with postoperative troponin elevation. We hypothesized that these visits would facilitate early detection of complications. Therefore, the aim of this study was to evaluate the effect of postoperative visits by dedicated anesthesiologists on early detection of complications and care utility.

Methods

This retrospective observational study included patients aged ≥ 60 years with an elevated troponin within the first 3 days after noncardiac surgery. Troponin elevation was detected by routine biomarker monitoring. The primary outcome was early detected myocardial infarctions by the dedicated anesthesiologist. Other outcomes were overall detected complications, additional diagnostic tests and treatment advised by the anesthesiologist, consultation of another medical specialist, and advised postoperative follow-up at the outpatient cardiac clinic within 1 week after surgery.

Results

Of the 811 patients, 509 (63%) received a postoperative consultation by the anesthesiologist. Anesthesiologists were involved in the early detection of 59% of all myocardial infarctions and in 12% of all complications. Besides cardiac ischemia, patients were also often diagnosed with noncardiac complications, including respiratory failure (8.9%), pneumonia (13.2%), and acute kidney injury (17.5%) within 1 week after surgery. In 75% of patients, anesthesiologists ordered additional diagnostics, most frequently existing of electrocardiograms and additional cardiac enzyme testing. Additionally, change in treatment was advised, most often a medication change, in 16% of patients.

Conclusions

Standard consultation of a dedicated anesthesiologist resulted in an early detection of 59% of all myocardial infarctions and involved a change in treatment in a considerable number of patients with postoperative troponin elevation. Whether this may improve patient outcomes remains to be elucidated.

Effect of Phenylephrine and Ephedrine on Cerebral (Tissue) Oxygen Saturation During Carotid Endarterectomy (PEPPER): A Randomized Controlled Trial

Background

Short-acting vasopressor agents like phenylephrine or ephedrine can be used during carotid endarterectomy (CEA) to achieve adequate blood pressure (BP) to prevent periprocedural stroke by preserving the cerebral perfusion. Previous studies in healthy subjects showed that these vasopressors also affected the frontal lobe cerebral tissue oxygenation (rSO₂) with a decrease after administration of phenylephrine. This decrease is unwarranted in patients with jeopardized cerebral perfusion, like CEA patients. The study aimed to evaluate the impact of both phenylephrine and ephedrine on the rSO₂ during CEA.

Methods

In this double-blinded randomized controlled trial, 29 patients with symptomatic carotid artery stenosis underwent CEA under volatile general anesthesia in a tertiary referral medical center. Patients were preoperative allocated randomly (1:1) for receiving either phenylephrine (50 µg; n = 14) or ephedrine (5 mg; n = 15) in case intraoperative hypotension occurred, defined as a decreased mean arterial pressure (MAP) ≥ 20% compared to (awake) baseline. Intraoperative MAP was measured by an intra-arterial cannula placed in the radial artery. After administration, the MAP, cardiac output (CO), heart rate (HR), stroke volume, and rSO₂ both ipsilateral and contralateral were measured. The timeframe for data analysis was 120 s before, until 600 s after administration.

Results

Both phenylephrine (70 ± 9 to 101 ± 22 mmHg; p < 0.001; mean ± SD) and ephedrine (75 ± 11 mmHg to 122 ± 22 mmHg; p < 0.001) adequately restored MAP. After administration, HR did not change significantly over time, and CO increased 19% for both phenylephrine and ephedrine. rSO₂ ipsilateral and contralateral did not change significantly after administration at 300 and 600 s for either phenylephrine or ephedrine (phenylephrine 73%, 73%, 73% and 73%, 73%, 74%; ephedrine 72%, 73%, 73% and 75%, 74%, 74%).

Conclusions

Within this randomized prospective study, MAP correction by either phenylephrine or ephedrine showed to be equally effective in maintaining rSO₂ in patients who underwent CEA.

Clinical Trial Registration ClincalTrials.gov, NCT01451294.

Anaesthesia geriatric evaluation to guide patient selection for preoperative multidisciplinary team care in cardiac surgery

BACKGROUND

A multidisciplinary approach to improve postoperative outcomes in frail elderly patients is gaining interest. Multidisciplinary team care should be targeted at complex patients at high risk for adverse postoperative outcome to limit the strain on available resources and to prevent an unnecessary increase in patient burden. This study aimed to improve patient selection for multidisciplinary care by identifying risk factors for disability after cardiac surgery in elderly patients.

METHODS

This was a two-centre prospective cohort study of 537 patients aged ≥70 yr undergoing elective cardiac surgery. Before surgery, 11 frailty characteristics were investigated. Outcome was disability at 3 months defined as World Health Organization Disability Assessment Schedule 2.0 ≥25%. Multivariable modelling using logistic regression, concordance statistic (c-statistic), and net reclassification index was used to identify factors contributing to patient selection.

RESULTS

Disability occurred in 91 (17%) patients. Ten out of 11 frailty characteristics were associated with disability. A multivariable model, including the European System for Cardiac Operative Risk Evaluation II and preoperative haemoglobin, yielded a c-statistic of 0.71 (95% confidence interval [CI]: 0.66-0.77). After adding pre-specified frailty characteristics (polypharmacy, gait speed, physical disability, preoperative health-related quality of life, and living alone) to this model, the c-statistic improved to 0.78 (95% CI: 0.73-0.83). The net reclassification index was 0.32 (P<0.001), showing improved discrimination for patients at risk for disability at 3 months.

CONCLUSIONS

The addition of preoperative frailty characteristics to a multivariable model improved discrimination between elderly patients with and without disability at 3 months after cardiac surgery, and can be used to guide patient selection for preoperative multidisciplinary team care.

CLINICAL TRIAL REGISTRATION

NCT02535728.

Added value of subjective assessed functional capacity before non-cardiac surgery in predicting postoperative myocardial injury

BACKGROUND

Functional capacity is used as an indicator for cardiac testing before non-cardiac surgery and is often performed subjectively. However, the value of subjectively estimated functional capacity in predicting cardiac complications is under debate. We determined the predictive value of subjectively assessed functional capacity on postoperative cardiac complications and mortality.

DESIGN

An observational cohort study in patients aged 60 years and over undergoing elective inpatient non-cardiac surgery in a tertiary referral hospital.

METHODS

Subjective functional capacity was determined by anaesthesiologists. The primary outcome was postoperative myocardial injury. Secondary outcomes were postoperative inhospital myocardial infarction and one year mortality. Logistic regression analysis and area under the receiver operating curves were used to determine the added value of functional capacity.

RESULTS

A total of 4879 patients was included; 824 (17%) patients had a poor subjective functional capacity. Postoperative myocardial injury occurred in 718 patients (15%). Poor functional capacity was associated with myocardial injury (relative risk (RR) 1.7, 95% confidence interval (CI) 1.5-2.0; P < 0.001), postoperative myocardial infarction (RR 2.9, 95% CI 1.9-4.2; P < 0.001) and one year mortality (RR 1.7, 95% CI 1.4-2.0; P < 0.001). After adjustment for other predictors, functional capacity was still a significant predictor for myocardial injury (odds ratio (OR) 1.3, 95% CI 1.0-1.7; P = 0.023), postoperative myocardial infarction (OR 2.0, 95% CI 1.3-3.0; P = 0.002) and one year mortality (OR 1.4, 95% CI 1.1-1.8; P = 0.003), but had no added value on top of other predictors.

CONCLUSIONS

Subjectively assessed functional capacity is a predictor of postoperative myocardial injury and death, but had no added value on top of other preoperative predictors.

Myocardial Injury in Patients With Sepsis and Its Association With Long-Term Outcome

BACKGROUND

Sepsis is frequently complicated by the release of cardiac troponin, but the clinical significance of this myocardial injury remains unclear. We studied the associations between troponin release during sepsis and 1-year outcomes.

METHODS AND RESULTS

We enrolled consecutive patients with sepsis in 2 Dutch intensive care units between 2011 and 2013. Subjects with a clinically apparent cause of troponin release were excluded. High-sensitivity cardiac troponin I (hs-cTnI) concentration in plasma was measured daily during the first 4 intensive care unit days, and multivariable Cox regression analysis was used to model its association with 1-year mortality while adjusting for confounding. In addition, we studied cardiovascular morbidity occurring during the first year after hospital discharge. Among 1258 patients presenting with sepsis, 1124 (89%) were eligible for study inclusion. Hs-cTnI concentrations were elevated in 673 (60%) subjects on day 1, and 755 (67%) ever had elevated levels in the first 4 days. Cox regression analysis revealed that high hs-cTnI concentrations were associated with increased death rates during the first 14 days (adjusted hazard ratio, 1.72; 95% confidence interval, 1.14-2.59 and hazard ratio, 1.70; 95% confidence interval, 1.10-2.62 for hs-cTnI concentrations of 100-500 and >500 ng/L, respectively) but not thereafter. Furthermore, elevated hs-cTnI levels were associated with the development of cardiovascular disease among 200 hospital survivors who were analyzed for this end point (adjusted subdistribution hazard ratio, 1.25; 95% confidence interval, 1.04-1.50).

CONCLUSIONS

Myocardial injury occurs in the majority of patients with sepsis and is independently associated with early-but not late-mortality, as well as postdischarge cardiovascular morbidity.

Succinylcholine Use and Dantrolene Availability for Malignant Hyperthermia Treatment: Database Analyses and Systematic Review

BACKGROUND

Although dantrolene effectively treats malignant hyperthermia (MH), discrepant recommendations exist concerning dantrolene availability. Whereas Malignant Hyperthermia Association of the United States guidelines state dantrolene must be available within 10 min of the decision to treat MH wherever volatile anesthetics or succinylcholine are administered, a Society for Ambulatory Anesthesia protocol permits Class B ambulatory facilities to stock succinylcholine for airway rescue without dantrolene. The authors investigated (1) succinylcholine use rates, including for airway rescue, in anesthetizing/sedating locations; (2) whether succinylcholine without volatile anesthetics triggers MH warranting dantrolene; and (3) the relationship between dantrolene administration and MH morbidity/mortality.

METHODS

The authors performed focused analyses of the Multicenter Perioperative Outcomes Group (2005 through 2016), North American MH Registry (2013 through 2016), and Anesthesia Closed Claims Project (1970 through 2014) databases, as well as a systematic literature review (1987 through 2017). The authors used difficult mask ventilation (grades III and IV) as a surrogate for airway rescue. MH experts judged dantrolene treatment. For MH morbidity/mortality analyses, the authors included U.S. and Canadian cases that were fulminant or scored 20 or higher on the clinical grading scale and in which volatile anesthetics or succinylcholine were given.

RESULTS

Among 6,368,356 queried outcomes cases, 246,904 (3.9%) received succinylcholine without volatile agents. Succinylcholine was used in 46% (n = 710) of grade IV mask ventilation cases (median dose, 100 mg, 1.2 mg/kg). Succinylcholine without volatile anesthetics triggered 24 MH cases, 13 requiring dantrolene. Among 310 anesthetic-triggered MH cases, morbidity was 20 to 37%. Treatment delay increased complications every 10 min, reaching 100% with a 50-min delay. Overall mortality was 1 to 10%; 15 U.S. patients died, including 4 after anesthetics in freestanding facilities.

CONCLUSIONS

Providers use succinylcholine commonly, including during difficult mask ventilation. Succinylcholine administered without volatile anesthetics may trigger MH events requiring dantrolene. Delayed dantrolene treatment increases the likelihood of MH complications. The data reported herein support stocking dantrolene wherever succinylcholine or volatile anesthetics may be used.

Vasoplegia after implantation of a continuous flow left ventricular assist device: incidence, outcomes and predictors

Background

Vasoplegia after routine cardiac surgery is associated with severe postoperative complications and increased mortality. It is also prevalent in patients undergoing implantation of pulsatile flow left ventricular assist devices (LVAD). However, less is known regarding vasoplegia after implantation of newer generations of continuous flow LVADs (cfLVAD). We aim to report the incidence, impact on outcome and predictors of vasoplegia in these patients.

Methods

Adult patients scheduled for primary cfLVAD implantation were enrolled into a derivation cohort (n = 118, 2006–2013) and a temporal validation cohort (n = 73, 2014–2016). Vasoplegia was defined taking into consideration low mean arterial pressure and/or low systemic vascular resistance, preserved cardiac index and high vasopressor support. Vasoplegia was considered after bypass and the first 48 h of ICU stay lasting at least three consecutive hours. This concept of vasoplegia was compared to older definitions reported in the literature in terms of the incidence of postoperative vasoplegia and its association with adverse outcomes. Logistic regression was used to identify independent predictors. Their ability to discriminate patients with vasoplegia was quantified by the area under the receiver operating characteristic curve (AUC).

Results

The incidence of vasoplegia was 33.1% using the unified definition of vasoplegia. Vasoplegia was associated with increased ICU length-of-stay (10.5 [6.9–20.8] vs 6.1 [4.6–10.4] p = 0.002), increased ICU-mortality (OR 5.8, 95% CI 1.9–18.2) and one-year-mortality (OR 3.9, 95% CI 1.5–10.2), and a higher incidence of renal failure (OR 4.3, 95% CI 1.8–10.4). Multivariable analysis identified previous cardiothoracic surgery, preoperative dopamine administration, preoperative bilirubin levels and preoperative creatinine clearance as independent preoperative predictors of vasoplegia. The resultant prediction model exhibited a good discriminative ability (AUC 0.80, 95% CI 0.71–0.89, p <  0.01). Temporal validation resulted in an AUC of 0.74 (95% CI 0.61–0.87, p <  0.01).

Conclusions

In the era of the new generation of cfLVADs, vasoplegia remains a prevalent (33%) and critical condition with worse short-term outcomes and survival. We identified previous cardiothoracic surgery, preoperative treatment with dopamine, preoperative bilirubin levels and preoperative creatinine clearance as independent predictors.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0645-y) contains supplementary material, which is available to authorized users.

Pulmonary Embolism After Endovascular Aortic Repair, a Retrospective Cohort Study

OBJECTIVES

Endovascular aortic repair (EVAR) is associated with an increased risk of pulmonary embolism, which is often clinically silent and therefore difficult to recognise. The aim was to investigate the incidence of pulmonary embolism after EVAR using routinely performed pre- and post-operative aortic computed tomography angiography (CTA), and the association between pulmonary embolism and mortality.

METHODS

This single centre retrospective cohort study included adult patients who underwent EVAR in the University Medical Centre Utrecht between January 2010 and July 2015 and who had a total aortic, thoracic aortic, or pulmonary CTA within one month post-operatively. Baseline and mortality data were obtained by reviewing hospital and general practitioner records. The primary outcome was pulmonary embolism within one month after surgery. Secondary outcomes were 30 day and six month mortality.

RESULTS

During the study period, 526 EVARs were performed. Seventy-four of these procedures were included in the analysis of which there were 40 thoracic and 34 abdominal EVARs. In nine patients (12%, 95% CI 7-22) pulmonary embolism was observed of which one was central, two were segmental, and six were subsegmental. Seven were clinically silent and two were present on the pre-operative CTA. Thirty day mortality was significantly higher in patients with pulmonary embolism (relative risk 14.4, 95% CI 1.4-143, p = .037) though none of the deaths seemed directly attributable to it.

CONCLUSIONS

This study, although preliminary, suggests that silent pulmonary embolism after EVAR occurs in approximately one in 10 patients, despite routine thrombo-embolism prophylaxis. Pulmonary embolism was associated with a higher 30 day mortality risk yet it was not the cause of death in any of these patients.

Causes and prevention of postoperative myocardial injury

Over the past few years non-cardiac surgery has been recognised as a serious circulatory stress test which may trigger cardiovascular events such as myocardial infarction, in particular in patients at high risk. Detection of these postoperative cardiovascular events is difficult as clinical symptoms often go unnoticed. To improve detection, guidelines advise to perform routine postoperative assessment of cardiac troponin. Troponin elevation - or postoperative myocardial injury - can be caused by myocardial infarction. However, also non-coronary causes, such as cardiac arrhythmias, sepsis and pulmonary embolism, may play a role in a considerable number of patients with postoperative myocardial injury. It is crucial to acquire more knowledge about the underlying mechanisms of postoperative myocardial injury because effective prevention and treatment options are lacking. Preoperative administration of beta-blockers, aspirin, statins, clonidine, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, and preoperative revascularisation have all been investigated as preventive options. Of these, only statins should be considered as the initiation or reload of statins may reduce the risk of postoperative myocardial injury. There is also not enough evidence for intraoperative measures such blood pressure optimisation or intensified medical therapy once patients have developed postoperative myocardial injury. Given the impact, better preoperative identification of patients at risk of postoperative myocardial injury, for example using preoperatively measured biomarkers, would be helpful to improve cardiac optimisation.

Cardiac events within one year after a subarachnoid haemorrhage: The predictive value of troponin elevation after aneurysm occlusion

BACKGROUND

Patients who survive after an aneurysmal subarachnoid haemorrhage (ASAH) have an increased incidence of cardiovascular events compared with the general population. We assessed whether troponin elevation after aneurysm occlusion, as marker of myocardial injury, can predict long-term cardiac events.

METHODS

We analysed a prospectively collected cohort of 159 patients with ASAH and early aneurysm occlusion, in whom routine post-intervention troponin I (TnI) measurements were performed. With competing risk regression modelling we estimated the association between TnI elevation after aneurysm occlusion and major adverse cardiac events within one year. Secondary outcome measures were all-cause mortality and neurological condition within one year. The predictive value of post-intervention TnI was compared with the predictive value of pre-intervention characteristics using c-statistics and the integrated discrimination improvement index.

RESULTS

Subdistribution hazard ratios for TnI elevation and major adverse cardiac events at one year were 1.05 (95% confidence interval (CI) 1.03-1.07) per 10 ng/l increase in TnI and 7.91 (95% CI 1.46-43.0) for any TnI elevation. After adjustment for pre-intervention variables, the subdistribution hazard ratios were 1.47 (95% CI 0.81-2.67) per 10 ng/l and 9.00 (95% CI 1.62-50.1) for any elevation. The c-statistic was 0.71 for TnI elevation as a continuous measure and 0.69 for any TnI elevation. The integrated discrimination improvement index showed a minimum improvement in prediction of 0.08 (interquartile range 0.06 to 0.09) for TnI as a continuous measure and 0.003 (interquartile range -0.004 to 0.01) for any TnI elevation, when compared with pre-intervention characteristics.

CONCLUSION

TnI elevation after occlusion of a ruptured intracranial aneurysm predicts the occurrence of a major adverse cardiac event within one year after ASAH.

The association between aortic cross clamp time and postoperative morbidity and mortality in mitral valve repair: a retrospective cohort study

BACKGROUND

The aim of this study was to estimate the association between aortic cross clamp time and postoperative morbidity and mortality in patients undergoing mitral valve repair.

METHODS

A retrospective cohort study between 2006 and 2014 was performed as a single Center study in the University Medical Center Utrecht. In total 1007 patients who underwent mitral valve repair were included. The patients were divided into a group who underwent isolated mitral valve repair and a group who underwent mitral valve repair with concomitant intervention(s). The primary endpoint was a composite consisting of in-hospital mortality or postoperative major complications.

RESULTS

In the isolated mitral valve group (N.=405), patients were significantly younger, healthier and had fewer complications (9.9%). Patients with concomitant intervention(s) had a twofold higher rate of postoperative complications and mortality (18.1%). After adjustment for confounding there was no association between aortic cross clamp time and the primary endpoint in both the isolated mitral valve group (odds ratio 1.04; 95% CI: 0.98-1.11) and the group with concomitant interventions (odds ratio 1.02; 95% CI: 0.97-1.06).

CONCLUSIONS

In patients undergoing mitral valve repair surgery a longer aortic cross clamp time was not associated with postoperative complications and mortality. The higher postoperative morbidity and mortality in combined procedures appears to be due to a higher age, more comorbidities and an extra intervention rather than to the duration of aortic cross clamp time.

Evaluating the impact of prediction models: lessons learned, challenges, and recommendations

An important aim of clinical prediction models is to positively impact clinical decision making and subsequent patient outcomes. The impact on clinical decision making and patient outcome can be quantified in prospective comparative-ideally cluster-randomized-studies, known as 'impact studies'. However, such impact studies often require a lot of time and resources, especially when they are (cluster-)randomized studies. Before envisioning such large-scale randomized impact study, it is important to ensure a reasonable chance that the use of the prediction model by the targeted healthcare professionals and patients will indeed have a positive effect on both decision making and subsequent outcomes. We recently performed two differently designed, prospective impact studies on a clinical prediction model to be used in surgical patients. Both studies taught us new valuable lessons on several aspects of prediction model impact studies, and which considerations may guide researchers in their decision to conduct a prospective comparative impact study. We provide considerations on how to prepare a prediction model for implementation in practice, how to present the model predictions, and how to choose the proper design for a prediction model impact study.

One-Year Mortality, Causes of Death, and Cardiac Interventions in Patients with Postoperative Myocardial Injury

BACKGROUND

To evaluate the role of routine troponin surveillance in patients undergoing major noncardiac surgery, unblinded screening with cardiac consultation per protocol was implemented at a tertiary care center. In this study, we evaluated 1-year mortality, causes of death, and consequences of cardiac consultation of this protocol.

METHODS

This observational cohort included 3224 patients ≥60 years old undergoing major noncardiac surgery. Troponin I was measured routinely on the first 3 postoperative days. Myocardial injury was defined as troponin I >0.06 μg/L. Regression analysis was used to determine the association between myocardial injury and 1-year mortality. The causes of death, the diagnoses of the cardiologists, and interventions were determined for different levels of troponin elevation.

RESULTS

Postoperative myocardial injury was detected in 715 patients (22%) and was associated with 1-year all-cause mortality (relative risk [RR] 1.4, P = 0.004; RR 1.6, P < 0.001; and RR 2.2, P < 0.001 for minor, moderate, and major troponin elevation, respectively). Cardiac death within 1 year occurred in 3%, 5%, and 11% of patients, respectively, in comparison with 3% of the patients without myocardial injury (P = 0.059). A cardiac consultation was obtained in 290 of the 715 patients (41%). In 119 (41%) of these patients, the myocardial injury was considered to be attributable to a predisposing cardiac condition, and in 111 patients (38%), an intervention was initiated.

CONCLUSIONS

Postoperative myocardial injury was associated with an increased risk of 1-year all-cause but not cardiac mortality. A cardiac consultation with intervention was performed in less than half of these patients. The small number of interventions may be explained by a low suspicion of a cardiac etiology in most patients and lack of consensus for standardized treatment in these patients.

Reference Values for Noninvasive Blood Pressure in Children during Anesthesia: A Multicentered Retrospective Observational Cohort Study

BACKGROUND

Although noninvasive blood pressure (NIBP) monitoring during anesthesia is a standard of care, reference ranges for blood pressure in anesthetized children are not available. We developed sex- and age-specific reference ranges for NIBP in children during anesthesia and surgery.

METHODS

In this retrospective observational cohort study, we included NIBP data of children with no or mild comorbidity younger than 18 yr old from the Multicenter Perioperative Outcomes Group data set. Sex-specific percentiles of the NIBP values for age were developed and extrapolated into diagrams and reference tables representing the 50th percentile (0 SD), +1 SD, -1 SD, and the upper (+2 SD) and lower reference ranges (-2 SD).

RESULTS

In total, 116,362 cases from 10 centers were available for the construction of NIBP age- and sex-specific reference curves. The 0 SD of the mean NIBP during anesthesia varied from 33 mmHg at birth to 67 mmHg at 18 yr. The low cutoff NIBP (2 SD below the 50th percentile) varied from 17 mmHg at birth to 47 mmHg at 18 yr old.

CONCLUSIONS

This is the first study to present reference ranges for blood pressure in children during anesthesia. These reference ranges based on the variation of values obtained in daily care in children during anesthesia could be used for rapid screening of changes in blood pressure during anesthesia and may provide a consistent reference for future blood pressure-related pediatric anesthesia research.

Kinetics of troponin I in patients with myocardial injury after noncardiac surgery

BACKGROUND

Myocardial injury after noncardiac surgery, as measured by troponin elevation, is strongly associated with mortality. However, it is unknown in which patients prognosis can be improved. The presence of kinetic changes of troponin may be associated with a worse prognosis and warrant more aggressive management. Therefore, we aimed to study the kinetics of troponin in patients with postoperative myocardial injury, and to determine the added predictive value of kinetic changes of troponin on mortality.

METHODS

This cohort study included patients with myocardial injury after noncardiac surgery. Troponin I (TnI) was measured on the first three postoperative days. The primary outcome was all-cause 1-year mortality. We studied both absolute and relative TnI changes, and determined the delta TnI that was associated with mortality to distinguish a rise-and-fall TnI pattern from a stable TnI pattern. Next, we determined the added predictive value of a rise-and-fall TnI pattern for mortality.

RESULTS

In total, 634 patients were included. The risk ratio (RR) for mortality increased significantly with an absolute delta TnI of ≥200 ng/L (RR 1.5, 99.4% CI 1.0-2.2, p=0.003). Using this delta TnI to define a rise-and-fall pattern, 459 patients (72%) had a stable TnI pattern and 175 patients (28%) had a rise-and-fall pattern. When added to a model including the highest TnI value and variables from the revised cardiac risk index (RCRI), the TnI pattern did not increase the predictive value for mortality.

CONCLUSIONS

A postoperative TnI rise-and-fall pattern was associated with 1-year mortality, but had no added value in addition to the highest TnI level to predict 1-year mortality. Therefore, postoperative TnI kinetics are not useful for further mortality risk stratification in patients with myocardial injury after noncardiac surgery.

Transforming the learning outcomes of anaesthesiology training into entrustable professional activities: A Delphi study

BACKGROUND

True competency-based medical education should produce graduates meeting fixed standards of competence. Current postgraduate programmes are usually based on a pre-determined length of time in training making them poorly suited for an individual approach. The concept of entrustable professional activities (EPAs) enables a more flexible, personalised and less time-dependent approach to training programmes. An EPA is a unit of professional practice, to be entrusted to a trainee to execute without supervision once they demonstrate sufficient competence. As EPAs relate competencies to clinical practice, they structure training and assessment more logically according to the way clinicians actually work. A first step in building an EPA-based curriculum is to identify the core EPAs of the profession.

OBJECTIVES

The aim of this study was to identify EPAs for postgraduate training in anaesthesiology and to provide an example of how an existing curriculum can be transformed into an EPA-based curriculum.

DESIGN

A modified Delphi method was used as a consensus approach applying three Delphi rounds.

SETTING

Postgraduate specialty training in anaesthesiology in the Netherlands.

PARTICIPANTS

All programme directors in anaesthesiology in the Netherlands except for a single programme director who was involved as a researcher in this study and could not participate.

MAIN OUTCOME MEASURES

Agreement among participants on a list of EPAs. Agreement was specified as a consensus rate of more than 80%.

RESULTS

In this study, 27 programme directors (69% overall response rate) reached consensus on a set of 45 EPAs that describe a curriculum in anaesthesiology for the Netherlands.

CONCLUSION

This study is a first step toward a more contemporary curriculum in competency-based postgraduate anaesthesiology training.

Barriers and facilitators perceived by physicians when using prediction models in practice

OBJECTIVES

Prediction models may facilitate risk-based management of health care conditions. In a large cluster-randomized trial, presenting calculated risks of postoperative nausea and vomiting (PONV) to physicians (assistive approach) increased risk-based management of PONV. This increase did not improve patient outcome-that is, PONV incidence. This prompted us to explore how prediction tools guide the decision-making process of physicians.

STUDY DESIGN AND SETTING

Using mixed methods, we interviewed eight physicians to understand how predicted risks were perceived by the physicians and how they influenced decision making. Subsequently, all 57 physicians of the trial were surveyed for how the presented risks influenced their perceptions.

RESULTS

Although the prediction tool made physicians more aware of PONV prevention, the physicians reported three barriers to use predicted risks in their decision making. PONV was not considered an outcome of utmost importance; decision making on PONV prophylaxis was mostly intuitive rather than risk based; prediction models do not weigh benefits and risks of prophylactic drugs.

CONCLUSION

Combining probabilistic output of the model with their clinical experience may be difficult for physicians, especially when their decision-making process is mostly intuitive. Adding recommendations to predicted risks (directive approach) was considered an important step to facilitate the uptake of a prediction tool.