The Danish Anaesthesia Database

Characteristics and outcomes for general anesthesia in Denmark

BACKGROUND

General anesthesia is common, but concerns regarding post-operative complications and mortality remain. No study has described the Danish patient population undergoing general anesthesia on a national level. The aim of this study was to describe the characteristics and outcomes of patients undergoing general anesthesia in Denmark.

METHODS

This study was a registry-based observational cohort study of adult patients (≥18 years) undergoing general anesthesia in Denmark during 2020 and 2021. Data from nationwide registries covering patient characteristics, anesthesia and procedure information, and patient outcomes were combined. Descriptive statistics were used to present findings, both overall and in subgroups based on the American Society of Anesthesiologists (ASA) classification.

RESULTS

We identified 453,133 cases of general anesthesia in 328,951 unique patients. The median age was 57 years (quartiles: 41, 71), and 242,679 (54%) were females. Data on ASA classification were missing for less than 1% of the population, and ASA II was the most prevalent ASA classification (49%). Among cases of general anesthesia, 0.1% experienced a stroke, 0.2% had in-hospital cardiac arrest, and 3.9% had a stay in the intensive care unit within 30 days. Mortality at 30 days and 1 year were 1.8% and 6.3%, respectively, increasing with a higher ASA classification.

CONCLUSION

This study offers the first comprehensive overview of adult patients undergoing general anesthesia in Denmark. Post-anesthesia complications were few and increased with ASA classification.

Prognostic Value of Pretreatment Plasma C-Reactive Protein in Patients with Early-Stage Breast Cancer

BACKGROUND

Breast cancer incidence is now the highest among all cancers and accountable for 6.6% of all cancer-related deaths worldwide. Studies of the prognostic utility of plasma C-reactive protein (CRP) measurement in early-stage breast cancer have given discrepant results.

METHODS

We identified 6,942 patients in the Danish Breast Cancer Cooperative Group database with early-stage breast cancer diagnosed between 2002 and 2016 who had a measure of pretreatment plasma CRP. Outcomes were recurrence-free interval and survival for a period up to 10 years. We analyzed associations with plasma CRP using Fine-Gray proportional subdistribution hazards model with recurrence-free interval. Data on plasma CRP were analyzed per doubling of concentration and in relation to CRP levels of <3 mg/L, 3 to 10 mg/L, and >10 mg/L and stratified according to standard clinical parameters in sensitivity analyses.

RESULTS

A doubling of the plasma CRP concentration was associated with increased risk of recurrence (multivariate adjusted HR, 1.05; 95% CI, 1.01-1.08) and shorter survival (HR, 1.13; 95% CI, 1.09-1.16) in multivariate analyses. Survival was shorter in patients with plasma CRP levels of 3 to 10 and >10 mg/L versus <3 mg/L, with multivariate adjusted HRs of 1.30; 95% CI, 1.17-1.45 and 1.65; 95% CI, 1.39-1.95, respectively.

CONCLUSIONS

Elevated plasma CRP measured before treatment in patients with early-stage breast cancer is an independent biomarker of increased risk of recurrence and early death.

IMPACT

CRP measures before treatment might be used to individualize follow-up of patients with early-stage breast cancer.

Is General Anesthesia for Peripheral Vascular Surgery Correlated with Impaired Outcome in Patients with Cardiac Comorbidity? A Closer Look into the Nationwide Danish Cohort

OBJECTIVE

General anesthesia (GA) may impair outcome after vascular surgery. The use of anticoagulant medication is often used in patients with cardiac comorbidity. Regional anesthesia (RA) requires planning of discontinuation before neuraxial blockade(s) in this subgroup. This study aimed to describe the effect of anesthesia choice on outcome after vascular surgery in patients with known cardiac comorbidity.

DESIGN

Retrospective cohort study.

SETTING

Danish hospitals.

PARTICIPANTS

6302 patients with known cardiac comorbidity, defined as ischemic heart disease, valve disease, pulmonary vascular disease, heart failure, and cardiac arrhythmias, undergoing lower extremity vascular surgery between 2005 and 2017.

INTERVENTIONS

GA versus RA.

MEASUREMENTS AND MAIN RESULTS

Data were extracted from national registries. GA was defined as anesthesia with mechanical ventilation. Multivariable regression models were used to describe the incidence of postoperative complications as well as 30-day mortality, hypothesizing that better outcomes would be seen after RA. The rate of RA decreased from 48% in 2005 to 20% in 2017. The number of patients with 1 or more complications was 9.7% vs 6.2% (p < 0.001), and 30-day mortality was 6.0% vs 3.4% (p < 0.001) after GA. After adjusting for baseline differences, the odds ratio (OR) was significantly lower for medical complications (cardiac, pulmonary, renal, new dialysis, intensive care unit and other medical complications; OR, 0.97; 95% confidence interval [CI], 0.95-0.98) and 30-day mortality (OR 0.98; 95% CI, 0.97-0.99) after RA.

CONCLUSIONS

RA may be associated with a better outcome than GA after lower extremity vascular surgery in patients with a cardiac comorbidity. Prioritizing RA, despite the inconvenience of discontinuing anticoagulants, may be recommended.

Impact on Survival of Early Versus Late Initiation of Adjuvant Chemotherapy After Pancreatic Adenocarcinoma Surgery: A Target Trial Emulation

BACKGROUND

We examined the impact of early (0-4 weeks after discharge) versus late (> 4-8 weeks after discharge) initiation of adjuvant chemotherapy on pancreatic adenocarcinoma survival.

METHODS

We used Danish population-based healthcare registries to emulate a hypothetical target trial using the clone-censor-weight approach. All eligible patients were cloned with one clone assigned to 'early initiation' and one clone assigned to 'late initiation'. Clones were censored when the assigned treatment was no longer compatible with the actual treatment. Informative censoring was addressed using inverse probability of censoring weighting.

RESULTS

We included 1491 patients in a hypothetical target trial, of whom 32.3% initiated chemotherapy within 0-4 weeks and 38.3% between > 4 and 8 weeks after discharge for pancreatic adenocarcinoma surgery; 206 (13.8%) initiated chemotherapy after > 8 weeks, and 232 (15.6%) did not initiate chemotherapy. Median overall survival was 30.4 and 29.9 months in late and early initiators, respectively. The absolute differences in OS, comparing late with early initiators, were 3.2% (95% confidence interval [CI] - 1.5%, 7.9%), - 0.7% (95% CI - 7.2%, 5.8%), and 3.2% (95% CI - 2.8%, 9.3%) at 1, 3, and 5 years, respectively. Late initiators had a higher increase in albumin levels as well as higher pretreatment albumin values.

CONCLUSIONS

Postponement of adjuvant chemotherapy up to 8 weeks after discharge from pancreatic adenocarcinoma surgery is safe and may allow more patients to receive adjuvant therapy due to better recovery.

Effect of adjuvant chemotherapy after pancreatectomy in patients with node-negative pancreatic cancer: target trial emulation

BACKGROUND

The effect of adjuvant therapy in node-negative pancreatic cancer is uncertain. The aim of this study was to estimate the effect of adjuvant chemotherapy on survival after surgery for pancreatic cancer in patients with node-negative (pN0) and node-positive (pN+) disease using target trial emulation.

METHODS

This was an observational cohort study emulating a hypothetical RCT by the clone-censor-weight approach using population-based Danish healthcare registries. The study included Danish patients undergoing curative-intent surgery for pancreatic cancer during 2008-2021, who were discharged alive no more than 4 weeks after surgery. At the time of discharge after surgery, the data for each patient were duplicated; one copy was assigned to the adjuvant chemotherapy strategy and the other to the no adjuvant chemotherapy strategy of the hypothetical trial. Copies were censored when the assigned treatment was no longer compatible with the observed treatment. To account for informative censoring, uncensored patients were weighted according to measured confounders. The primary outcomes were absolute difference in 2-year survival and median overall survival, comparing adjuvant with no adjuvant chemotherapy.

RESULTS

Some 424 patients with pN0 and 953 with pN+ disease were included. Of these, 62.0 and 74.6% respectively initiated adjuvant chemotherapy within the 8-week grace period. Among patients with pN0 tumours, the difference in 2-year survival between those with and without adjuvant therapy was -2.2 (95% c.i. -11.8 to 7.4)%. In those with pN+ disease, the difference in 2-year survival was 9.9 (1.6 to 18.1)%. Median overall survival was 24.9 (i.q.r. 12.8-49.4) and 15.0 (8.0-34.0) months for patients having adjuvant and no adjuvant therapy respectively.

CONCLUSION

In a target trial emulation using observational data, adjuvant chemotherapy did not improve survival after surgery for node-negative pancreatic cancer.

Beta-blocker use and survival after pancreatic cancer surgery: A nationwide population-based cohort study

PURPOSE

We examined the association between use of beta-blockers and survival in pancreatic cancer patients after curative-intent surgery.

METHODS

Using Danish healthcare registries, we conducted a population-based cohort study of all patients undergoing curative-intent surgery for pancreatic cancer in Denmark 1997-2021. We defined beta-blocker use according to exposure before surgery as current (≤90 days), recent (91-365 days), or former (366-730 days) use, requiring at least one filled prescription. Patients were followed from the date of surgery for up to 5 years. We used Cox regression to compute hazard ratios (HRs) of deaths with 95% confidence intervals (CIs), adjusting for age, sex, year of diagnosis, cardiovascular disease, diabetes, liver disease, alcohol, and smoking. We also conducted an active comparator analysis, where we used angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers as comparators instead of nonusers.

RESULTS

We included 2592 patients, of which 16.7% were beta-blocker users. Median survival for the entire population was 24.4 months. Beta-blocker use was associated with increased mortality (adjusted HR: 1.18; 95% CI: 1.04-1.34). This was evident in current (adjusted HR: 1.19; 95% CI: 1.02-1.38) and recent (adjusted HR: 1.29; 95% CI: 1.04-1.59) but not former (adjusted HR: 0.91; 95% CI: 0.64-1.43) users. In the active comparator analysis, the association between beta-blocker exposure and mortality attenuated slightly (adjusted HR: 1.12; 95% CI: 0.93-1.35).

CONCLUSIONS

We observed an association between beta-blocker use and increased mortality in patients operated for pancreatic cancer. Findings are likely explained by confounding by indication.

Impact of prior cancer diagnosis on pancreatic cancer outcomes: A Danish Nationwide, population-based Cohort study

BACKGROUND

The overall survival of pancreatic cancer (PC) remains low, underlining the need of further research to improve PC directed therapy. Some patients with PC may have experienced a prior cancer, refraining them from inclusion in clinical trials, despite not knowing the precise effect of a prior cancer on disease course of PC.

OBJECTIVE

To examine the influence of prior cancer on the disease course in patients with PC.

METHODS

We conducted a cohort study including Danish patients diagnosed with PC between 2004 and 2020 crosslinking data from the Danish Cancer Registry, the Danish National Patient Registry among several other databases. Using the Kaplan-Meier estimator, we calculated the overall and American Joint Committee on Cancer (AJCC) disease stage stratified survival, comparing patients with and without prior cancer. Furthermore, using inverse probability of treatment weighting (IPTW), we presented a covariate-adjusted model of the average treatment effect in the treated (ATT) of prior cancer on the overall PC survival and stratified for AJCC disease stage.

RESULTS

We included 11,147 patients diagnosed with PC, of which 906 (8.1%) had a prior cancer. Comparing patients with and without prior cancer, the IPTW-adjusted survival, indicated a slightly better survival (ATT: 1.5 months; 95% CI: 0.7; 2.2 months). After stratifying by PC tumor stage, the difference was restricted to patients with stage IV PC disease (ATT: 1.1 months; 95% CI: 0.5; 1.7 months). Patients with prior cancer were slightly less prone to present with stage IV PC disease and were more likely to not receive active treatment compared with patients without prior cancer.

CONCLUSION

Prior cancer was associated with a slightly better survival in patients with PC, but only in patients with stage IV PC disease. This is likely explained by lead time bias.

Real-Time Identification of Pancreatic Cancer Cases Using Artificial Intelligence Developed on Danish Nationwide Registry Data

PURPOSE

Pancreatic cancer is expected to be the second leading cause of cancer-related deaths worldwide within few years. Most patients are not diagnosed in time for curative-intent treatment. Accelerating the time of diagnosis is a key component of reducing pancreatic cancer mortality. We developed and tested a dynamic algorithm aiming at proactively identifying patients with a substantially elevated risk of having undiagnosed pancreatic cancer.

METHODS

Machine learning methodology was applied to a live stream of nationwide Danish registry data. A hybrid case-control and prospective cohort design relying on incidence density sampling was used. Three models with minimal tuning were tested. All performance evaluation metrics were based on out-of-sample, out-of-time data in a monthly walk-forward strategy to avoid any temporal biases or inflation of performance metrics. Outcome was a diagnosis of pancreatic cancer.

RESULTS

Subgroups identified had a 10.1% risk of being diagnosed with pancreatic cancer within 1 year, corresponding to a number needed to screen of 9.9. When considering competing, potentially computed tomography-detectable GI cancers, this number is reduced to 5.7. The time of diagnosis can be accelerated by up to 142 days.

CONCLUSION

Currently available nationwide live data and computational resources are sufficient for real-time identification of individuals with at least 10.1% risk of having undiagnosed pancreatic cancer and 17.7% risk of any GI cancer in the Danish population. For prospective identification of high-risk patients, the area under the curve is not a useful indication of the positive predictive values achieved. Viable design solutions are demonstrated, which address the main shortfalls of the existing cancer prediction efforts in relation to temporal biases, leaks, and performance metric inflation. Efficacy evaluations with resection rates and mortality as end points are needed.

The Nordic perioperative and intensive care registries-Collaboration and research possibilities

BACKGROUND

The Nordic perioperative and intensive care registries have been built up during the last 25 years to improve quality in intensive and perioperative care. We aimed to describe the Nordic perioperative and intensive care registries and to highlight possibilities and challenges in future research collaboration between these registries.

MATERIAL AND METHOD

We present an overview of the following Nordic registries: Swedish Perioperative Registry (SPOR), the Danish Anesthesia Database (DAD), the Finnish Perioperative Database (FIN-AN), the Icelandic Anesthesia Database (IS-AN), the Danish Intensive Care Database (DID), the Swedish Intensive Care Registry (SIR), the Finnish Intensive Care Consortium, the Norwegian Intensive Care and Pandemic Registry (NIPaR), and the Icelandic Intensive Care Registry (IS-ICU).

RESULTS

Health care systems and patient populations are similar in the Nordic countries. Despite certain differences in data structure and clinical variables, the perioperative and intensive care registries have enough in common to enable research collaboration. In the future, even a common Nordic registry could be possible.

CONCLUSION

Collaboration between the Nordic perioperative and intensive care registries is both possible and likely to produce research of high quality. Research collaboration between registries may have several add-on effects and stimulate international standardization regarding definitions, scoring systems, and benchmarks, thereby improving overall quality of care.

Quality indicators for anesthesia and perioperative medicine

PURPOSE OF REVIEW

Routine monitoring of care quality is fundamental considering the high reported rates of preventable perioperative morbidity and mortality. However, no set of valid and feasible quality indicators is available as the gold standard for comprehensive routine monitoring of the overall quality of perioperative care. The purpose of this review is to describe underlying difficulties, to summarize current trends and initiatives and to outline the perspectives in support of suitable perioperative quality indicators.

RECENT FINDINGS

Most perioperative quality indicators used in the clinical setting are based on low or no evidence. Evidence-based perioperative quality indicators validated for research purposes are not always applicable in routine care. Developing a core set of perioperative quality indicators for clinical practice may benefit from matching feasible routine indicators with evidence-based indicators validated for research, from evaluating additional new indicators, and from including patients' views.

SUMMARY

A core set of valid and feasible quality indicators is essential for monitoring perioperative care quality. The development of such a set may benefit from matching evidence-based indicators with feasible standard indicators and from including patients' views.

Implementation of video laryngoscopes and the development in airway management strategy and prevalence of difficult tracheal intubation: A national cohort study

BACKGROUND

We aimed to determine the development in the use of video laryngoscopy over a 9-year period, and its possible impact on airway planning and management.

METHODS

We retrieved 822,259 records of tracheal intubations recorded from 2008 to 2016 in the Danish Anaesthesia Database. The circumstances regarding pre-operative airway assessment, the scheduled airway management plan and the actual airway management concerning video laryngoscopy were reported for each year of observation. Further, the association between year of observation and various airway management related outcomes was evaluated by multivariate logistic regression.

RESULTS

There was a significant increase in airway management with 'advanced technique successfully used within two attempts' from 2.7% in 2008 to 15.5% in 2016 (p < .0001). This predominantly reflects use of video laryngoscopy. The prevalence of tracheal intubations 'scheduled for video laryngoscopy' increased from 3.5% in 2008 to 10.6% in 2016 (p < .0001). We found a significant increase in the prevalence of anticipated difficulties with intubations by direct laryngoscopy from 1.8% in 2008 to 5.2% in 2016 (p < .0001). The prevalence of failed tracheal intubations decreased from 0.14% in 2008 to 0.05% in 2016 (p < .0001).

CONCLUSION

From 2008 to 2016, a period of massive implementation of video laryngoscopes, a significant change in airway management behaviour was recorded. Increasingly, video laryngoscopy is becoming a first-choice device for both acute and routine airway management. Most importantly, the data showed a noticeable reduction in failed intubation over the time of observation.

Big data: Airway management at a university hospital over 16 years; a retrospective analysis

Purpose

Little is known about the current practice of airway management in Germany and its development over the last decades. The present study was, therefore, designed to answer the following questions. Which airway management procedures have been performed over the last 16 years and how has the frequency of these procedures changed over time? Is there a relationship between patient characteristics or surgical specialisation and the type of airway management performed?

Methods

In the present study, we used our in-house data acquisition and accounting system to retrospectively analyse airway management data for all patients who underwent a surgical or medical procedure with anaesthesiological care at our tertiary care facility over the past 16 years. 340,748 airway management procedures were analysed by type of procedure, medical/surgical specialty, and type of device used. Logistic regression was used to identify trends over time.

Results

Oral intubation was the most common technique over 16 years (65.7%), followed by supraglottic airway devices (18.1%), nasal intubation (7.5%), mask ventilation (1.6%), tracheal cannula (1.3%), double lumen tube (0.7%), and jet ventilation (0.6%). On average, the odds ratio of using supraglottic airway devices increased by 17.0% per year (OR per year = 1.072, 95% CI = 1.071–1.088) while oral intubation rates decreased. In 2005, supraglottic airway devices were used in about 10% of all airway management procedures. Until 2020, this proportion steadily increased by 27%. Frequency of oral intubation on the other hand decreased and was about 75% in 2005 and 53% in 2020.

Over time, second-generation supraglottic airway devices were used more frequently than first-generation supraglottic airway devices. While second-generation devices made up about 9% of all supraglottic airway devices in 2010, in 2020 they represented a proportion of 82%.

The use of fibreoptic intubation increased over time in otorhinolaryngology and dental, oral, and maxillofacial surgery, but showed no significant trends over the entire 16-year period.

Conclusion

Our data represent the first large-scale evaluation of airway management procedures over a long time. There was a significant upward trend in the use of supraglottic airway devices, with an increase in the use of second-generation masks while a decrease in oral intubations was observed.

Epidural Analgesia and Postoperative Complications in Colorectal Cancer Surgery. An Observational Registry-based Study

BACKGROUND

In colorectal cancer, surgical resection is fundamental for curative treatment. Epidural analgesia mitigates the perioperative physiologic stress response caused by surgery, and reduction in perioperative stress may reduce postoperative complications. Nevertheless, epidural analgesia also causes hypotension and lower limb motor weakness that can impair postoperative recovery. Here, we aimed to assess the association between epidural analgesia and postoperative complications after colorectal cancer surgery.

METHODS

We identified patients undergoing colorectal cancer surgery 2008-2018 in Denmark in the Danish Colorectal Cancer Group Database and obtained anaesthesia data from the Danish Anaesthesia Database. The Danish National Prescription Registry was used to obtain data on prescriptions filled preoperatively reflecting current comorbidities. Databases were linked using the Danish Central Person Registry number and the operation day. Patients were classified according to preoperative insertion of an epidural catheter for analgesia. Confounders were adjusted by propensity score matching. Logistic regression was used to compute effect estimates of epidural analgesia on postoperative complications.

RESULTS

We identified 19932 individuals undergoing colorectal cancer surgery with available anaesthesia data. Propensity score matching yielded 5691 individuals in each group with balanced preoperative covariates. In the epidural analgesia group 1400 (24.6%) experienced complications compared with 1453 (25.5%) without epidural analgesia. We found no statistically significant association between epidural use and postoperative complications (OR 0.95, 95% CI 0.87-1.04).

CONCLUSION

In total, in this observational study based on Danish registries, we found no association between epidural analgesia and postoperative complications after colorectal cancer surgery.

Inhalation anaesthesia compared with total intravenous anaesthesia and postoperative complications in colorectal cancer surgery: an observational registry-based study†

BACKGROUND

Postoperative complications are common after colorectal surgery, and possibly related to the type of anaesthesia. We aimed to determine associations between the type of anaesthesia and complications after colorectal cancer surgery using Danish registries.

METHODS

Patients undergoing colorectal cancer surgery (2004-18) were identified in the Danish Colorectal Cancer Group Database. The cohort was enriched with the Danish Anaesthesia Database and Danish National Prescription Registry data linked by Danish Central Person Registration number. Patients were classified according to type of general anaesthesia: inhalation or TIVA. Confounders were adjusted by propensity score matching. The primary outcome was complications within 30 days postoperatively. Secondarily, we assessed specific medical and surgical complications.

RESULTS

We identified 22 179 individuals undergoing colorectal cancer surgery with accompanying anaesthesia data. Propensity score matching yielded 8722 individuals per group. After propensity score matching, postoperative complications were seen in 1933 (22.2%) patients undergoing inhalation anaesthesia and in 2199 (25.2%) undergoing TIVA (odds ratio [OR]=0.84; 95% confidence interval [CI], 0.79-0.91). Although no difference was observed for medical complications, 1369 (15.7%) undergoing inhalation anaesthesia had surgical complications compared with 1708 (19.6%) undergoing TIVA (OR=0.76; 95% CI, 0.71-0.83). Rates of wound dehiscence, anastomotic leak, ileus, wound abscess, intra-abdominal abscess, and sepsis were statistically significantly lower in the inhalation anaesthesia group.

CONCLUSION

In this propensity score-matched registry study, use of inhalation anaesthesia was associated with fewer postoperative complications after colorectal cancer surgery than use of TIVA. Inhalation anaesthesia was associated with fewer complications related to wound healing and surgical infections.

Epidural Analgesia and Recurrence after Colorectal Cancer Surgery: A Danish Retrospective Registry-based Cohort Study

BACKGROUND

Surgery is the main curative treatment for colorectal cancer. Yet the immunologic and humoral response to surgery may facilitate progression of micro-metastases. It has been suggested that epidural analgesia preserves immune competency and prevents metastasis formation. Hence, the authors tested the hypothesis that epidural analgesia would result in less cancer recurrence after colorectal cancer surgery.

METHODS

The Danish Colorectal Cancer Group Database and the Danish Anesthesia Database were used to identify patients operated for colorectal cancer between 2004 and 2018 with no residual tumor tissue left after surgery. The exposure group was defined by preoperative insertion of an epidural catheter for analgesia. The primary outcome was colorectal cancer recurrence, and the secondary outcome was mortality. Recurrences were identified using a validated algorithm based on data from Danish health registries. Follow-up was until death or September 7, 2018. The authors used propensity score matching to adjust for potential preoperative confounders.

RESULTS

In the study population of 11,618 individuals, 3,496 (30.1%) had an epidural catheter inserted before surgery. The epidural analgesia group had higher proportions of total IV anesthesia, laparotomies, and rectal tumors, and epidural analgesia was most frequently used between 2009 and 2012. The propensity score-matched study cohort consisted of 2,980 individuals in each group with balanced baseline covariates. Median follow-up was 58 months (interquartile range, 29 to 86). Recurrence occurred in 567 (19.0%) individuals in the epidural analgesia group and 610 (20.5%) in the group without epidural analgesia. The authors found no association between epidural analgesia and recurrence (hazard ratio, 0.91; 95% CI, 0.82 to 1.02) or mortality (hazard ratio, 1.01; 95% CI, 0.92 to 1.10).

CONCLUSIONS

In colorectal cancer surgery, epidural analgesia was not statistically significantly associated with less cancer recurrence.

EDITOR’S PERSPECTIVE

General or regional anaesthesia for postpartum haemorrhage-A national population-based cohort study

BACKGROUND

Anaesthesia is required to assist the treatment of postpartum haemorrhage (PPH) when manual removal of the placenta or emptying of the uterine cavity is required. The choice between general or regional anaesthesia may depend upon factors such as existing epidural, airway, hypovolaemia, and tradition.

METHODS

Data from a randomized controlled trial of PPH (FIB-PPH) was used to reveal differences between delivery centres. In addition, national data of 5,601 PPH procedures requiring anaesthesia during 2010-2015 was collected from the Danish Medical Birth Registry, the National Danish Patient Registry, and the Danish Anaesthesia Database. The aim is to describe the variation in choice of anaesthesia for treatment of PPH.

RESULTS

Data from the randomized trial showed large differences in practice between centres not explained by physiological factors. Using national Danish registry data, we show that large delivery centres as compared to small centres prefer regional anaesthesia for PPH procedures in opposed to general anaesthesia. Sevoflurane was used despite it causing uterine relaxation. The use of general anaesthesia was associated with younger parturients, larger blood loss, and larger Body-Mass Index. Aspiration was recorded in one case (0.02%). In the postoperative care-unit general anaesthesia was associated with a shorter stay, but also higher pain score at admission.

CONCLUSION

Practice varies immensely between delivery centres with large centres preferring regional anaesthesia. Difference in practice might be explained by level of experience, here large centres might be more confident using regional anaesthesia. Knowledge is being extrapolated from literature on caesarean sections. Future studies should address the optimal choice of anaesthesia for PPH procedures.

Ischaemic vascular disease and long-term mortality in emergency abdominal surgical patients: A population-based cohort study

BACKGROUND

Emergency abdominal surgery carries a high mortality, as patients are often frail with significant comorbidity. We aimed to evaluate the association between co-existing ischaemic vascular disease (IVD) and long-term mortality in patients undergoing emergency abdominal surgery.

METHODS

We included adult emergency abdominal surgical patients operated on 13 Danish hospitals between 1 January 2009 and 31 December 2010. Appendectomies were excluded. Data were retrieved from the National Patient Registry (NPR) and the Danish Anaesthesia Database. Preoperative IVD status was retrieved from NPR. We used crude and adjusted Cox regression analysis. The primary outcome was mortality within eight years. The secondary outcome was mortality within 30 days.

RESULTS

We included 4864 patients, of which 2584 (53.7%) died within 8 years. Some 20.9% (1019/4864) had preoperative IVD. The adjusted association between preoperative IVD and mortality within 8 years was hazard ratio (HR) 1.10 (95% confidence interval [CI], 1.00-1.20; P = .045). At 30 days, this association was HR 0.97 (95% CI, 0.84-1.13).

CONCLUSION

In adult major emergency abdominal surgical patients, preoperative IVD was prevalent and associated with a 10% relative increase in long-term mortality, but not in short-term mortality.

Current practice of German anesthesiologists in airway management : Results of a national online survey

BACKGROUND

There is a worldwide consensus among experts that guidelines and algorithms on airway management contribute to improved patient safety in anesthesia. The present study aimed to determine the current practice of airway management of German anesthesiologists and assess the safety gap, defined as the difference between observed and recommended practice, amongst these practitioners.

OBJECTIVE

To determine the effect of implementing the guidelines on airway management practice in Germany amongst anesthesiologists and identify potential safety gaps.

METHODS

A survey was conducted in September 2019 by contacting all registered members of the German Society of Anaesthesiology and Intensive Care Medicine (DGAI) via email. The participants were asked about their personal and institutional background, adherence to recommendations of the current German S1 guidelines and availability of airway devices.

RESULTS

A total of 1862 DGAI members completed the questionnaire (response rate 17%). The main outcome was that anesthesiologists mostly adhered to the guidelines, yet certain recommendations, particularly pertaining to specifics of preoxygenation and training, showed a safety gap. More than 90% of participants had a video laryngoscope and half had performed more than 25 awake intubations using a flexible endoscope; however, only 81% had a video laryngoscope with a hyperangulated blade. An estimated 16% of all intubations were performed with a video laryngoscope, and 1 in 4 participants had performed awake intubation with it. Nearly all participants had cared for patients with suspected difficult airways. Half of the participants had already faced a "cannot intubate, cannot oxygenate" (CICO) situation and one in five had to perform an emergency front of neck access (eFONA) at least once. In this case, almost two thirds used puncture-based techniques and one third scalpel-based techniques.

CONCLUSION

Current practice of airway management showed overall adherence to the current German guidelines on airway management, yet certain areas need to be improved.

Big Data in Studying Acute Pain and Regional Anesthesia

The digital transformation of healthcare is advancing, leading to an increasing availability of clinical data for research. Perioperative big data initiatives were established to monitor treatment quality and benchmark outcomes. However, big data analyses have long exceeded the status of pure quality surveillance instruments. Large retrospective studies nowadays often represent the first approach to new questions in clinical research and pave the way for more expensive and resource intensive prospective trials. As a consequence, the utilization of big data in acute pain and regional anesthesia research has considerably increased over the last decade. Multicentric clinical registries and administrative databases (e.g., healthcare claims databases) have collected millions of cases until today, on which basis several important research questions were approached. In acute pain research, big data was used to assess postoperative pain outcomes, opioid utilization, and the efficiency of multimodal pain management strategies. In regional anesthesia, adverse events and potential benefits of regional anesthesia on postoperative morbidity and mortality were evaluated. This article provides a narrative review on the growing importance of big data for research in acute postoperative pain and regional anesthesia.

Malignant hyperthermia 2020: Guideline from the Association of Anaesthetists

Malignant hyperthermia is defined in the International Classification of Diseases as a progressive life-threatening hyperthermic reaction occurring during general anaesthesia. Malignant hyperthermia has an underlying genetic basis, and genetically susceptible individuals are at risk of developing malignant hyperthermia if they are exposed to any of the potent inhalational anaesthetics or suxamethonium. It can also be described as a malignant hypermetabolic syndrome. There are no specific clinical features of malignant hyperthermia and the condition may prove fatal unless it is recognised in its early stages and treatment is promptly and aggressively implemented. The Association of Anaesthetists has previously produced crisis management guidelines intended to be displayed in all anaesthetic rooms as an aide memoire should a malignant hyperthermia reaction occur. The last iteration was produced in 2011 and since then there have been some developments requiring an update. In these guidelines we will provide background information that has been used in updating the crisis management recommendations but will also provide more detailed guidance on the clinical diagnosis of malignant hyperthermia. The scope of these guidelines is extended to include practical guidance for anaesthetists dealing with a case of suspected malignant hyperthermia once the acute reaction has been reversed. This includes information on care and monitoring during and after the event; appropriate equipment and resuscitative measures within the operating theatre and ICU; the importance of communication and teamwork; guidance on counselling of the patient and their family; and how to make a referral of the patient for confirmation of the diagnosis. We also review which patients presenting for surgery may be at increased risk of developing malignant hyperthermia under anaesthesia and what precautions should be taken during the peri-operative management of the patients.

Inhalation or total intravenous anaesthesia and recurrence after colorectal cancer surgery: a propensity score matched Danish registry-based study

BACKGROUND

During colorectal cancer surgery, the immune-modulating effects of inhalation anaesthesia may create a favourable environment for metastasis formation, leading to increased risk of recurrence. Our aim was to assess the association between inhalation vs intravenous anaesthesia and cancer recurrence in patients undergoing colorectal cancer surgery.

METHODS

Patients undergoing colorectal cancer surgery in 2004-18 were identified in the Danish Colorectal Cancer Group Database and Danish Anaesthesia Database. After exclusion of patients with residual tumour registered in postoperative pathology reports, local endoscopic resections, and stent insertions, we classified patients according to exposure to inhalation anaesthesia. The primary outcome was recurrence (time to recurrence), whereas secondary outcomes were all-cause mortality (time to death) and disease-free survival (time to either recurrence or death). Events of recurrence and death were identified using The Danish Civil Registration System, Danish National Pathology Registry, and Danish National Patient Registry. The sub-distribution hazards approach was used to estimate hazard ratios (HRs) for recurrence, and Cox regression was used for all-cause mortality and disease-free survival.

RESULTS

We identified 5238 patients exposed to inhalation anaesthesia and 6322 to intravenous anaesthesia. Propensity score matching yielded 4347 individuals in each group with balanced baseline covariates. We found a weak association between recurrence and exposure to inhalation anaesthesia (HR=1.12; 95% confidence interval [CI], 1.02-1.23). The HR estimates for all-cause mortality and disease-free survival were 1.00 (95% CI, 0.93-1.07) and 1.04 (95% CI, 0.98-1.11) respectively.

CONCLUSION

Exposure to inhalation anaesthesia was associated with increased risk of recurrence after colorectal cancer surgery.

Routinely collected data and patient-centred research in anaesthesia and peri-operative care: a narrative review

Randomised controlled trials are the gold standard in clinical research, but remain rare due to their expense and a perceived lack of 'real-world' applicability. At the same time, there has been an exponential increase in routinely collected data which presents opportunities for audit, quality improvement, adverse event reporting and more efficient clinical research. Registry-based research benefits from reduced cost, large sample size and real-world applicability, with methodological developments, particularly registry-based randomised controlled trials and causal inference techniques, showing promise. Limitations include data quality and validity, the need for data linkage, the restrictions of fixed data fields, regulatory barriers, and privacy and security concerns. However, the principal factor hampering current efforts is a lack of anaesthesia-specific datasets in the UK and the fact that most surgical registries do not collect any anaesthetic data. This presents an opportunity for anaesthetists, through enhanced engagement and collaboration, to influence and improve the design of these datasets and increase the value and volume of data collected. Better datasets, coupled with a growing appreciation of new analysis methodologies, would allow significant progress towards realising the potential of routinely collected data for patient benefit. At the same time, work should begin on the development of a minimum dataset for anaesthesia to underpin new data sharing networks and, ideally, a national registry of anaesthesia.

Anesthesiology airway-related medicolegal cases from the Canadian Medical Protection Association

Purpose

We analyzed closed civil legal cases in 2007-2016 from the Canadian Medical Protective Association (CMPA) involving specialist anesthesiologists where airway management was the central concern.

Methods

We included all airway-related civil legal cases involving specialist anesthesiologists that closed from 2007 to 2016. The following variables were abstracted by CMPA medical analysts: clinical context, peer expert opinions of contributing factors, and patient and legal outcomes.

Results

We found 46 of the 406 (11%) closed cases involving anesthesiologists to be airway-related. Twenty-six cases (57%) involved elective surgery and 31 patients (67%) were categorized as American Society of Anesthesiologists physical status III. Twenty-five cases (54%) occurred outside the operating room (e.g., postanesthesia care unit, intensive care unit, or other satellite locations). In 19 (42%) cases, there was at least one predictor of a difficult airway. Peer experts identified judgement failures in 30 cases (65%), most commonly inadequate airway evaluation. In 30 cases (65%), the patient died or had a permanent brain injury. The medicolegal outcome favoured the patient in 27 (59%) cases, with a median [interquartile range] payment of 422,845 [257,637-935,673] CAD.

Conclusions

Severe patient harm is common when airway management is the focus of a CMPA medicolegal complaint involving anesthesiologists. Patients were otherwise typically low risk cases presenting for elective surgery. Failure to assess or to change management based on the airway exam or encountered difficulty were the most common errors. Our findings support the continued need for adoption, adherence, and practice of guidelines for anticipated and unanticipated difficult airway management for every patient encounter.

Reoperation after antireflux surgery: a population-based cohort study

Background

Antireflux surgery for gastro-oesophageal reflux disease (GORD) and/or hiatal hernia is effective. Between 10 and 20 per cent of patients undergo reoperation for recurrent symptoms. Most studies are undertaken in a single centre and possibly underestimate the rate of reoperation. The aim of this nationwide population-based cohort study was to investigate long-term reoperation rates after antireflux surgery.

Methods

This study included patients who underwent antireflux surgery between 2000 and 2017 in Denmark, and were registered in the Danish nationwide health registries. Reoperation rates were calculated for 1, 5, 10 and 15 years after the primary antireflux operation for GORD and/or hiatal hernia. Duration of hospital stay, 30- and 90-day mortality and morbidity, and use of endoscopic pneumatic dilatation were assessed.

Results

This study included a total of 4258 antireflux procedures performed in 3717 patients. Some 3252 patients had only primary antireflux surgery and 465 patients underwent reoperation. The 1-, 5-, 10- and 15-year rates of repeat antireflux surgery were 3·1, 9·3, 11·7 and 12·8 per cent respectively. Thirty- and 90-day mortality rates were similar for primary surgery (0·4 and 0·6 per cent respectively) and reoperations. The complication rate was higher for repeat antireflux surgery (7·0 and 8·3 per cent at 30 and 90 days respectively) than primary operation (3·4 and 4·8 per cent). A total of 391 patients (10·5 per cent of all patients) underwent endoscopic dilatation after primary antireflux surgery, of whom 95 (24·3 per cent) had repeat antireflux surgery.

Conclusion

In this population-based study in Denmark, the reoperation rate 15 years after antireflux surgery was 12·8 per cent. Reoperations were associated with more complications.

APACHE II score validation in emergency abdominal surgery. A post hoc analysis of the InCare trial

BACKGROUND

Patients undergoing emergency abdominal surgery are at high risk of morbidity and mortality. Accurate identification of high-risk patients is important. The Acute Physiology and Chronic Health Evaluation (APACHE) II score needs to be validated in a larger heterogeneous population before implementation. We aimed to assess the predictive value of the APACHE II score in emergency abdominal surgical patients. Furthermore, we compared the APACHE II score with the American Society of Anesthesiologists (ASA) physical status score and the Charlson Comorbidity Index (CCI).

METHODS

We included adult patients undergoing emergency abdominal surgery screened for enrolment in the InCare trial from October 2010 to November 2012. The APACHE II score was evaluated with area under the receiver operating characteristics curve (AUROC) statistics. The primary outcome was 30-day mortality. Secondary outcomes included 90-day mortality and admission to the intensive care unit.

RESULTS

We included a total of 885 patients. All-cause 30-day mortality was 5.0%, 90-day mortality was 8.9%, and a total of 7.9% of the patients were admitted to the intensive care unit. The AUROC (95% confidence interval) of the APACHE II score was 0.72 (0.65-0.80) for 30-day mortality, 0.70 (0.64-0.76) for 90-day mortality and 0.65 (0.59-0.71) for admission to the intensive care unit. The CCI performed better in prediction of 90-day mortality (P = .04). All other results for the ASA score and CCI were comparable with the APACHE II score.

CONCLUSION

The APACHE II score predicted mortality moderately and admission to intensive care unit poorly in emergency abdominal surgical patients.

The association between epidural analgesia and mortality in emergency abdominal surgery: A population-based cohort study

BACKGROUND

Emergency abdominal surgery carries a considerable risk of mortality and post-operative complications, including pulmonary complications. In major elective surgery, epidural analgesia reduces mortality and pulmonary complications. We aimed to evaluate the association between epidural analgesia and mortality in emergency abdominal surgery.

METHODS

In this population-based cohort study with prospective data collection, we included adults undergoing emergency abdominal laparotomy or laparoscopy between 1 January 2009 and 31 December 2010 at 13 Danish hospitals. Appendectomies were excluded. The primary outcome was 90-day mortality. Secondary outcomes included 30-day mortality and serious adverse events. We used binary logistic regression analyses (odds ratios (ORs) with 95% confidence intervals (CIs)).

RESULTS

We included 4920 patients, of whom 1134 (23.0%) died within 90 days. Overall, 27.9% of the patients were treated with epidural analgesia perioperatively. This increased to 34.0% among patients undergoing major laparotomy. The crude and adjusted association between epidural analgesia and 90-day mortality was OR 0.99 (95%CI: 0.86-1.15, P = .94) and OR 0.80 (95%CI: 0.67-0.94; P = .01), respectively. For 30-day mortality the corresponding estimates were OR 0.90 (95% CI: 0.76-1.06, P = .21) and OR 0.75 (95% CI: 0.62-0.90, P < .01), respectively. No serious adverse events were reported.

CONCLUSION

In this population-based cohort study of adult patients undergoing emergency abdominal surgery, we found that the use of epidural analgesia perioperatively was associated with a decreased risk of mortality in the adjusted analysis.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

Introduction

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

Objective

This systematic review aims to identify barriers and facilitators to health data harmonization—including data sharing and linkage—by a comparative analysis of studies from Denmark and Switzerland.

Methods

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

Results

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

Conclusion

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

The Danish health care system and epidemiological research: from health care contacts to database records

Denmark has a large network of population-based medical databases, which routinely collect high-quality data as a by-product of health care provision. The Danish medical databases include administrative, health, and clinical quality databases. Understanding the full research potential of these data sources requires insight into the underlying health care system. This review describes key elements of the Danish health care system from planning and delivery to record generation. First, it presents the history of the health care system, its overall organization and financing. Second, it details delivery of primary, hospital, psychiatric, and elderly care. Third, the path from a health care contact to a database record is followed. Finally, an overview of the available data sources is presented. This review discusses the data quality of each type of medical database and describes the relative technical ease and cost-effectiveness of exact individual-level linkage among them. It is shown, from an epidemiological point of view, how Denmark’s population represents an open dynamic cohort with complete long-term follow-up, censored only at emigration or death. It is concluded that Denmark’s constellation of universal health care, long-standing routine registration of most health and life events, and the possibility of exact individual-level data linkage provides unlimited possibilities for epidemiological research.

The DIFFMASK score for predicting difficult facemask ventilation: a cohort study of 46,804 patients

Facemask ventilation is an essential part of airway management. Correctly predicting difficulties in facemask ventilation may reduce the risk of morbidity and mortality among patients at risk. We aimed to develop and evaluate a weighted risk score for predicting difficult facemask ventilation during anaesthesia. We analysed a cohort of 46,804 adult patients who were assessed pre-operatively airway for 13 predictors of difficult airway management and subsequently underwent facemask ventilation during general anaesthesia. We developed the Difficult Facemask (DIFFMASK) score in two consecutive steps: first, a multivariate regression analysis was performed; and second, the regression coefficients of the adjusted regression model were converted into a clinically applicable weighted point score. The predictive accuracy of the DIFFMASK score was evaluated by assessment of receiver operating characteristic curves. The prevalence of difficult facemask ventilation was 1.06% (95%CI 0.97-1.16). Following conversion of regression coefficients into 0, 1, 2 or 3 points, the cumulated DIFFMASK score ranged from 0 to 18 points and the area under the receiver operating characteristic curve was 0.82. The Youden index indicated a sum score ≥ 5 as an optimal cut-off value for prediction of difficult facemask ventilation giving a sensitivity of 85% and specificity of 59%. The DIFFMASK score indicated that a score of 6-10 points represents a population of patients who may require heightened attention when facemask ventilation is planned, compared with those patients who are obviously at a high- or low risk of difficulties. The DIFFMASK score may be useful in a clinical context but external, prospective validation is needed.

Supraglottic airway devices in difficult airway management: a retrospective cohort study of 658,104 general anaesthetics registered in the Danish Anaesthesia Database

Indications for using supraglottic airway devices have widened over time and they now hold a prominent role in guidelines for difficult airway management. We aimed to describe the use of supraglottic airway devices in difficult airway management. We included adult patients undergoing general anaesthesia registered in the Danish Anaesthesia Database from 2008 to 2012 whose airway management had been recorded as difficult, defined as: ≥ 3 tracheal intubation attempts; failed tracheal intubation; or difficult facemask ventilation. In the Danish Anaesthesia Database, a separate difficult airway management module requires the technique used in each successive airway management attempt to be recorded. The primary aim of the study was to describe the use of supraglottic airway devices in cases of difficult airway management. Secondary aims were to examine success rates of supraglottic airway devices in difficult airway management cases, and specifically in the cases of 'cannot intubate, cannot facemask ventilate'. Difficult airway management occurred in 4898 (0.74% (95%CI 0.72-0.76%)) of 658,104 records of general anaesthesia. Supraglottic airway devices were used or use was attempted in 607 cases of difficult airway management (12.4% (95%CI 11.5-13.3%)), and were successful in 395 (65.1% (95%CI 61.2-68.8%)) cases. In 'cannot intubate, cannot facemask ventilate' situations, supraglottic airway devices were used in 86 (18.9% (95%CI 15.6-22.8%)) of 455 records and were successful in 54 (62.8% (95%CI 52.2-72.3%)) cases. We found that supraglottic airway devices are not widely used in the management of the difficult airway despite their prominent role in difficult airway management guidelines.