Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study.

Healthcare workers involved in aerosol-generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID-19. However, the magnitude of this risk is unknown. We conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID-19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self-reporting. The primary endpoint was the incidence of laboratory-confirmed COVID-19 diagnosis or new symptoms requiring self-isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure-related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR [range]) follow-up of 32 (18-48 [0-116]) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID-19 subsequently reported a COVID-19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID-19 transmission.

Intraoperative hypotension and the risk of postoperative adverse outcomes: a systematic review.

BACKGROUND: Intraoperative hypotension is a common side effect of general anaesthesia and might lead to inadequate organ perfusion. It is unclear to what extent hypotension during noncardiac surgery is associated with unfavourable outcomes. METHODS: We conducted a systematic search in PubMed, Embase, Web of Science, and CINAHL, and classified the quality of retrieved articles according to predefined adapted STROBE and CONSORT criteria. Reported strengths of associations from high-quality studies were classified into end-organ specific injury risks, such as acute kidney injury, myocardial injury, and stroke, and overall organ injury risks for various arterial blood pressure thresholds. RESULTS: We present an overview of 42 articles on reported associations between various absolute and relative intraoperative hypotension definitions and their associations with postoperative adverse outcomes after noncardiac surgery. Elevated risks of end-organ injury were reported for prolonged exposure (≥10 min) to mean arterial pressures <80 mm Hg and for shorter durations <70 mm Hg. Reported risks increase with increased durations for mean arterial pressures <65-60 mm Hg or for any exposure <55-50 mm Hg. CONCLUSIONS: The reported associations suggest that organ injury might occur when mean arterial pressure decreases <80 mm Hg for ≥10 min, and that this risk increases with blood pressures becoming progressively lower. Given the retrospective observational design of the studies reviewed, reflected by large variability in patient characteristics, hypotension definitions and outcomes, solid conclusions on which blood pressures under which circumstances are truly too low cannot be drawn. We provide recommendations for the design of future studies. CLINICAL REGISTRATION NUMBER: (PROSPERO ID). CRD42013005171.

Different methods of modelling intraoperative hypotension and their association with postoperative complications in patients undergoing non-cardiac surgery.

BACKGROUND: Associations between intraoperative hypotension (IOH) and postoperative complications have been reported. We examined whether using different methods to model IOH affected the association with postoperative myocardial injury (POMI) and acute kidney injury (AKI). METHODS: This two-centre cohort study included 10 432 patients aged ≥50 yr undergoing non-cardiac surgery. Twelve different methods to statistically model IOH [representing presence, depth, duration, and area under the threshold (AUT)] were applied to examine the association with POMI and AKI using logistic regression analysis. To define IOH, eight predefined thresholds were chosen. RESULTS: The incidences of POMI and AKI were 14.9% and 14.8%, respectively. Different methods to model IOH yielded effect estimates differing in size and statistical significance. Methods with the highest odds were absolute maximum decrease in blood pressure (BP) and mean episode AUT, odds ratio (OR) 1.43 [99% confidence interval (CI): 1.15-1.77] and OR 1.69 (99% CI: 0.99-2.88), respectively, for the absolute mean arterial pressure 50 mm Hg threshold. After standardisation, the highest standardised ORs were obtained for depth-related methods, OR 1.12 (99% CI: 1.05-1.20) for absolute and relative maximum decrease in BP. No single method always yielded the highest effect estimate in every setting. However, methods with the highest effect estimates remained consistent across different BP types, thresholds, outcomes, and centres. CONCLUSIONS: In studies on IOH, both the threshold to define hypotension and the method chosen to model IOH affects the association of IOH with outcome. This makes different studies on IOH less comparable and hampers clinical application of reported results.

Postoperative pain management after esophagectomy: a systematic review and meta-analysis.

Effective pain management after esophagectomy is essential for patient comfort, early recovery, low surgical morbidity, and short hospitalization. This systematic review and meta-analysis aims to determine the best pain management modality focusing on the balance between benefits and risks. Medline, Embase, and the Cochrane library were systematically searched to identify all studies investigating different pain management modalities after esophagectomy in relation to primary outcomes (postoperative pain scores at 24 and 48 hours, technical failure, and opioid consumption), and secondary outcomes (pulmonary complications, nausea and vomiting, hypotension, urinary retention, and length of hospital stay). Ten studies investigating systemic, epidural, intrathecal, intrapleural and paravertebral analgesia involving 891 patients following esophagectomy were included. No significant differences were found in postoperative pain scores between systemic and epidural analgesia at 24 (mean difference (MD) 0.89; 95% confidence interval (CI) -0.47-2.24) and 48 hours (MD 0.15; 95%CI -0.60-0.91), nor described for systemic and other regional analgesia. Also, no significant differences in pulmonary complication rates were identified between systemic and epidural analgesia (relative risk (RR) 1.69; 95%CI 0.86-3.29), or between systemic and paravertebral analgesia (RR 1.49; 95%CI 0.31-7.12). Technical failure ranged from 17% to 22% for epidural analgesia. Sample sizes were too small to draw inferences on opioid consumption, the risk of nausea and vomiting, hypotension, urinary retention, and length of hospital stay when comparing the different pain management modalities including systemic, epidural, intrathecal, intrapleural, and paravertebral analgesia. This systematic review and meta-analysis shows no differences in postoperative pain scores or pulmonary complications after esophagectomy between systemic and epidural analgesia, and between systemic and paravertebral analgesia. Further randomized controlled trails are warranted to determine the optimal pain management modality after esophagectomy.

Validation of non-invasive arterial pressure monitoring during carotid endarterectomy.

BACKGROUND: Patients undergoing carotid endarterectomy require strict arterial blood pressure (BP) control to maintain adequate cerebral perfusion. In this study we tested whether non-invasive beat-to-beat Nexfin finger BP (BPfin) can replace invasive beat-to-beat radial artery BP (BPrad) in this setting. METHODS: In 25 consecutive patients (median age 71 yr) scheduled for carotid endarterectomy and receiving general anaesthesia, BPfin and BPrad were monitored simultaneously and ipsilaterally during the 30-min period surrounding carotid artery cross-clamping. Validation was guided by the standard set by the Association for the Advancement of Medical Instrumentation (AAMI), which considers a BP monitor adequate when bias (precision) is <5 (8) mm Hg, respectively. RESULTS: BPfin vs BPrad bias (precision) was -3.3 (10.8), 6.1 (5.7) and 3.5 (5.2) mm Hg for systolic, diastolic, and mean BP, respectively. One subject was excluded due to a poor quality BP curve. In another subject, mean BPfin overestimated mean BPrad by 13.5 mm Hg. CONCLUSION: Mean BPfin could be considered as an alternative for mean BPrad during a carotid endarterectomy, based on the AAMI criteria. In 23 of 24 patients, the use of mean BPfin would not lead to decisions to adjust mean BPrad values outside the predefined BP threshold. CLINICALTRIALSGOV: NCT01451294.

Clinical Relevance of Cardiac Troponin Assessment in Patients Undergoing Carotid Endarterectomy.

OBJECTIVE: Myocardial infarction (MI) is a frequent complication of carotid endarterectomy (CEA), yet most events are silent. Routine post-operative monitoring of cardiac troponin was implemented to facilitate timely recognition of MI and stratify high risk patients. The aim was to evaluate the incidence of troponin elevation after CEA and its association with adverse cardiovascular events. METHODS: This analysis included patients ≥60 years old who underwent CEA, whose troponin-I levels were routinely monitored post-operatively and were included in a cohort study that assessed clinical outcomes. A clinical troponin cutoff of 60 ng/L was used. The primary endpoint was the composite of MI, stroke, and cardiovascular death. Secondary endpoints were MI, stroke, coronary intervention, cardiovascular death, and all cause death. RESULTS: 225 consecutive patients were included in the analysis. Troponin elevation occurred in 34 patients (15%) and a post-operative MI was diagnosed in eight patients. After a median follow up of 1.8 years (IQR 1.0-2.6), the primary endpoint occurred in 29% of patients with troponin elevation versus 6.3% without (HR 5.6, 95% CI 2.4-13), MI in 24% versus 1.6% (HR 18.0, 95% CI 4.7-68), stroke in 5.9% versus 4.2% (HR 1.4, 95% CI 0.3-6.7), coronary intervention in 5.9% versus 2.6% (HR 2.7, 95% CI 0.5-14), cardiovascular death in 5.9% versus 0.5% (HR 11.8, 95% CI 1.1-131), and all cause death in 15% versus 5.8% (HR 3.0, 95% CI 1.0-8.7), respectively. Incidences of the primary endpoint and all cause mortality in patients with a post-operative MI versus "troponin only" were 25% versus 7.7% and 25% versus 12%, respectively. CONCLUSION: Troponin elevation after CEA occurred in 15% of patients. The incidence of adverse cardiovascular events was significantly higher in patients with troponin elevation, which was mainly attributable to silent non-ST segment elevation MIs that occurred in the early post-operative phase.

Intraoperative hypotension and delirium after on-pump cardiac surgery.

BACKGROUND: Delirium is a common complication after cardiac surgery and may be as a result of inadequate cerebral perfusion. We studied delirium after cardiac surgery in relation to intraoperative hypotension (IOH). METHODS: This observational single-centre, cohort study was nested in a randomized trial, on a single intraoperative dose of dexamethasone vs placebo during cardiac surgery. During the first four postoperative days, patients were screened for delirium based on the Confusion Assessment Method (CAM) for Intensive Care Unit on the intensive care unit, CAM on the ward, and by inspection of medical records. To combine depth and duration of IOH, we computed the area under the curve for four blood pressure thresholds. Logistic regression analyses were performed to investigate the association between IOH and the occurrence of postoperative delirium, adjusting for confounding and using a 99% confidence interval to correct for multiple testing. RESULTS: Of the 734 included patients, 99 patients (13%) developed postoperative delirium. The adjusted Odds Ratio for the Mean Arterial Pressure <60 mm Hg threshold was 1.04 (99% confidence interval: 0.99-1.10) for each 1000 mm Hg(2) min(2) AUC(2) increase. IOH, as defined according to the other three definitions, was not associated with postoperative delirium either. Deep and prolonged IOH seemed to increase the risk of delirium, but this was not statistically significant. CONCLUSIONS: Independent of the applied definition, IOH was not associated with the occurrence of delirium after cardiac surgery.

Impact of adding therapeutic recommendations to risk assessments from a prediction model for postoperative nausea and vomiting.

BACKGROUND: In a large cluster-randomized trial on the impact of a prediction model, presenting the calculated risk of postoperative nausea and vomiting (PONV) on-screen (assistive approach) increased the administration of risk-dependent PONV prophylaxis by anaesthetists. This change in therapeutic decision-making did not improve the patient outcome; that is, the incidence of PONV. The present study aimed to quantify the effects of adding a specific therapeutic recommendation to the predicted risk (directive approach) on PONV prophylaxis decision-making and the incidence of PONV. METHODS: A prospective before-after study was conducted in 1483 elective surgical inpatients. The before-period included care-as-usual and the after-period included the directive risk-based (intervention) strategy. Risk-dependent effects on the administered number of prophylactic antiemetics and incidence of PONV were analysed by mixed-effects regression analysis. RESULTS: During the intervention period anaesthetists administered 0.5 [95% confidence intervals (CIs): 0.4-0.6] more antiemetics for patients identified as being at greater risk of PONV. This directive approach led to a reduction in PONV [odds ratio (OR): 0.60, 95% CI: 0.43-0.83], with an even greater reduction in PONV in high-risk patients (OR: 0.45, 95% CI: 0.28-0.72). CONCLUSIONS: Anaesthetists administered more prophylactic antiemetics when a directive approach was used for risk-tailored intervention compared with care-as-usual. In contrast to the previously studied assistive approach, the increase in PONV prophylaxis now resulted in a lower PONV incidence, particularly in high-risk patients. When one aims for a truly 'PONV-free hospital', a more liberal use of prophylactic antiemetics must be accepted and lower-risk thresholds should be set for the actionable recommendations.

Postoperative hemoglobin levels and its association with myocardial ischemia in non-cardiac surgical patients.

BACKGROUND: Low hemoglobin (Hb) levels as well as cardiac complications are common conditions in postoperative surgical patients and both are associated with poor outcome. The aim of this study was to determine the influence of postoperative Hb levels on myocardial ischemia in high-risk patients who underwent non-cardiac surgery. METHODS: In this retrospective observational cohort study, we evaluated 3638 consecutive patients admitted to the 24-hour postoperative anesthesia care unit between 2006 and 2010; 273 (8%) high-risk patients, defined as three or more cardiac risk factors, were selected for analyses. Postoperative Hb levels were divided into tertiles (low, intermediate and high). The endpoint of this study was myocardial ischemia which was defined as new electrocardiographic abnormalities and/or elevated levels of troponin-T. The relationship between postoperative Hb levels and myocardial ischemia was assessed using logistic regression analyses stratified by gender. RESULTS: Postoperative myocardial ischemia was present in 73 (27%) of the 273 patients. After adjustment for significant pre-, intra- and postoperative risk factors, 4 independent risk factors remained for postoperative myocardial ischemia in male patients: age (OR 1.1; 95% CI: 1.0-1.1), a history of ischemic heart diseases (OR 4.2; 95% CI: 1.0-17.8), renal failure (OR 5.4; 95% CI: 2.1-13.9) and postoperative Hb levels: intermediate tertile (10.3-11.6 g/dL) (OR 5.8; 95% CI: 1.6-20.9) and lowest tertile (7.9-10.2 g/dL) (OR 12.9; 95% CI: 3.0-55.5). CONCLUSION: Postoperative Hb levels are independently associated with postoperative myocardial ischemia in high-risk patients undergoing non-cardiac surgery.

The aetiology of myocardial injury after non-cardiac surgery.

Recognition of myocardial injury after non-cardiac surgery is difficult, since strong analgesics (e.g. opioids) can mask anginal symptoms, and ECG abnormalities are subtle or transient. Thorough knowledge of the pathophysiological mechanisms is therefore essential. These mechanisms can be subdivided into four groups: type I myocardial infraction (MI), type II MI, non-ischaemic cardiac pathology, and non-cardiac pathology. The incidence of type I MI in patients with a clinical suspicion of perioperative acute coronary syndrome (ACS) is 45-57 %. This percentage is higher in patients with a high likelihood of MI such as patients with ST-elevation ACS. Of note, the generalisability of this statement is limited due to significant study limitations. Non-ischaemic cardiac pathology and non-cardiac pathology should not be overlooked as a cause of perioperative myocardial injury (PMI). Especially pulmonary embolism and dysrhythmias are a common phenomenon, and may convey important prognostic value. Implementation of routine postoperative troponin assessment and accessible use of minimally invasive imaging should be considered to provide adequate individualised therapy. Also, addition of preoperative imaging may improve the stratification of high-risk patients who may benefit from preoperative or perioperative interventions.

Internal validation of risk models in clustered data: a comparison of bootstrap schemes.

Internal validity of a risk model can be studied efficiently with bootstrapping to assess possible optimism in model performance. Assumptions of the regular bootstrap are violated when the development data are clustered. We compared alternative resampling schemes in clustered data for the estimation of optimism in model performance. A simulation study was conducted to compare regular resampling on only the patient level with resampling on only the cluster level and with resampling sequentially on both the cluster and patient levels (2-step approach). Optimism for the concordance index and calibration slope was estimated. Resampling of only patients or only clusters showed accurate estimates of optimism in model performance. The 2-step approach overestimated the optimism in model performance. If the number of centers or intraclass correlation coefficient was high, resampling of clusters showed more accurate estimates than resampling of patients. The 3 bootstrap schemes also were applied to empirical data that were clustered. The results presented in this paper support the use of resampling on only the clusters for estimation of optimism in model performance when data are clustered.

Occurrence and determinants of poor response to short-term pre-operative erythropoietin treatment.

BACKGROUND: This study aimed to explore the occurrence and determinants of poor response to short-term pre-operative erythropoietin treatment and the effect of such poor response on transfusion in total hip arthroplasty patients. METHODS: We studied total hip arthroplasty patients who received erythropoietin before surgery. The primary outcome was the pre-operative increase in haemoglobin (delta haemoglobin) as response to erythropoietin therapy. Additionally, patients were classified in tertiles based on this delta haemoglobin: poor responders (cases), responders and good responders (controls) to erythropoietin. Patient characteristics, comedication and co-morbidity were collected as potential determinants of erythropoietin response. Regression techniques were used to estimate the strength of the associations and to assess the effect of poor response on transfusion requirement. RESULTS: A total of 379 patients receiving erythropoietin were eligible to enter the study. Mean delta haemoglobin was 19.3 g/l (standard deviation 9.4). Factors significantly associated with delta haemoglobin were the use of angiotensin II antagonists [-3.1 g/l; 95% confidence interval (CI) -5.7 to -0.6] and vitamin K antagonists (-6.9 g/l; 95% CI -10.0 to -0.2), together with body mass index (BMI) (-0.3 g/l per unit>; 95% CI -0.5 to -0.2). The additional case-control analysis yielded comparable results. Poor response to erythropoietin was associated with an increased transfusion risk (odds ratio 4.6, 95% CI 2.0-11). CONCLUSION: Use of angiotensin II receptor antagonists and vitamin K antagonists, and having a high BMI were determinants of poor response to short-term pre-operative erythropoietin treatment in total hip arthroplasty patients. Poor responders had a higher risk for perioperative blood transfusion.

Effects of the introduction of the WHO "Surgical Safety Checklist" on in-hospital mortality: a cohort study.

OBJECTIVE: To evaluate the effect of implementation of the WHO's Surgical Safety Checklist on mortality and to determine to what extent the potential effect was related to checklist compliance. BACKGROUND: Marked reductions in postoperative complications after implementation of a surgical checklist have been reported. As compliance to the checklists was reported to be incomplete, it remains unclear whether the benefits obtained were through actual completion of a checklist or from an increase in overall awareness of patient safety issues. METHODS: This retrospective cohort study included 25,513 adult patients undergoing non-day case surgery in a tertiary university hospital. Hospital administrative data and electronic patient records were used to obtain data. In-hospital mortality within 30 days after surgery was the main outcome and effect estimates were adjusted for patient characteristics, surgical specialty and comorbidity. RESULTS: After checklist implementation, crude mortality decreased from 3.13% to 2.85% (P = 0.19). After adjustment for baseline differences, mortality was significantly decreased after checklist implementation (odds ratio [OR] 0.85; 95% CI, 0.73-0.98). This effect was strongly related to checklist compliance: the OR for the association between full checklist completion and outcome was 0.44 (95% CI, 0.28-0.70), compared to 1.09 (95% CI, 0.78-1.52) and 1.16 (95% CI, 0.86-1.56) for partial or noncompliance, respectively. CONCLUSIONS: Implementation of the WHO Surgical Checklist reduced in-hospital 30-day mortality. Although the impact on outcome was smaller than previously reported, the effect depended crucially upon checklist compliance.

Medication discontinuity errors in the perioperative period.

BACKGROUND: Inappropriate withdrawal or continuation of medication in the perioperative period is associated with an increased risk for adverse events. To reduce this risk, it is important that patients take their regular medication as prescribed. We evaluated this treatment objective by studying the frequency and reasons for errors related to medication discontinuity in the perioperative period. METHODS: Patients scheduled for non-cardiac surgery were included in this cross-sectional study. Perioperative medication intake was assessed at the holding area of the operation theatre complex and on the ward during the first 24 h after surgery. Medication intake data were obtained from medical records and by questioning patients and compared with pre-operative instructions. RESULTS: The study included 701 patients, of whom 485 (69%) used regular medication. Medication was incorrectly taken or discontinued before surgery in 27% of the patients. In 57% of these patients, the reason for incorrect intake was an unclear or a falsely understood instruction before surgery. Post-operative medication errors occurred in 26% of the patients. CONCLUSION: Medication errors occur frequently in the perioperative period, even in the era of an electronic medication file. Errors in prescription, administration and intake of medication are not easily solved because no single health care professional is responsible for adequate intake of medication in surgical patients. The anaesthesiologist should take on a more prominent role in regulating perioperative medication intake in surgical patients.

Feedback system to estimate the quality of outpatient preoperative evaluation records: an analysis of end-user satisfaction.

BACKGROUND: During preanaesthesia evaluation at an outpatient clinic, information is summarized and structured. We aimed to estimate the effectiveness of this process by determining the proportion of patients presenting for surgery who had valid preoperative anaesthesia assessment records, and also the proportion of patients with a record that contained sufficient information. METHODS: This study included all non-cardiac surgery procedures performed in adults in 2006 and 2007 in a university hospital. In each case, we asked the anaesthesiologist actually providing anaesthesia to assess the quality of the preoperative record on an electronic feedback form showing a predefined drop down menu and a free text box. The primary outcome was the proportion of procedures with a valid record (< 6 months old) that also contained sufficient and adequate information to safely provide anaesthesia. Secondly, all predefined remarks were assessed for relevance and the proportion of (relevant) remarks per individual anaesthesiologist was calculated. RESULTS: During the study period, 21 454 procedures were performed. A valid record was available in 20 700 procedures (97%). In 459 (2%) cases, a remark (mostly about not detected comorbidity) was given by the anaesthesia provider, of which 347 (76%) were assessed as 'relevant', resulting in 20 353 (95%) valid records containing sufficient and adequate information. Between individual anaesthesiologists, the percentage remarks ranged from 0.4% to 12.7%. CONCLUSIONS: On entering the operating theatre, 95% of elective surgery patients had a preanaesthesia evaluation record that contained sufficient and adequate information to safely provide anaesthesia. There was large variability in reporting remarks.

[Use of medicines to reduce the risk of postoperative cardiac death: too early for guidelines]. / Medicamenteuze reductie van de kans op postoperatieve cardiale sterfte: te vroeg voor een richtlijn.

In a review in this journal, Feringa et al. focused on the prevention of cardiovascular complications after non-cardiac surgery. Beta-blockers and statins appear to be the most effective in reducing post-operative mortality due to cardiac events. We have doubts about the external validity of the studies on cardiovascular risks after non-cardiac surgery. A major limitation is that conclusions for all patients have been drawn from relatively small samples with a selection of high-risk patients. Guidelines based upon such studies are 'premature', possibly dangerous and unethical, since the acceptance of such guidelines would preclude large scale studies to confirm the conclusions of the small studies so far performed. Perioperative beta-blockade is only needed in a subgroup of patients with a high-risk cardiac profile.