Detection of Advanced Lesions of Atherosclerosis in Carotid Arteries Using 3-Dimensional Motion-Sensitized Driven-Equilibrium Prepared Rapid Gradient Echo (3D-MERGE) Magnetic Resonance Imaging as a Screening Tool.

BACKGROUND AND PURPOSE: Two-dimensional high-resolution multicontrast magnetic resonance imaging (2D-MC MRI) is currently the most reliable and reproducible noninvasive carotid vessel wall imaging technique. However, the long scan time required for 2D-MC MRI restricts its practical clinical application. Alternatively, 3-dimensional motion-sensitized driven-equilibrium prepared rapid gradient echo (3D-MERGE) vessel wall MRI can provide high isotropic resolution with extensive coverage in two minutes. In this study, we sought to prove that 3D-MERGE alone can serve as a screening tool to identify advanced carotid lesions. METHODS: Two hundred twenty-seven subjects suspected of recent ischemic stroke or transient ischemic attack were imaged using 2D-MC MRI with an imaging time of 30 minutes, then with 3D-MERGE with an imaging time of 2 minutes, on 3T-MRI scanners. Two experienced reviewers interpreted plaque components using 2D-MC MRI as the reference standard and categorized plaques using a modified American Heart Association lesion classification for MRI. Plaques of American Heart Association type IV and above were classified as advanced. Arteries of American Heart Association types I to II and III were categorized as normal or with early lesions, respectively. One radiologist independently reviewed only 3D-MERGE and labeled the plaques as advanced if they had a wall thickness of >2 mm with high or low signal intensity compared with the adjacent sternocleidomastoid muscle. Sensitivity, specificity, and accuracy for 3D-MERGE were calculated. RESULTS: Four hundred forty-nine arteries from 227 participants (mean age 61.2 years old, 64% male) were included in the analysis. Sensitivity, specificity, and accuracy for identification of advanced lesions on 3D-MERGE were 95.0% (95% CI, 91.8-97.2), 86.9% (95% CI, 81.4-92.0), 93.8% (95% CI, 91.1-95.8), respectively. CONCLUSIONS: 3D-MERGE can accurately identify advanced carotid atherosclerotic plaques in patients suspected of stroke or transient ischemic attack. It has a more extensive coverage and higher sensitivity and specificity for advanced plaque detection with a much shorter acquisition time than 2D-MC MRI. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02017756.

Association Between Repeated Tracheal Intubation Attempts and Adverse Events in Children in the Emergency Department.

STUDY OBJECTIVES: Studies have shown that multiple intubation attempts are associated with a higher risk of intubation-related adverse events. However, little is known about the relationship in children in the emergency department (ED). METHODS: This is an analysis of the data from 2 prospective, observational, multicenter registries of emergency airway management. The data were collected from consecutive patients who underwent emergency airway management in 19 EDs across Japan from March 2010 to November 2017. We included children 18 years or younger who underwent tracheal intubation in the ED. The primary exposure was the number of intubation attempts (1 vs ≥2). The primary outcome was an adverse event during or immediately after the intubation. RESULTS: A total of 439 children were eligible for the analysis. Of 279 children with first-pass success, 24 children (9%) had an adverse event. By contrast, of 160 children with ≥2 intubation attempts, 50 children patients (31%) had an adverse event. In the unadjusted model, multiple intubation attempts were significantly associated with a higher rate of adverse events (unadjusted odds ratio, 4.83; 95% confidence interval, 2.57-9.06; P < 0.001). This association remained significant after adjusting for 7 potential confounders and patient clustering within the hospital (adjusted odds ratio, 4.49; 95% confidence interval, 2.36-8.53; P < 0.001). Similar associations were found across different age groups and among children without cardiac arrest (all, P < 0.05). CONCLUSIONS: In this analysis of large prospective multicenter data, multiple intubation attempts were associated with a significantly higher rate of intubation-related adverse events in children in the ED.

Domain adaptive and fully automated carotid artery atherosclerotic lesion detection using an artificial intelligence approach (LATTE) on 3D MRI.

PURPOSE: To develop and evaluate a domain adaptive and fully automated review workflow (lesion assessment through tracklet evaluation, LATTE) for assessment of atherosclerotic disease in 3D carotid MR vessel wall imaging (MR VWI). METHODS: VWI of 279 subjects with carotid atherosclerosis were used to develop LATTE, mainly convolutional neural network (CNN)-based domain adaptive lesion classification after image quality assessment and artery of interest localization. Heterogeneity in test sets from various sites usually causes inferior CNN performance. With our novel unsupervised domain adaptation (DA), LATTE was designed to accurately classify arteries into normal arteries and early and advanced lesions without additional annotations on new datasets. VWI of 271 subjects from four datasets (eight sites) with slightly different imaging parameters/signal patterns were collected to assess the effectiveness of DA of LATTE using the area under the receiver operating characteristic curve (AUC) on all lesions and advanced lesions before and after DA. RESULTS: LATTE had good performance with advanced/all lesion classification, with the AUC of >0.88/0.83, significant improvements from >0.82/0.80 if without DA. CONCLUSIONS: LATTE can locate target arteries and distinguish carotid atherosclerotic lesions with consistently improved performance with DA on new datasets. It may be useful for carotid atherosclerosis detection and assessment on various clinical sites.

Association Between Carotid Bifurcation Geometry and Atherosclerotic Plaque Vulnerability: A Chinese Atherosclerosis Risk Evaluation Study.

OBJECTIVE: Carotid bifurcation geometry has been believed to be a risk factor for the initiation of atherosclerosis because of its influence on hemodynamics. However, the relationships between carotid bifurcation geometry and plaque vulnerability are not fully understood. This study aimed to determine the association between carotid bifurcation geometry and plaque vulnerability using magnetic resonance vessel wall imaging. Approach and Results: A total of 501 carotid arteries with nonstenotic atherosclerosis were included from the cross-sectional, multicenter CARE II study (Chinese Atherosclerosis Risk Evaluation). Four standardized carotid bifurcation geometric parameters (bifurcation angle, internal carotid artery planarity, luminal expansion FlareA, and tortuosity Tort2D) were derived from time-of-flight magnetic resonance angiography. Presence of vulnerable plaque, which was characterized by intraplaque hemorrhage, large lipid-rich necrotic core, or disrupted luminal surface, was determined based on multicontrast carotid magnetic resonance vessel wall images. Vulnerable plaques (N=43) were found to occur at more distal locations (ie, near the level of flow divider) than stable plaques (N=458). Multivariable logistic regression showed that the luminal expansion FlareA (odds ratio, 0.45 [95% CI, 0.25-0.81]; P=0.008) was associated with plaque vulnerability after adjustment for age, sex, maximum wall thickness, plaque location, and other geometric parameters. CONCLUSIONS: Smaller luminal expansion at carotid bifurcation is associated with vulnerable plaque. The finding needs to be verified with longitudinal studies and the underlying mechanism should be further explored with hemodynamics measurement in the future.

Bilaterally Asymmetric Associations Between Extracranial Carotid Artery Atherosclerosis and Ipsilateral Middle Cerebral Artery Stenosis in Symptomatic Patients: A CARE-II Study.

OBJECTIVE: To determine the bilaterally asymmetrical associations between extracranial carotid artery atherosclerosis and ipsilateral middle cerebral artery (MCA) stenosis in symptomatic patients using magnetic resonance vessel wall imaging. Approach and Results: Patients with symptomatic carotid artery atherosclerosis were recruited from the Chinese Atherosclerosis Risk Evaluation, a multicenter study. All subjects underwent intracranial magnetic resonance angiography and extracranial carotid artery magnetic resonance imaging. Severe stenosis (stenosis ≥50%) of MCA, carotid moderate-to-severe stenosis (stenosis ≥50%), plaque compositions, and high-risk plaque on symptomatic side were evaluated in all subjects. Associations between ipsilateral MCA stenosis and extracranial carotid plaque features were evaluated. A total of 363 patients (mean age: 61.2±10.4 years old; 254 males) were included. In the left symptomatic cerebrovascular group (n=186), carotid moderate-to-severe stenosis (odds ratio [OR], 3.00 [95% CI, 1.03-8.79]; P=0.045), intraplaque hemorrhage (OR, 3.68 [95% CI, 1.21-11.19]; P=0.021), fibrous cap rupture (OR, 5.70 [95% CI, 1.60-20.31]; P=0.007), and high-risk plaque (OR, 2.95 [95% CI, 1.19-7.35]; P=0.020) were significantly associated with ipsilateral severe MCA stenosis, after adjusting for confounding factors. In the right symptomatic cerebrovascular group (n=177), severe MCA stenosis was significantly associated with ipsilateral carotid moderate-to-severe stenosis (OR, 3.98 [95% CI, 1.54-10.32]; P=0.004) but not with other extracranial carotid plaque features (all P>0.05), after adjusting for confounding factors. CONCLUSIONS: In the symptomatic arteries, vulnerable plaque features are independently associated with ipsilateral severe MCA stenosis on the left side, but this association is not found on the right side, indicating the associations of atherosclerotic disease between intracranial and extracranial carotid arteries are asymmetrical.

Association of advanced age with intubation-related adverse events in the emergency department: a multicentre prospective observational study.

BACKGROUND: While the older population accounts for an increasing proportion of emergency department (ED), little is known about intubation-related adverse events in this high-risk population. We sought to determine whether advanced age is associated with a higher risk of intubation-related adverse events in the ED. METHODS: This is an analysis of data from a prospective, 15-centre, observational study-the second Japanese Emergency Airway Network (JEAN-2) study. The current analysis included adult (aged ≥18 years) patients who underwent intubation in the ED between 2012 and 2018. The primary exposure was age (18-39, 40-64, 65-74, 75-84 and ≥85 years). The primary outcome was overall intubation-related adverse events during or immediately after an intubation. Adverse events were further categorised into major (hypotension, hypoxaemia, oesophageal intubation, cardiac arrest, dysrhythmia and death) and minor (endobronchial intubation, oesophageal intubation with early recognition, dental/lip trauma, airway trauma and regurgitation) adverse events. We constructed multivariable logistic regression models adjusting for seven potential confounders with generalised estimating equations that account for patients clustering within the ED. RESULTS: Among 9714 patients eligible for the analysis, 15% were aged ≥85 years, and 16% had adverse events. In the unadjusted models, advanced age was not significantly associated with the risk of overall adverse events. In the adjusted models, the association was significant (adjusted OR 1.41 in age ≥85 years (95% CI, 1.09 to 1.81) compared with age 18-39 years). Specifically, older patients had a significantly higher risk of major adverse events (adjusted OR in age ≥85 years 2.65 (95% CI, 1.78 to 3.94)), which was driven by the association of advanced age with an increased risk of hypotension (adjusted OR in ≥85 years, 5.69 (95% CI, 3.13 to 10.37)). By contrast, advanced age was not associated with minor adverse events. CONCLUSION: Based on the data from a prospective multicentre study, advanced age was associated with higher risks of major adverse events.

Characterization of Carotid Atherosclerotic Plaques Using 3-Dimensional MERGE Magnetic Resonance Imaging and Correlation With Stroke Risk Factors.

Background and Purpose- High-resolution magnetic resonance imaging is capable of characterizing carotid atherosclerotic plaque morphology and composition. Most reported carotid plaque imaging techniques are 2-dimensional (2D) based with limited longitudinal coverage of ≈30 mm, which may be insufficient for complete visualization of extracranial carotid atheroma. A 3D black-blood imaging technique, motion-sensitized driven equilibrium prepared rapid gradient echo technique (3D-MERGE) can provide larger coverage. We sought to use 3D-MERGE to investigate carotid atherosclerosis plaque distribution and to analyze their correlation with clinical information and stroke risk factors. Methods- From 5 hospitals in China, 97 subjects suspected of recent stroke or transient ischemic attack were imaged with 3D-MERGE within 2 weeks of symptoms using 3T magnetic resonance imaging. Images were analyzed by 2 reviewers. Plaque length was calculated and categorized as plaques within, partially outside, or completely outside of typical 2D magnetic resonance imaging coverage. Associations between plaque features and clinical information, stroke risk factors were assessed. Results- Ninety-seven subjects with 194 carotid arteries (70 men and 27 women, mean age 60 years) were analyzed. Of the 136 plaques identified, 68 (50%) were within, 46 (33.8%) were partially outside, and 22 (16.2%) were completely outside of 2D magnetic resonance imaging coverage. Total plaque length was significantly positively associated with male sex (P<0.001), hypertension (P=0.011), and history of smoking (P<0.001). Hypertensive subjects were more likely to have at least one plaque completely outside the 2D magnetic resonance imaging coverage than nonhypertensive subjects (P=0.007). Conclusions- The 3D-MERGE allows for the identification of substantially more carotid plaques than 2D black-blood techniques. The extent and distribution of plaque, identified by the larger coverage afforded by 3D-MERGE, were found to correlate significantly with male sex and risk factors that are common among patients with stroke, including hypertension and history of cigarette smoking.

Fully automated and robust analysis technique for popliteal artery vessel wall evaluation (FRAPPE) using neural network models from standardized knee MRI.

PURPOSE: To develop a fully automated vessel wall (VW) analysis workflow (fully automated and robust analysis technique for popliteal artery evaluation, FRAPPE) on the popliteal artery in standardized knee MR images. METHODS: Popliteal artery locations were detected from each MR slice by a deep neural network model and connected into a 3D artery centerline. Vessel wall regions around the centerline were then segmented using another neural network model for segmentation in polar coordinate system. Contours from vessel wall segmentations were used for vascular feature calculation, such as mean wall thickness and wall area. A transfer learning and active learning framework was applied in training the localization and segmentation neural network models to maintain accuracy while reducing manual annotations. This new popliteal artery analysis technique (FRAPPE) was validated against manual segmentation qualitatively and quantitatively in a series of 225 cases from the Osteoarthritis Initiative (OAI) dataset. RESULTS: FRAPPE demonstrated high accuracy and robustness in locating popliteal arteries, segmenting artery walls, and quantifying arterial features. Qualitative evaluations showed 1.2% of slices had noticeable major errors, including segmenting the wrong target and irregular vessel wall contours. The mean Dice similarity coefficient with manual segmentation was 0.79, which is comparable to inter-rater variations. Repeatability evaluations show most of the vascular features have good to excellent repeatability from repeated scans of same subjects, with intra-class coefficient ranging from 0.80 to 0.98. CONCLUSION: This technique can be used in large population-based studies, such as OAI, to efficiently assess the burden of atherosclerosis from routine MR knee scans.

Differences in Carotid Plaques Between Symptomatic Patients With and Without Diabetes Mellitus.

Objective- Diabetes mellitus is associated with high-risk atherosclerotic plaques. This study aimed to compare characteristics of carotid atherosclerotic plaques in symptomatic Chinese diabetic and nondiabetic patients using vessel wall magnetic resonance imaging. Approach and Results- Patients with cerebral ischemic symptoms in the anterior circulation and carotid atherosclerotic plaque determined by ultrasound were recruited from a cross-sectional, observational, multicenter study of CARE-II (Chinese Atherosclerosis Risk Evaluation). All patients underwent magnetic resonance imaging for carotid arteries. The morphological and compositional characteristics of carotid plaques were compared between diabetic and nondiabetic patients using linear (continuous variables) and logistic regression (binary variables). In a total of 584 recruited patients, 182 (31.2%) had diabetes mellitus. From the univariate analysis, diabetic patients had significantly greater mean wall area (33.7 versus 31.1 mm2; P=0.002), maximum wall thickness (3.2 versus 2.8 mm; P<0.001), and mean normalized wall index (43.8% versus 41.0%; P<0.001) and had significantly higher prevalence of calcification (51.6% versus 36.6%; P=0.001), lipid-rich necrotic core (77.5% versus 58.5%; P<0.001), and high-risk plaque (29.7% versus 19.9%; P=0.011) than nondiabetic patients. After adjusting for clinical characteristics, the differences in presence of calcification ( P=0.018) and lipid-rich necrotic core ( P=0.001) remained statistically significant. Conclusions- Symptomatic Chinese diabetic patients are more likely to have carotid plaques with calcification and lipid-rich necrotic core than nondiabetic patients, suggesting that diabetic patients may develop more severe atherosclerotic disease that should be accounted for in their clinical management.

Understanding Atherosclerosis Through an Osteoarthritis Data Set.

Atherosclerotic cardiovascular disease remains a worldwide epidemic and one of the leading causes of death nowadays. Vessel wall imaging can be used to understand the development and progression of atherosclerosis, but it is rarely done because of the high cost. We recently identified the Osteoarthritis Initiative, a large prospective cohort study of knee osteoarthritis, which might serve as a valuable source for atherosclerosis research with its serial knee magnetic resonance imaging data. We have found that these images are suitable for vessel wall image analysis of the lower extremity arteries. Here, we will introduce the Osteoarthritis Initiative data set and explain why it could be used for cardiovascular research purposes. Also, we will briefly comment on peripheral artery atherosclerosis as it is covered in the Osteoarthritis Initiative image data set and review the use of vessel wall imaging for studying atherosclerosis. We think data mining of imaging studies, not originally designed on cardiovascular research, can not only maximize the value of the imaging data set but also boost our understanding of atherosclerosis.

Comparison of Carotid Atherosclerosis between Patients at High Altitude and Sea Level: A Chinese Atherosclerosis Risk Evaluation Study.

OBJECTIVES: To investigate the differences in characteristics of carotid plaques between patients Xining at high altitude and Jinan at sea level using magnetic resonance (MR) imaging. METHODS: Subjects were recruited from a cross-sectional, observational, multicenter imaging study of CARE-II study. Forty-nine (mean age 63.3 ± 12.0 years, 33 males) and 51 (mean age 64.5 ± 12.0 years, 34 males) patients were recruited from a site located in a high altitude region and a site located near sea level, respectively. All patients underwent multicontrast MR vessel wall imaging for carotid arteries on 3.0 T MR scanner. The carotid plaques features were compared between 2 patient groups. RESULTS: Compared with patients at sea level, those at high altitude had significantly greater lumen area (58.5 ± 17.8 mm2 versus 50.0 ± 19.6 mm2, P = .008), smaller maximum normalized wall index (48.6% ± 14.2% versus 57.8% ± 16.3%, P = .002), and smaller percentage volume of calcium (0.9% versus 5.6%, P < .001) in the symptomatic carotid artery. After adjustment for clinical risk factors including age, sex, systolic blood pressure, LDL-C, and statin use, these differences in plaque morphology and composition remained statistically significant. After further adjustment for normalized wall index as a measure of plaque burden, percentage volume of calcification was still significantly smaller in patients at high altitude area than that in patients at sea level area (P = .047). CONCLUSION: Symptomatic subjects from a high altitude area have lower plaque burden and less calcification in the carotid artery compared to those from an area near sea level.

Carotid Artery Remodeling Is Segment Specific: An In Vivo Study by Vessel Wall Magnetic Resonance Imaging.

OBJECTIVE: Early atherosclerosis is often undetected due in part to compensatory enlargement of the outer wall, termed positive remodeling. Variations in hemodynamic conditions and clinical factors influence the patterns of remodeling. The carotid artery provides an opportunity to examine these variations because of the unique geometry of the carotid bulb. This study aimed to determine differences in remodeling of the common, internal, and bifurcation segments of the carotid using magnetic resonance imaging. APPROACH AND RESULTS: Carotid arteries of 525 subjects without history of cardiovascular disease were imaged by magnetic resonance imaging. The carotid artery was divided into 3 segments: common carotid artery; bifurcation; and internal carotid artery. Remodeling patterns were characterized using linear regression analysis of lumen and total vessel areas (dependent variables) compared with maximum wall thickness (independent variable) for each segment, adjusted for age, sex, and height. The common carotid artery demonstrated a pattern consistent with positive remodeling, whereas the bifurcation demonstrated negative remodeling. The internal carotid artery demonstrated a mixed pattern of outer wall expansion and lumen constriction. Females and subjects with diabetes mellitus showed more positive remodeling, hypertension was associated with attenuated positive remodeling, and those with hypercholesterolemia showed more negative remodeling. CONCLUSIONS: In this cohort of 55- to 80-year-old individuals without history of cardiovascular disease, the pattern of early carotid artery remodeling was segment specific and appeared to be associated with sex and clinical characteristics. These findings provide the groundwork for longitudinal studies to define local and systemic factors such as hemodynamic and clinical conditions on carotid artery remodeling.

3D true-phase polarity recovery with independent phase estimation using three-tier stacks based region growing (3D-TRIPS).

OBJECTIVES: A postprocessing technique termed 3D true-phase polarity recovery with independent phase estimation using three-tier stacks based region growing (3D-TRIPS) was developed, which directly reconstructs phase-sensitive inversion-recovery images without acquisition of phase-reference images. The utility of this technique is demonstrated in myocardial late gadolinium enhancement (LGE) imaging. MATERIALS AND METHODS: A data structure with three tiers of stacks was used for 3D-TRIPS to directly achieve reliable region growing for successful background-phase estimation. Fifteen patients undergoing postgadolinium 3D phase-sensitive inversion recovery (PSIR) cardiac LGE magnetic resonance imaging (MRI) were recruited, and 3D-TRIPS LGE reconstructions were compared with standard PSIR. Objective voxel-by-voxel comparison was performed. Additionally, blinded review by two radiologists compared scar visibility, clinical acceptability, voxel polarity error, or groups and blurring. RESULTS: 3D-TRIPS efficiently reconstructed postcontrast phase-sensitive myocardial LGE images. Objective analysis showed an average 95% voxel-by-voxel agreement between 3D-TRIPS and PSIR images. Blinded radiologist review demonstrated similar image quality between 3D-TRIPS and PSIR reconstruction. CONCLUSION: 3D-TRIPS provided similar image quality to PSIR for phase-sensitive myocardial LGE MRI reconstruction. 3D-TRIPS does not require acquisition of a reference image and can therefore be used to accelerate phase-sensitive LGE imaging.

Association of fentanyl use in rapid sequence intubation with post-intubation hypotension.

BACKGROUND: The anesthesia literature has reported that pre-intubation fentanyl use is associated with post-intubation hypotension which is a risk factor of poor post-emergency department (ED) prognosis. However, little is known about the relations between fentanyl use for intubation and post-intubation hypotension in the ED. We aimed to determine whether pretreatment with fentanyl was associated with a higher risk of post-intubation hypotension in the ED. METHODS: We conducted a secondary analysis of data of ED airway management collected from a multicenter prospective study of 14 Japanese EDs from February 2012 through November 2016. We included all adult non-cardiac-arrest patients who underwent rapid sequence intubation for medical indication. Patients were divided into fentanyl and non-fentanyl groups. The primary outcome was post-intubation hypotension (systolic blood pressure ≤90mmHg) in the ED. RESULTS: Of 1263 eligible patients, 466 (37%) patients underwent pretreatment with fentanyl. The fentanyl group had a higher risk of post-intubation hypotension (17% vs. 6%; unadjusted OR, 1.73; 95%CI, 1.01-2.97; P=0.048) compared to the non-fentanyl group. In the multivariable analysis adjusting for age, sex, weight, principal indication, sedatives, intubator's specialty, number of intubation attempts, and patient clustering within EDs, the fentanyl group had a higher risk of post-intubation hypotension (adjusted OR, 1.87; 95%CI, 1.05-3.34; P=0.03) compared to the non-fentanyl group. In the sensitivity analysis using propensity score matching, this association remained significant (OR, 3.17; 95%CI, 1.96-5.14; P<0.01). CONCLUSION: In this prospective multicenter study of ED airway management, pretreatment with fentanyl in rapid sequence intubation was associated with higher risks of post-intubation hypotension.

Prospective validation of the modified LEMON criteria to predict difficult intubation in the ED.

BACKGROUND: Evidence to predict difficult intubation remains scarce in the emergency department (ED) setting. A previously defined clinical decision rule, the modified LEMON criteria, may provide a reliable and reproducible means of identifying difficult intubations. We aimed to prospectively evaluate the external validity of the modified LEMON criteria in the EDs. METHODS: We conducted a 13-center prospective observational study, the second Japanese Emergency Airway Network study. We prospectively collected data on all patients undergoing intubations in the ED from February 2012 through September 2014. The primary outcomes were sensitivity, specificity, and predictive values of the modified LEMON criteria for predicting difficult intubation (≥2 attempts by emergency attending physicians or anesthesiologists). RESULTS: The database recorded a total of 4034 encounters (capture rate, 96%) in the EDs. Of these, 3313 patients (84%) underwent the intubation attempt with a direct laryngoscope and 610 patients (16%) with a video laryngoscope. The proportion of difficult intubation was 5.4% (95% confidence interval [CI], 4.7%-6.2%) in the direct laryngoscope group and 7.4% (95% CI, 5.6%-9.7%) in the video laryngoscope group. The sensitivity was 85.7% (95% CI, 79.3%-90.4%) with direct laryngoscope and 94.9% (95% CI, 83.5%-98.6%) with video laryngoscope. The specificity was 47.6% (95% CI, 47.2%-47.9%) and 40.3% (95% CI, 39.4%-40.6%), respectively. The negative predictive value was 98.2% (95% CI, 97.5%-98.8%) and 99.0% (95% CI, 96.6%-99.7%), respectively. CONCLUSIONS: In this multicenter prospective study, we found a high sensitivity and a negative predictive value of the modified LEMON criteria for predicting difficult intubation. The modified LEMON might assist ED providers in better identifying difficult intubations.

Repeated attempts at tracheal intubation by a single intubator associated with decreased success rates in emergency departments: an analysis of a multicentre prospective observational study.

OBJECTIVE: To determine whether the success rate of repeated attempts at tracheal intubation by a single intubator was lower than those by alternate intubators in the emergency department (ED). METHODS: An analysis of data from a multicentre prospective registry (Japanese Emergency Airway Network Registry) of 13 academic and community EDs in Japan between April 2010 and August 2012. We included all adult and paediatric patients who underwent repeated attempts at tracheal intubation in the ED. We compared the intubation success rates at the second and third attempts between attempts at intubation by a single intubator who performed the previous attempts, and the attempts by alternate intubators. RESULTS: We recorded 4094 patients (capture rate, 96%); 1289 patients with repeated attempts at tracheal intubation were eligible for this study. Among these, 871 patients (68%) had a second attempt at intubation by single intubators. At the second attempt, tracheal intubation by a single intubator was associated with a decreased success rate (adjusted odds ratio or AOR, 0.50; 95% CI 0.36 to 0.71), compared with alternate intubators. At the third attempt, intubation by a single intubator was also associated with a decreased success rate (58% vs 70%; unadjusted OR, 0.58; 95% CI 0.38 to 0.89). However, after adjustment for potential confounders, the association lost statistical significance (AOR, 0.89; 95% CI 0.52 to 1.56). CONCLUSIONS: In this large multicentre study of ED patients undergoing tracheal intubation, second attempts at intubation by a single intubator, compared with those by alternate intubators, were independently associated with a decreased success rate.

Association of airway obstruction with first-pass success and intubation-related adverse events in the emergency department: multicenter prospective observational studies.

Background: Airway obstruction is a relatively rare but critical condition that requires urgent intervention in the emergency department (ED). The present study aimed to investigate the association of airway obstruction with first-pass success and intubation-related adverse events in the ED. Methods: We analyzed data from two prospective multicenter observational studies of ED airway management. We included adults (aged ≥18 years) who underwent tracheal intubation for non-trauma indications from 2012 through 2021 (113-month period). Outcome measures were first-pass success and intubation-related adverse events. We constructed a multivariable logistic regression model adjusting for age, sex, modified LEMON score (without airway obstruction), intubation methods, intubation devices, bougie use, intubator's specialty, and ED visit year with accounting for patients clustering within the ED. Results: Of 7,349 eligible patients, 272 (4%) underwent tracheal intubation for airway obstruction. Overall, 74% of patients had first-pass success and 16% had intubation-related adverse events. The airway obstruction group had a lower first-pass success rate (63% vs. 74%; unadjusted odds ratio [OR], 0.63; 95% CI, 0.49-0.80), compared to the non-airway obstruction group. This association remained significant in the multivariable analysis (adjusted OR 0.60, 95%CI 0.46-0.80). The airway obstruction group also had a significantly higher risk of adverse events (28% vs. 16%; unadjusted OR, 1.93; 95% CI, 1.48-2.56, adjusted OR, 1.70; 95% CI, 1.27-2.29). In the sensitivity analysis using multiple imputation, the results remained consistent with the main results: the airway obstruction group had a significantly lower first-pass success rate (adjusted OR, 0.60; 95% CI, 0.48-0.76). Conclusion: Based on these multicenter prospective data, airway obstruction was associated with a significantly lower first-pass success rate and a higher intubation-related adverse event rate in the ED.

Corrigendum: Association of airway obstruction with first-pass success and intubation-related adverse events in the emergency department: multicenter prospective observational studies.

[This corrects the article DOI: 10.3389/fmed.2023.1199750.].