Time to Renitrogenation After Maximal Denitrogenation in Healthy Volunteers in the Supine and Sitting Positions.

INTRODUCTION: Prior to intubation, preoxygenation is performed to denitrogenate the lungs and create an oxygen reservoir. After oxygen is removed, it is unclear whether renitrogenation after preoxygenation occurs faster in the supine vs the sitting position. METHODS: We enrolled 80 healthy volunteers who underwent two preoxygenation and loss of preoxygenation procedures (one while supine and one while sitting) via bag-valve-mask ventilation with spontaneous breathing. End-tidal oxygen (ETO2) measurements were recorded as fraction of expired oxygen prior to preoxygenation, at the time of adequate preoxygenation (ETO2 >85%), and then every five seconds after the oxygen was removed until the ETO2 values reached their recorded baseline. RESULTS: The mean ETO2 at completion of preoxygenation was 86% (95% confidence interval 85-88%). Volunteers in both the supine and upright position lost >50% of their denitrogenation in less than 60 seconds. Within 25 seconds, all subjects had an ETO2 of <70%. Complete renitrogenation, defined as return to baseline ETO2, occurred in less than 160 seconds for all volunteers. CONCLUSION: Preoxygenation loss, or renitrogenation, occurred rapidly after oxygen removal and was not different in the supine and sitting positions. After maximal denitrogenation in healthy volunteers, renitrogenation occurred rapidly after oxygen removal and was not different in the supine and sitting positions.

Early Intubation and Increased Coronavirus Disease 2019 Mortality: A Propensity Score-Matched Retrospective Cohort Study.

OBJECTIVES: There has been controversy about the timing and indications for intubation and mechanical ventilation in novel coronavirus disease 2019. This study assessed the effect of early intubation and mechanical ventilation on all-cause, inhospital mortality for coronavirus disease 2019 patients. DESIGN: Multicenter retrospective cohort study. SETTING: Eleven municipal hospitals in New York City from March 1, 2020, to December 1, 2020. PATIENTS: Adult patients who tested positive for coronavirus disease 2019 in the emergency department were subsequently admitted. Patients with do-not-intubate orders at admission were excluded. INTERVENTIONS: Intubation within 48 hours of triage and intubation at any point during hospital stay. MEASUREMENTS AND MAIN RESULTS: Data from 7,597 coronavirus disease 2019 patients were included; of these, 1,628 (21%) were intubated overall and 807 (11%) were intubated within 48 hours of triage. After controlling for available confounders, intubation rates for coronavirus disease 2019 patients varied significantly across hospitals and decreased steadily as the pandemic progressed. After nearest neighbor propensity score matching, intubation within 48 hours of triage was associated with higher all-cause mortality (hazard ratio, 1.30 [1.15-1.48]; p < 0.0001), as was intubation at any time point (hazard ratio, 1.62 [1.45-1.80]; p < 0.0001). Among intubated patients, intubation within 48 hours of triage was not significantly associated with differences in mortality (hazard ratio, 1.09 [0.94-1.26]; p = 0.26). These results remained robust to multiple sensitivity analyses. CONCLUSIONS: Intubation within 48 hours of triage, as well as at any time point in the hospital course, was associated with increased mortality in coronavirus disease 2019 patients in this observational study.

Emergency physician use of end-tidal oxygen monitoring for rapidsequence intubation.

BACKGROUND: End-tidal oxygen (ETO2) monitoring is used by anesthesiologists to quantify the efficacy of preoxygenation before intubation but is generally not used in emergency departments (EDs). We have previously published our findings describing preoxygenation practices in the ED during blinded use of ETO2. The purpose of this investigation is to determine whether the unblinded use of ETO2 monitoring led to improvements in preoxygenation during rapid sequence intubation in the ED and also the oxygen device or technique changes that were used to achieve higher ETO2 levels. METHODS: We conducted an interventional study at 2 academic EDs in Sydney, Australia and New York City, New York using ETO2 monitoring to investigate the preoxygenation process and effectiveness. We used data collected during a previous descriptive study for the control group, in which care teams in the same 2 EDs were blinded to the ETO2 value. In the study group, clinicians could utilize ETO2 to improve preoxygenation. Following an education process, clinicians were able to choose the method of preoxygenation and the techniques required to attempt to achieve an ETO2 level >85%. The primary outcome was the difference in ETO2 levels at the time of induction between the control and study group and the secondary outcome included the methods that were attempted to improve preoxygenation. RESULTS: A convenience sample of 100 patients was enrolled in each group. The median ETO2 level achieved at the time of induction was 80% (interquartile range 61 to 86, overall range 73) in the control group and 90% in the study group (interquartile range 83 to 92, overall range 41); the median difference was 12 (95% confidence interval: 8, 16, P = < 0.001). The majority of oxygen device changes were from non-rebreather mask to bag-valve-mask (BVM) (15%, n = 15) and changes in technique from improvements in mask seal (54%, n = 34). The final device used in the study group was BVM in 87% of cases. CONCLUSIONS: In 2 clinical studies of ETO2 in academic EDs, we have demonstrated that the use of ETO2 is feasible and associated with specific and potentially improved approaches to preoxygenation. A clinical trial is needed to further study the impact of ETO2 on the preoxygenation process and the rate of hypoxemia.

Conscious Proning: An Introduction of a Proning Protocol for Nonintubated, Awake, Hypoxic Emergency Department COVID-19 Patients.

The novel coronavirus, or COVID-19, has rapidly become a global pandemic. A major cause of morbidity and mortality due to COVID-19 has been the worsening hypoxia that, if untreated, can progress to acute respiratory distress syndrome (ARDS) and respiratory failure. Past work has found that intubated patients with ARDS experience physiological benefits to the prone position, because it promotes better matching of pulmonary perfusion to ventilation, improved secretion clearance, and recruitment of dependent areas of the lungs. We created a systemwide multi-institutional (New York-Presbyterian Hospital enterprise) protocol for placing awake, nonintubated, emergency department patients with suspected or confirmed COVID-19 in the prone position. In this piece, we describe the background literature and the approach we have taken at our institution as we care for a high burden of COVID-19 cases with respiratory symptoms.

Early Self-Proning in Awake, Non-intubated Patients in the Emergency Department: A Single ED's Experience During the COVID-19 Pandemic.

OBJECTIVE: Prolonged and unaddressed hypoxia can lead to poor patient outcomes. Proning has become a standard treatment in the management of patients with ARDS who have difficulty achieving adequate oxygen saturation. The purpose of this study was to describe the use of early proning of awake, non-intubated patients in the emergency department (ED) during the COVID-19 pandemic. METHODS: This pilot study was carried out in a single urban ED in New York City. We included patients suspected of having COVID-19 with hypoxia on arrival. A standard pulse oximeter was used to measure SpO2 . SpO2 measurements were recorded at triage and after 5 minutes of proning. Supplemental oxygenation methods included non-rebreather mask (NRB) and nasal cannula. We also characterized post-proning failure rates of intubation within the first 24 hours of arrival to the ED. RESULTS: Fifty patients were included. Overall, the median SpO2 at triage was 80% (IQR 69 to 85). After application of supplemental oxygen was given to patients on room air it was 84% (IQR 75 to 90). After 5 minutes of proning was added SpO2 improved to 94% (IQR 90 to 95). Comparison of the pre- to post-median by the Wilcoxon Rank-sum test yielded P = 0.001. Thirteen patients (24%) failed to improve or maintain their oxygen saturations and required endotracheal intubation within 24 hours of arrival to the ED. CONCLUSION: Awake early self-proning in the emergency department demonstrated improved oxygen saturation in our COVID-19 positive patients. Further studies are needed to support causality and determine the effect of proning on disease severity and mortality.

Behind the Scenes of Successful Research in Emergency Medicine: Nine Tips for Junior Investigators.

Education related to clinical research often focuses on methodology, statistics, ethics, and study design. While knowledge of these conventional skills is essential to the operationalization of research, many "soft" skills related to leadership, communication, and team management are critical to the successful conduct research in the real world. Conducting clinical research in the emergency department is generally a challenging endeavor. Based on our prior experience as clinical researchers and a narrative review of the published literature, we offer nine practical strategies to help junior investigators conduct research. To successfully execute a research study, investigators must know how to motivate their team, create a brand around their study, communicate effectively, maximize clinician and patient engagement, and celebrate victory, among other skills. These skills and strategies are often missing from the formal research education and in peer-reviewed manuscripts but are, in fact, invaluable to the successful development of junior investigators. Thus, we offer the "story behind the study" in an effort to contribute to research education with material that is not typically covered in formal curricula.

Novel Use of a Gas Analyzer Can Reliably Predict the Arterial Oxygen among Emergency Department Patients Undergoing Rapid Sequence Intubation.

BACKGROUND: To our knowledge, no study has assessed the correlation of fraction of inspired oxygen (FiO2) and end-tidal oxygen (EtO2) values obtained from a gas analyzer during the preoxygenation period of rapid sequence intubation (RSI) to predict partial pressure of oxygen (PaO2) among patients requiring intubation in the emergency department (ED). OBJECTIVE: The purpose of this study was to determine whether a simple equation using EtO2 and FiO2 at time of induction could reliably estimate minimal PaO2 in ED patients undergoing RSI. METHODS: We conducted an observational pilot study performed in an adult ED utilizing a gas analyzer to obtain EtO2 and FiO2 values in ED patients undergoing RSI from data collectors blinded to our objective. The Pearson correlation coefficient was calculated between the equation's predicted PaO2 and the PaO2 drawn from an arterial blood gas shortly after intubation. A Bland-Altman plot analysis was performed to identify any additional bias. RESULTS: Seventy-five patients were enrolled. The equation's mean predicted minimal PaO2 and mean PaO2 from an arterial blood gas within 3 min after intubation was 178 mm Hg (95% confidence interval [CI] 145-211 mm Hg) and 209 mm Hg (95% CI 170-258 mm Hg), respectively. The Pearson correlation coefficient between the predicted minimal PaO2 and post-intubation PaO2 demonstrated a strong correlation (r2 = 0.89). The Bland-Altman plot indicated no bias affecting the correlation between the predicted and actual PaO2. CONCLUSIONS: Among ED patients undergoing RSI, the use of a gas analyzer to measure EtO2 and FiO2 can provide a reliable measure of the minimal PaO2 at the time of induction during the RSI phase of preoxygenation.

Effect of a fluid bolus on cardiovascular collapse among critically ill adults undergoing tracheal intubation (PrePARE): a randomised controlled trial.

BACKGROUND: Tracheal intubation is common in the care of critically ill adults and is frequently complicated by hypotension, cardiac arrest, or death. We aimed to evaluate administration of an intravenous fluid bolus to prevent cardiovascular collapse during intubation of critically ill adults. METHODS: We did a pragmatic, multicentre, unblinded, randomised trial in nine sites (eight ICUs and one emergency department) around the USA. Critically ill adults (≥18 years) undergoing tracheal intubation were randomly assigned (1:1, block sizes of 2, 4, and 6, stratified by study site) to either an intravenous infusion of 500 mL of crystalloid solution or no fluid bolus. The primary outcome, assessed in the intention-to-treat population, was cardiovascular collapse, defined as a new systolic blood pressure <65 mm Hg; new or increased vasopressor receipt between induction and 2 min after tracheal intubation; or cardiac arrest or death within 1 h of tracheal intubation. Adverse events were assessed in the as-treated population. This trial, which is now complete, is registered with ClinicalTrials.gov, number NCT03026777. FINDINGS: Patients were enrolled from Feb 6, 2017, to Jan 9, 2018, when the data and safety monitoring board stopped the trial on the basis of futility. By trial termination, 337 (63%) of 537 screened adults had been randomly assigned. Cardiovascular collapse occurred in 33 (20%) of 168 patients in the fluid bolus group compared with 31 (18%) of 169 patients in the no fluid bolus group (absolute difference 1·3% [95% CI -7·1% to 9·7%]; p=0·76). The individual components of the cardiovascular collapse composite outcome did not differ between groups (new systolic blood pressure <65 mm Hg 11 [7%] in the bolus group vs ten [6%] in the no-bolus group, new or increased vasopressor 32 [19%] vs 31 [18%], cardiac arrest within 1 h seven [4%] vs two [1%], death within 1 h of intubation two [1%] vs one [1%]). In-hospital mortality was not significantly different in the fluid bolus group (48 [29%]) compared with no fluid bolus (59 [35%]). INTERPRETATION: Administration of an intravenous fluid bolus did not decrease the overall incidence of cardiovascular collapse during tracheal intubation of critically ill adults compared with no fluid bolus in this trial. FUNDING: US National Institutes of Health.

Use of End Tidal Oxygen Monitoring to Assess Preoxygenation During Rapid Sequence Intubation in the Emergency Department.

STUDY OBJECTIVE: Preoxygenation is important to prevent oxygen desaturation during emergency airway management. The purpose of this study is to describe the use of end tidal oxygen (eto2) during rapid sequence intubation in the emergency department. METHODS: This study was carried out in 2 academic centers in Sydney, Australia, and New York City. We included patients undergoing rapid sequence intubation in the emergency department. A standard gas analyzer was used to measure eto2. Preoxygenation methods included nonrebreather mask and bag-valve-mask ventilation. We measured eto2 before preoxygenation and at administration of rapid sequence intubation medications. We also characterized peri-intubation SpO2, identifying instances of SpO2 less than 90%. RESULTS: We included 100 patients during a 6-month period. Median eto2 level before and after preoxygenation was 53% (interquartile range [IQR] 43% to 65%) and 78% (IQR 64% to 86%), respectively. One fourth of patients achieved an eto2 level greater than 85%. Median eto2 level achieved varied with preoxygenation method, ranging from 80% (IQR 60% to 87%) for the nonrebreather mask group to 77% (IQR 65% to 86%) for the bag-valve-mask group. The method with the highest median eto2 level was nonrebreather mask at flush rate (86%; IQR 80% to 90%) and the lowest median eto2 level was nonrebreather mask at 15 L/min (57%; IQR 53% to 60%). Eighteen patients (18%) experienced oxygen desaturation (SpO2 <90%); of these, 14 (78%) did not reach an eto2 level greater than 85% at induction. CONCLUSION: ETO2 varied with different preoxygenation techniques employed in the emergency department. Most patients undergoing rapid sequence intubation did not achieve maximal preoxygenation. Measuring ETO2 in the emergency department may be a valuable adjunct for optimizing preoxygenation during emergency airway management.

Respiratory adjusted shock index for identifying occult shock and level of Care in Sepsis Patients.

OBJECTIVE: Early identification of shock allows for timely resuscitation. Previous studies note the utility of bedside calculations such as the shock index (SI) and quick sepsis-related organ failure assessment (qSOFA) to detect occult shock. Respiratory rate may also be an important marker of occult shock. The goal of our study was to evaluate whether using a modified SI with respiratory rate would improve identification of emergency department sepsis patients admitted to an ICU or stepdown unit. METHODS: A prospective, observational cohort study of the respiratory adjusted shock index (RASI), defined as HR/SBP × RR/10, was conducted. RASI was calculated from triage vital signs and compared to serum lactate. Primary outcome was admission to a higher level of care defined as ICU or stepdown unit. A multivariable logistic regression model including RASI, SI, lactate, age and sex was performed with disposition as the outcome variable. Areas under the curve (AUC) were calculated to detect occult shock and level of care for RASI, SI, and qSOFA. RESULTS: 408 patients were enrolled, 360 were included in the analysis. Regression analysis revealed that lactate (OR 1.55, z = 4.38, p < 0.0001) and RASI (OR 2.27, z = 3.03, p < 0.002) were predictive of need for higher level of care. The AUC for RASI, SI, and qSOFA to detect occult shock were 0.71, 0.6, and 0.61 respectively. RASI also had a significant AUC in predicting level of care at 0.75 compared to SI (0.64) and qSOFA (0.62). CONCLUSIONS: RASI may have utility as a rapid bedside tool for predicting critical illness in sepsis patients.

Do Out-of-Hospital Cardiac Arrest Patients Have Increased Chances of Survival When Transported to a Cardiac Resuscitation Center?

Background Patients suffering from an out-of-hospital cardiac arrest are often transported to the closest hospital. Although it has been suggested that these patients be transported to cardiac resuscitation centers, few jurisdictions have acted on this recommendation. To better evaluate the evidence on this subject, a systematic review and meta-analysis of the currently available literature evaluating the association between the destination hospital's capability (cardiac resuscitation center or not) and resuscitation outcomes for adult patients suffering from an out-of-hospital cardiac arrest was performed. Methods and Results PubMed, EMBASE , and the Cochrane Library databases were first searched using a specifically designed search strategy. Both original randomized controlled trials and observational studies were considered for inclusion. Cardiac resuscitation centers were defined as having on-site percutaneous coronary intervention and targeted temperature management capability at all times. The primary outcome measure was survival. Twelve nonrandomized observational studies were retained in this review. A total of 61 240 patients were included in the 10 studies that could be included in the meta-analysis regarding the survival outcome. Being transported to a cardiac resuscitation center was associated with an increase in survival (odds ratio=1.95 [95% confidence interval 1.47-2.59], P<0.001). Conclusions Adult patients suffering from an out-of-hospital cardiac arrest transported to cardiac resuscitation centers have better outcomes than their counterparts. When possible, it is reasonable to transport these patients directly to cardiac resuscitation centers (class II a, level of evidence B, nonrandomized). Clinical Trial Registration URL : www.crd.york.ac.uk/PROSPERO/ . Unique identifier: CRD 42018086608.

Right-left propensity of cardiogenic cerebral embolism in standard versus bovine aortic arch variant.

Left-hemispheric ischemic strokes are more frequent overall and often have a worse outcome than their right-hemispheric counterparts. We hypothesized that the right-left propensity of CE cerebral infarcts differs between patients with standard and bovine arch variants. We retrospectively identified all patients with acute stroke of the anterior circulation admitted to our primary stroke center between January 2011 and June 2017 who had moderate- to high-risk cardio-embolic sources according to the SSS-TOAST classification. From amongst these patients, only those with available cross-sectional imaging of the aortic arch were included. Lesion side and patterns on diffusion-weighted magnetic resonance imaging were determined blinded to the aortic arch imaging. One hundred and nineteen patients met the TOAST criteria for moderate- or high-risk cardio-embolic source. Of these, 58 (49%) were men and the median age was 71.9 years; 33% of the patients had a bovine arch. The most common etiologies of CE were atrial fibrillation (n = 80 [67%]) and congestive heart failure with ejection fraction <30% (n = 18 [15%]). In patients with bovine arch there was an approximately 50% chance of having a right- or left-sided infarct. Although there was a trend towards right-sided lesions in patients with standard arches, this did not reach statistical significance. No statistically significant difference in embolic stroke laterality was demonstrated in our relatively small sample. Bovine arch could be an independent risk factor for cardio-embolic embolism. Clin. Anat. 31:310-313, 2018. © 2018 Wiley Periodicals, Inc.

Peri-intubation factors affecting emergency physician choice of paralytic agent for rapid sequence intubation of trauma patients.

INTRODUCTION: No study has assessed predictors of physician choice between the succinylcholine (Succ) and rocuronium (Roc) for rapid sequence intubation (RSI) during the initial resuscitation of trauma patients in the emergency department (ED). METHODS: We retrospectively evaluated of the use of Succ and Roc for adult trauma patients undergoing RSI at a Level 1 trauma center. The primary outcome was to identify factors affecting physician choice of paralytic agent for RSI analyzed by cluster analysis using pre-intubation vital signs and early mortality. The secondary outcome was to identify factors influencing physician choice of paralytic agent using a logistic regression model reported as adjusted odds ratios (aOR). RESULTS: The analysis included 215 patients, including 148 receiving Succ and 67 receiving Roc. The two groups were similar in regard to age, provider level of training, mean GCS (10 vs. 10) and median ISS (27 vs. 27). Cluster analysis using peri-intubation patient vital signs and early mortality indicates that patients with predominantly abnormal vital signs and early mortality were more likely to receive Roc (74%) than those without abnormal vital signs prior to intubation or early mortality (24%). Hypoxemia prior to RSI (aOR 12.3 [2.5-60.9]) and the use of video laryngoscopy (VL) (aOR 5.5 [1.2-24.6]) were associated with the choice to use Roc. CONCLUSIONS: Roc was more frequently chosen for paralysis in the patient cluster with predominantly abnormal peri-intubation vital signs and higher rate of early ED mortality. The use of Roc was associated with hypoxemia prior to RSI and VL.