Noninvasive Ventilation for Preoxygenation during Emergency Intubation.

BACKGROUND: Among critically ill adults undergoing tracheal intubation, hypoxemia increases the risk of cardiac arrest and death. The effect of preoxygenation with noninvasive ventilation, as compared with preoxygenation with an oxygen mask, on the incidence of hypoxemia during tracheal intubation is uncertain. METHODS: In a multicenter, randomized trial conducted at 24 emergency departments and intensive care units in the United States, we randomly assigned critically ill adults (age, ≥18 years) undergoing tracheal intubation to receive preoxygenation with either noninvasive ventilation or an oxygen mask. The primary outcome was hypoxemia during intubation, defined by an oxygen saturation of less than 85% during the interval between induction of anesthesia and 2 minutes after tracheal intubation. RESULTS: Among the 1301 patients enrolled, hypoxemia occurred in 57 of 624 patients (9.1%) in the noninvasive-ventilation group and in 118 of 637 patients (18.5%) in the oxygen-mask group (difference, -9.4 percentage points; 95% confidence interval [CI], -13.2 to -5.6; P<0.001). Cardiac arrest occurred in 1 patient (0.2%) in the noninvasive-ventilation group and in 7 patients (1.1%) in the oxygen-mask group (difference, -0.9 percentage points; 95% CI, -1.8 to -0.1). Aspiration occurred in 6 patients (0.9%) in the noninvasive-ventilation group and in 9 patients (1.4%) in the oxygen-mask group (difference, -0.4 percentage points; 95% CI, -1.6 to 0.7). CONCLUSIONS: Among critically ill adults undergoing tracheal intubation, preoxygenation with noninvasive ventilation resulted in a lower incidence of hypoxemia during intubation than preoxygenation with an oxygen mask. (Funded by the U.S. Department of Defense; PREOXI ClinicalTrials.gov number, NCT05267652.).

Video versus Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults.

BACKGROUND: Whether video laryngoscopy as compared with direct laryngoscopy increases the likelihood of successful tracheal intubation on the first attempt among critically ill adults is uncertain. METHODS: In a multicenter, randomized trial conducted at 17 emergency departments and intensive care units (ICUs), we randomly assigned critically ill adults undergoing tracheal intubation to the video-laryngoscope group or the direct-laryngoscope group. The primary outcome was successful intubation on the first attempt. The secondary outcome was the occurrence of severe complications during intubation; severe complications were defined as severe hypoxemia, severe hypotension, new or increased vasopressor use, cardiac arrest, or death. RESULTS: The trial was stopped for efficacy at the time of the single preplanned interim analysis. Among 1417 patients who were included in the final analysis (91.5% of whom underwent intubation that was performed by an emergency medicine resident or a critical care fellow), successful intubation on the first attempt occurred in 600 of the 705 patients (85.1%) in the video-laryngoscope group and in 504 of the 712 patients (70.8%) in the direct-laryngoscope group (absolute risk difference, 14.3 percentage points; 95% confidence interval [CI], 9.9 to 18.7; P<0.001). A total of 151 patients (21.4%) in the video-laryngoscope group and 149 patients (20.9%) in the direct-laryngoscope group had a severe complication during intubation (absolute risk difference, 0.5 percentage points; 95% CI, -3.9 to 4.9). Safety outcomes, including esophageal intubation, injury to the teeth, and aspiration, were similar in the two groups. CONCLUSIONS: Among critically ill adults undergoing tracheal intubation in an emergency department or ICU, the use of a video laryngoscope resulted in a higher incidence of successful intubation on the first attempt than the use of a direct laryngoscope. (Funded by the U.S. Department of Defense; DEVICE ClinicalTrials.gov number, NCT05239195.).

Individualized Treatment Effects of Bougie versus Stylet for Tracheal Intubation in Critical Illness.

Rationale: A recent randomized trial found that using a bougie did not increase the incidence of successful intubation on first attempt in critically ill adults. The average effect of treatment in a trial population, however, may differ from effects for individuals. Objective: We hypothesized that application of a machine learning model to data from a clinical trial could estimate the effect of treatment (bougie vs. stylet) for individual patients based on their baseline characteristics ("individualized treatment effects"). Methods: This was a secondary analysis of the BOUGIE (Bougie or Stylet in Patients Undergoing Intubation Emergently) trial. A causal forest algorithm was used to model differences in outcome probabilities by randomized group assignment (bougie vs. stylet) for each patient in the first half of the trial (training cohort). This model was used to predict individualized treatment effects for each patient in the second half (validation cohort). Measurements and Main Results: Of 1,102 patients in the BOUGIE trial, 558 (50.6%) were the training cohort, and 544 (49.4%) were the validation cohort. In the validation cohort, individualized treatment effects predicted by the model significantly modified the effect of trial group assignment on the primary outcome (P value for interaction = 0.02; adjusted qini coefficient, 2.46). The most important model variables were difficult airway characteristics, body mass index, and Acute Physiology and Chronic Health Evaluation II score. Conclusions: In this hypothesis-generating secondary analysis of a randomized trial with no average treatment effect and no treatment effect in any prespecified subgroups, a causal forest machine learning algorithm identified patients who appeared to benefit from the use of a bougie over a stylet and from the use of a stylet over a bougie using complex interactions between baseline patient and operator characteristics.

Laryngoscopy and Tracheal Intubation: Does Use of a Video Laryngoscope Facilitate Both Steps of the Procedure?

STUDY OBJECTIVE: To compare the effect of the use of a video laryngoscope versus a direct laryngoscope on each step of emergency intubation: laryngoscopy (step 1) and intubation of the trachea (step 2). METHODS: In a secondary observational analysis of data from 2 multicenter, randomized trials that enrolled critically ill adults undergoing tracheal intubation but did not control for laryngoscope type (video laryngoscope vs direct laryngoscope), we fit mixed-effects logistic regression models examining the 1) the association between laryngoscope type (video laryngoscope vs direct laryngoscope) and the Cormack-Lehane grade of view and 2) the interaction between grade of view, laryngoscope type (video laryngoscope vs direct laryngoscope), and the incidence of successful intubation on the first attempt. RESULTS: We analyzed 1,786 patients: 467 (26.2%) in the direct laryngoscope group and 1,319 (73.9%) in the video laryngoscope group. The use of a video laryngoscope was associated with an improved grade of view as compared with a direct laryngoscope (adjusted odds ratio for increasingly favorable grade of view 3.14, 95% confidence interval [CI] 2.47 to 3.99). Successful intubation on the first attempt occurred in 83.2% of patients in the video laryngoscope group and 72.2% of patients in the direct laryngoscope group (absolute difference 11.1%, 95% CI 6.5% to 15.6%). Video laryngoscope use modified the association between grade of view and successful intubation on the first attempt such that intubation on the first attempt was similar between video laryngoscope and direct laryngoscope at a grade 1 view and higher for video laryngoscope than direct laryngoscope at grade 2 to 4 views (P<.001 for interaction term). CONCLUSIONS: Among critically ill adults undergoing tracheal intubation, the use of a video laryngoscope was associated both with a better view of the vocal cords and with a higher probability of successfully intubating the trachea when the view of the vocal cords was incomplete in this observational analysis. However, a multicenter, randomized trial directly comparing the effect of a video laryngoscope with a direct laryngoscope on the grade of view, success, and complications is needed.

Defining Successful Intubation on the First Attempt Using Both Laryngoscope and Endotracheal Tube Insertions: A Secondary Analysis of Clinical Trial Data.

STUDY OBJECTIVES: Successful intubation on the first attempt has historically been defined as successful placement of an endotracheal tube (ETT) using a single laryngoscope insertion. More recent studies have defined successful placement of an ETT using a single laryngoscope insertion followed by a single ETT insertion. We sought to estimate the prevalence of first-attempt success using these 2 definitions and estimate their associations with the duration of intubation and serious complications. METHODS: We performed a secondary analysis of data from 2 multicenter randomized trials of critically ill adults being intubated in the emergency department or ICU. We calculated the percent difference in successful intubations on the first attempt, median difference in the duration of intubation, and percent difference in the development of serious complications by definition. RESULTS: The study population included 1,863 patients. Successful intubation on the first attempt decreased by 4.9% (95% confidence interval 2.5% to 7.3%) when defined as 1 laryngoscope insertion followed by 1 ETT insertion (81.2%) compared with when defined as only 1 laryngoscope insertion (86.0%). When successful intubation with 1 laryngoscope and 1 ETT insertion was compared with 1 laryngoscope and multiple ETT insertions, the median duration of intubation decreased by 35.0 seconds (95% confidence interval 8.9 to 61.1 seconds). CONCLUSION: Defining successful intubation on the first attempt as placement of an ETT in the trachea using 1 laryngoscope and 1 ETT insertion identifies attempts with the shortest apneic time.

Effect of Use of a Bougie vs Endotracheal Tube With Stylet on Successful Intubation on the First Attempt Among Critically Ill Patients Undergoing Tracheal Intubation: A Randomized Clinical Trial.

Importance: For critically ill adults undergoing emergency tracheal intubation, failure to intubate the trachea on the first attempt occurs in up to 20% of cases and is associated with severe hypoxemia and cardiac arrest. Whether using a tracheal tube introducer ("bougie") increases the likelihood of successful intubation compared with using an endotracheal tube with stylet remains uncertain. Objective: To determine the effect of use of a bougie vs an endotracheal tube with stylet on successful intubation on the first attempt. Design, Setting, and Participants: The Bougie or Stylet in Patients Undergoing Intubation Emergently (BOUGIE) trial was a multicenter, randomized clinical trial among 1102 critically ill adults undergoing tracheal intubation in 7 emergency departments and 8 intensive care units in the US between April 29, 2019, and February 14, 2021; the date of final follow-up was March 14, 2021. Interventions: Patients were randomly assigned to use of a bougie (n = 556) or use of an endotracheal tube with stylet (n = 546). Main Outcomes and Measures: The primary outcome was successful intubation on the first attempt. The secondary outcome was the incidence of severe hypoxemia, defined as a peripheral oxygen saturation less than 80%. Results: Among 1106 patients randomized, 1102 (99.6%) completed the trial and were included in the primary analysis (median age, 58 years; 41.0% women). Successful intubation on the first attempt occurred in 447 patients (80.4%) in the bougie group and 453 patients (83.0%) in the stylet group (absolute risk difference, -2.6 percentage points [95% CI, -7.3 to 2.2]; P = .27). A total of 58 patients (11.0%) in the bougie group experienced severe hypoxemia, compared with 46 patients (8.8%) in the stylet group (absolute risk difference, 2.2 percentage points [95% CI, -1.6 to 6.0]). Esophageal intubation occurred in 4 patients (0.7%) in the bougie group and 5 patients (0.9%) in the stylet group, pneumothorax was present after intubation in 14 patients (2.5%) in the bougie group and 15 patients (2.7%) in the stylet group, and injury to oral, glottic, or thoracic structures occurred in 0 patients in the bougie group and 3 patients (0.5%) in the stylet group. Conclusions and Relevance: Among critically ill adults undergoing tracheal intubation, use of a bougie did not significantly increase the incidence of successful intubation on the first attempt compared with use of an endotracheal tube with stylet. Trial Registration: ClinicalTrials.gov Identifier: NCT03928925

Ultrasonography in the emergency department.

Point-of-care ultrasonography (POCUS) is a useful imaging technique for the emergency medicine (EM) physician. Because of its growing use in EM, this article will summarize the historical development, the scope of practice, and some evidence supporting the current applications of POCUS in the adult emergency department. Bedside ultrasonography in the emergency department shares clinical applications with critical care ultrasonography, including goal-directed echocardiography, echocardiography during cardiac arrest, thoracic ultrasonography, evaluation for deep vein thrombosis and pulmonary embolism, screening abdominal ultrasonography, ultrasonography in trauma, and guidance of procedures with ultrasonography. Some applications of POCUS unique to the emergency department include abdominal ultrasonography of the right upper quadrant and appendix, obstetric, testicular, soft tissue/musculoskeletal, and ocular ultrasonography. Ultrasonography has become an integral part of EM over the past two decades, and it is an important skill which positively influences patient outcomes.

Prophylactic Administration of Vasopressors Prior to Emergency Intubation in Critically Ill Patients: A Secondary Analysis of Two Multicenter Clinical Trials.

Hypotension affects approximately 40% of critically ill patients undergoing emergency intubation and is associated with an increased risk of death. The objective of this study was to examine the association between prophylactic vasopressor administration and the incidence of peri-intubation hypotension and other clinical outcomes. DESIGN: A secondary analysis of two multicenter randomized clinical trials. The clinical effect of prophylactic vasopressor administration was estimated using a one-to-one propensity-matched cohort of patients with and without prophylactic vasopressors. SETTING: Seven emergency departments and 17 ICUs across the United States. PATIENTS: One thousand seven hundred ninety-eight critically ill patients who underwent emergency intubation at the study sites between February 1, 2019, and May 24, 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was peri-intubation hypotension defined as a systolic blood pressure less than 90 mm Hg occurring between induction and 2 minutes after tracheal intubation. A total of 187 patients (10%) received prophylactic vasopressors prior to intubation. Compared with patients who did not receive prophylactic vasopressors, those who did were older, had higher Acute Physiology and Chronic Health Evaluation II scores, were more likely to have a diagnosis of sepsis, had lower pre-induction systolic blood pressures, and were more likely to be on continuous vasopressor infusions prior to intubation. In our propensity-matched cohort, prophylactic vasopressor administration was not associated with reduced risk of peri-intubation hypotension (41% vs 32%; p = 0.08) or change in systolic blood pressure from baseline (-12 vs -11 mm Hg; p = 0.66). CONCLUSIONS: The administration of prophylactic vasopressors was not associated with a lower incidence of peri-intubation hypotension in our propensity-matched analysis. To address potential residual confounding, randomized clinical trials should examine the effect of prophylactic vasopressor administration on peri-intubation outcomes.

DirEct versus VIdeo LaryngosCopE (DEVICE): protocol and statistical analysis plan for a randomised clinical trial in critically ill adults undergoing emergency tracheal intubation.

INTRODUCTION: Among critically ill patients undergoing orotracheal intubation in the emergency department (ED) or intensive care unit (ICU), failure to visualise the vocal cords and intubate the trachea on the first attempt is associated with an increased risk of complications. Two types of laryngoscopes are commonly available: direct laryngoscopes and video laryngoscopes. For critically ill adults undergoing emergency tracheal intubation, it remains uncertain whether the use of a video laryngoscope increases the incidence of successful intubation on the first attempt compared with the use of a direct laryngoscope. METHODS AND ANALYSIS: The DirEct versus VIdeo LaryngosCopE (DEVICE) trial is a prospective, multicentre, non-blinded, randomised trial being conducted in 7 EDs and 10 ICUs in the USA. The trial plans to enrol up to 2000 critically ill adults undergoing orotracheal intubation with a laryngoscope. Eligible patients are randomised 1:1 to the use of a video laryngoscope or a direct laryngoscope for the first intubation attempt. The primary outcome is successful intubation on the first attempt. The secondary outcome is the incidence of severe complications between induction and 2 min after intubation, defined as the occurrence of one or more of the following: severe hypoxaemia (lowest oxygen saturation <80%); severe hypotension (systolic blood pressure <65 mm Hg or new or increased vasopressor administration); cardiac arrest or death. Enrolment began on 19 March 2022 and is expected to be completed in 2023. ETHICS AND DISSEMINATION: The trial protocol was approved with waiver of informed consent by the single institutional review board at Vanderbilt University Medical Center and the Human Research Protection Office of the Department of Defense. The results will be presented at scientific conferences and submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT05239195).

Protocol and statistical analysis plan for the PREOXI trial of preoxygenation with noninvasive ventilation vs oxygen mask.

Background: Hypoxemia is a common and life-threatening complication during emergency tracheal intubation of critically ill adults. The administration of supplemental oxygen prior to the procedure ("preoxygenation") decreases the risk of hypoxemia during intubation. Research Question: Whether preoxygenation with noninvasive ventilation prevents hypoxemia during tracheal intubation of critically ill adults, compared to preoxygenation with oxygen mask, remains uncertain. Study Design and Methods: The PRagmatic trial Examining OXygenation prior to Intubation (PREOXI) is a prospective, multicenter, non-blinded randomized comparative effectiveness trial being conducted in 7 emergency departments and 17 intensive care units across the United States. The trial compares preoxygenation with noninvasive ventilation versus oxygen mask among 1300 critically ill adults undergoing emergency tracheal intubation. Eligible patients are randomized in a 1:1 ratio to receive either noninvasive ventilation or an oxygen mask prior to induction. The primary outcome is the incidence of hypoxemia, defined as a peripheral oxygen saturation <85% between induction and 2 minutes after intubation. The secondary outcome is the lowest oxygen saturation between induction and 2 minutes after intubation. Enrollment began on 10 March 2022 and is expected to conclude in 2023. Interpretation: The PREOXI trial will provide important data on the effectiveness of noninvasive ventilation and oxygen mask preoxygenation for the prevention of hypoxemia during emergency tracheal intubation. Specifying the protocol and statistical analysis plan prior to the conclusion of enrollment increases the rigor, reproducibility, and interpretability of the trial. Clinical trial registration number: NCT05267652.

Letter to the Editor: "Use of inhaled epoprostenol with high flow nasal oxygen in non-intubated patients with severe COVID-19".

PURPOSE: Acute lung injury associated with COVID-19 contributes significantly to its morbidity and mortality. Though invasive mechanical ventilation is sometimes necessary, the use of high flow nasal oxygen may avoid the need for mechanical ventilation in some patients. For patients approaching the limits of high flow nasal oxygen support, addition of inhaled pulmonary vasodilators is becoming more common but little is known about its effects. This is the first descriptive study of a cohort of patients receiving inhaled epoprostenol with high flow nasal oxygen for COVID-19. MATERIALS AND METHODS: We collected clinical data from the first fifty patients to receive inhaled epoprostenol while on high flow nasal oxygen at our institution. We compared the characteristics of patients who did and did not respond to epoprostenol addition. RESULTS: The 18 patients that did not stabilize or improve following initiation of inhaled epoprostenol had similar rates of invasive mechanical ventilation as those who improved or stabilized (50% vs 56%). Rates of mortality were not significantly different between the two groups (17% and 31%). CONCLUSIONS: In patients with COVID-19 induced hypoxemic respiratory failure, the use of inhaled epoprostenol with high flow nasal oxygen is feasible, but physiologic signs of response were not related to clinical outcomes.

BOugie or stylet in patients UnderGoing Intubation Emergently (BOUGIE): protocol and statistical analysis plan for a randomised clinical trial.

INTRODUCTION: Intubation-related complications are less frequent when intubation is successful on the first attempt. The rate of first attempt success in the emergency department (ED) and intensive care unit (ICU) is typically less than 90%. The bougie, a semirigid introducer that can be placed into the trachea to facilitate a Seldinger-like technique of tracheal intubation and is typically reserved for difficult or failed intubations, might improve first attempt success. Evidence supporting its use, however, is from a single academic ED with frequent bougie use. Validation of these findings is needed before widespread implementation. METHODS AND ANALYSIS: The BOugie or stylet in patients Undergoing Intubation Emergently trial is a prospective, multicentre, non-blinded randomised trial being conducted in six EDs and six ICUs in the USA. The trial plans to enrol 1106 critically ill adults undergoing orotracheal intubation. Eligible patients are randomised 1:1 for the use of a bougie or use of an endotracheal tube with stylet for the first intubation attempt. The primary outcome is successful intubation on the first attempt. The secondary outcome is severe hypoxaemia, defined as an oxygen saturation less than 80% between induction until 2 min after completion of intubation. Enrolment began on 29 April 2019 and is expected to be completed in 2021. ETHICS AND DISSEMINATION: The trial protocol was approved with waiver of informed consent by the Central Institutional Review Board at Vanderbilt University Medical Center or the local institutional review board at an enrolling site. The results will be submitted for publication in a peer-reviewed journal and presented at scientific conferences. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT03928925).

Feasibility, Utility, and Safety of Midodrine During Recovery Phase From Septic Shock.

BACKGROUND: We describe the feasibility, utility, and safety of oral midodrine to replace IV vasopressors during recovery from septic shock. METHODS: This was a retrospective study performed in a medical ICU. All study subjects had a diagnosis of septic shock requiring at least 24 hours of IV vasopressors and demonstrated clinical stability with stable or decreasing doses of IV vasopressors. The two groups compared were those who received IV vasopressors only and those who received IV vasopressors with adjunctive midodrine. RESULTS: Of the 275 study patients, 140 received an IV vasopressor only and 135 received midodrine in addition to an IV vasopressor. There was no difference between the groups' demographics (age, sex, Acute Physiology and Chronic Health Evaluation 4 score). Mean IV vasopressor duration was 3.8 days in the IV vasopressor only group and 2.9 days in the IV vasopressor with midodrine group (P < .001). An IV vasopressor was reinstituted after discontinuation in 21 of 140 (15%) patients in the IV vasopressor only group and in 7 of 135 (5.2%) patients in the IV vasopressor with midodrine group (P = .007). ICU length of stay was 9.4 days in the IV vasopressor only group and 7.5 days in the IV vasopressor with midodrine group (P = .017). There were no complications associated with midodrine use except transient bradycardia in one patient, which resolved upon discontinuation of midodrine. CONCLUSIONS: Midodrine may reduce the duration of IV vasopressors during recovery phase from septic shock and may be associated with a reduction in length of stay in the ICU.