The Pitfalls of Using Pop-Off Valves in Adult Emergency Airway.

BACKGROUND: Although common in pediatric airway equipment, positive-pressure relief ("pop-off") valves are also present on some adult resuscitator bags. These valves are designed to decrease barotrauma but, in doing so, limit the airway pressure provided during manual bag-assisted ventilation. In critically ill adult patients with high airway pressures, these valves can be detrimental and result in hypoventilation and subsequent hypoxemia. CASE REPORTS: In the 7 days after an unannounced introduction of new resuscitator bags with pop-off valves in the emergency department, there were 3 adult patients for whom an open pop-off valve resulted in hypoventilation and hypoxemia. These cases involved both medical and traumatic pathologies. In each case, there was a delay in discovering the change to a resuscitator bag equipped with a pop-off valve. Once the emergency physicians noticed the pop-off valve and closed them, there was significant improvement in ventilation and oxygenation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Hand-operated resuscitator bags are an essential tool for airway management. These cases represent two main lessons: changing airway equipment without notifying staff is dangerous, and an open pop-off valve will result in inadequate ventilation when patients have high airway pressures, without the tactile feedback of difficult bagging. Emergency physicians should be aware of equipment changes and know to disable the pop-off valve on resuscitator bags if they find them in their departments.

A Practical Solution for Preoxygenation in the Prehospital Setting: A Nonrebreather Mask with Flush Rate Oxygen.

OBJECTIVE: Prehospital clinicians need a practical means of providing adequate preoxygenation prior to intubation. A bag-valve-mask (BVM) can be used for preoxygenation in perfect conditions but is likely to fail in emergency settings. For this reason, many airway experts have moved away from using BVM for preoxygenation and instead suggest using a nonrebreather (NRB) mask with flush rate oxygen.Literature on preoxygenation has suggested that a NRB mask delivering flush rate oxygen (on a 15 L/min O2 regulator, maximum flow, ∼50 L/min) is noninferior to BVM at 15 L/min held with a tight seal. However, in the prehospital setting, where emergency airway management success varies, preoxygenation techniques have not been deeply explored. Our study seeks to determine whether preoxygenation can be optimally performed with NRB at flush rate oxygen. METHODS: We performed a crossover trial using healthy volunteers. Subjects underwent 3-min trials of preoxygenation with NRB mask at 25 L/min oxygen delivered from a portable tank, NRB at flush rate oxygen from a portable tank, NRB with flush rate oxygen from an onboard ambulance tank, and BVM with flush rate oxygen from an onboard ambulance tank. The primary outcome was the fraction of expired oxygen (FeO2). We compared the FeO2 of the BVM-flush to other study groups, using a noninferiority margin of 10%. RESULTS: We enrolled 30 subjects. Mean FeO2 values for NRB-25, NRB-flush ambulance, NRB-flush portable, and BVM-flush were 63% (95% confidence interval [CI] 58-68%), 74% (95%, CI 70-78%), 78% (95%, CI 74-83%), and 80% (95%, CI 75-84%), respectively. FeO2 values for NRB-flush on both portable tank and ambulance oxygen were noninferior to BVM-flush on the ambulance oxygen system (FeO2 differences of 1%, 95% CI -3% to 6%; and 6%, 95% CI 1-10%). FeO2 for the NRB-25 group was inferior to BVM-flush (FeO2 difference 16%, 95% CI 12-21%). CONCLUSIONS: Among healthy volunteers, flush rate preoxygenation using NRB masks is noninferior to BVM using either a portable oxygen tank or ambulance oxygen. This is significant because preoxygenation using NRB masks with flush rate oxygen presents a simpler alternative to the use of BVMs. Preoxygenation using NRB masks at 25 L/min from a portable tank is inferior to BVM at flush rate.

Sedative Dose for Rapid Sequence Intubation and Postintubation Hypotension: Is There an Association?

STUDY OBJECTIVE: For patients with hemodynamic instability undergoing rapid sequence intubation, experts recommend reducing the sedative medication dose to minimize the risk of further hemodynamic deterioration. Scant data support this practice for etomidate and ketamine. We sought to determine if the dose of etomidate or ketamine was independently associated with postintubation hypotension. METHODS: We analyzed data from the National Emergency Airway Registry from January 2016 to December 2018. Patients aged 14 years or older were included if the first intubation attempt was facilitated with etomidate or ketamine. We used multivariable modeling to determine whether drug dose in milligrams per kilogram of patient weight was independently associated with postintubation hypotension (systolic blood pressure < 100 mm Hg). RESULTS: We analyzed 12,175 intubation encounters facilitated by etomidate and 1,849 facilitated by ketamine. The median drug doses were 0.28 mg/kg (interquartile range [IQR] 0.22 mg/kg to 0.32 mg/kg) for etomidate and 1.33 mg/kg (IQR 1 mg/kg to 1.8 mg/kg) for ketamine. Postintubation hypotension occurred in 1,976 patients (16.2%) who received etomidate and in 537 patients (29.0%) who received ketamine. In multivariable models, neither the etomidate dose (adjusted odds ratio [aOR] 0.95, 95% confidence interval [CI] 0.90 to 1.01) nor ketamine dose (aOR 0.97, 95% CI 0.81 to 1.17) was associated with postintubation hypotension. Results were similar in sensitivity analyses excluding patients with preintubation hypotension and including only patients intubated for shock. CONCLUSION: In this large registry of patients intubated after receiving either etomidate or ketamine, we observed no association between the weight-based sedative dose and postintubation hypotension.

First attempt success with continued versus paused chest compressions during cardiac arrest in the emergency department.

AIM: Tracheal intubation is associated with interruption in cardiopulmonary resuscitation (CPR). Current knowledge of tracheal intubation during active CPR focuses on the out-of-hospital environment. We aim to describe characteristics of tracheal intubation during active CPR in the emergency department (ED) and determine whether first attempt success was associated with CPR being continued vs paused. MEASUREMENTS: We reviewed overhead video from adult ED patients receiving chest compressions at the start of the orotracheal intubation attempt. We recorded procedural detail including method of CPR, whether CPR was continued vs paused, and first attempt intubation success (primary outcome). We performed logistic regression to determine whether continuing CPR was associated with first attempt success. RESULTS: We reviewed 169 instances of tracheal intubation, including 143 patients with continued CPR and 26 patients with paused CPR. Those with paused CPR were more likely to be receiving manual rather than mechanical chest compressions. Video laryngoscopy and bougie use were common. First attempt success was higher in the continued CPR group (87%, 95% CI 81% to 92%) than the interrupted CPR group (65%, 95% CI 44% to 83%, difference 22% [95% CI 3% to 41%]). The multivariable model demonstrated an adjusted odds ratio of 0.67 (95% CI 0.17 to 2.60) for first attempt intubation success when CPR was interrupted vs continued. CONCLUSIONS: It was common to continue CPR during tracheal intubation, with success comparable to that achieved in patients without cardiac arrest. It is reasonable to attempt tracheal intubation without interrupting CPR, pausing only if necessary.

The Pediatric Bougie for the First Tracheal Intubation Attempt in Critically Ill Children.

STUDY OBJECTIVE: Bougie use during emergency tracheal intubation has not been well studied in children. METHODS: This was a 10-year observational study of pediatric intubations (<18 years of age) in the emergency department (ED) of an academic institution. Bougie training and use are standard in our ED, including for emergency medicine residents. Study data were collected by a combination of charts and video reviews. We compare first-attempt intubation success and procedural complications between pediatric patients with and without bougie use during tracheal intubation in the ED. In addition, we evaluate the independent association of bougie use with first-attempt intubation success using multivariable logistic regression. RESULTS: We collected data on intubation success and bougie use for 195 pediatric patients over more than 10 years. On the first tracheal intubation attempt, a pediatric bougie was used in 126 patients (65%). Median patient age was 5 years (interquartile range 1.7 to 9) in the bougie group and 1.7 years (interquartile range 0.2 to 5) in the no bougie group. Intubation was successful on the first attempt in 72% of intubations with a bougie versus 78% without a bougie (absolute difference -6%, 95% confidence interval [CI] -19 to 6%); the adjusted odds of first-attempt success with a bougie were 0.54 (95% CI 0.24 to 1.19). A procedural complication occurred for 38% of patients in the bougie group versus 51% in the no bougie group (-13%, 95% CI -27% to 2%). Two neonates, one in each group, experienced a potential injury to the airway or lower respiratory tract. CONCLUSION: In an academic ED where the bougie is commonly used, bougie use in children was not associated with procedural success or complications. Our study suggests that a randomized clinical trial is needed to determine the effect of bougie use during emergency pediatric intubation.

Prehospital Ultrasound Diagnosis of Massive Pulmonary Embolism by Non-Physicians: A Case Series.

Massive pulmonary embolism (hemodynamically unstable, defined as systolic BP <90 mmHg) has significant morbidity and mortality. Point of care ultrasound (POCUS) has allowed clinicians to detect evidence of massive pulmonary embolism much earlier in the patient's clinical course, especially when patient instability precludes computerized tomography confirmation. POCUS detection of massive pulmonary embolism has traditionally been performed by physicians. This case series demonstrates four cases of massive pulmonary embolism diagnosed with POCUS performed by non-physician prehospital personnel.

Bronchoscopy in the emergency department.

BACKGROUND: Flexible bronchoscopy has been safely used for decades in ambulatory and critical care settings to aid in the diagnosis and treatment of tracheobronchial tree disorders. Although emergency physicians have the requisite skills to operate and interpret flexible bronchoscopy, no reports exist on the use of bronchoscopy by emergency physicians apart from endotracheal tube placement and confirmation. OBJECTIVE: The primary goal of this study was to describe the indications, outcomes and complications of flexible bronchoscopy performed by emergency physicians in an urban academic emergency department. METHODS: This was a single-center retrospective cohort study involving chart and video review of 146 patients over a 10.5-year study period. Patients of any age were included if they had been tracheally intubated or mechanically ventilated and underwent flexible bronchoscopy in the emergency department. After patients were identified, manual chart and video review was used to collect data on patient demographics, indications for intubation, indications for bronchoscopy, details of the bronchoscopy procedure, procedural findings, outcomes of the procedure, complications, provider training levels, and additional bronchoscopies performed after admission. The data was analyzed using descriptive statistics. RESULTS: 146 patients were included in the study and all bronchoscopies were performed or supervised by attending emergency physicians. After bronchoscopy, 24% of patients displayed improvement in oxygenation or lobar collapse while most patients had no change in clinical status. One patient had temporary hypoxemia after bronchoscopy. When another physician performed a subsequent bronchoscopy during admission, the findings were in agreement with the ED bronchoscopy 86% of the time. CONCLUSION: At our institution, emergency physicians can safely and effectively use flexible bronchoscopy to diagnose and treat critically ill patients.

Emergency Airway Management in a Patient with a T-Tube Tracheal Stent.

BACKGROUND: Abnormal anatomy complicates emergency airway management. In this case, we describe definitive airway management in a critically injured emergency department (ED) patient with a history of partial tracheal resection who had a Montgomery T-tube, a type of T-shaped tracheal stent, in place at the time of the motor vehicle collision. The Montgomery T-tube is not a useful artificial airway during resuscitation, as it lacks a cuff or the necessary adapter for positive pressure ventilation. CASE REPORT: We describe a case of a 51-year-old man who required emergency airway management after a motor vehicle collision. The patient had a Montgomery T-tube in place, which was removed with facilitation by ketamine sedation and topical anesthesia. The patient was successfully intubated through the tracheal stoma after removal of the T-tube. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians must recognize the Montgomery T-tube, which resembles a standard tracheostomy tube externally, and have some understanding of how to manage a critically ill patient with this rare device in place. When a patient with a Montgomery T-tube in place requires positive pressure ventilation, the device may require emergent removal and replacement with a cuffed tracheostomy or endotracheal tube.

Prehospital Surgical Airway Management: An NAEMSP Position Statement and Resource Document.

Bag-valve-mask ventilation and endotracheal intubation have been the mainstay of prehospital airway management for over four decades. Recently, supraglottic device use has risen due to various factors. The combination of bag-valve-mask ventilation, endotracheal intubation, and supraglottic devices allows for successful airway management in a majority of patients. However, there exists a small portion of patients who are unable to be intubated and cannot be adequately ventilated with either a facemask or a supraglottic airway. These patients require an emergent surgical airway. A surgical airway is an important component of all airway algorithms, and in some cases may be the only viable approach; therefore, it is imperative that EMS agencies that are credentialed to manage airways have the capability to perform surgical airways when appropriate. The National Association of Emergency Medical Services Physicians (NAEMSP) recommends the following for emergency medical services (EMS) agencies that provide advanced airway management.A surgical airway is reasonable in the prehospital setting when the airway cannot be secured by less invasive means.When indicated, a surgical airway should be performed without delay.A surgical airway is not a substitute for other airway management tools and techniques. It should not be the only rescue option available.Success of an open surgical approach using a scalpel is higher than that of percutaneous Seldinger techniques or needle-jet ventilation in the emergency setting.

Adjunct Devices for the Pediatric Difficult Airway: A Case Report.

This is a case report of a pediatric patient with a difficult airway, in which several airway adjuncts were used simultaneously to successfully provide adequate oxygenation and ventilation during cardiac arrest. Difficult airways are low-incidence, high-risk emergencies in children, and airway adjuncts may be used infrequently, let alone in combination. Included in the discussion of this case are a description of each airway adjunct and a discussion of the process needed to incorporate airway adjuncts safely and effectively into patient care.

Feasibility, utility, and safety of fully incorporating transesophageal echocardiography into emergency medicine practice.

INTRODUCTION: Transthoracic echocardiography (TTE) is a standard procedure for emergency physicians (EPs). Transesophageal echocardiography (TEE) is known to have great utility in patients who are critically ill or in cardiac arrest and has been used by some EPs with specialized ultrasound (US) training, but it is generally considered outside the reach of the majority of EPs. We surmised that all of our EPs could learn to perform focused TEE (F-TEE), so we trained and credentialed all of the physicians in our group. METHODS: We trained 52 EPs to perform and interpret F-TEEs using a 4-h simulator-based course. We kept a database of all F-TEE examinations for quality assurance and continuous quality feedback. Data are reported using descriptive statistics. RESULTS: Emergency physicians attempted 557 total F-TEE examinations (median = 10, interquartile range = 5-15) during the 42-month period following training. Clinically relevant images were obtained in 99% of patients. EPs without fellowship or other advanced US training performed the majority of F-TEEs (417, 74.9%) and 94.3% (95% confidence interval [CI] = 91.4%-96.3%) had interpretable images recorded. When TTE and TEE were both performed (n = 410), image quality of TEE was superior in 378 (93.3%, 95% CI = 89.7%-95%). Indications for F-TEE included periarrest states (55.7%), cardiac arrest (32.1%), and shock (12.2%). There was one case of endotracheal tube dislodgement during TEE placement, but this was immediately identified and replaced without complication. CONCLUSION: After initiating a mandatory group F-TEE training and credentialing program, we report the largest series to date of EP-performed resuscitative F-TEE. The majority of F-TEE examinations (75%) were performed by EPs without advanced US training beyond residency.

Rapid Sequence Airway with the Intubating Laryngeal Mask in the Emergency Department.

BACKGROUND: The administration of sedation and neuromuscular blockade to facilitate extraglottic device (EGD) placement is known as rapid sequence airway (RSA). In the emergency department (ED), EGDs are used largely as rescue devices. In select patients, there may be significant advantages to using EGDs over laryngoscopy as the primary airway device in the ED. OBJECTIVE: Our study sought to describe the practice of RSA in the ED, including rates of successful oxygenation, ventilation, and complications from EGD use. METHODS: We identified patients in the ED between 2007 and 2017 who underwent RSA with the LMA® Fastrach™ (hereafter termed ILMA; Teleflex Medical Europe Ltd., Athlone, Ireland) placed as the first definitive airway management device. A trained abstractor performed chart and video review of the cases to determine patient characteristics, physician use of the ILMA, indication for ILMA placement, success of oxygenation and ventilation, success of intubation, and complications related to the device. RESULTS: During the study period, 94 patients underwent RSA with the ILMA. Of those, 93 (99%) were successfully oxygenated and ventilated, and when intubation was attempted, 89% were able to be intubated through the ILMA. The incidence of vomiting and aspiration was 1% and 3%, respectively. There were 30 different attending physicians who supervised RSA and the median number was 2 per physician in the 10-year study period. CONCLUSION: The practice of RSA with the ILMA in the ED is associated with a high rate of successful oxygenation, ventilation, and intubation with infrequent complications, even when performed by physicians with few experiences in the approach.

Emergency cricothyrotomy in morbid obesity: comparing the bougie-guided and traditional techniques in a live animal model.

BACKGROUND: Cricothyrotomy is a rare, time sensitive procedure that is more challenging to perform when anatomical landmarks are not easily palpated before the initial incision. There is a paucity of literature describing the optimal technique for cricothyrotomy in patients with impalpable airway structures, such as in morbid obesity. In this study, we used a live sheep model of morbid obesity to compare the effectiveness of two common cricothyrotomy techniques. METHODS: We randomly assigned emergency medicine residents to perform one of two cricothyrotomy techniques on a live anesthetized sheep. To simulate the anterior soft tissue neck thickness of an adult with morbid obesity we injected 120 mL of a mixture of autologous blood and saline into the anterior neck of the sheep. The traditional technique (as described in the New England Journal Video titled "Cricothyroidotomy") used a Shiley tracheostomy tube and no bougie, and the bougie-guided technique used a bougie and a standard endotracheal tube. The primary outcome was the total procedure time; the secondary outcome was first attempt success. RESULTS: 23 residents were included, 11 assigned to the bougie-guided technique and 12 to the traditional technique. After injection of blood and saline, the median depth from skin to cricothyroid membrane was 3.0 cm (IQR 2.5-3.4 cm). The median time for the bougie technique was 118 s (IQR 77-200 s) compared to 183 s (IQR 134-270 s) for the traditional technique (median difference 62 s, 95% CI 10-144 s). Success on the first attempt occurred in 7/11 (64%) in the bougie group and 6/12 (50%) in the traditional technique group. CONCLUSION: In this study, which simulated morbid obesity on a living animal model complete with active hemorrhage and time pressure caused by extubation before the procedure, the bougie-guided technique was faster than the traditional technique using a tracheostomy tube without a bougie.

Erector Spinae Plane Block in the Emergency Department for Upper Extremity: A Case Report.

INTRODUCTION: The erector spinae plane block (ESPB) has been described as an effective analgesic modality in the emergency department (ED) for thoracic pain. It has not previously been described to treat ED patients with pain in the upper extremity. CASE REPORT: We present a case of a 52-year-old female who presented to the ED with an acute exacerbation of her chronic radicular left arm pain originating after a fall she sustained one year prior. After a variety of analgesic modalities failed to control her pain, an ESPB was used to successfully treat her pain and facilitate discharge from the ED. CONCLUSION: A significant portion of patients who present to the ED have underlying chronic pain; however, opioids are a potentially dangerous and ineffective modality to treat chronic pain. In addition to avoiding opiates, the ESPB has the advantage of preserving motor function, thus avoiding the complications associated with brachial plexus blockade.

Engagement of the Median Glossoepiglottic Fold and Laryngeal View During Emergency Department Intubation.

STUDY OBJECTIVE: When using a standard geometry laryngoscope, experts recommend engaging the hyoepiglottic ligament-a ligament deep to the vallecula not visible to the intubator. The median glossoepiglottic fold (hereafter termed midline vallecular fold) is a superficial mucosal structure, visible to the intubator, that lies in the midline of the vallecula. We aimed to determine whether engaging the midline vallecular fold with a standard geometry blade tip during orotracheal intubation improved laryngeal visualization. METHODS: We reviewed laryngoscopic videos from intubations by emergency physicians using standard geometry video laryngoscopes over a 2-year period. Two reviewers watched each video and recorded whether the blade tip engaged the midline vallecular fold (obscured the fold with the blade tip) and the best modified Cormack-Lehane grade and percent of glottic opening obtained. We compared laryngeal views in the presence and absence of fold engagement. RESULTS: We analyzed 183 discrete laryngoscopic episodes, including 113 instances in which the midline vallecular fold was engaged and 70 instances in which the fold was not engaged. The proportion with a Cormack-Lehane grade 1 or 2a was higher with fold engagement (96%) than without (87%) (absolute difference 9% [95% confidence interval (CI) 1 to 18%]). Ordinal logistic regression demonstrated that midline vallecular fold engagement was associated with a more favorable Cormack-Lehane grade (odds ratio 2.1 [95% CI 1.1 to 4.2]). The median percent of glottic opening score was 95% (interquartile range 90 to 100%) with fold engagement and 95% (65 to 100%) without engagement (median difference 0% [95% CI 0 to 5%]). CONCLUSION: Engaging the midline vallecular fold with the laryngoscope blade tip during orotracheal intubation when using a standard geometry blade was associated with improved laryngeal visualization.

Emergency Department Vacuum Extraction of an Obstructing Tracheal Foreign Body Using a Meconium Aspirator and Modified Endotracheal Tube.

BACKGROUND: A meconium aspirator is a simple plastic adapter that allows for rapid suctioning of the trachea when attached to an endotracheal tube and a source of continuous negative pressure, as was historically done for suspected neonatal meconium aspiration. Adaptation of this technique for the emergent vacuum extraction of an obstructing tracheal foreign body in an adult has not been previously described. CASE REPORT: We report the case of a 33-year-old woman with cardiorespiratory arrest after choking on food. Complete tracheal obstruction precluding oxygenation and ventilation due to aspirated chicken was diagnosed by emergency physicians and managed immediately with vacuum extraction using the technique described in this report. No additional airway interventions were necessary and the patient made a full neurologic recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Vacuum extraction using a meconium aspirator and modified endotracheal tube is a novel and potentially life-saving approach to the emergency management of airway obstruction after choking, especially if the foreign material is below the vocal cords and not amenable to manual extraction with a Magill forceps.

The feasibility of bedside transvaginal ultrasonography in non-pregnant women in the emergency department.

STUDY OBJECTIVE: We recorded data on the routine use of point-of-care transvaginal ultrasound (POC TVUS) for the evaluation of non-pregnant women with pelvic complaints in the Emergency Department (ED), and sought to determine how it altered the diagnostic impression and management. METHODS: This was a prospective observational study. Adult non-pregnant women with pelvic complaints undergoing POC TVUS were enrolled. Pre and post ultrasound, the treating physician completed a data collection form indicating the most likely cause of the patient's pain, current treatment plan, and expected ultrasound findings. Immediately after the ultrasound, the treating physician completed another form to indicate details about the sonographic process and findings, and whether a radiologyperformed TVUS was planned. RESULTS: Of 113 women enrolled, 79% had both ovaries visualized and the POC TVUS led to changes in plan in 43% of patients, including 3 emergent/urgent interventions; 48% of patients had unexpected findings. Of the 25% who had an additional radiology exam, there were no instances of discordant findings when both ovaries were assessed to be normal on ED Ultrasound. The ultrasound added <10 minutes in 92% of patients. With an ED ultrasound only (n = 85), the median length of stay (LOS) was 282 (IQR 197-323) minutes, compared to 437 (IQR 367-500) minutes when a radiology ultrasound was required (n = 28) (median difference,170 minutes [95% CI 122-212 min]). CONCLUSION: In this study, emergency physicians were able to efficiently obtain and interpret POC TVUS images that changed assessment of non-pregnant women with pelvic pain without significantly increasing the ED length of stay.

Success and Complications of the Ketamine-Only Intubation Method in the Emergency Department.

BACKGROUND: Rapid sequence intubation (RSI), defined as near-simultaneous administration of a sedative and neuromuscular blocking agent, is the most common and successful method of tracheal intubation in the emergency department. However, RSI is sometimes avoided when the physician believes there is a risk of a can't intubate/can't oxygenate scenario or critical hypoxemia because of distorted anatomy or apnea intolerance. Traditionally, topical anesthesia alone or in combination with low-dose sedation are used when physicians deem RSI too risky. Recently, a ketamine-only strategy has been suggested as an alternative approach. OBJECTIVE: We compared first attempt success and complications between ketamine-only, topical anesthesia alone or with low-dose sedation, and RSI approaches. METHODS: We analyzed registry data from the National Emergency Airway Registry, comprising emergency department intubation data from 25 centers from January 2016 to December 2018. We excluded pediatric patients (<14 years of age), those in cardiac and respiratory arrest, or those with an alternate pharmacologic approach (i.e., neuromuscular blocking agent only or nonketamine sedative alone). We analyzed first attempt intubation success and adverse events across the 3 intubation approaches. We calculated differences in outcomes between the ketamine-only and topical anesthesia groups. RESULTS: During the study period, 12,511 of 19,071 intubation encounters met inclusion criteria, including 102 (0.8%) intubated with ketamine alone, 80 (0.6%) who had intubation facilitated by topical anesthesia, and 12,329 (98.5%) who underwent RSI. Unadjusted first attempt success was 61%, 85%, and 90% for the 3 groups, respectively. Hypoxemia (defined as oxygen saturation <90%) occurred in 16%, 13%, and 8% of patients during the first attempt, respectively. At least 1 adverse event occurred in 32%, 19%, and 14% of the courses of intubation for the 3 groups, respectively. In comparing the ketamine-only and topical anesthesia groups, the difference in first pass success was -24% (95% confidence interval -37% to -12%), and the difference in number of cases with ≥1 adverse event was 13% (95% confidence interval 0-25%), both favoring the topical anesthesia group. CONCLUSION: Although sometimes advocated, the ketamine-only intubation approach is uncommon and is associated with lower success and higher complications compared with topical anesthesia and RSI approaches.

Time to Loss of Preoxygenation in Emergency Department Patients.

BACKGROUND: In patients requiring emergency rapid sequence intubation (RSI), 100% oxygen is often delivered for preoxygenation to replace alveolar nitrogen with oxygen. Sometimes, however, preoxygenation devices are prematurely removed from the patient prior to the onset of apnea, which can lead to rapid loss of preoxygenation. OBJECTIVE: We sought to determine the elapsed time, on average, between removing the oxygen source and the loss of preoxygenation among non-critically ill patients in the emergency department (ED). METHODS: We conducted a prospective, crossover study of non-critically ill patients in the ED. Each patient received two identical preoxygenation trials for 4 min using a non-rebreather mask with oxygen flow at flush rate and a nasal cannula with oxygen flow at 10 L/min. After each preoxygenation trial, patients underwent two trials in random order while continuing spontaneous breathing: 1) removal of both oxygen sources and 2) removal of non-rebreather mask with nasal cannula left in place. We defined loss of preoxygenation as an end-tidal oxygen (exhaled oxygen percentage; EtO2) value < 70%. We measured EtO2 breath by breath until loss of preoxygenation occurred. RESULTS: We enrolled 42 patients, median age was 43 years (interquartile range [IQR] 30 to 54 years) and 72% were male. Median time to loss of preoxygenation was 20 s (IQR 17-25 s, 4.5 breaths) when all oxygen devices were removed, and 39 s (IQR 21-56 s, 8 breaths) when the nasal cannula was left in place. CONCLUSIONS: In this population of non-critically ill ED patients, most had loss of preoxygenation after 5 breaths if all oxygen devices were removed, and after 8 breaths if a nasal cannula was left in place. These data suggest that during ED RSI, preoxygenation devices should be left in place until the patient is completely apneic.