Multicenter Comparison of Nonsupine Versus Supine Positioning During Intubation in the Emergency Department: A National Emergency Airway Registry (NEAR) Study

First-Attempt Success Between Anatomically and Physiologically Difficult Airways in the National Emergency Airway Registry

BACKGROUND

In the emergency department (ED), certain anatomical and physiological airway characteristics may predispose patients to tracheal intubation complications and poor outcomes. We hypothesized that both anatomically difficult airways (ADAs) and physiologically difficult airways (PDAs) would have lower first-attempt success than airways with neither in a cohort of ED intubations.

METHODS

We performed a retrospective, observational study using the National Emergency Airway Registry (NEAR) to examine the association between anticipated difficult airways (ADA, PDA, and combined ADA and PDA) vs those without difficult airway findings (neither ADA nor PDA) with first-attempt success. We included adult (age ≥14 years) ED intubations performed with sedation and paralysis from January 1, 2016 to December 31, 2018 using either direct or video laryngoscopy. We excluded patients in cardiac arrest. The primary outcome was first-attempt success, while secondary outcomes included first-attempt success without adverse events, peri-intubation cardiac arrest, and the total number of airway attempts. Mixed-effects models were used to obtain adjusted estimates and confidence intervals (CIs) for each outcome. Fixed effects included the presence of a difficult airway type (independent variable) and covariates including laryngoscopy device type, intubator postgraduate year, trauma indication, and patient age as well as the site as a random effect. Multiplicative interaction between ADAs and PDAs was assessed using the likelihood ratio (LR) test.

RESULTS

Of the 19,071 subjects intubated during the study period, 13,938 were included in the study. Compared to those without difficult airway findings (neither ADA nor PDA), the adjusted odds ratios (aORs) for first-attempt success were 0.53 (95% CI, 0.40-0.68) for ADAs alone, 0.96 (0.68-1.36) for PDAs alone, and 0.44 (0.34-0.56) for both. The aORs for first-attempt success without adverse events were 0.72 (95% CI, 0.59-0.89) for ADAs alone, 0.79 (0.62-1.01) for PDAs alone, and 0.44 (0.37-0.54) for both. There was no evidence that the interaction between ADAs and PDAs for first-attempt success with or without adverse events was different from additive (ie, not synergistic/multiplicative or antagonistic).

CONCLUSIONS

Compared to no difficult airway characteristics, ADAs were inversely associated with first-attempt success, while PDAs were not. Both ADAs and PDAs, as well as their interaction, were inversely associated with first-attempt success without adverse events.

Bed tilt and ramp positions are associated with increased first-pass success of adult endotracheal intubation in the emergency department: A registry study

OBJECTIVE

Successful endotracheal intubation in the ED requires optimum body positioning. In patients with obesity, the ramp position was suggested to achieve better intubating conditions. However, limited data are available on the airway management practices for patients with obesity in Australasian EDs. The aim of this study was to identify current patient positioning practices during endotracheal intubation and its association with first-pass success (FPS) at intubation and adverse event (AE) rates in obese and non-obese populations.

METHODS

Prospectively collected data from the Australia and New Zealand ED Airway Registry (ANZEDAR) between 2012 and 2019 were analysed. Patients were categorised into two groups according to their weight: <100 kg (non-obese) or ≥100 kg (obese). Four position categories were investigated; supine, pillow or occipital pad, bed tilt and ramp or head-up with relation to FPS and complication rate using logistic regression modelling.

RESULTS

A total of 3708 intubations from 43 EDs were included. Overall, the non-obese cohort had a greater FPS rate (85.9%) compared to the obese group (77.0%). The bed tilt position had the highest FPS rate (87.2%), whereas the supine position had the lowest (83.0%). AE rates were highest in the ramp position (31.2%) compared to all other positions (23.8%). Regression analysis showed ramp, or bed tilt positions and a consultant-level intubator were associated with higher FPS. Obesity, in addition to other factors, was independently associated with lower FPS.

CONCLUSION

Obesity was associated with lower FPS, which could be improved through performing a bed tilt or ramp positioning.

Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient

RATIONALE

Controversies and practice variations exist related to the pharmacologic and nonpharmacologic management of the airway during rapid sequence intubation (RSI).

OBJECTIVES

To develop evidence-based recommendations on pharmacologic and nonpharmacologic topics related to RSI.

DESIGN

A guideline panel of 20 Society of Critical Care Medicine members with experience with RSI and emergency airway management met virtually at least monthly from the panel's inception in 2018 through 2020 and face-to-face at the 2020 Critical Care Congress. The guideline panel included pharmacists, physicians, a nurse practitioner, and a respiratory therapist with experience in emergency medicine, critical care medicine, anesthesiology, and prehospital medicine; consultation with a methodologist and librarian was available. A formal conflict of interest policy was followed and enforced throughout the guidelines-development process.

METHODS

Panelists created Population, Intervention, Comparison, and Outcome (PICO) questions and voted to select the most clinically relevant questions for inclusion in the guideline. Each question was assigned to a pair of panelists, who refined the PICO wording and reviewed the best available evidence using predetermined search terms. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework was used throughout and recommendations of "strong" or "conditional" were made for each PICO question based on quality of evidence and panel consensus. Recommendations were provided when evidence was actionable; suggestions, when evidence was equivocal; and best practice statements, when the benefits of the intervention outweighed the risks, but direct evidence to support the intervention did not exist.

RESULTS

From the original 35 proposed PICO questions, 10 were selected. The RSI guideline panel issued one recommendation (strong, low-quality evidence), seven suggestions (all conditional recommendations with moderate-, low-, or very low-quality evidence), and two best practice statements. The panel made two suggestions for a single PICO question and did not make any suggestions for one PICO question due to lack of evidence.

CONCLUSIONS

Using GRADE principles, the interdisciplinary panel found substantial agreement with respect to the evidence supporting recommendations for RSI. The panel also identified literature gaps that might be addressed by future research.

Facilitated Intubation: Time to Re-examine an Old Technique With Its Associated Risks Mitigated by New Technology

BACKGROUND

Facilitated intubation (FI) refers to intubation performed using a sedative or anesthetic drug as an induction agent, without the use of a paralytic (neuromuscular blocking agent). In comparison, rapid sequence intubation (RSI) employs both an induction agent and a paralytic drug. RSI has been seen to outperform FI in terms of first-pass success when performing direct laryngoscopy and was quickly adopted as the gold standard in all situations. Recently, ketamine-only intubation has been used in situations where there is distorted anatomy or apnea intolerance (physically and physiologically difficult airways) resulting in an increased risk of a can't intubate/can't oxygenate scenario or significant hypoxemia. Frequent and recurring national ketamine shortages have resulted in renewed interest in whether or not other forms of FI are feasible in an era where other factors that mitigate complictions in achieving first-pass success (video laryngoscopy, bougie use, semi-Fowler positioning) are commonly used. We present a case series with outcomes for profoundly hypoxic patients with coronavirus disease 2019 (COVID-19) (physiologically difficult airways) undergoing FI during a time of national ketamine shortage, using modern techniques and technology to maximize first-pass success and minimize peri-intubation complication.

METHODS

We included patients with COVID-19 pneumonia with pre-intubation oxygen saturations of less than 80% (significant hypoxemia) requiring intubation who presented to a tertiary care center in southern United States between August 25, 2021, and October 22, 2021. In this specific cohort, patients underwent endotracheal intubation with midazolam for induction without the use of paralytic agents. We used video-assisted laryngoscopy to increase the success of the first-pass attempt as well as placing the patients in a semi-Fowler position (head of bed elevation 30-45°) and bilevel positive pressure pre-oxygenation to minimize peri-intubation complications.

RESULTS

Our case series included 29 consecutive patients that met the inclusion criteria. The mean ± standard deviation (SD) age of the patients was 49.5±15.0 years. The mean±SD pre-intubation oxygenation of our cohort was 73.1±5.9%. All 29 intubations were successful on the first-pass attempt. Only one patient (3.4%) required a rescue paralytic to facilitate oral opening. Of note, 27/29 (93%) of the patients did not receive any immunizations (including partial) for COVID-19. There were no incidents of peri-intubation arrest (cardiac arrest within 30 minutes of induction) or aspiration.

CONCLUSIONS

In 29 physiologically difficult patients with acute respiratory failure, in whom the physician determined that RSI posed a higher than normal risk, FI assisted by VL, semi-Fowler positioning, and bilevel positive pressure pre-oxygenation resulted in excellent successful first-pass intubation rates without any incidences of peri-intubation arrest or aspiration. While this cohort was small, our study reveals that FI with midazolam does not likely pose a higher risk than ketamine-only intubation and warrants further study.

Pilot Study Examining Bed Angles and Heights During Ramped Position Intubation in the Emergency Department

INTRODUCTION

Ramped positioning during emergent endotracheal intubation has been associated with fewer peri-intubation complications, including a decrease in difficult intubations, esophageal intubations, pulmonary aspiration, and hypoxemia. However, the optimal bed angle and height for ramped position intubation have not been determined. Our objective was to examine the effect bed angle and height in the ramped position may have on laryngeal views during emergent intubation in the emergency department (ED).

MATERIALS AND METHODS

We performed a secondary analysis of prospectively collected quality improvement data on intubations from our ED. All adult medical intubations performed with ramped positioning in the ED over a 24-month study period (September 1, 2020, through August 30, 2022) were eligible. We compared laryngeal views using the percentage of glottic opening (POGO) score between ramp angles (≥30° and <30° from horizontal) and bed heights (relative to the intubator, including xiphoid or above, umbilicus or below, and between xiphoid and umbilicus).

RESULTS

Of the 251 patients intubated during the study period, 201 were intubated in the supine position and 50 in the ramped position. Data forms were completed for 25 patients intubated using ramped position in the ED during the study period. The median ramp angle was 30° (interquartile range (IQR) 25, 40) with 16 (64%) subjects intubated at ≥30° and 9 (36%) subjects at <30°. The median POGO scores for bed angles ≥30° and <30° were 95% (IQR 79, 100) and 90% (IQR 75, 100), respectively. Bed heights varied, with four (16%) intubated at the xiphoid or above height, one (4%) at the umbilicus or below, and 20 (80%) between the xiphoid and umbilicus. The median POGO scores at each position were 95% (IQR 76, 100), 0% (IQR 0, 0), and 95% (IQR 79, 100), respectively.

CONCLUSION

ED clinicians use a variety of bed angles and heights when intubating in the ramped position. More robust investigations are necessary to determine the optimal bed angle and height for ramped position intubation in the ED.

Effect of inclined positioning on first-pass success during endotracheal intubation: a systematic review and meta-analysis

BACKGROUND

Endotracheal intubation is a high-risk procedure. Optimisation of all aspects of the procedure, including patient positioning, is important to facilitate success and minimise complications. The objective of this systematic review was to determine the association between inclined patient positioning and first-pass success and other clinically important outcomes among patients undergoing endotracheal intubation.

METHODS

A search of PubMed, CINAHL, SCOPUS, EMBASE and Cochrane, from inception through October 2020 was conducted. Studies were assessed independently by two authors to determine eligibility for inclusion. Included studies were any randomised or observational study that compared supine to inclined patient positioning for endotracheal intubation and assessed one of our predefined outcomes. Simulation studies were excluded. Study results were meta-analysed using a random effects model. The quality of the evidence for outcomes of interest was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach.

RESULTS

A total of 5113 studies were identified, of which 10 studies representing 18 371 intubations were included for meta-analysis. There was no statistically significant difference in the primary outcome of first-pass success rate (relative risk 1.02, 95% CI 0.98 to 1.05) or secondary outcomes of oesophageal intubation, glottic view, hypotension, hypoxaemia, mortality or peri-intubation arrest. Likewise, there were no statistically significant differences in any of the outcomes in predefined subgroup analyses of randomised controlled trials, intubations in acute settings or intubations performed with >45 degrees of incline. Overall quality of evidence was rated as low or very low for most outcomes.

CONCLUSIONS

This systematic review and meta-analysis found no evidence of benefit or harm with inclined versus supine patient positioning during endotracheal intubation in any setting.

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.

Comparing postinduction hypoxemia between ramped and supine position endotracheal intubations with apneic oxygenation in the emergency department

INTRODUCTION

Ramped position and apneic oxygenation are strategies to mitigate hypoxemia; however, the benefits of these strategies when utilized together remain unclear. Therefore, we compared first-attempt, postinduction hypoxemia between adult emergency department (ED) endotracheal intubations performed with apneic oxygenation in the ramped versus supine positions.

METHODS

We used the National Emergency Airway Registry (NEAR), a multicenter registry of data on ED intubations from 25 academic and community sites. We included first-attempt intubations with direct (DL) and video (VL) laryngoscopy in subjects ≥ 18 years old with nontrauma indications receiving apneic oxygenation. We examined patient characteristics (e.g., sex, obesity) and key intubation outcomes, including hypoxemia (primary outcome), first-pass success, and other adverse events (e.g., bradycardia). In addition, we examined unadjusted odds ratios (OR) and adjusted ORs (aOR) for key variables and stratified by laryngoscope type.

RESULTS

We included 210 ramped cases and 1,820 supine cases in the DL cohort and 202 ramped and 1,626 supine cases in the VL cohort. Rates of postinduction hypoxemia were similar between supine and ramped position in both the DL cohort (supine 6.5% and ramped 7.6%, aOR [95% CI] = 0.96 [0.55 to 1.67]) and the VL cohort (supine 10.1% and ramped 12.4%, aOR [95% CI] = 0.97 [0.60 to 1.56]). Other outcomes were also similar between groups.

CONCLUSION

Using this large national data set, we did not identify a difference in postinduction hypoxemia between ramped and supine positions in this cohort of ED intubations with apneic oxygenation.

Prehospital Drug Assisted Airway Management: An NAEMSP Position Statement and Resource Document

Airway management is a critical intervention for patients with airway compromise, respiratory failure, and cardiac arrest. Many EMS agencies use drug-assisted airway management (DAAM) - the administration of sedatives alone or in combination with neuromuscular blockers - to facilitate advanced airway placement in patients with airway compromise or impending respiratory failure who also have altered mental status, agitation, or intact protective airway reflexes. While DAAM provides several benefits including improving laryngoscopy and making insertion of endotracheal tubes and supraglottic airways easier, DAAM also carries important risks. NAEMSP recommends:DAAM is an appropriate tool for EMS clinicians in systems with clear guidelines, sufficient training, and close EMS physician oversight. DAAM should not be used in settings without adequate resources.EMS physicians should develop clinical guidelines informed by evidence and oversee the training and credentialing for safe and effective DAAM.DAAM programs should include best practices of airway management including patient selection, assessmenct and positioning, preoxygenation strategies including apneic oxygenation, monitoring and management of physiologic abnormalities, selection of medications, post-intubation analgesia and sedation, equipment selection, airway confirmation and monitoring, and rescue airway techniques.Post-DAAM airway placement must be confirmed and continually monitored with waveform capnography.EMS clinicians must have the necessary equipment and training to manage patients with failed DAAM, including bag mask ventilation, supraglottic airway devices and surgical airway approaches.Continuous quality improvement for DAAM must include assessment of individual and aggregate performance metrics. Where available for review, continuous physiologic recordings (vital signs, pulse oximetry, and capnography), audio and video recordings, and assessment of patient outcomes should be part of DAAM continuous quality improvement.

Rapid sequence induction/intubation controversies

Backgrounds:

Since its first definition and publication on 1970, Rapid Sequence Induction / Intubation (RSI) technique has been accepted globally as the “standard” for doing rapid intubation after induction of anesthesia for patients with high risk of aspiration, especially in emergency situation. However, this technique is not so much a “standard” as there are numerous variations on its practice based on national surveys. Anesthesia providers have their own opinions on the practice of RSI components which need to be discussed to assess their advantages and disadvantages, while there has been no review article which discussed these controversies in the last ten years.

Objectives:

To review the technique differences within RSI protocols.

Methods:

Online databases were searched, including MEDLINE and COCHRANE for each step in the original RSI protocol using keywords such as: “rapid sequence induction” or “rapid sequence intubation” or “RSI” and “controversies” or “head position” or “cricoid pressure” or “neuromuscular blocking agent” or “NMBA” or positive pressure ventilation” or “PPV”; and so on. Articles were then sorted out based on relevancy.

Results and conclusion:

Supported by new evidence, RSI practices may differ in: the positioning of patient, choices of induction agent, application of cricoid pressure, choices of neuromuscular blocking agent, and the use of positive pressure ventilation. A more updated and standardized guideline should be established by referring and evaluating to these controversies.

Massive Gastrointestinal Hemorrhage

Massive gastrointestinal hemorrhage is a life-threatening condition that can result from numerous causes and requires skilled resuscitation to decrease patient morbidity and mortality. Successful resuscitation begins with placement of large-bore intravenous or intraosseous access; early blood product administration; and early consultation with a gastroenterologist, interventional radiologist, and/or surgeon. Activate a massive transfusion protocol when initial red blood cell transfusion does not restore effective perfusion or the patient's shock index is greater than 1.0. Promptly reverse coagulopathies secondary to oral anticoagulant or antiplatelet use. Use thromboelastography or rotational thromboelastometry to guide further transfusions. Secure a definitive airway and minimize aspiration.

High-Risk Airway Management in the Emergency Department: Diseases and Approaches, Part II

BACKGROUND

Successful airway management is critical to the practice of emergency medicine. Thus, emergency physicians must be ready to optimize and prepare for airway management in critically ill patients with a wide range of physiologic challenges. Challenges in airway management commonly encountered in the emergency department are discussed using a pearl and pitfall discussion in this second part of a 2-part series.

OBJECTIVE

This narrative review presents an evidence-based approach to airway and patient management during endotracheal intubation in challenging cases commonly encountered in the emergency department.

DISCUSSION

Adverse events during emergent airway management are common with postintubation cardiac arrest, reported in as many as 1 in 25 intubations. Many of these adverse events can be avoided by proper identification and understanding the underlying physiology, preparation, and postintubation management. Those with high-risk features including trauma, elevated intracranial pressure, upper gastrointestinal bleed, cardiac tamponade, aortic stenosis, morbid obesity, and pregnancy must be managed with airway expertise.

CONCLUSIONS

This narrative review discusses the pearls and pitfalls of commonly encountered physiologic high-risk intubations with a focus on the emergency clinician.

Impact of bed angle and height on intubation success during simulated endotracheal intubation in the ramped position

OBJECTIVE

The ramped position is often used during endotracheal intubation to improve oxygenation, improve laryngeal views, and reduce airway complications. We sought to compare the impact of ramp angle and bed height on intubation outcomes during simulated endotracheal intubation.

METHODS

We enrolled emergency medicine residents and fourth-year medical students to perform simulated direct laryngoscopy and endotracheal intubation in random order with the mannequin in the following combinations of ramp angles and bed heights; ramp angles of 25° and 45° at bed heights including knee, mid-thigh, umbilicus, xiphoid, and nipple/intermammary fold. Our primary outcome was the reported percentage of glottic opening (POGO) score. Secondary outcomes included number of laryngoscopy attempts and intubation time.

RESULTS

We enrolled 25 participants. There was no difference in reported POGO scores at 25° between bed heights, but at 45°, the umbilicus bed height had an improved reported POGO score (20; 95% confidence interval [CI] 7-33, P < 0.01) relative to xyphoid. The nipple/inframammary fold height required longer intubation times in seconds (mean difference [MD] 95% CI) at 25°, (MD, 23.9 [4.6-37.6], P < 0.01) and more laryngoscopy attempts at 45° (MD, 0.48 [0.16-0.79], P < 0.01) relative to xyphoid. There was no difference in laryngoscopy attempts and video POGO between 25° and 45° at all bed heights, but reported POGO at the umbilicus position was better at 25° than 45° (12 [1-23], P = 0.03).

CONCLUSION

The umbilicus bed height resulted in the highest reported POGO at 45°. Nipple/inframammary fold height resulted in worse intubating conditions.