Emergency Department use of Apneic Oxygenation Versus Usual Care During Rapid Sequence Intubation: A Randomized Controlled Trial (The ENDAO Trial)

Pre-oxygenation using high-flow nasal oxygen versus tight facemask in trauma patients undergoing emergency anaesthesia

BACKGROUND

Patients suffering from major traumatic injuries frequently require emergency anaesthesia. Due to often compromised physiology and the time-sensitive management, trauma patients may be more prone to desaturate during induction of anaesthesia. We hypothesised that pre-oxygenation using high-flow nasal oxygen would decrease the risk of desaturation during induction of anaesthesia in trauma patients and the study therefore aimed to compare the frequency of desaturation when pre-oxygenation was performed with high-flow nasal oxygen or a traditional facemask.

METHODS

This exploratory, prospective, before-and-after study was conducted at the Karolinska University Hospital, Sweden. Adult (≥18 years of age) patients suffering major traumatic injuries needing emergency anaesthesia were included around the clock. Patients were pre-oxygenated using a tight-fitting facemask during the first nine months of enrollment. High-flow nasal oxygen was then introduced as a method for pre-oxygenation of trauma patients. The primary outcome was the proportion of patients desaturating <93% during induction of anaesthesia, assessed from the start of pre-oxygenation until one minute after intubation. Secondary outcomes included perceived difficulty of pre-oxygenation among anaesthetists (assessed on a scale between 1 and 10) and safety outcomes, such as incidence of regurgitations and intracranial gas (assessed radiologically).

RESULTS

Data from 96 patients were analysed. Facemask pre-oxygenation was performed in 66 patients, while 30 patients were pre-oxygenated with high-flow nasal oxygen. The most frequent trauma mechanisms were stabbing injuries (n = 34 (35%)) and fall injuries (n = 21 (22%)). There were no differences in patient characteristics between the groups. Eight (12%) versus three (10%) patients desaturated <93% in the facemask and high-flow nasal oxygen group respectively, OR 0.81 (95% CI 0.20-3.28), p = .76. Anaesthetists assessed pre-oxygenation using high-flow nasal oxygen as easier compared to facemask pre-oxygenation. No patient in any group showed signs of regurgitation. Among patients with facial or skull fractures requiring anaesthesia before radiology was performed, intracranial gas was seen in four (40%) patients pre-oxygenated with a facemask and in no patient pre-oxygenated with HFNO (p = .23).

CONCLUSION

In this prospective study investigating trauma patients undergoing emergency anaesthesia, we could not see any difference in the number of patients desaturating when pre-oxygenation was performed with high-flow nasal oxygen compared to a tight-fitting facemask. Pre-oxygenation using high-flow nasal oxygen was assessed as easier compared to facemask pre-oxygenation.

High-Flow Nasal Cannula versus Bag Valve Mask for Preoxygenation during Rapid Sequence Intubation in the Emergency Department: A Single-Center, Prospective, Randomized Controlled Trial

OBJECTIVE

Hypoxia is a frequently reported complication during the intubation procedure in the emergency department (ED) and may cause bad outcomes. Therefore, oxygenation plays an important role in emergency airway management. The efficacy of oxygenation with high-flow nasal cannula (HFNC) in the ED has been studied, though the evidence is limited. The study aim was to compare two methods of preoxygenation in patients undergoing rapid sequence intubation (RSI) in the ED: (1) HFNC and (2) bag-valve mask (BVM) oxygenation.

METHODS

This is a single-center, prospective, randomized controlled trial (RCT) in adult ED patients requiring RSI. Patients were randomized to receive preoxygenation with either HFNC or BVM. While HFNC therapy was continued during the intubation procedure, BVM oxygenation was interrupted for laryngoscopy. The primary outcome was the lowest peripheral oxygen saturation (SpO2) level during intubation. Secondary outcomes were incidence of desaturation (SpO2<90%) and severe hypoxemia (SpO2<80%) throughout the procedure, intubation time, rate of failed intubation, and 30-day survival rates.

RESULTS

A total of 135 patients were randomized into two groups (HFNC n = 68; BVM n = 67). The median lowest SpO2 value measured during intubation was 96% (88.8%-99.0%) in the HFNC group and 92% (86.0%-97.5%) in the BVM group (P = .161). During the intubation procedure, severe hypoxemia occurred in 13.2% (n = 9) of patients in the HFNC group and 8.9% (n = 6) in the BVM group, while mild hypoxemia was observed in 35.8% (n = 24) of the BVM group and 26.5% (n = 18) of the HFNC group. However, there was no statistically significant difference between the groups in terms of hypoxemia development (P = .429 and P = .241, respectively). No significant difference was reported in the rate of failed intubation between the groups. Thirty-day mortality was observed in 73.1% of the BVM group and 57.4% of the HFNC group, with a borderline statistically significant difference (difference 15.7; 95% CI of the difference: -0.4 to 30.7; P = .054).

CONCLUSION

The use of HFNC for preoxygenation, when compared to standard care with BVM oxygenation, did not improve the lowest SpO2 levels during intubation. Also, the use of HFNC during intubation did not provide benefits in reducing the incidence of severe hypoxemia. However, the 30-day survival rates were slightly better in the HFNC group compared to the BVM group.

Oxygenation during the apnoeic phase preceding intubation in adults in prehospital, emergency department, intensive care and operating theatre environments

BACKGROUND

Apnoeic oxygenation is the delivery of oxygen during the apnoeic phase preceding intubation. It is used to prevent respiratory complications of endotracheal intubation that have the potential to lead to significant adverse events including dysrhythmia, haemodynamic decompensation, hypoxic brain injury and death. Oxygen delivered by nasal cannulae during the apnoeic phase of intubation (apnoeic oxygenation) may serve as a non-invasive adjunct to endotracheal intubation to decrease the incidence of hypoxaemia, morbidity and mortality.

OBJECTIVES

To evaluate the benefits and harms of apnoeic oxygenation before intubation in adults in the prehospital, emergency department, intensive care unit and operating theatre environments compared to no apnoeic oxygenation during intubation.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 4 November 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared the use of any form of apnoeic oxygenation including high flow and low flow nasal cannulae versus no apnoeic oxygenation during intubation. We defined quasi-randomization as participant allocation to each arm by means that were not truly random, such as alternation, case record number or date of birth. We excluded comparative prospective cohort and comparative retrospective cohort studies, physiological modelling studies and case reports.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. hospital stay and 2. incidence of severe hypoxaemia. Our secondary outcomes were 3. incidence of hypoxaemia, 4. lowest recorded saturation of pulse oximetry (SpO2), 5. intensive care unit (ICU) stay, 6. first pass success rate, 7. adverse events and 8.

MORTALITY

We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included 23 RCTs (2264 participants) in our analyses. Eight studies (729 participants) investigated the use of low-flow (15 L/minute or less), and 15 studies (1535 participants) investigated the use of high-flow (greater than 15 L/minute) oxygen. Settings were varied and included the emergency department (2 studies, 327 participants), ICU (7 studies, 913 participants) and operating theatre (14 studies, 1024 participants). We considered two studies to be at low risk of bias across all domains. None of the studies reported on hospital length of stay. In predominately critically ill people, there may be little to no difference in the incidence of severe hypoxaemia (SpO2 less than 80%) when using apnoeic oxygenation at any flow rate from the start of apnoea until successful intubation (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.66 to 1.11; P = 0.25, I² = 0%; 15 studies, 1802 participants; low-certainty evidence). There was insufficient evidence of any effect on the incidence of hypoxaemia (SpO2 less than 93%) (RR 0.58, 95% CI 0.23 to 1.46; P = 0.25, I² = 36%; 3 studies, 489 participants; low-certainty evidence). There may be an improvement in the lowest recorded oxygen saturation, with a mean increase of 1.9% (95% CI 0.75% to 3.05%; P < 0.001, I² = 86%; 15 studies, 1525 participants; low-certainty evidence). There may be a reduction in the duration of ICU stay with the use of apnoeic oxygenation during intubation (mean difference (MD) ‒1.13 days, 95% CI ‒1.51 to ‒0.74; P < 0.0001, I² = 46%; 5 studies, 815 participants; low-certainty evidence). There may be little to no difference in first pass success rate (RR 1.00, 95% CI 0.93 to 1.08; P = 0.79, I² = 0%; 8 studies, 826 participants; moderate-certainty evidence). There may be little to no difference in incidence of adverse events including oral trauma, arrhythmia, aspiration, hypotension, pneumonia and cardiac arrest when apnoeic oxygenation is used. There was insufficient evidence about any effect on mortality (RR 0.84, 95% CI 0.70 to 1.00; P = 0.06, I² = 0%; 6 studies, 1015 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

There was some evidence that oxygenation during the apnoeic phase of intubation may improve the lowest recorded oxygen saturation. However, the differences in oxygen saturation were unlikely to be clinically significant. This did not translate into any measurable effect on the incidence of hypoxaemia or severe hypoxaemia in a group of predominately critically ill people. We were unable to assess the influence on hospital length of stay; however, there was a reduction in ICU stay in the apnoeic oxygenation group. The mechanism for this is unclear as there was little to no difference in first pass success or adverse event rates.

Effectiveness of Face mask only oxygenation and apnoeic oxygenation in addition to face mask in sustaining PaO2 during rapid sequence induction - A randomized control trial

Background and Aims

Apnoeic oxygenation, although useful during elective intubations, has not shown consistent beneficial results during emergency intubations in critically ill patients. We aimed to study the effectiveness of adding apnoeic oxygenation to our routine practice of using facemask alone, in emergency laparotomy patients needing rapid sequence induction (RSI), for sustaining partial pressure of oxygen (PaO2).

Material and Methods

Seventy-two patients undergoing RSI for emergency laparotomy were randomly allocated to either receive pre-oxygenation with 5 L/min of oxygen (O2) with a facemask (Group-FM) or apnoeic oxygenation with 10 L/min of O2 through a nasal catheter in addition to pre-oxygenation (Group-NC). Apnoea (90 s) was allowed from the removal of the facemask before the resumption of ventilation. Arterial blood gas analysis was done at the baseline, following pre-oxygenation and after 90 s of apnoea to study the PaO2 and partial pressure of carbon dioxide (PaCO2). The circuit O2 concentrations (fraction of inspired [FiO2] and end-tidal [EtO2]) were also noted to ensure a steady state of O2 uptake was reached.

Results

The circuit O2 concentrations were 90 ± 4% in group FM and 93 ± 5% in Group-NC. The FiO2-EtO2 difference was 4% in both groups. During the 90 s apnoea following pre-oxygenation, there was a fall in the PaO2 by 38% in Group-FM and 12% in Group-NC (P = 0.000). Increase in PaCO2 was similar in both groups (Group-FM: 44 [range: 32-55] mmHg; Group-NC: 42 [range: 33-54] mmHg, P = 0.809).

Conclusion

Apnoeic insufflation of O2 using a nasopharyngeal catheter along with facemask oxygenation is more effective in sustaining PaO2 for 90 s during RSI than facemask-only oxygenation in patients undergoing emergency laparotomy.

Inclusion of older adults and reporting of consent processes in randomized controlled trials in the emergency department: A scoping review

Objective

Conducting research in the emergency department (ED) is often complicated by patients' acute and chronic illnesses, which can adversely affect cognition and subsequently capacity to consent for research, especially in older adults. Validated screening tools to assess capacity to consent for research exist, but neither the frequency of use nor which ones are used for ED research are known.

Methods

We conducted a scoping review using standard review techniques. Inclusion criteria included (1) randomized controlled trials (RCTs) from publication years 2014-2019 that (2) enrolled participants only in the ED, (3) included patients aged 65+ years, and (4) were fully published in English. Articles were sourced from Embase and screened using Covidence.

Results

From 3130 search results, 269 studies passed title/abstract and full text screening. Average of the mean or median ages was 55.7 years (SD 14.2). The mean number of study participants was 311.9 [range 8-10,807 participants]. A few (n = 13, 4.8%) waived or had exception from informed consent. Of the 256 studies requiring consent, a fourth (26.5%, n = 68) specifically excluded patients due to impaired capacity to consent. Only 11 (4.3%) documented a formal capacity screening tool and only 13 (5.1%) reported consent by legally authorized representative (LAR).

Conclusions

Most RCTs enrolling older adults in EDs did not report assessment of capacity to consent or use of LARs. This snapshot of informed consent procedures is potentially concerning and suggests that either research consent processes for older patients and/or reporting of consent processes require improvement.

Use of pragmatic and explanatory trial designs in acute care research: lessons from COVID-19

Unique challenges arise when conducting trials to evaluate therapies already in common clinical use, including difficulty enrolling patients owing to widespread open-label use of trial therapies and the need for large sample sizes to detect small but clinically meaningful treatment effects. Despite numerous successes in trials evaluating novel interventions such as vaccines, traditional explanatory trials have struggled to provide definitive answers to time-sensitive questions for acutely ill patients with COVID-19. Pragmatic trials, which can increase efficiency by allowing some or all trial procedures to be embedded into clinical care, are increasingly proposed as a means to evaluate therapies that are in common clinical use. In this Personal View, we use two concurrently conducted COVID-19 trials of hydroxychloroquine (the US ORCHID trial and the UK RECOVERY trial) to contrast the effects of explanatory and pragmatic trial designs on trial conduct, trial results, and the care of patients managed outside of clinical trials. In view of the potential advantages and disadvantages of explanatory and pragmatic trial designs, we make recommendations for their optimal use in the evaluation of therapies in the acute care setting.

Bag-Mask Ventilation Versus Apneic Oxygenation During Tracheal Intubation in Critically Ill Adults: A Secondary Analysis of 2 Randomized Trials

Background: Hypoxemia is common during tracheal intubation in intensive care units. To prevent hypoxemia during intubation, 2 methods of delivering oxygen between induction and laryngoscopy have been proposed: bag-mask ventilation and supplemental oxygen delivered by nasal cannula without ventilation (apneic oxygenation). Whether one of these approaches is more effective for preventing hypoxemia during intubation of critically ill patients is unknown. Methods: We performed a secondary analysis of data from 138 patients enrolled in 2, consecutive randomized trials of airway management in an academic intensive care unit. A total of 61 patients were randomized to receive bag-mask ventilation in a trial comparing bag-mask ventilation to none, and 77 patients were randomized to receive 100% oxygen at 15 L/min by nasal cannula in a trial comparing apneic oxygenation to none. Using multivariable linear regression accounting for age, body mass index, severity of illness, and oxygen saturation at induction, we compared patients assigned to bag-mask ventilation with those assigned to apneic oxygenation regarding lowest oxygen saturations from induction to 2 min after intubation. Results: Patients assigned to bag-mask ventilation and apneic oxygenation were similar at baseline. The median lowest oxygen saturation was 96% (interquartile range [IQR] 89%-100%) in the bag-mask ventilation group and 92% (IQR 84%-99%) in the apneic oxygenation group. After adjustment for prespecified confounders, bag-mask ventilation was associated with a higher lowest oxygen saturation compared to apneic oxygenation (mean difference, 4.2%; 95% confidence interval, 0.7%-7.8%; P = .02). The incidence of severe hypoxemia (oxygen saturation<80%) was 6.6% in the bag-mask ventilation group and 15.6% in the apneic oxygenation group (adjusted odds ratio, 0.33; P = .09). Conclusions: This secondary analysis of patients assigned to bag-mask ventilation and apneic oxygenation during 2 clinical trials suggests that bag-mask ventilation is associated with higher oxygen saturation during intubation compared to apneic oxygenation.

The efficacy of apneic oxygenation to prevent hypoxemia during rapid sequence intubation in trauma patients

PURPOSE OF REVIEW

Rapid and effective airway management is priority for trauma patients. Trauma patients are often at an increased risk of experiencing hypoxia, and thus at increased risk of morbidity and mortality. Apneic oxygenation has been widely debated but has been reported to provide benefit in terms of increased peri-intubation oxygen saturation and decreased rates of desaturation. This review aims to evaluate the current literature on the efficacy of apneic oxygenation in the setting of rapid sequence intubation (RSI) in trauma patients.

RECENT FINDINGS

Two prospective studies published this year, demonstrated that apneic oxygenation was effective in reducing hypoxic events and hypoxic duration during RSI.

SUMMARY

The use of apneic oxygenation can play an important role in preventing hypoxic events in trauma patients undergoing RSI. The use of apneic oxygenation is cheap, and should be considered to reduce hypoxemic events. Additional studies are required to see the effects of apneic oxygenation on outcomes in trauma patients undergoing RSI, specifically desaturation and hypoxemic events and duration, and early onset mortality.

Re-creating reality: validation of fresh frozen full cadaver airway training with videolaryngoscopy and bougie FIRST strategy

Background

Tracheal intubation is the gold standard in emergency airway management. One way of measuring intubation quality is first pass success rate (FPSR). Mastery of tracheal intubation and maintenance of the skill is challenging for non-anesthesiologists. A combination of individual measures can increase FPSR. Videolaryngoscopy is an important tool augmenting laryngeal visualization. Bougie-first strategy can further improve FPSR in difficult airways. Standardized positioning maneuvers and manipulation of the soft tissues can enhance laryngeal visualization. Fresh frozen cadavers (FFC) are superior models compared to commercially manufactured manikins. By purposefully manipulating FFCs, it is possible to mimic the pre-hospital intubation conditions of helicopter emergency medical service (HEMS).

Methods

Twenty-four trauma surgeons (12 per Group, NOVICES: no pre-hospital experience, HEMS: HEMS physicians) completed an airway training course using FFCs. The FFCs were modified to match airway characteristics of 60 prospectively documented intubations by HEMS physicians prior to the study (BASELINE). In four scenarios the local HEMS airway standard (1: unaided direct laryngoscopy (DL), OLD) was compared to two scenarios with modifications of the intubation technique (2: augmented DL (bougie and patient positioning), 3: augmented videolaryngoscopy (aVL)) and a control scenario (4: VL and bougie, positioning by participant, CONTROL). FPSR, POGO score, Cormack and Lehane grade and duration of intubation were recorded. No participant had anesthesiological qualifications or experience in VL.

Results

The comparison between CONTROL and BASELINE revealed a significant increase of FPSR and achieved C&L grade for HEMS group (FPSR 100%, absolute difference 23%, p ≤ .001). The use of videolaryngoscopy, bougie, and the application of positioning techniques required significantly more time in the CONTROL scenario (HEMS group: mean 34.0 s (IQR 28.3–47.5), absolute difference to BASELINE: 13.0 s, p = .045). The groups differed significantly in the median number of real-life intubations performed in any setting (NOVICES n = 5 (IQR 0–18.75), HEMS n = 68 (IQR 37.25–99.75)). In the control scenario no significant differences were found between both groups. The airway characteristics of the FFC showed no significant differences compared to BASELINE.

Conclusion

Airway characteristics of a pre-hospital patient reference group cared for by HEMS were successfully reproduced in a fresh frozen cadaver model. In this setting, a combination of evidence based airway management techniques results in high FPSR and POGO rates of non-anesthesiological trained users. Comparable results (FPSR, POGO, duration of intubation) were achieved regardless of previous provider experience. The BOAH concept can therefore be used in the early stages of airway training and for skill maintenance.

Pre- and apnoeic high-flow oxygenation for rapid sequence intubation in the emergency department (the Pre-AeRATE trial): A multicentre randomised controlled trial

INTRODUCTION

Evidence regarding the efficacy of high-flow nasal cannula (HFNC) oxygenation for preoxygenation and apnoeic oxygenation is conflicting. Our objective is to evaluate whether HFNC oxygenation for preoxygenation and apnoeic oxygenation maintains higher oxygen saturation (SpO₂) during rapid sequence intubation (RSI) in ED patients compared to usual care.

METHODS

This was a multicentre, open-label, randomised controlled trial in adult ED patients requiring RSI. Patients were randomly assigned 1:1 to either intervention (HFNC oxygenation at 60L/min) group or control (non-rebreather mask for preoxygenation and nasal prongs of at least 15L/min oxygen flow for apnoeic oxygenation) group. Primary outcome was lowest SpO₂ during the first intubation attempt. Secondary outcomes included incidence of SpO₂ falling below 90% and safe apnoea time.

RESULTS

One hundred and ninety patients were included, with 97 in the intervention and 93 in the control group. Median lowest SpO₂ during the first intubation attempt was 100% in both groups. Incidence of SpO₂ falling below 90% was lower in the intervention group (15.5%) compared to the control group (22.6%) (adjusted relative risk=0.68, 95% confidence interval [CI] 0.37-1.25). Post hoc quantile regression analysis showed that the first quartile of lowest SpO₂ during the first intubation attempt was greater by 5.46% (95% CI 1.48-9.45%, P=0.007) in the intervention group.

CONCLUSION

Use of HFNC for preoxygenation and apnoeic oxygenation, when compared to usual care, did not improve lowest SpO₂ during the first intubation attempt but may prolong safe apnoea time.

Impact of Succinylcholine vs. Rocuronium on Apnea Duration for Rapid Sequence Induction: A Prospective Cohort Study

OBJECTIVE

The present study aimed to evaluate the impact of 1.5 mg/kg succinylcholine or 1.2 mg/kg rocuronium, vs. 1.0 mg/kg succinylcholine on apnea duration in patients underwent rapid sequence induction (RSI).

METHODS

This prospective cohort study was conducted in the Department of Anesthesiology in Shanghai General Hospital from July 2020 to November 2020. Apnea duration was defined as the time from apnea prompted by the PETCO2 waveform to the time the point of oxygen saturation declined to 90% (T90) and 95% (T95) after succinylcholine or rocuronium administration. The primary outcome included T90 and T95 changes in 1.5 mg/kg vs. 1.0 mg/kg succinylcholine groups and 1.5 mg/kg succinylcholine vs. 1.2 mg/kg rocuronium groups.

RESULTS

A total of 265 participants were subjected for analysis. The succinylcholine (1.0 mg/kg) group had a significantly longer T90 (50.72, 95% confidence interval [CI, 7.60, 94.38], P = 0.015) and T95 (48.09, 95% CI [7.11, 89.07], P = 0.012) than the succinylcholine (1.5 mg/kg) group. In addition, significantly longer T90 (56.84, 95% CI [16.24, 97.44], P = 0.003) and T95 (50.57, 95% CI [12.58, 88.57], P = 0.003) were observed in the rocuronium (1.2 mg/kg) group than those in the succinylcholine (1.5 mg/kg) group. No severe side events were observed during the operation.

CONCLUSION

Rocuronium and the lower dose of succinylcholine may be recommended to patients underwent RSI.

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).

Rapid sequence induction: where did the consensus go?

Background

Rapid Sequence Induction (RSI) was introduced to minimise the risk of aspiration of gastric contents during emergency tracheal intubation. It consisted of induction with the use of thiopentone and suxamethonium with the application of cricoid pressure.

This narrative review describes how traditional RSI has been modified in the UK and elsewhere, aiming to deliver safe and effective emergency anaesthesia outside the operating room environment. Most of the key aspects of traditional RSI – training, technique, drugs and equipment have been challenged and often significantly changed since the procedure was first described. Alterations have been made to improve the safety and quality of the intervention while retaining the principles of rapidly securing a definitive airway and avoiding gastric aspiration. RSI is no longer achieved by an anaesthetist alone and can be delivered safely in a variety of settings, including in the pre-hospital environment.

Conclusion

The conduct of RSI in current emergency practice is far removed from the original descriptions of the procedure. Despite this, the principles – rapid delivery of a definitive airway and avoiding aspiration, are still highly relevant and the indications for RSI remain relatively unchanged.

Airway Management in the Critically Ill Patient

Purpose of Review

This paper will evaluate the recent literature and best practices in airway management in critically ill patients.

Recent Findings

Cardiac arrest remains a common complication of intubation in these high-risk patients. Patients with desaturation or peri-intubation hypotension are at high risk of cardiac arrest, and each of these complications have been reported in up to half of all intubations in critically ill patient populations.

Summary

There have been significant advances in preoxygenation and devices available for performing laryngoscopy and rescue oxygenation. However, the risk of cardiovascular collapse remains concerningly high with few studies to guide therapeutic maneuvers to reduce this risk.

Difficult Airway Management in Adult COVID-19 Patients: Statement by the Society of Airway Management

The COVID-19 disease, caused by Coronavirus SARS-CoV-2, often results in severe hypoxemia requiring airway management. Because SARS CoV-2 virus is spread via respiratory droplets, bag-mask ventilation, intubation, and extubation may place health care workers (HCW) at risk. While existing recommendations address airway management in patients with COVID-19, no guidance exists specifically for difficult airway management. Some strategies normally recommended for difficult airway management may not be ideal in the setting of COVID-19 infection. To address this issue the Society for Airway Management (SAM) created a task force to review existing literature and current Practice Guidelines for management of the difficult airway by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. SAM task force created recommendations for management of known or suspected difficult airway in the setting of known or suspected COVID-19 infection. The goal of the task force was to optimize successful airway management while minimizing exposure risk. Each member conducted a literature review on specific clinical practice section utilizing standard search engines (PubMed, Ovid, Google Scholar). Existing recommendations and evidence for difficult airway management in COVID-19 context were developed. Each specific recommendation was discussed among task force members and modified until unanimously approved by all task force members. Elements of AGREE Reporting Checklist for dissemination of clinical practice guidelines were utilized to develop this statement. Airway management in the COVID-19 patient increases HCW exposure risk. and difficult airway management often takes longer, may involve multiple procedures with aerosolization potential, strict adherence to personal protective equipment (PPE) protocols is mandatory to reduce risk to providers. When patient's airway risk assessment suggests awake tracheal intubation is an appropriate choice of technique, procedures that may cause increased aerosolization of secretions should be avoided. Optimal preoxygenation before induction with tight seal facemask may be performed to reduce risk of hypoxemia. Unless the patient is experiencing oxygen desaturation, positive pressure bag-mask ventilation after induction may be avoided to reduce aerosolization. For optimal intubating conditions, patients should be anesthetized with full muscle relaxation. Videolaryngoscopy is recommended as first-line strategy for airway management. If emergent invasive airway access is indicated, we recommend a surgical technique such as scalpel-bougie-tube, rather than an aerosolizing generating procedure, such as transtracheal jet ventilation. This statement represents recommendations by SAM task force for the difficult airway management of adults with COVID-19 with the goal to optimize successful airway management while minimizing the risk of clinician exposure.

Evaluation and Management of the Physiologically Difficult Airway: Consensus Recommendations From Society for Airway Management

Multiple international airway societies have created guidelines for the management of the difficult airway. In critically ill patients, there are physiologic derangements beyond inadequate airway protection or hypoxemia. These risk factors contribute to the "physiologically difficult airway" and are associated with complications including cardiac arrest and death. Importantly, they are largely absent from international guidelines. Thus, we created management recommendations for the physiologically difficult airway to provide practical guidance for intubation in the critically ill. Through multiple rounds of in-person and telephone conferences, a multidisciplinary working group of 12 airway specialists (Society for Airway Management's Special Projects Committee) over a time period of 3 years (2016-2019) reviewed airway physiology topics in a modified Delphi fashion. Consensus agreement with the following recommendations among working group members was generally high with 80% of statements showing agreement within a 10% range on a sliding scale from 0% to 100%. We limited the scope of this analysis to reflect the resources and systems of care available to out-of-operating room adult airway providers. These recommendations reflect the practical application of physiologic principles to airway management available during the analysis time period.

Apnoeic oxygenation for emergency anaesthesia of pre-hospital trauma patients

BACKGROUND

Efficient and timely airway management is universally recognised as a priority for major trauma patients, a proportion of whom require emergency intubation in the pre-hospital setting. Adverse events occur more commonly in emergency airway management, and hypoxia is relatively frequent. The aim of this study was to establish whether passive apnoeic oxygenation was effective in reducing the incidence of desaturation during pre-hospital emergency anaesthesia.

METHODS

A prospective before-after study was performed to compare patients receiving standard care and those receiving additional oxygen via nasal prongs. The primary endpoint was median oxygen saturation in the peri-rapid sequence induction period, (2 minutes pre-intubation to 2 minutes post-intubation) for all patients. Secondary endpoints included the incidence of hypoxia in predetermined subgroups.

RESULTS

Of 725 patients included; 188 patients received standard treatment and 537 received the intervention. The overall incidence of hypoxia (first recorded SpO₂ < 90%) was 16.7%; 10.9% had SpO₂ < 85%. 98/725 patients (13.5%) were hypoxic post-intubation (final SpO₂ < 90% 10 minutes post-intubation). Median SpO₂ was 100% vs. 99% for the standard vs. intervention group. There was a statistically significant benefit from apnoeic oxygenation in reducing the frequency of peri-intubation hypoxia (SpO₂ < =90%) for patients with initial SpO₂ > 95%, p = 0.0001. The other significant benefit was observed in the recovery phase for patients with severe hypoxia prior to intubation.

CONCLUSION

Apnoeic oxygenation did not influence peri-intubation oxygen saturations, but it did reduce the frequency and duration of hypoxia in the post-intubation period. Given that apnoeic oxygenation is a simple low-cost intervention with a low complication rate, and that hypoxia can be detrimental to outcome, application of nasal cannulas during the drug-induced phase of emergency intubation may benefit a subset of patients undergoing emergency anaesthesia.

Canadian Airway Focus Group updated consensus-based recommendations for management of the difficult airway: part 2. Planning and implementing safe management of the patient with an anticipated difficult airway

PURPOSE

Since the last Canadian Airway Focus Group (CAFG) guidelines were published in 2013, the published airway management literature has expanded substantially. The CAFG therefore re-convened to examine this literature and update practice recommendations. This second of two articles addresses airway evaluation, decision-making, and safe implementation of an airway management strategy when difficulty is anticipated.

SOURCE

Canadian Airway Focus Group members, including anesthesia, emergency medicine, and critical care physicians were assigned topics to search. Searches were run in the Medline, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL databases. Results were presented to the group and discussed during video conferences every two weeks from April 2018 to July 2020. These CAFG recommendations are based on the best available published evidence. Where high-quality evidence is lacking, statements are based on group consensus.

FINDINGS AND KEY RECOMMENDATIONS

Prior to airway management, a documented strategy should be formulated for every patient, based on airway evaluation. Bedside examination should seek predictors of difficulty with face-mask ventilation (FMV), tracheal intubation using video- or direct laryngoscopy (VL or DL), supraglottic airway use, as well as emergency front of neck airway access. Patient physiology and contextual issues should also be assessed. Predicted difficulty should prompt careful decision-making on how most safely to proceed with airway management. Awake tracheal intubation may provide an extra margin of safety when impossible VL or DL is predicted, when difficulty is predicted with more than one mode of airway management (e.g., tracheal intubation and FMV), or when predicted difficulty coincides with significant physiologic or contextual issues. If managing the patient after the induction of general anesthesia despite predicted difficulty, team briefing should include triggers for moving from one technique to the next, expert assistance should be sourced, and required equipment should be present. Unanticipated difficulty with airway management can always occur, so the airway manager should have a strategy for difficulty occurring in every patient, and the institution must make difficult airway equipment readily available. Tracheal extubation of the at-risk patient must also be carefully planned, including assessment of the patient's tolerance for withdrawal of airway support and whether re-intubation might be difficult.

Apnoeic oxygenation was associated with decreased desaturation rates during rapid sequence intubation in multiple Australian and New Zealand emergency departments

Apnoeic oxygenation (ApOx) has been demonstrated to reduce the incidence of desaturation, although evidence of benefit has been conflicting depending on the technique used. The aim of this study was to compare the incidence of desaturation between patients who received ApOx via conventional nasal cannula (NC) and those who did not, using a large, multicentre airway registry.

METHODS

This study is an analysis of 24 months of prospectively collected data in the Australia and New Zealand Emergency Department Airway Registry (June 2013-June 2015). The registry includes information on all intubated adults from 43 emergency departments. Patients intubated during cardiac arrest (n=393), those who received active ventilation prior to the first intubation attempt (n=486), and where the use of ApOx was not recorded either way (n=312) were excluded. The proportion of patients who desaturated (Sa0₂ <93) in the group that received ApOx and those that did not were compared. To evaluate the association of ApOx with patient desaturation, a logistic regression model based on factors expected to influence desaturation was performed.

RESULTS

Of 2519 patients analysed, 1669 (66.3%) received ApOx via NC while 850 (33.7%) did not. Desaturation in the cohort receiving ApOx was 10.4% compared with standard care (no ApOx) 13.7%. ApOx had a protective effect for desaturation (OR 0.71 95% CI 0.53 to 0.95). Single intubation attempt was associated with reduced risk of desaturation of (OR 0.10, 95% CI 0.06 to 0.17); this was increased on second attempt (OR 0.37, 95% CI 0.21 to 0.68). Desaturation was also associated with the physician recording that they had anticipated a difficult airway (OR 1.83, 95% CI 1.34 to 2.48).

CONCLUSION

This large multicentre registry study provides evidence that ApOx delivered through a conventional NC is associated with a lower incidence of desaturation in patients undergoing rapid sequence intubation.

TRIAL REGISTRATION NUMBER

ACTRN12613001052729.

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.

Compared Efficacy of Four Preoxygenation Methods for Intubation in the ICU: Retrospective Analysis of McGrath Mac Videolaryngoscope Versus Macintosh Laryngoscope (MACMAN) Trial Data

OBJECTIVES

Severe hypoxemia is the most common serious adverse event during endotracheal intubation. Preoxygenation is performed routinely as a preventive measure. The relative efficacy of the various available preoxygenation devices is unclear. Here, our objective was to assess associations between preoxygenation devices and pulse oximetry values during endotracheal intubation.

DESIGN

Post hoc analysis of data from a multicenter randomized controlled superiority trial (McGrath Mac Videolaryngoscope Versus Macintosh Laryngoscope [MACMAN]) comparing videolaryngoscopy to Macintosh laryngoscopy for endotracheal intubation in critical care.

SETTING

Seven French ICUs.

PATIENTS

Three-hundred nineteen of the 371 critically ill adults requiring endotracheal intubation who were included in the MACMAN trial.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Minimal pulse oximetry value during endotracheal intubation was the primary endpoint. We also sought risk factors for pulse oximetry below 90%. Of 319 patients, 157 (49%) had bag-valve-mask, 71 (22%) noninvasive ventilation, 71 (22%) non-rebreathing mask, and 20 (7%) high-flow nasal oxygen for preoxygenation. Factors independently associated with minimal pulse oximetry value were the Simplified Acute Physiology Score II severity score (p = 0.03), baseline pulse oximetry (p < 0.001), baseline PaO2/FIO2 ratio (p = 0.02), and number of laryngoscopies (p = 0.001). The only independent predictors of pulse oximetry less than 90% were baseline pulse oximetry (odds ratio, 0.71; 95% CI, 0.64-0.79; p < 0.001) and preoxygenation device: with bag-valve-mask as the reference, odds ratios were 1.10 (95% CI, 0.25-4.92) with non-rebreathing mask, 0.10 (95% CI, 0.01-0.80) with noninvasive ventilation, and 5.75 (95% CI, 1.15-28.75) with high-flow nasal oxygen.

CONCLUSIONS

Our data suggest that the main determinants of hypoxemia during endotracheal intubation may be related to critical illness severity and to preexisting hypoxemia. The differences across preoxygenation methods suggest that noninvasive ventilation may deserve preference in patients with marked hypoxemia before endotracheal intubation. Ongoing studies will provide further clarification about the optimal preoxygenation method for endotracheal intubation in critically ill patients.

Teaching Endotracheal Intubation Using a Cadaver Versus a Manikin-based Model: a Randomized Controlled Trial

INTRODUCTION

The optimal method to train novice learners to perform endotracheal intubation (ETI) is unknown. The study objective was to compare two models: unembalmed cadaver vs simulation manikin.

METHODS

Fourth-year medical students, stratified by baseline ETI experience, were randomized 1:1 to train on a cadaver or simulation manikin. Students were tested and video recorded on a separate cadaver; two reviewers, blinded to the intervention, assessed the videos. Primary outcome was time to successful ETI, analyzed with a Cox proportional hazards model. Authors also compared percentage of glottic opening (POGO), number of ETI attempts, learner confidence, and satisfaction.

RESULTS

Of 97 students randomized, 78 were included in the final analysis. Median time to ETI did not differ significantly (hazard ratio [HR] 1.1; 95% CI [confidence interval], 0.7-1.8): cadaver group = 34.5 seconds (interquartile ratio [IQR]: 23.3-55.8) vs manikin group = 35.5 seconds (IQR: 23.8-80.5), with no difference in first-pass success (odds ratio [OR] = 1; 95% CI, 0.1-7.5) or median POGO: 80% cadaver vs 90% manikin (95% CI, -14-34%). Satisfaction was higher for cadavers (median difference = 0.5; p = 0.002; 95% CI, 0-1) as was change in student confidence (median difference = 0.5; p = 0.03; 95% CI, 0-1). Students rating their confidence a 5 ("extremely confident") demonstrated decreased time to ETI (HR = 4.2; 95% CI, 1.0-17.2).

CONCLUSION

Manikin and cadaver training models for ETI produced similar time to ETI, POGO, and first-pass success. Cadaver training was associated with increased student satisfaction and confidence; subjects with the highest confidence level demonstrated decreased time to ETI.

Study Enrollment When "Preconsent" Is Utilized for a Randomized Clinical Trial of Two Treatments for Acute Agitation in the Emergency Department

BACKGROUND

Acute agitation in the emergency department (ED) represents a danger to both patients and their caregivers. Medication is often needed, and few high-quality randomized trials have evaluated the optimal drugs for this vulnerable population. In the United States, as of 2017, randomized trials of drugs typically cannot be conducted under Waiver of Consent (46 CFR 45.116), and Exception From Informed Consent trials (21 CFR 50.24) are limited to life-threatening conditions, are onerous, and require filing an investigational new drug application with the FDA. We sought to conduct a randomized double-dummy trial of inhaled loxapine versus intramuscular haloperidol + lorazepam for acute agitation in the ED by obtaining consent in advance ("preconsent") in patients at risk of future agitation, allowing study drug administration up to 3 years later if the patient presented with acute agitation.

OBJECTIVE

We sought to report the successful enrollment rate of patients preconsented at an earlier ED visit for this trial.

METHODS

This was an analysis of patients age 18 to 64 with bipolar I disorder or schizophrenia preconsented for enrollment in the trial (clinicaltrials.gov, NCT02877108) conducted at a single urban academic center seeing approximately 60,000 patients per year. Eligible patients were assessed for capacity to consent by trained research associates, and informed consent was obtained at an ED visit for the possibility of administering drugs for agitation within the next 3 years. In the event the patient later presented to the ED and the attending physician deemed the patient required treatment for acute agitation, preconsent was confirmed and study drug would be administered.

RESULTS

Over 67 days, 1,461 patients were screened in the ED, 269 had bipolar I or schizophrenia, 194 of whom had a contraindication to inhaled loxapine leaving 75 eligible patients; preconsent was obtained in 43 patients. Four additional patients who had not preconsented were consented for the trial in real time (three by surrogate, one patient had capacity while agitated) resulting in a total of 47 consented patients. Of these 47, a total of 12 were later removed from the study: 10 patients had unrecognized exclusion criteria for inhaled loxapine, one preconsented patient contacted the investigators at a later date and asked to be removed, and one surrogate revoked consent immediately after providing it. Only two patients were successfully enrolled, neither by preconsent: one was enrolled via a surrogate the day of enrollment, and the other was mildly agitated and had capacity to consent. The remaining patient with a valid surrogate consent did not receive study medication.

CONCLUSIONS

Utilization of preconsent to enroll patients in a randomized trial of treatments for acute agitation in the ED requires substantial resources and may not be feasible.

Manual ventilation to prevent hypoxaemia during endotracheal intubation of critically ill adults: protocol and statistical analysis plan for a multicentre randomised trial

INTRODUCTION

Hypoxaemia is the most common complication during endotracheal intubation of critically ill adults, and it increases the risk of cardiac arrest and death. Manual ventilation between induction and intubation has been hypothesised to decrease the incidence of hypoxaemia, but efficacy and safety data are lacking.

METHODS AND ANALYSIS

The Preventing Hypoxemia with Manual Ventilation during Endotracheal Intubation trial is a prospective, multicentre, non-blinded randomised clinical trial being conducted in seven intensive care units in the USA. A total of 400 critically ill adults undergoing endotracheal intubation will be randomised 1:1 to receive prophylactic manual ventilation between induction and endotracheal intubation using a bag-valve-mask device or no prophylactic ventilation. The primary outcome is the lowest arterial oxygen saturation between induction and 2 min after successful endotracheal intubation, which will be analysed as an unadjusted, intention-to-treat comparison of patients randomised to prophylactic ventilation versus patients randomised to no prophylactic ventilation. The secondary outcome is the incidence of severe hypoxaemia, defined as any arterial oxygen saturation of less than 80% between induction and 2 min after endotracheal intubation. Enrolment began on 2 February 2017 and is expected to be complete in May 2018.

ETHICS AND DISSEMINATION

The trial was approved by the institutional review boards or designees of all participating centres. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences.

TRIAL REGISTRATION NUMBER

NCT03026322; Pre-results.

Does apneic oxygenation prevent desaturation during emergency airway management? A systematic review and meta-analysis

RéSUMé: OBJECTIF: L'oxygénation apnéique (OA) par lunettes nasales est une méthode de prévention de la désaturation en oxygène au cours des intubations en urgence. L'objectif de cette revue systématique était de déterminer l'efficacité de l'OA sur la prévention de la désaturation en oxygène au cours des intubations en urgence.

SOURCE

Des recherches systématiques ont été effectuées dans trois bases de données électroniques (MEDLINE, EMBASE et CINAHL) pour identifier les études portant sur la prévention de la désaturation en oxygène au moyen de l'OA par lunettes nasales. Notre critère d'évaluation principal était l'incidence des désaturations telle que définie dans chaque étude; nous avons ensuite évalué l'incidence de la désaturation sévère en oxygène (SpO₂ < 80%). Une méta-analyse a été effectuée sur les études présentant des données sur la désaturation en oxygène telle que définie par chaque étude et chez des patients ayant une désaturation sévère pour générer une estimation groupée de l'effet.

CONSTATATIONS PRINCIPALES

Au total, 544 études ont été examinées, parmi lesquelles dix (2 322 patients) satisfaisaient tous les critères d'éligibilité. Comparativement à l'absence d'OA, l'utilisation de cette méthode a été associée à une réduction de la désaturation en oxygène (risque relatif [RR] : 0,76; intervalle de confiance à 95% [IC] : 0,61 à 0,95; P = 0,02), mais n'a pas été associée à une réduction de la désaturation sévère (RR, 0,65; IC à 95% : 0,38 à 1,11; P = 0,12). Néanmoins, il y avait une hétérogénéité significative des facteurs liés aux patients, des interventions et des définitions de la désaturation en oxygène entre les études.

CONCLUSION

Nos constatations suggèrent que l'OA par lunettes nasales est associée à un moindre risque de désaturation en oxygène au cours des intubations en urgence. Cependant, compte de tenu de l'hétérogénéité des études, d'autres essais de grande qualité sont nécessaires pour déterminer quels patients pourraient bénéficier de l'OA au cours des intubations d'urgence.

Apneic oxygenation reduces hypoxemia during endotracheal intubation in the pediatric emergency department

BACKGROUND

Apneic oxygenation (AO) has been evaluated in adult patients as a means of reducing hypoxemia during endotracheal intubation (ETI). While less studied in pediatric patients, its practice has been largely adopted.

OBJECTIVE

Determine association between AO and hypoxemia in pediatric patients undergoing ETI.

METHODS

Observational study at an urban, tertiary children's hospital emergency department. Pediatric patients undergoing ETI were examined during eras without (January 2011-June 2011) and with (August 2014-March 2017) apneic oxygenation. The primary outcome was hypoxemia, defined as pulse oximetry (SpO₂) < 90%. The χ² and Wilcoxon rank-sum tests examined differences between cohorts. Multivariable regression models examined adjusted associations between covariates and hypoxemia.

RESULTS

149 patients were included. Cohorts were similar except for greater incidence of altered mental status in those receiving AO (26% vs. 7%, p = 0.03). Nearly 50% of the pre-AO cohort experienced hypoxemia during ETI, versus <25% in the AO cohort. Median [IQR] lowest SpO₂ during ETI was 93 (69, 99) for pre-AO and 100 [95, 100] for the AO cohort (p < 0.001). In a multivariable logistic regression model, hypoxemia during ETI was associated with AO (aOR 0.3, 95% confidence interval [CI] 0.1-0.8), increased age (for 1 year, aOR 0.8, 95% CI 0.7-1.0), lowest SpO₂ before ETI (for 1% increase, aOR 0.9, 95% CI 0.8-1.0), and each additional intubation attempt (aOR 4.0, 95% CI 2.2-7.2).

CONCLUSIONS

Apneic oxygenation is an easily-applied intervention associated with decreases in hypoxemia during pediatric ETI. Nearly 50% of children not receiving AO experienced hypoxemia.

Apneic oxygenation provides incremental benefit during intubation of patients in the emergency medicine and critical care settings

Clinical questionShould I use apneic oxygenation when intubating patients in the emergency department to increase peri-intubation oxygen saturation and first-pass success?Article chosenOliveira JE, Silva L, Cabrera D, Barrionuevo P, et al. Effectiveness of apneic oxygenation during intubation: a systematic review and meta-analysis. Ann Emerg Med 2017;70(4):483-94.

OBJECTIVE

The purpose of this study was to synthesize and appraise the apneic oxygenation literature for its effect on peri-intubation outcomes.

Nasal Cannula Apneic Oxygenation Prevents Desaturation During Endotracheal Intubation: An Integrative Literature Review

Patients requiring emergency airway management may be at greater risk of acute hypoxemic events because of underlying lung pathology, high metabolic demands, insufficient respiratory drive, obesity, or the inability to protect their airway against aspiration. Emergency tracheal intubation is often required before complete information needed to assess the risk of procedural hypoxia is acquired (i.e., arterial blood gas level, hemoglobin value, or chest radiograph). During pre-oxygenation, administering high-flow nasal oxygen in addition to a non-rebreather face mask can significantly boost the effective inspired oxygen. Similarly, with the apnea created by rapid sequence intubation (RSI) procedures, the same high-flow nasal cannula can help maintain or increase oxygen saturation during efforts to secure the tube (oral intubation). Thus, the use of nasal oxygen during pre-oxygenation and continued during apnea can prevent hypoxia before and during intubation, extending safe apnea time, and improve first-pass success attempts. We conducted a literature review of nasal-cannula apneic oxygenation during intubation, focusing on two components: oxygen saturation during intubation, and oxygen desaturation time. We performed an electronic literature search from 1980 to November 2017, using PubMed, Elsevier, ScienceDirect, and EBSCO. We identified 14 studies that pointed toward the benefits of using nasal cannula during emergency intubation.

Tracheal intubation in critically ill patients: a comprehensive systematic review of randomized trials

BACKGROUND

We performed a systematic review of randomized controlled studies evaluating any drug, technique or device aimed at improving the success rate or safety of tracheal intubation in the critically ill.

METHODS

We searched PubMed, BioMed Central, Embase and the Cochrane Central Register of Clinical Trials and references of retrieved articles. Finally, pertinent reviews were also scanned to detect further studies until May 2017. The following inclusion criteria were considered: tracheal intubation in adult critically ill patients; randomized controlled trial; study performed in Intensive Care Unit, Emergency Department or ordinary ward; and work published in the last 20 years. Exclusion criteria were pre-hospital or operating theatre settings and simulation-based studies. Two investigators selected studies for the final analysis. Extracted data included first author, publication year, characteristics of patients and clinical settings, intervention details, comparators and relevant outcomes. The risk of bias was assessed with the Cochrane Collaboration's Risk of Bias tool.

RESULTS

We identified 22 trials on use of a pre-procedure check-list (1 study), pre-oxygenation or apneic oxygenation (6 studies), sedatives (3 studies), neuromuscular blocking agents (1 study), patient positioning (1 study), video laryngoscopy (9 studies), and post-intubation lung recruitment (1 study). Pre-oxygenation with non-invasive ventilation (NIV) and/or high-flow nasal cannula (HFNC) showed a possible beneficial role. Post-intubation recruitment improved oxygenation, while ramped position increased the number of intubation attempts and thiopental had negative hemodynamic effects. No effect was found for use of a checklist, apneic oxygenation (on oxygenation and hemodynamics), videolaryngoscopy (on number and length of intubation attempts), sedatives and neuromuscular blockers (on hemodynamics). Finally, videolaryngoscopy was associated with severe adverse effects in multiple trials.

CONCLUSIONS

The limited available evidence supports a beneficial role of pre-oxygenation with NIV and HFNC before intubation of critically ill patients. Recruitment maneuvers may increase post-intubation oxygenation. Ramped position increased the number of intubation attempts; thiopental had negative hemodynamic effects and videolaryngoscopy might favor adverse events.