A Meta-Analysis of Prehospital Airway Control Techniques Part I: Orotracheal and Nasotracheal Intubation Success Rates

Predictive Factors for First-Pass Intubation Failure in Trauma Patients

Objective

The primary objective of this study was to elucidate risk factors for multiple intubation attempts (MIA) in trauma patients requiring emergent tracheal intubation (ETI). Risk factors for mortality, intensive care unit (ICU) admission, and prolonged ventilation were assessed as secondary outcomes. The association between multiple intubation attempts and adverse outcomes has been well described in the literature. Though previous studies have identified anatomical risk factors for difficult airways, no study to date has investigated predictors for MIA in a trauma setting.

Methods

The retrospective study involved 174 adult patients who required ETI and who presented to a Level 1 Trauma Center's emergency department between January 2019 and December 2022. Comorbidities, demographic information, triage vitals, intubation characteristics, and patient outcomes were identified to ascertain predictive risk factors for MIA. Variables were assessed for statistical significance on unadjusted analysis. Significant variables were entered into multivariate logistic regression models to test for adjusted associations, with p≤.0.05 as statistically significant, and presented as adjusted odds ratios with 95% confidence intervals.

Results

Twenty-six (14.9%) of the 174 patients required multiple intubation attempts. There were no significant associations between MIA and patient gender, age, BMI, race, injury mechanism, or specific body region injuries. On univariate analysis, the MIA group had a statistically significant elevation in mean systolic blood pressure (151.71 ± 45.96 vs 133.55 ± 32.11, p = 0.019) and heart rate (106.30 ± 34.92 vs 93.35 ± 24.82, p < 0.032) compared to subjects with first-pass success. Elevation in systolic blood pressure (SBP) (151.71 ± 45.96 vs 133.55 ± 32.11, aOR 1.03 (1.01-1.06), p < 0.015) was an independent predictor of multiple intubation attempts.

Conclusion

Elevation in SBP was a significant predictor of multiple intubation attempts. Critical appraisal of patients requiring ETI with elevated SBP may mitigate risk in trauma settings.

Pediatric Intubations in a Semiurban Helicopter Emergency Medicine Service: A Retrospective Review

OBJECTIVE

Although a small proportion of helicopter emergency medical service (HEMS) missions are for pediatric patients, it is recognized that children do present unique challenges. This case series aims to evaluate the intubation first-pass success rate in HEMS pediatric patients for both medical and trauma patients in a UK semiurban environment.

METHODS

A retrospective review of the computerized records system was performed from January 1, 2015, to July 31, 2022, at 1 UK HEMS. Anonymous data relating to advanced airway interventions in patients < 16 years of age were extracted. Primary analysis related to the first-pass success rate was performed; secondary analysis relating to the initial Glasgow Coma Scale (GCS) of the pediatric patients requiring prehospital anesthesia (rapid sequence induction with drugs) and first-pass success rates by clinician group was also performed.

RESULTS

Of the pediatric patients, 15.8% required intubation. The overall first-pass success rate for intubation (including in cardiac arrest) was 83.5%; for prehospital anesthesia (drugs administered), it was 98.4%. First-pass success rates were lowest for those under 2 years of age (45.2% without drugs and 87.5% with drugs). There was no difference between physician background in the first-pass success rate. The median GCS for pediatric prehospital anesthesia was 7 versus 5 for adults (P = .012). No children with an initial GCS of 15 had prehospital anesthesia.

CONCLUSION

The overall intubation first-pass success rates for pediatric patients is high at 83.5% and higher still for prehospital anesthesia (98.4%). However, it remains a rare intervention for clinicians, and children under 2 years of age require special consideration.

Tick-tock: Prehospital intubation is associated with longer field time without any survival benefit

BACKGROUND

Prehospital endotracheal intubation is a debated topic, and few studies have found it beneficial after trauma. A growing body of evidence suggests that prehospital endotracheal intubation is associated with increased morbidity and mortality. Our study was designed to compare patients with attempted prehospital endotracheal intubation to those intubated promptly upon emergency department arrival.

METHODS

A retrospective review of a single-center trauma research data repository was utilized. Inclusion criteria included age ≥15 years, transport from the scene by ground ambulance, and undergoing prehospital endotracheal intubation attempts or intubation within 10 minutes of emergency department arrival without prior prehospital endotracheal intubation attempt. Propensity score matching was used to minimize differences in baseline characteristics between groups. Standard mean differences are also presented for pre- and post-matching datasets to evaluate for covariate balance.

RESULTS

In total, 208 patients met the inclusion criteria. Of these, 95 patients (46%) underwent prehospital endotracheal intubation, which was successful in 47% of cases. A control group of 113 patients (54%) were intubated within 10 minutes of emergency department arrival. We performed propensity score matching between cohorts based on observed differences after univariate analysis and used standard mean differences to estimate covariate balance. After propensity score matching, patients who underwent prehospital endotracheal intubation experienced a longer time on scene as compared with those intubated in the emergency department (9 minutes [interquartile range 6-12] vs 6 minutes [interquartile range 5-9], P < .01) without difference in overall mortality (67% vs 65%, P = 1.00). Rapid sequence intubation was not used in the field; however, it was used for 58% of patients intubated within 10 minutes of emergency department arrival. After matched analysis, patients with a failed prehospital intubation attempt were equally likely to receive rapid sequence intubation during re-intubation in the emergency department as compared with those undergoing a first attempt (n = 13/28, 46% vs n = 28/63, 44%, P = 1.00, standard mean differences 0.04). Among patients with prehospital arrest (n = 98), prehospital endotracheal intubation was associated with shorter time to death (8 minutes [interquartile range 3-17] vs 14 minutes [interquartile range 8-45], P = .008) and longer total transport time (23 minutes [interquartile range 19-31] vs 19 minutes [interquartile range 16-24], P = .006), but there was no difference in observed mortality (n = 29/31, 94% vs n = 30/31, 97%, P = 1.00, standard mean differences = 0.15) after propensity score matching.

CONCLUSION

Prehospital providers should prioritize expeditious transport over attempting prehospital endotracheal intubation, as prehospital endotracheal intubation is inconsistently successful, may delay definitive care, and appears to have no survival benefit.

Out-of-Hospital emergency airway management practices: A nationwide observational study from Aotearoa New Zealand

Background and Objectives

Airway management is crucial for emergency care in critically ill patients outside the hospital setting. An Airway Registry is useful in providing essential information for quality improvement purposes. Therefore, this study aimed to develop an out-of-hospital airway registry and describe airway management practices in Aotearoa New Zealand (AoNZ).

Methods

Data from the Aotearoa New Zealand Paramedic Care Collection (ANZPaCC) database were used in a retrospective cohort study covering July 2020 to June 2021. All patients receiving airway interventions were included. An airway intervention was defined as one or more of the following: non-drug assisted endotracheal intubation (NDA-ETI), drug-assisted endotracheal intubation (DA-ETI; where a combination of paralytic agent and sedative were used to aid in intubation), laryngeal mask airway (LMA), oropharyngeal airway (OPA), nasopharyngeal airway (NPA), surgical airway (cricothyroidotomy), suction, jaw thrust. Descriptive statistics were analysed using Chi-Square and logistic regression modelling investigated the relationship between advanced airway success and patient characteristics.

Results

The study included 4,529 patients who underwent 7,779 airway interventions. Basic airway interventions were used most frequently: OPA (45.1%), NPA (29.3%), LMA (28.9%), suction (19.9%) and jaw thrust (17.6%). Advanced airway interventions were used less frequently: NDA-ETI (19.8%), DA-ETI (8.7%), and surgical airways (0.2%). The success rate for ETI (including both NDA-ETI and DA-ETI) was 89.4%, with NDA-ETI success at 85.8% and DA-ETI success at 97.7%. ETI first-pass success rates were significantly lower for males (aOR 0.65, 95%CI 0.48-0.87, p < 0.001) and higher for non-cardiac arrest injury patients (aOR 2.94, 95%CI 1.43-6.00, p < 0.001). In this cohort receiving airway interventions the 1-day mortality rate was 41.1%, demonstrating that a high proportion of these patients were severely clinically compromised.

Conclusions

Out-of-hospital airway management practices and success rates in AoNZ are comparable to those elsewhere. This research has determined the variables to be used as the AoNZ Paramedic Airway Registry ongoing and has demonstrated baseline outcomes in airway management for ongoing quality improvement using this registry.

Success rate of prehospital emergency front-of-neck access (FONA): a systematic review and meta-analysis

BACKGROUND

Front-of-neck access (FONA) is an emergency procedure used as a last resort to achieve a patent airway in the prehospital environment. In this systematic review with meta-analysis, we aimed to evaluate the number and success rate of FONA procedures in the prehospital setting, including changes since 2017, when a surgical technique was outlined as the first-line prehospital method.

METHODS

A systematic literature search (PROSPERO CRD42022348975) was performed from inception of databases to July 2022 to identify studies in patients of any age undergoing prehospital FONA, followed by data extraction. Meta-analysis was used to derive pooled success rates. Methodological quality of included studies was interpreted using the Cochrane risk of bias tool, and rated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

From 909 studies, 69 studies were included (33 low quality; 36 very low quality) with 3292 prehospital FONA attempts described (1229 available for analysis). The crude median success rate increased from 99.2% before 2017 to 100.0% after 2017. Meta-analysis revealed a pooled overall FONA success rate of 88.0% (95% confidence interval [CI], 85.0-91.0%). Surgical techniques had the highest success rate at a median of 100.0% (pooled rate=92.0%; 95% CI, 88.0-95.0%) vs 50.0% for needle techniques (pooled rate=52.0%; 95% CI, 28.0-76.0%).

CONCLUSIONS

Despite being a relatively rare procedure in the prehospital setting, the success rate for FONA is high. A surgical technique for FONA appears more successful than needle techniques, and supports existing UK prehospital guidelines.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42022348975.

The Difficult Airway Redefined

There is no all-encompassing or universally accepted definition of the difficult airway, and it has traditionally been approached as a problem chiefly rooted in anesthesiology. However, with airway obstruction reported as the second leading cause of mortality on the battlefield and first-pass success (FPS) rates for out-of-hospital endotracheal intubation (ETI) as low as 46.4%, the need to better understand the difficult airway in the context of the prehospital setting is clear. In this review, we seek to redefine the concept of the “difficult airway” so that future research can target solutions better tailored for prehospital, and more specifically, combat casualty care. Contrasting the most common definitions, which narrow the scope of practice to physicians and a handful of interventions, we propose that the difficult airway is simply one that cannot be quickly obtained. This implies that it is a situation arrived at through a multitude of factors, namely the Patient, Operator, Setting, and Technology (POST), but also more importantly, the interplay between these elements. Using this amended definition and approach to the difficult to manage airway, we outline a target-specific approach to new research questions rooted in this system-based approach to better address the difficult airway in the prehospital and combat casualty care settings.

Updated guideline on equipment to manage difficult airways: Australian and New Zealand College of Anaesthetists

The Australian and New Zealand College of Anaesthetists (ANZCA) recently reviewed and updated the guideline on equipment to manage a difficult airway. An ANZCA-established document development group, which included representatives from the Australasian College for Emergency Medicine and the College of Intensive Care Medicine of Australia and New Zealand, performed the review, which is based on expert consensus, an extensive literature review, and bi-nationwide consultation. The guideline (PG56(A) 2021, https://www.anzca.edu.au/getattachment/02fe1a4c-14f0-4ad1-8337-c281d26bfa17/PS56-Guideline-on-equipment-to-manage-difficult-airways) is accompanied by a detailed background paper (PG56(A)BP 2021, https://www.anzca.edu.au/getattachment/9ef4cd97-2f02-47fe-a63a-9f74fa7c68ac/PG56(A)BP-Guideline-on-equipment-to-manage-difficult-airways-Background-Paper), from which the current recommendations are reproduced on behalf of, and with the permission of, ANZCA. The updated 2021 guideline replaces the 2012 version and aims to provide an updated, objective, informed, transparent, and evidence-based review of equipment to manage difficult airways.

Video versus direct laryngoscopy by specialist paramedics in New South Wales: Preliminary results from a new airway registry

OBJECTIVES

Video laryngoscopy (VL) is increasingly used as an alternative to direct laryngoscopy (DL) to improve airway visualisation and endotracheal intubation (ETI) success. Intensive Care Paramedics in New South Wales Ambulance, Australia started using VL in 2020, and recorded success in a new advanced airway registry. We used this registry to compare VL to DL.

METHODS

The present study was a retrospective analysis of out-of-hospital data for ETI by specialist paramedics using an airway registry. We calculated overall and first-pass success for VL versus DL, and compared success using a Χ² test.

RESULTS

The DL overall success was 61 out of 78 (78.2%) and VL was 233 out of 246 (94.7%); difference of 16.5% (P < 0.001). First-pass for DL was successful for 49 out of 78 (62.8%) and for VL in 195 out of 246 (79.3%); difference of 16.5% (P = 0.003). There were five (1.6%) patients where both VL and DL were used and in all instances, DL was used first.

CONCLUSIONS

This analysis of a new airway registry used by specialist paramedics in New South Wales shows a substantial increase in overall and first-pass intubation success with the use of VL when compared to DL.

Supraglottic airway device versus tracheal intubation in the initial airway management of out-of-hospital cardiac arrest: the AIRWAYS-2 cluster RCT

BACKGROUND

When a cardiac arrest occurs, cardiopulmonary resuscitation should be started immediately. However, there is limited evidence about the best approach to airway management during cardiac arrest.

OBJECTIVE

The objective was to determine whether or not the i-gel® (Intersurgical Ltd, Wokingham, UK) supraglottic airway is superior to tracheal intubation as the initial advanced airway management strategy in adults with non-traumatic out-of-hospital cardiac arrest.

DESIGN

This was a pragmatic, open, parallel, two-group, multicentre, cluster randomised controlled trial. A cost-effectiveness analysis accompanied the trial.

SETTING

The setting was four ambulance services in England.

PARTICIPANTS

Patients aged ≥ 18 years who had a non-traumatic out-of-hospital cardiac arrest and were attended by a participating paramedic were enrolled automatically under a waiver of consent between June 2015 and August 2017. Follow-up ended in February 2018.

INTERVENTION

Paramedics were randomised 1 : 1 to use tracheal intubation (764 paramedics) or i-gel (759 paramedics) for their initial advanced airway management and were unblinded.

MAIN OUTCOME MEASURES

The primary outcome was modified Rankin Scale score at hospital discharge or 30 days after out-of-hospital cardiac arrest, whichever occurred earlier, collected by assessors blinded to allocation. The modified Rankin Scale, a measure of neurological disability, was dichotomised: a score of 0-3 (good outcome) or 4-6 (poor outcome/death). The primary outcome for the economic evaluation was quality-adjusted life-years, estimated using the EuroQol-5 Dimensions, five-level version.

RESULTS

A total of 9296 patients (supraglottic airway group, 4886; tracheal intubation group, 4410) were enrolled [median age 73 years; 3373 (36.3%) women]; modified Rankin Scale score was known for 9289 patients. Characteristics were similar between groups. A total of 6.4% (311/4882) of patients in the supraglottic airway group and 6.8% (300/4407) of patients in the tracheal intubation group had a good outcome (adjusted difference in proportions of patients experiencing a good outcome: -0.6%, 95% confidence interval -1.6% to 0.4%). The supraglottic airway group had a higher initial ventilation success rate than the tracheal intubation group [87.4% (4255/4868) vs. 79.0% (3473/4397), respectively; adjusted difference in proportions of patients: 8.3%, 95% confidence interval 6.3% to 10.2%]; however, patients in the tracheal intubation group were less likely to receive advanced airway management than patients in the supraglottic airway group [77.6% (3419/4404) vs. 85.2% (4161/4883), respectively]. Regurgitation rate was similar between the groups [supraglottic airway group, 26.1% (1268/4865); tracheal intubation group, 24.5% (1072/4372); adjusted difference in proportions of patients: 1.4%, 95% confidence interval -0.6% to 3.4%], as was aspiration rate [supraglottic airway group, 15.1% (729/4824); tracheal intubation group, 14.9% (647/4337); adjusted difference in proportions of patients: 0.1%, 95% confidence interval -1.5% to 1.8%]. The longer-term outcomes were also similar between the groups (modified Rankin Scale: at 3 months, odds ratio 0.89, 95% confidence interval 0.69 to 1.14; at 6 months, odds ratio 0.91, 95% confidence interval 0.71 to 1.16). Sensitivity analyses did not alter the overall findings. There were no unexpected serious adverse events. Mean quality-adjusted life-years to 6 months were 0.03 in both groups (supraglottic airway group minus tracheal intubation group difference -0.0015, 95% confidence interval -0.0059 to 0.0028), and total costs were £157 (95% confidence interval -£270 to £583) lower in the tracheal intubation group. Although the point estimate of the incremental cost-effectiveness ratio suggested that tracheal intubation may be cost-effective, the huge uncertainty around this result indicates no evidence of a difference between groups.

LIMITATIONS

Limitations included imbalance in the number of patients in each group, caused by unequal distribution of high-enrolling paramedics; crossover between groups; and the fact that participating paramedics, who were volunteers, might not be representative of all paramedics in the UK. Findings may not be applicable to other countries.

CONCLUSION

Among patients with out-of-hospital cardiac arrest, randomisation to the supraglottic airway group compared with the tracheal intubation group did not result in a difference in outcome at 30 days. There were no notable differences in costs, outcomes and overall cost-effectiveness between the groups.

FUTURE WORK

Future work could compare alternative supraglottic airway types with tracheal intubation; include a randomised trial of bag mask ventilation versus supraglottic airways; and involve other patient populations, including children, people with trauma and people in hospital.

TRIAL REGISTRATION

This trial is registered as ISRCTN08256118.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and supported by the NIHR Comprehensive Research Networks and will be published in full in Health Technology Assessment; Vol. 26, No. 21. See the NIHR Journals Library website for further project information.

Prehospital Supraglottic Airways: An NAEMSP Position Statement and Resource Document

Supraglottic airway (SGA) devices provide effective conduits for oxygenation and ventilation and may offer protection from gastric aspiration. SGA devices are widely used by EMS clinicians as both rescue and primary airway management devices. While in common use for more than four decades, major developments in SGA education, science, and technology have influenced clinical strategies of SGA insertion and use in prehospital airway management for patients of all ages. NAEMSP recommends:SGAs have utility as a primary or secondary EMS airway intervention. EMS agencies should select SGA strategies that best suit available resources and local clinician skillset, as well as the nature of their clinical practice setting.EMS agencies that perform endotracheal intubation must also equip their clinicians with SGA devices and ensure adequate training and competence.In select situations, drug-assisted airway management may be used by properly credentialed EMS clinicians to facilitate SGA insertion.Confirmation of initial and continuous SGA placement using waveform capnography is strongly encouraged as a best practice.When it is functioning properly, EMS clinicians should refrain from converting an SGA to an endotracheal tube. The decision to convert an SGA to an endotracheal tube must consider the patient's condition, the effectiveness of SGA ventilations, and the clinical context and course of initial SGA insertionSGA training, competency, and clinical use must be continuously evaluated by EMS agencies using focused quality management programs.

Application of a Healthcare Failure Modes and Effects Analysis to Identify and Mitigate Potential Risks in the Implementation of a National Prehospital Pediatric Rapid Sequence Intubation Program

INTRODUCTION

Rapid sequence intubation (RSI) has become the de facto airway method of choice in the emergency airway management of adult and pediatric patients. There is significant controversy regarding pediatric RSI in the prehospital setting, given not only the complexities inherent in both the procedure and patient population, but in variations in emergency medical service models, prehospital qualifications, scope of practice, and patient exposure too.

METHODS

A Healthcare Failure Mode and Effects Analysis was conducted to identify and mitigate potential hazards in the national implementation of a prehospital pediatric RSI program. A process map and potential failure points were developed and identified. Probabilities, severity, and hazards scores were calculated for each failure point, and actions items developed to address these.

RESULTS

One hundred four potential failure points were identified among 44 subprocesses, divided between nine major processes. In terms of severity, most were classified as either major (n = 39 [37.5%]) or catastrophic (n = 35 [33.7%]) with just more than half falling within the uncommon category (n = 56 [53.9%]) in terms of probability. Five strategic actions items were identified to mitigate against the failure points meeting criteria for action. To monitor the success of these, 11 quality and performance indicators were developed for concurrent implementation.

CONCLUSIONS

The Healthcare Failure Mode and Effects Analysis represents a simple yet comprehensive first step toward risk analysis of complex procedures within the prehospital emergency care setting. Application of the methodology provided guidance for the consensus identification of hazards associated with prehospital pediatric RSI and appropriate actions to mitigate them.

Procedural Sedation Intubation in a Paramedic-Staffed Helicopter Emergency Medical System in Northern Finland

OBJECTIVE

Airway management to ensure sufficient gas exchange is of major importance in emergency care. Prehospital endotracheal intubation (ETI) by paramedics is a widely debated method to ensure a patent airway. ETI is performed with procedural sedation in comatose patients because of the regulation. The use of medications increases the rate of successful airway management compared with nonmedication ETI and may also improve outcomes in patients with traumatic brain injury. In the absence of an operative emergency physician and with long distances, paramedic-induced airway management may increase the survival of patients in selected scenarios. A paramedic-staffed helicopter emergency medical system in Northern Finland operates in a rural area without an emergency physician and paralytic medications and treats critically ill patients using basic or advanced life support ground units. The aim of this study was to evaluate the success rates of ETI performed by a small, appropriately trained, and experienced group of 8 nurse paramedics in an out-of-hospital setting.

METHODS

The inclusion criterion for the study was an attempted intubation in patients with medical or traumatic indication for airway management by nurse paramedic.

RESULTS

Fifty-one patients were treated with ETI. The first-pass success rate was 72.5%, the second-pass success rate was 94.1%, and the overall success rate was 100% within 4 attempts. The median on-scene time was 54 minutes, and there were no signs of aspiration during laryngoscopy or after successful ETI. The primary mortality rate was 11.7%.

CONCLUSION

The use of a rigid standard operating procedure for paramedic rapid sequence induction, paralytics, a video laryngoscope, and a gum elastic bougie might positively affect the ETI first-pass success rate. A follow-up study after these future modifications is needed. This small study suggests that intubation might be 1 option for airway management by an experienced nonanesthesiologist in Lapland.

Understanding the Cognitive Demands, Skills, and Assessment Approaches for Endotracheal Intubation: A Cognitive Task Analysis (Preprint)

Background

Proper airway management is an essential skill for hospital personnel and rescue services to learn, as it is a priority for the care of patients who are critically ill. It is essential that providers be properly trained and competent in performing endotracheal intubation (ETI), a widely used technique for airway management. Several metrics have been created to measure competence in the ETI procedure. However, there is still a need to improve ETI training and evaluation, including a focus on collaborative research across medical specialties, to establish greater competence-based training and assessments. Training and evaluating ETI should also incorporate modern, evidence-based procedural training methodologies.

Objective

This study aims to use the cognitive task analysis (CTA) framework to identify the cognitive demands and skills needed to proficiently perform a task, elucidate differences between novice and expert performance, and provide an understanding of the workload associated with a task. The CTA framework was applied to ETI to capture a broad view of task and training requirements from the perspective of multiple medical specialties.

Methods

A CTA interview was developed based on previous research into the tasks and evaluation methods of ETI. A total of 6 experts from across multiple medical specialties were interviewed to capture the cognitive skills required to complete this task. Interviews were coded for main themes, subthemes in each category, and differences among specialties. These findings were compiled into a skills tree to identify the training needs and cognitive requirements of each task.

Results

The CTA revealed that consistency in equipment setup and planning, through talk or think-aloud methods, is critical to successfully mastering ETI. These factors allow the providers to avoid errors due to patient characteristics and environmental factors. Variation among specialties derived primarily from the environment in which ETI is performed, subsequent treatment plans, and available resources. Anesthesiology typically represented the most ideal cases with a large potential for training, whereas paramedics faced the greatest number of constraints based on the environment and available equipment.

Conclusions

Although the skills tree cannot perfectly capture the complexity and detail of all potential cases, it provided insight into the nuanced skills and training techniques used to prepare novices for the variability they may find in practice. Importantly, the CTA identified ways in which challenges faced by novices may be overcome and how this training can be applied to future cases. By making these implicit skills and points of variation explicit, they can be better translated into teachable details. These findings are consistent with previous studies looking at developing improved assessment metrics for ETI and expanding upon their work by delving into methods of feedback and strategies to assist novices.

First pass success of tracheal intubation using the C-MAC PM videolaryngoscope as first-line device in prehospital cardiac arrest compared with other emergencies: An observational study

BACKGROUND

Successful airway management is a priority in the resuscitation of critically ill or traumatised patients. Several studies have demonstrated the importance of achieving maximum first pass success, particularly in prehospital advanced airway management.

OBJECTIVE

To compare success rates of emergency intubations between patients requiring cardiopulmonary resuscitation (CPR) for cardiac arrest (CPR group) and other emergencies (non-CPR group) using the C-MAC PM videolaryngoscope.

DESIGN

Ongoing analysis of prospective collected prehospital advanced airway management core variables.

SETTING

Single helicopter emergency medical service (HEMS) 'Christoph 22', Ulm Military Hospital, Germany, May 2009 to July 2018.

PATIENTS

We included all 1006 HEMS patients on whom prehospital advanced airway management was performed by board-certified anaesthesiologists on call at HEMS 'Christoph 22'.

INTERVENTIONS

The C-MAC PM was used as the first-line device. The initial direct laryngoscopy was carried out using the C-MAC PM without the monitor in sight. After scoring the direct laryngoscopic view according to the Cormack and Lehane grade, the monitor was folded within the sight of the physician and tracheal intubation was performed using the videolaryngoscopic view without removing the blade.

MAIN OUTCOME MEASURES

The primary outcome was successful airway management. Secondary outcomes were the patient's position during airway management, necessity for suction, direct and videolaryngoscopic view according to Cormack and Lehane grading, as well as number of attempts needed for successful intubation.

RESULTS

A patent airway was achieved in all patients including rescue techniques. There was a lower first pass success rate in the CPR group compared with the non-CPR group (84.4 vs. 91.4%, P = 0.01). In the CPR group, direct laryngoscopy resulted more often in a clinically unfavourable (Cormack and Lehane grade 3 or 4) glottic view (CPR vs. non-CPR-group 37.2 vs. 26.7%, P = 0.0071). Using videolaryngoscopy reduced the clinically unfavourable grading to Cormack and Lehane 1 or 2 (P < 0.0001). The odds of achieving first pass success were approximately 12-fold higher with a favourable glottic view than with an unfavourable glottic view (OR 12.6, CI, 6.70 to 23.65).

CONCLUSION

Airway management in an anaesthesiologist-staffed HEMS is associated with a high first pass success rate but even with skilled providers using the C-MAC PM videolaryngoscope routinely, patients who require CPR offer more difficulties for successful prehospital advanced airway management at the first attempt.

TRIAL REGISTRATION

German Clinical trials register (drks.de) DRKS00020484.

Age-related laryngoscopic visual acuity

Background

Endotracheal intubation by direct laryngoscopy is a mainstay of advanced airway management performed both in the prehospital environment and in the Emergency Department. Many factors may affect the quality of view during direct laryngoscopy, one of them being the visual acuity (VA) of the intubator under these demanding conditions. While some individual variation in VA is to be expected in younger populations, VA naturally deteriorates in older populations particularly beyond the age of 40 years. This study aimed to describe VA in a younger (n=19) and an older (≥40 years of age, n=20) cohort of intubators at baseline and during simulated adult laryngoscopy, and to compare VA between these two age cohorts.

Methods

A baseline near VA test was done using a Sloan Early Treatment Diabetic Retinopathy Study (EDTRS) near vision chart at 40 cm under ambient indoor light. Participants in both age cohorts were then requested to perform laryngoscopy using an airway simulator at 40 cm viewing distance and again at a viewing distance of their choice. Both binocular and monocular VA were tested using a near VA chart placed anterior to the vocal cords of the airway trainer. VA was quantified using the logarithm of the minimum angle of resolution (logMAR). Differences in VA between age cohorts were assessed using independent samples t-tests and differences within age cohorts were assessed using paired samples t-tests.

Results

Binocular and monocular near VA was significantly reduced in the older cohort compared to the younger cohort at baseline (both eyes −0.129 logMAR; p = 0.04, right eye −0.147 logMAR; p = 0.005, left eye −0.197 logMAR; p = 0.002). Within each age cohort VA was significantly reduced during laryngoscopy at a fixed viewing distance (younger; both eyes −0.111 logMAR; p < 0.001, right eye −0.095 logMAR; p < 0.001, left eye −0.105 logMAR; p < 0.001; older; both eyes −0,08 logMAR; p < 0.001, right eye −0.110 logMAR; p < 0.001, left eye −0.065 logMAR; p = 0.01) but this was improved by reducing viewing distance.

Conclusion

Increased age was associated with a significant reduction in VA at baseline and during laryngoscopy, which can be partially compensated for by adjusting viewing distance. Although it is currently unknown to what extent this age-related reduction of VA might negatively affect time to place an endotracheal tube or success of placement under direct vision, older intubators should be aware of this effect and consider specialized corrective eyewear in order to maintain an adequate level of VA.

Airway strategy and chest compression quality in the Pragmatic Airway Resuscitation Trial

BACKGROUND

Chest compression (CC) quality is associated with improved out-of-hospital cardiopulmonary arrest (OHCA) outcomes. Airway management efforts may adversely influence CC quality. We sought to compare the effects of initial laryngeal tube (LT) and initial endotracheal intubation (ETI) airway management strategies upon chest compression fraction (CCF), rate and interruptions in the Pragmatic Airway Resuscitation Trial (PART).

METHODS

We analyzed CPR process files collected from adult OHCA enrolled in PART. We used automated signal processing techniques and a graphical user interface to calculate CC quality measures and defined interruptions as pauses in chest compressions longer than 3 s. We determined CC fraction, rate and interruptions (number and total duration) for the entire resuscitation and compared differences between LT and ETI using t-tests. We repeated the analysis stratified by time before, during and after airway insertion as well as by successive 3-min time segments. We also compared CC quality between single vs. multiple airway insertion attempts, as well as between bag-valve-mask (BVM-only) vs. ETI or LT.

RESULTS

Of 3004 patients enrolled in PART, CPR process data were available for 1996 (1001 LT, 995 ETI). Mean CPR analysis duration were: LT 22.6 ± 10.8 min vs. ETI 25.3 ± 11.3 min (p < 0.001). Mean CC fraction (LT 88% vs. ETI 87%, p = 0.05) and rate (LT 114 vs. ETI 114 compressions per minute (cpm), p = 0.59) were similar between LT and ETI. Median number of CC interruptions were: LT 11 vs. ETI 12 (p = 0.001). Total CC interruption duration was lower for LT than ETI (LT 160 vs. ETI 181 s, p = 0.002); this difference was larger before airway insertion (LT 56 vs. ETI 78 s, p < 0.001). There were no differences in CC quality when stratified by 3-min time epochs.

CONCLUSION

In the PART trial, compared with ETI, LT was associated with shorter total CC interruption duration but not other CC quality measures. CC quality may be associated with OHCA airway management.

Airway insertion first pass success and patient outcomes in adult out-of-hospital cardiac arrest: The Pragmatic Airway Resuscitation Trial

OBJECTIVE

While emphasized in clinical practice, the association between advanced airway insertion first-pass success (FPS) and patient outcomes is incompletely understood. We sought to determine the association of airway insertion FPS with adult out-of-hospital cardiac arrest (OHCA) outcomes in the Pragmatic Airway Resuscitation Trial (PART).

METHODS

We performed a secondary analysis of PART, a multicenter clinical trial comparing LT and ETI upon adult OHCA outcomes. We defined FPS as successful LT insertion or ETI on the first attempt as reported by EMS personnel. We examined the outcomes return of spontaneous circulation (ROSC), 72-h survival, hospital survival, and hospital survival with favorable neurologic status (Modified Rankin Scale ≤3). Using multivariable GEE (generalized estimating equations), we determined the association between FPS and OHCA outcomes, adjusting for age, sex, witnessed arrest, bystander CPR, initial rhythm, and initial airway type.

RESULTS

Of 3004 patients enrolled in the trial, 1423 received LT, 1227 received ETI, 354 received bag-valve-mask ventilation only. FPS was: LT 86.2% and ETI 46.7%. FPS was associated with increased ROSC (aOR 1.23; 95%CI: 1.07-1.41)), but not 72-h survival (1.22; 0.94-1.58), hospital survival (0.90; 0.68-1.19) or hospital survival with favorable neurologic status (0.66; 0.37-1.19).

CONCLUSION

In adult OHCA, airway insertion FPS was associated with increased ROSC but not other OHCA outcomes. The influence of airway insertion FPS upon OHCA outcomes is unclear.

Feasibility of Prehospital Rapid Sequence Intubation in the Cabin of an AW169 Helicopter

OBJECTIVE

Prehospital rapid sequence intubation (RSI) is an important aspect of prehospital care for helicopter emergency medical services (HEMS). This study examines the feasibility of in-aircraft (aircraft on the ground) RSI in different simulated settings.

METHODS

Using an AW169 aircraft cabin simulator at Air Ambulance Kent Surrey Sussex, 3 clinical scenarios were devised. All required RSI in a "can intubate, can ventilate" (easy variant) and a "can't intubate, can't ventilate" scenario (difficult variant). Doctor-paramedic HEMS teams were video recorded, and elapsed times for prespecified end points were analyzed.

RESULTS

Endotracheal intubation (ETI) was achieved fastest outside the simulator for the easy variant (median = 231 seconds, interquartile range = 28 seconds). Time to ETI was not significantly longer for in-aircraft RSI compared with RSI outside the aircraft, both in the easy (p = .14) and difficult variant (p = .50). Wearing helmets with noise distraction did not impact the time to intubation when compared with standard in-aircraft RSI, both in the easy (p = .28) and difficult variant (p = .24).

CONCLUSION

In-aircraft, on-the-ground RSI had no significant impact on the time to successful completion of ETI. Future studies should prospectively examine in-cabin RSI and explore the possibilities of in-flight RSI in civilian HEMS services.

Oxygenation strategies prior to and during prehospital emergency anaesthesia in UK HEMS practice (PREOXY survey)

Background

Maintaining effective oxygenation throughout the process of Pre-Hospital Emergency Anaesthesia (PHEA) is critical. There are multiple strategies available to clinicians to oxygenate patients both prior to and during PHEA. The optimal pre-oxygenation technique remains unclear, and it is unknown what techniques are being used by United Kingdom Helicopter Emergency Medical Services (HEMS). This study aimed to determine the current pre- and peri-PHEA oxygenation strategies used by UK HEMS services.

Methods

An electronic questionnaire survey was delivered to all UK HEMS services between 05 July and 26 December 2019. Questions investigated service standard operating procedures (SOPs) and individual clinician practice regarding oxygenation strategies prior to airway instrumentation (pre-oxygenation) and oxygenation strategies during airway instrumentation (apnoeic oxygenation). Service SOPs were obtained to corroborate questionnaire replies.

Results

Replies were received from all UK HEMS services (n = 21) and 40 individual clinicians. All services specified oxygenation strategies within their PHEA/RSI SOP and most referred to pre-oxygenation as mandatory (81%), whilst apnoeic oxygenation was mandatory in eight (38%) SOPs. The most commonly identified pre-oxygenation strategies were bag-valve-mask without PEEP (95%), non-rebreathable face mask (81%), and nasal cannula at high flow (81%). Seven (33%) services used Mapleson C circuits, whilst there were eight services (38%) that did not carry bag-valve-masks with PEEP valve nor Mapleson C circuits. All clinicians frequently used pre-oxygenation, however there was variability in clinician use of apnoeic oxygenation by nasal cannula. Nearly all clinicians (95%) reported manually ventilating patients during the apnoeic phase, with over half (58%) stating this was their routine practice. Differences in clinician pre-hospital and in-hospital practice related to availability of humidified high flow nasal oxygenation and Mapleson C circuits.

Conclusions

Pre-oxygenation is universal amongst UK HEMS services and is most frequently delivered by bag-valve-mask without PEEP or non-rebreathable face masks, whereas apnoeic oxygenation by nasal cannula is highly variable. Multiple services carry Mapleson C circuits, however many services are unable to deliver PEEP due to the equipment they carry. Clinicians are regularly manually ventilating patients during the apnoeic phase of PHEA. The identified variability in clinical practice may indicate uncertainty and further research is warranted to assess the impact of different strategies on clinical outcomes.

Beyond Tools: Continuous High-Fidelity Training at the Center of Successful First-Pass Intubation in Ground Emergency Medical Services

OBJECTIVE

Increased emphasis on the use of video laryngoscopy in emergency medical services has potentially caused providers to forfeit the skills required to perform direct laryngoscopy. The purpose of this study was to determine if the introduction of a continuous high-fidelity training program improves first-pass intubation success in a non-rapid sequence induction ground-based emergency medical services agency with an established video laryngoscopy program.

METHODS

This is a retrospective analysis of quality improvement data of advanced airway management performed by an ambulance service between 2012 and 2019. A mandatory biannual high-fidelity simulation training curriculum was introduced at the beginning of 2017.

RESULTS

A total of 459 patients underwent intubation attempts during the 7-year study period. First-pass intubation success improved from 57.6% to 81.4%, an improvement of 23.8% (95% confidence interval [CI], 15.4-31.5; P < .001), and overall intubation success improved from 77% to 91%, an improvement of 14.1% (95% CI, 7.3-20.3; P < .001). The average number of intubation attempts per patient decreased by 0.19 (95% CI, 0.09-0.29; P < .0003). The mean time of arrival to intubation time increased by 2.21 minutes (95% CI, 0.84-3.58; P = .0016).

CONCLUSION

Implementation of a high-fidelity airway training program is associated with improvements in overall endotracheal intubation and first-pass endotracheal intubation success rates in all adult patient categories.

Maintaining Preparedness to Severe Though Infrequent Threats-Can It Be Done?

Background: A mass casualty incident (MCI) caused by toxicological/chemical materials constitutes a potential though uncommon risk that may cause great devastation. Presentation of casualties exposed to such materials in hospitals, if not immediately identified, may cause secondary contamination resulting in dysfunction of the emergency department. The study examined the impact of a longitudinal evaluation process on the ongoing emergency preparedness of hospitals for toxicological MCIs, over a decade. Methods: Emergency preparedness for toxicological incidents of all Israeli hospitals were periodically evaluated, over ten years. The evaluation was based on a structured tool developed to encourage ongoing preparedness of Standard Operating Procedures (SOPs), equipment and infrastructure, knowledge of personnel, and training and exercises. The benchmarks were distributed to all hospitals, to be used as a foundation to build and improve emergency preparedness. Scores were compared within and between hospitals. Results: Overall mean scores of emergency preparedness increased over the five measurements from 88 to 95. A significant increase between T1 (first evaluation) and T5 (last evaluation) occurred in SOPs (p = 0.006), training and exercises (p = 0.003), and in the overall score (p = 0.004). No significant changes were found concerning equipment and infrastructure and knowledge; their scores were consistently very high throughout the decade. An interaction effect was found between the cycles of evaluation and the hospitals’ geographical location (F _(1,20) = 3.0, p = 0.056), proximity to other medical facilities (F _(1,20) = 10.0 p = 0.005), and type of area (Urban vs. Periphery) (F _(1,20) = 13.1, p = 0.002). At T5, all hospitals achieved similar high scores of emergency preparedness. Conclusions: Use of accessible benchmarks, which clearly delineate what needs to be continually implemented, facilitates an ongoing sustenance of effective levels of emergency preparedness. As this was demonstrated for a risk that does not frequently occur, it may be assumed that it is possible and practical to achieve and maintain emergency preparedness for other potential risks.

Endotracheal intubation during out-of-hospital cardiac arrest: New insights from recent clinical trials

Airway management is an important intervention during resuscitation of out-of-hospital cardiac arrest (OHCA). Endotracheal intubation is commonly used by emergency medical services paramedics in the advanced airway management of OHCA, but numerous studies question its safety and effectiveness. Furthermore, there is now increasing use of supraglottic airway devices. In this review, we provide an overview of 3 recent randomized clinical trials of advanced airway management (Pragmatic Airway Resuscitation Trial [PART], AIRWAYS-2, and Cardiac Arrest Airway Management [CAAM]) and highlight new information that is available to guide OHCA airway management practices.

Advanced airway management success rates in a national cohort of emergency medical services agencies

OBJECTIVE

Despite its important role in care of the critically ill, there have been few large-scale descriptions of the epidemiology of Emergency Medical Services (EMS) advanced airway management (AAM) and the variations in care with different patient subsets. We sought to characterize AAM performance in a national cohort of EMS agencies.

METHODS

We used data from ESO Solutions, Inc., a national EMS electronic health record system. We analyzed EMS emergency patient encounters during 2011-2015 with attempted AAM. We categorized AAM techniques as conventional endotracheal intubation (cETI), neuromuscular blockade assisted intubation (NMBA-ETI), supraglottic airway (SGA), and cricothyroidotomy (needle and open). Determination of successful AAM was based on EMS provider report. We analyzed the data using descriptive statistics, determining the incidence and clinical characteristics of AAM cases. We determined success rates for each AAM technique, stratifying by the subsets cardiac arrest, medical non-arrest, trauma, and pediatrics (age ≤12 years).

RESULTS

AAM occurred in 57,209 patients. Overall AAM success was 89.1% (95% CI: 88.8-89.3%) across all patients and techniques. Intubation success rates varied by technique; cETI (n = 38,004; 76.9%, 95% CI: 76.5-77.3%), NMBA-ETI (n = 6768; 89.7%, 88.9-90.4%). SGAs were used both for initial (n = 9461, 90.1% success, 95% CI: 89.5-90.7%) and rescue (n = 5994, 87.3% success, 95% CI: 86.4-88.1%) AAM. Cricothyroidotomy success rates were low: initial cricothyroidotomy (n = 202, 17.3% success, 95% CI: 12.4-23.3%), rescue cricothyroidotomy (n = 85, 52.9% success, 95% CI: 41.8-88%). AAM success rates varied by patient subset: cardiac arrest (n = 35,782; 91.7%, 95% CI: 91.4-92.0), medical non-arrest (n = 17,086; 84.7%, 84.2-85.2%); trauma (n = 4341; 84.3%, 83.1-85.3%); pediatric (n = 1223; 73.7%, 71.2-76.2%).

CONCLUSION

AAM success rates varied by airway technique and patient subset. In this national cohort, these results offer perspectives of EMS AAM practices.

Impact of Suction-Assisted Laryngoscopy and Airway Decontamination Technique on Intubation Quality Metrics in a Helicopter Emergency Medical Service: An Educational Intervention

OBJECTIVE

Suction-assisted laryngoscopy and airway decontamination (SALAD) was created to assist with the decontamination of a massively soiled airway. This study aims to investigate the usefulness of SALAD training to prehospital emergency providers to improve their ability to intubate a massively contaminated airway.

METHODS

This was a prospective study conducted as a before and after teaching intervention. Participants were made up of prehospital providers who were present at regularly scheduled training sessions and were asked to intubate a high-fidelity mannequin simulating large-volume emesis before and after SALAD instruction. They were subsequently tested on 3-month skill retention. Twenty subjects participated in all stages of the study and were included in the analysis.

RESULTS

The median time to successful intubation for all study participants before instruction was 60.5 seconds (interquartile range [IQR] = 44.0-84.0); post-training was 43.0 seconds (IQR = 38.0-57.5); and at the 3-month follow-up, it was 29.5 seconds (IQR = 24.5-39.0). The greatest improvement was seen on subgroup analysis of the slowest 50th percentile where the median time before instruction was 84.0 seconds (IQR = 68.0-96.0); post-instruction was 41.5 seconds (IQR = 36.0-65.0); and at the 3-month follow-up, it was 29.5 seconds (IQR = 25.0-39.0).

CONCLUSION

The implementation of the SALAD technique through a structured educational intervention improved time to intubation and the total number of attempts.

Impact of the laryngeal tube as supraglottic airway device on blood flow of the internal carotid artery in patients undergoing general anaesthesia

INTRODUCTION

Laryngeal tubes (LT) are supraglottic airway devices routinely used in emergency airway management. During cardiac arrest in a swine model, the carotid artery blood flow is reduced after insertion of a LT. A compression of the internal carotid (ICA) artery by the inflated cuff was shown. Up to now there is no information if the LT has similar effects in humans with possible negative implications for use of the LT in case of cardiac arrest.

OBJECTIVE

We hypothesized that the use of a LT in humans significantly reduces the blood flow in the ICA compared facemask ventilation. A significant reduction was defined as a 25% reduction from baseline values.

MATERIAL AND METHODS

After induction of general anaesthesia and reaching a haemodynamic steady state (stable heart rate >50/min and mean arterial pressure >60 mmHg), blood flow within the ICA was measured via doppler sonography during pressure-controlled ventilation with facemask-, laryngeal tube- and laryngeal mask.

RESULTS

We found no differences in the carotid blood flow. Neither between the facemask ventilation (right side 419 ± 159 ml min^-1, left side 355 ± 120 ml min^-1) and the laryngeal tube ventilation (right side 400 ± 131 ml min^-1, left side 384 ± 124 ml min^-1. p = 0.86 and p = 0.12), nor the facemask-ventilation and the laryngeal mask ventilation (right ICA 415 ± 150 ml min^-1, left ICA 485 ± 274 ml min^-1, p = 0.49 and 0.26).

CONCLUSIONS

In humans the LT does not impair blood flow of the internal carotid artery during ventilation in general anaesthesia. Further studies are needed to confirm our findings under the conditions of cardiac arrest.

A descriptive analysis of endotracheal intubation in a South African Helicopter Emergency Medical Service

Introduction

Helicopter Emergency Medical Services (HEMS) exists to supplement the operations of ground-based emergency care providers, mainly in high acuity cases. One of the important procedures frequently carried out by HEMS personnel is endotracheal intubation. Several HEMS providers exist in South Africa, with a mix of advanced life support personnel, however intubation success rates and adverse events have not been described in any local HEMS operation.

Methods

This was a retrospective chart review of intubation-related data collected by a HEMS operation based in Johannesburg over a 16-month period. First-pass and overall success rates were described, in addition to perceived airway difficulty, adverse events and other data.

Results

Of the 49 cases recorded in the study period, one was excluded leaving 48 cases for analysis. Most cases (n = 34, 71%) involved young male trauma patients who were intubated with rapid sequence intubation. The first pass success rate was 79% (n = 38) with an overall success rate of 98% (n = 47). At least one factor suggesting airway difficulty was present in 29% (n = 14) of cases, with most perceived airway difficulty related to the high prevalence of trauma cases. At least one adverse event occurred in 27% (n = 13) of cases with hypoxaemia, hypotension and bradycardia most prevalent.

Discussion

In this small sample of South African HEMS intubation cases, we found overall and first-pass success rates comparable to those reported in similar contexts.

Airway management in pre-hospital critical care: a review of the evidence for a 'top five' research priority

The conduct and benefit of pre-hospital advanced airway management and pre-hospital emergency anaesthesia have been widely debated for many years. In 2011, prehospital advanced airway management was identified as a ‘top five’ in physician-provided pre-hospital critical care. This article summarises the evidence for and against this intervention since 2011 and attempts to address some of the more controversial areas of this topic.

An original design of remote robot-assisted intubation system

The success rate of pre-hospital endotracheal intubation (ETI) by paramedics is lower than physicians. We aimed to establish a remote robot-assisted intubation system (RRAIS) and expected it to improve success rate of pre-hospital ETI. To test the robot’s feasibility, 20 pigs were intubated by direct laryngoscope or the robot system. Intubation time, success rate, airway complications were recorded during the experiment. The animal experiment showed that participants achieved a higher success rate in absolute numbers by the robot system. In summary, we have successfully developed a remote robot-assisted intubation system. It is promising for RRAIS to improve the success rate of pre-hospital ETI and change the current rescue model.

Intubation Success after Introduction of a Quality Assurance Program Using Video Laryngoscopy

OBJECTIVE

The deployment of video laryngoscopy devices that include recording capability presents a new and unique opportunity for medical directors to review prehospital patient encounters. We sought to evaluate the effect of introducing a video laryngoscope and video quality assurance program to an air medical program on measures of intubation success including overall success, first-pass success, success within 2 attempts, and the total number of attempts.

METHODS

This was a retrospective review of data collected on intubations by nurses and paramedics of the Virginia State Police Med-Flight 1 air medical program.

RESULTS

After introduction of the video laryngoscope and quality assurance program, the overall intubation success improved to 100% but did not reach statistical significance (95% confidence interval [CI], -4.40 to 12.57; P = .25). First-pass success improved from 76.19% to 92.86% (CI, 1.14-33.14; P = .02), whereas the average attempts declined from 1.31 to 1.09 per patient encounter (CI, -.41 to -.03; P = .02). Success within 2 attempts was 92.86% before the intervention and 98.21% after (CI, 4.25-17.82; P = .19).

CONCLUSION

Video laryngoscopy and a robust means for medical director oversight are important components of a high-performance airway management program and demonstrably improve intubation first-pass success.

Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial

IMPORTANCE

Emergency medical services (EMS) commonly perform endotracheal intubation (ETI) or insertion of supraglottic airways, such as the laryngeal tube (LT), on patients with out-of-hospital cardiac arrest (OHCA). The optimal method for OHCA advanced airway management is unknown.

OBJECTIVE

To compare the effectiveness of a strategy of initial LT insertion vs initial ETI in adults with OHCA.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter pragmatic cluster-crossover clinical trial involving EMS agencies from the Resuscitation Outcomes Consortium. The trial included 3004 adults with OHCA and anticipated need for advanced airway management who were enrolled from December 1, 2015, to November 4, 2017. The final date of follow-up was November 10, 2017.

INTERVENTIONS

Twenty-seven EMS agencies were randomized in 13 clusters to initial airway management strategy with LT (n = 1505 patients) or ETI (n = 1499 patients), with crossover to the alternate strategy at 3- to 5-month intervals.

MAIN OUTCOMES AND MEASURES

The primary outcome was 72-hour survival. Secondary outcomes included return of spontaneous circulation, survival to hospital discharge, favorable neurological status at hospital discharge (Modified Rankin Scale score ≤3), and key adverse events.

RESULTS

Among 3004 enrolled patients (median [interquartile range] age, 64 [53-76] years, 1829 [60.9%] men), 3000 were included in the primary analysis. Rates of initial airway success were 90.3% with LT and 51.6% with ETI. Seventy-two hour survival was 18.3% in the LT group vs 15.4% in the ETI group (adjusted difference, 2.9% [95% CI, 0.2%-5.6%]; P = .04). Secondary outcomes in the LT group vs ETI group were return of spontaneous circulation (27.9% vs 24.3%; adjusted difference, 3.6% [95% CI, 0.3%-6.8%]; P = .03); hospital survival (10.8% vs 8.1%; adjusted difference, 2.7% [95% CI, 0.6%-4.8%]; P = .01); and favorable neurological status at discharge (7.1% vs 5.0%; adjusted difference, 2.1% [95% CI, 0.3%-3.8%]; P = .02). There were no significant differences in oropharyngeal or hypopharyngeal injury (0.2% vs 0.3%), airway swelling (1.1% vs 1.0%), or pneumonia or pneumonitis (26.1% vs 22.3%).

CONCLUSIONS AND RELEVANCE

Among adults with OHCA, a strategy of initial LT insertion was associated with significantly greater 72-hour survival compared with a strategy of initial ETI. These findings suggest that LT insertion may be considered as an initial airway management strategy in patients with OHCA, but limitations of the pragmatic design, practice setting, and ETI performance characteristics suggest that further research is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02419573.

Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome: The AIRWAYS-2 Randomized Clinical Trial

IMPORTANCE

The optimal approach to airway management during out-of-hospital cardiac arrest is unknown.

OBJECTIVE

To determine whether a supraglottic airway device (SGA) is superior to tracheal intubation (TI) as the initial advanced airway management strategy in adults with nontraumatic out-of-hospital cardiac arrest.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, cluster randomized clinical trial of paramedics from 4 ambulance services in England responding to emergencies for approximately 21 million people. Patients aged 18 years or older who had a nontraumatic out-of-hospital cardiac arrest and were treated by a participating paramedic were enrolled automatically under a waiver of consent between June 2015 and August 2017; follow-up ended in February 2018.

INTERVENTIONS

Paramedics were randomized 1:1 to use TI (764 paramedics) or SGA (759 paramedics) as their initial advanced airway management strategy.

MAIN OUTCOMES AND MEASURES

The primary outcome was modified Rankin Scale score at hospital discharge or 30 days after out-of-hospital cardiac arrest, whichever occurred sooner. Modified Rankin Scale score was divided into 2 ranges: 0-3 (good outcome) or 4-6 (poor outcome; 6 = death). Secondary outcomes included ventilation success, regurgitation, and aspiration.

RESULTS

A total of 9296 patients (4886 in the SGA group and 4410 in the TI group) were enrolled (median age, 73 years; 3373 were women [36.3%]), and the modified Rankin Scale score was known for 9289 patients. In the SGA group, 311 of 4882 patients (6.4%) had a good outcome (modified Rankin Scale score range, 0-3) vs 300 of 4407 patients (6.8%) in the TI group (adjusted risk difference [RD], -0.6% [95% CI, -1.6% to 0.4%]). Initial ventilation was successful in 4255 of 4868 patients (87.4%) in the SGA group compared with 3473 of 4397 patients (79.0%) in the TI group (adjusted RD, 8.3% [95% CI, 6.3% to 10.2%]). However, patients randomized to receive TI were less likely to receive advanced airway management (3419 of 4404 patients [77.6%] vs 4161 of 4883 patients [85.2%] in the SGA group). Two of the secondary outcomes (regurgitation and aspiration) were not significantly different between groups (regurgitation: 1268 of 4865 patients [26.1%] in the SGA group vs 1072 of 4372 patients [24.5%] in the TI group; adjusted RD, 1.4% [95% CI, -0.6% to 3.4%]; aspiration: 729 of 4824 patients [15.1%] vs 647 of 4337 patients [14.9%], respectively; adjusted RD, 0.1% [95% CI, -1.5% to 1.8%]).

CONCLUSIONS AND RELEVANCE

Among patients with out-of-hospital cardiac arrest, randomization to a strategy of advanced airway management with a supraglottic airway device compared with tracheal intubation did not result in a favorable functional outcome at 30 days.

TRIAL REGISTRATION

ISRCTN Identifier: 08256118.

Consensus statement: a framework for safe and effective intubation by paramedics

This consensus statement provides profession-specific guidance in relation to tracheal intubation by paramedics – a procedure that the College of Paramedics supports.

Tracheal intubation by paramedics has been the subject of professional and legal debate as well as crown investigation. It is therefore timely that the College of Paramedics, through this consensus group, reviews the available evidence and expert opinion in order to prevent patient harm and promote patient safety, clinical effectiveness and professional standards.

It is not the purpose of this consensus statement to remove the skill of tracheal intubation from paramedics. Neither is it intended to debate the efficacy of intubation or the effect on mortality or morbidity, as other formal research studies will answer those questions.

The consensus of this group is that paramedics can perform tracheal intubation safely and effectively. However, a safe, well-governed system of continual training, education and competency must be in place to serve both patients and the paramedics delivering their care.

Efficacy of pre-hospital rapid sequence intubation in paediatric traumatic brain injury: A 9-year observational study

INTRODUCTION

Prehospital airway management of the paediatric patient with traumatic brain injury (TBI) is controversial. Endotracheal intubation of children in the field requires specific skills and has potential benefits but also carries potentially serious complications. We aimed to compare mortality and functional outcomes after six months between children with TBI who either underwent prehospital rapid sequence intubation (RSI) by trained Intensive Care paramedics (ICP) or received no intubation.

METHODS

We conducted a retrospective study of patients aged ≤14 years with suspected TBI in Victoria, Australia. Patients were either transported via helicopter and received RSI by an ICP (2005-2013) or via road ambulance and received no intubation (2006-2013). Prehospital data was linked to hospital and 6-month follow-up data to assess mortality and functional outcome.

RESULTS

A total of 106 patients were included in the study of which 87 received RSI by paramedics and 19 did not receive intubation. Overall, the intubation success rate was 99% (86/87), with a first-pass success rate of 93% (81/87). In total, 67% of patients (n = 41) receiving RSI had a favourable functional outcome, compared with 54% of non-intubated patients (n = 7) (p = 0.36). In the 75 children with major trauma, prehospital RSI was associated with a significant decrease in length of hospital stay (523 h vs. 1939 h, p = 0.03). In the 53 children in this subgroup with available six months data the difference in favourable functional outcome increased to 66% (n = 31)vs. 17% (n = 1) (p = 0.06).

DISCUSSION

Prehospital RSI in paediatric patients with TBI can safely be performed by highly trained paramedics. Overall, we observed more favourable long-term outcomes in patients who received prehospital intubation than those who did not, however our study is not powered to detect a significant difference. Intubation prior to transport might be beneficial for major trauma patients.

Definitive airway management after prehospital supraglottic rescue airway in pediatric trauma

INTRODUCTION

Supraglottic airway (SGA) use and outcomes in pediatric trauma are poorly understood. We compared outcomes between patients receiving prehospital SGA versus bag mask ventilation (BVM).

METHODS

We reviewed pediatric multisystem trauma patients (2005-2016), comparing SGA and BVM. Primary outcome was adequacy of oxygenation and ventilation. Additional measures included tracheostomy, mortality and abbreviated injury scores (AIS).

RESULTS

Ninety patients were included (SGA, n=17 and BVM, n=73). SGA patients displayed increased median head AIS (5 [4-5] vs 2 [0-4], p=0.001) and facial AIS (1 [0-2] vs 0 [0-0], p=0.03). SGA indications were multiple failed intubation attempts (n=12) and multiple failed attempts with poor visualization (n=5). Median intubation attempts were 2 [1-3] whereas BVM patients had none. Compared to BVM, SGA patients demonstrated inadequate oxygenation/ventilation (75% vs 41%), increased tracheostomy rates (31% vs 8.1%), and increased 24-h (38% vs 10.8%) and overall mortality (75% vs 14%) (all p<0.05).

CONCLUSIONS

Escalating intubation attempts and severe facial AIS were associated with tracheostomy. Inadequacy of oxygenation/ventilation was more frequent in SGA compared to BVM patients. SGA patients demonstrate poor clinical outcomes; however, SGAs may be necessary in increased craniofacial injury patterns. These factors may be incorporated into a management algorithm to improve definitive airway management after SGA.

Flight Versus Ground Out-of-hospital Rapid Sequence Intubation Success: a Systematic Review and Meta-analysis

INTRODUCTION

Endotracheal intubation (ETI) is a critical procedure performed by both air medical and ground based emergency medical services (EMS). Previous work has suggested that ETI success rates are greater for air medical providers. However, air medical providers may have greater airway experience, enhanced airway education, and access to alternative ETI options such as rapid sequence intubation (RSI). We sought to analyze the impact of the type of EMS on RSI success.

METHODS

A systematic literature search of Medline, Embase, and the Cochrane Library was conducted and eligibility, data extraction, and assessment of risk of bias were assessed independently by two reviewers. A bias-adjusted meta-analysis using a quality-effects model was conducted for the primary outcomes of overall intubation success and first-pass intubation success.

RESULTS

Forty-nine studies were included in the meta-analysis. There was no difference in the overall success between flight and ground based EMS; 97% (95% CI 96-98) vs. 98% (95% CI 91-100), and no difference in first-pass success for flight compared to ground based RSI; 82% (95% CI 73-89) vs. 82% (95% CI 70-93). Compared to flight non-physicians, flight physicians have higher overall success 99% (95% CI 98-100) vs. 96% (95% CI 94-97) and first-pass success 89% (95% CI 77-98) vs. 71% (95% CI 57-84). Ground-based physicians and non-physicians have a similar overall success 98% (95% CI 88-100) vs. 98% (95% CI 95-100), but no analysis for physician ground first pass was possible.

CONCLUSIONS

Both overall and first-pass success of RSI did not differ between flight and road based EMS. Flight physicians have a higher overall and first-pass success compared to flight non-physicians and all ground based EMS, but no such differences are seen for ground EMS. Our results suggest that ground EMS can use RSI with similar outcomes compared to their flight counterparts.

Evaluation of Physiologic Alterations during Prehospital Paramedic-Performed Rapid Sequence Intubation

OBJECTIVE

Physiologic alterations during rapid sequence intubation (RSI) have been studied in several emergency airway management settings, but few data exist to describe physiologic alterations during prehospital RSI performed by ground-based paramedics. To address this evidence gap and provide guidance for future quality improvement initiatives in our EMS system, we collected electronic monitoring data to evaluate peri-intubation vital signs changes occurring during prehospital RSI.

METHODS

Electronic patient monitor data files from cases in which paramedic RSI was attempted were prospectively collected over a 15-month study period to supplement the standard EMS patient care documentation. Cases were analyzed to identify peri-intubation changes in oxygen saturation, heart rate, and blood pressure.

RESULTS

Data from 134 RSI cases were available for analysis. Paramedic-assigned prehospital diagnostic impression categories included neurologic (42%), respiratory (26%), toxicologic (22%), trauma (9%), and cardiac (1%). The overall intubation success rate (95%) and first-attempt success rate (82%) did not differ across diagnostic impression categories. Peri-intubation desaturation (SpO₂ decrease to below 90%) occurred in 43% of cases, and 70% of desaturation episodes occurred on first-attempt success. The incidence of desaturation varied among patient categories, with a respiratory diagnostic impression associated with more frequent, more severe, and more prolonged desaturations, as well as a higher incidence of accompanying cardiovascular instability. Bradycardia (HR decrease to below 60 bpm) occurred in 13% of cases, and 60% of bradycardia episodes occurred on first-attempt success. Hypotension (systolic blood pressure decrease to below 90 mmHg) occurred in 7% of cases, and 63% of hypotension episodes occurred on first-attempt success. Peri-intubation cardiac arrest occurred in 2 cases, one of which was on first-attempt success. Only 11% of desaturations and no instances of bradycardia were reflected in the standard EMS patient care documentation.

CONCLUSIONS

In this study, the majority of peri-intubation physiologic alterations occurred on first-attempt success, highlighting that first-attempt success is an incomplete and potentially deceptive measure of intubation quality. Supplementing the standard patient care documentation with electronic monitoring data can identify unrecognized physiologic instability during prehospital RSI and provide valuable guidance for quality improvement interventions.

Can use of video Laryngoscopes by Emergency Medical Technicians Facilitate Endotracheal Intubation during Continuous Chest Compression? A Manikin Study

Introduction

We conducted this study to evaluate the utility of two video laryngoscopes (VLs) [Pentax-AWS (AWS), GlideScope (GVL)], compared to the conventional Macintosh laryngoscope (ML), on endotracheal intubation (ETI) involving chest compressions by Level 1 Korean emergency medical technicians (EMTs) who are the equivalent of EMT-I in the United States.

Methods

This was a randomised crossover simulation study. Fifty EMTs performed endotracheal intubation in randomised sequence following two different scenarios: normal airway and difficult airway.

Results

In normal airway scenario, overall success rate did not differ between the three devices. However AWS required a shorter run-time (14.1 [10.9-19.8] seconds) to complete ETI (TC) than ML (17.7 [13.5-21.3] seconds) (p=0.017). And both VLs showed a significant superiority over ML in time required to visualise vocal cords (TVC), percentage of glottic opening (POGO) score, and incidence of dental compression (IDC). In difficult airway scenario, overall success rate of both VLs was significantly higher than ML. The TC of AWS (13.7 [11.2-16.9] seconds) and GVL (20.7 [15.1-25.9] seconds) was shorter than that of ML (24.7 [18.1-34.5] seconds) (p<0.001). The TVC of GVL was significantly shorter than that of AWS and ML. The POGO score, IDC, and ease of intubation were significantly superior with AWS, GVL, and ML, respectively.

Conclusions

Video laryngoscopes can facilitate EMT performing a faster and easier intubation without interrupting chest compressions. Moreover, AWS improves the success rate comparing to ML in difficult airway management. (Hong Kong j.emerg.med. 2014;21:308-315)

Efficacy of Pentax airway scope versus Macintosh laryngoscope when used by novice personnel: A prospective randomized controlled study

Objective

To determine whether intubation education using the Pentax Airway Scope (AWS) in normal airways is more useful than direct laryngoscopy (Macintosh laryngoscope) in novice personnel.

Methods

Eleven intern doctors without intubation experience performed 60 sequential intubations with each device on a manikin and 10 sequential intubations in adult patients. The time required for successful intubation, percentage of glottic opening (POGO) score, number of intubation attempts, and number of dental injuries were analyzed for each intubation technique.

Results

The mean (standard deviation) time required for successful intubation decreased as the number of intubations increased and was significantly shorter with the Pentax AWS than direct laryngoscope [22.6 (7.3) vs. 29.6 (10.0) and 33.0 (8.0) vs. 44.7 (5.6) s, respectively] in both the manikin and clinical studies. The Pentax AWS was also associated with higher POGO scores than the direct laryngoscope [81.7 (8.9) vs. 55.1 (13.2) and 80.9 (9.7) vs. 49.6 (16.5), respectively] and fewer intubation attempts. Fewer dental injuries occurred with the Pentax AWS in the manikin study.

Conclusions

Novices performed intubation more rapidly and easily with an improved laryngeal view using the Pentax AWS. We suggest that intubation education with video laryngoscopy should be mandatory along with direct laryngoscope training.

Unrecognized failed airway management using a supraglottic airway device

BACKGROUND

911 Emergency Medical Services (EMS) systems utilize supraglottic devices for either primary advanced airway management, or for airway rescue following failed attempts at direct laryngoscopy endotracheal intubation. There is, however, limited data on objective confirmation of supraglottic airway placement in the prehospital environment. Furthermore, the ability of EMS field providers to recognize a misplaced airway is unknown.

METHODS

Retrospective review of patients who underwent airway management using the King LTS-D supraglottic airway in a large urban EMS system, between 3/1/15-9/30/2015. Subjective success was defined as documentation of successful airway placement by the EMS provider. Objective success was confirmed by review of waveform capnography, with the presence of a 4-phase waveform greater than 5mmHg. Sensitivity and specificity of the field provider's assessment of success were then calculated.

RESULTS

A total of 344 supraglottic airway attempts were reviewed. No patients met obvious death criteria. 269 attempts (85.1%) met criteria for both subjective and objective success. 19 attempts (5.6%) were recognized failures by the EMS provider. 47 (13.8%) airways were misplaced but unrecognized by the EMS provider. 4 attempts (1.2%) were correctly placed but misidentified as failures, leading to the unnecessary removal and replacement of the airway. Sensitivity of the provider's assessment was 98.5%; specificity was 28.7%.

CONCLUSION

The use of supraglottic airway devices results in unrecognized failed placement. Appropriate utilization and review of waveform capnography may remedy a potential blind-spot in patient safety, and systemic monitoring/feedback processes may therefore be used to prevent unrecognized misplaced airways.

Paramedic Intubation Experience Is Associated With Successful Tube Placement but Not Cardiac Arrest Survival

STUDY OBJECTIVE

Paramedic experience with intubation may be an important factor in skill performance and patient outcomes. Our objective is to examine the association between previous intubation experience and successful intubation. In a subcohort of out-of-hospital cardiac arrest cases, we also measure the association between patient survival and previous paramedic intubation experience.

METHODS

We analyzed data from Ambulance Victoria electronic patient care records and the Victorian Ambulance Cardiac Arrest Registry for January 1, 2008, to September 26, 2014. For each patient case, we defined intubation experience as the number of intubations attempted by each paramedic in the previous 3 years. Using logistic regression, we estimated the association between intubation experience and (1) successful intubation and (2) first-pass success. In the out-of-hospital cardiac arrest cohort, we determined the association between previous intubation experience and patient survival.

RESULTS

During the 6.7-year study period, 769 paramedics attempted intubation in 14,857 patients. Paramedics typically performed 3 intubations per year (interquartile range 1 to 6). Most intubations were successful (95%), including 80% on the first attempt. Previous intubation experience was associated with intubation success (odds ratio 1.04; 95% confidence interval 1.03 to 1.05) and intubation first-pass success (odds ratio 1.02; 95% confidence interval 1.01 to 1.03). In the out-of-hospital cardiac arrest subcohort (n=9,751), paramedic intubation experience was not associated with patient survival.

CONCLUSION

Paramedics in this Australian cohort performed few intubations. Previous experience was associated with successful intubation. Among out-of-hospital cardiac arrest patients for whom intubation was attempted, previous paramedic intubation experience was not associated with patient survival.