High-Risk Airway Management in the Emergency Department. Part I: Diseases and Approaches

Management of high-risk pulmonary embolism in the emergency department: A narrative review

BACKGROUND

High-risk pulmonary embolism (PE) is a complex, life-threatening condition, and emergency clinicians must be ready to resuscitate and rapidly pursue primary reperfusion therapy. The first-line reperfusion therapy for patients with high-risk PE is systemic thrombolytics (ST). Despite consensus guidelines, only a fraction of eligible patients receive ST for high-risk PE.

OBJECTIVE

This review provides emergency clinicians with a comprehensive overview of the current evidence regarding the management of high-risk PE with an emphasis on ST and other reperfusion therapies to address the gap between practice and guideline recommendations.

DISCUSSION

High-risk PE is defined as PE that causes hemodynamic instability. The high mortality rate and dynamic pathophysiology of high-risk PE make it challenging to manage. Initial stabilization of the decompensating patient includes vasopressor administration and supplemental oxygen or high-flow nasal cannula. Primary reperfusion therapy should be pursued for those with high-risk PE, and consensus guidelines recommend the use of ST for high-risk PE based on studies demonstrating benefit. Other options for reperfusion include surgical embolectomy and catheter directed interventions.

CONCLUSIONS

Emergency clinicians must possess an understanding of high-risk PE including the clinical assessment, pathophysiology, management of hemodynamic instability and respiratory failure, and primary reperfusion therapies.

Diagnosis and Management of Acute Respiratory Failure

Acute hypoxemic respiratory failure is defined by Pao2 less than 60 mm Hg or SaO2 less than 88% and may result from V/Q mismatch, shunt, hypoventilation, diffusion limitation, or low inspired oxygen tension. Acute hypercapnic respiratory failure is defined by Paco2 ≥ 45 mm Hg and pH less than 7.35 and may result from alveolar hypoventilation, increased fraction of dead space, or increased production of carbon dioxide. Early diagnostic maneuvers, such as measurement of SpO2 and arterial blood gas, can differentiate the type of respiratory failure and guide next steps in evaluation and management.

A Market Assessment of Introducer Technology to Aid With Endotracheal Intubation

INTRODUCTION

Endotracheal intubation is a potentially lifesaving procedure. Previously, data demonstrated that intubation remains the most performed airway intervention in the Role 1 setting. Additionally, deployed data demonstrate that casualties intubated in the prehospital setting have worse survival than those intubated in the emergency department setting. Technological solutions may improve intubation success in this setting. Certain intubation practices, including the use of endotracheal tube introducer bougies, facilitate intubation success especially in patients with difficult airways. We sought to determine the current state of the market for introducer devices.

MATERIALS AND METHODS

This market review utilized Google searches to find products for intubation. The search criteria aimed to identify any device ideal for intubation in the emergency setting. Device data retrieved included manufacturer, device, cost, and design descriptions.

RESULTS

We identified 12 introducer-variants on the market. Devices varied with regards to composition (latex, silicone, polyethylene, combination of several materials, etc.), tip shape, special features for ease of intubation (markings for depth and visibility, size, etc.), disposability/reuse capability, measurements, and prices. The cost of each device ranged from approximately $5 to $100.

CONCLUSIONS

We identified 12 introducer-variants on the market. Clinical studies are necessary to determine which devices may improve patient outcomes in the Role 1 setting.

Pre-operative gastric ultrasound in patients at risk of pulmonary aspiration: a prospective observational cohort study

Point-of-care gastric sonography offers an objective approach to assessing individual pulmonary aspiration risk before induction of general anaesthesia. We aimed to evaluate the potential impact of routine pre-operative gastric ultrasound on peri-operative management in a cohort of adult patients undergoing elective or emergency surgery at a single centre. According to pre-operative gastric ultrasound results, patients were classified as low risk (empty, gastric fluid volume ≤ 1.5 ml.kg-1 body weight) or high risk (solid, mixed or gastric fluid volume > 1.5 ml.kg-1 body weight) of aspiration. After sonography, examiners were asked to indicate changes in aspiration risk management (none; more conservative; more liberal) to their pre-defined anaesthetic plan and to adapt it if patient safety was at risk. We included 2003 patients, 1246 (62%) of which underwent elective and 757 (38%) emergency surgery. Among patients who underwent elective surgery, 1046/1246 (84%) had a low-risk and 178/1246 (14%) a high-risk stomach, with this being 587/757 (78%) vs. 158/757 (21%) among patients undergoing emergency surgery, respectively. Routine pre-operative gastric sonography enabled changes in anaesthetic management in 379/2003 (19%) of patients, with these being a more liberal approach in 303/2003 (15%). In patients undergoing elective surgery, pre-operative gastric sonography would have allowed a more liberal approach in 170/1246 (14%) and made a more conservative approach indicated in 52/1246 (4%), whereas in patients undergoing emergency surgery, 133/757 (18%) would have been managed more liberally and 24/757 (3%) more conservatively. We showed that pre-operative gastric ultrasound helps to identify high- and low-risk situations in patients at risk of aspiration and adds useful information to peri-operative management. Our data suggest that routine use of pre-operative gastric ultrasound may improve individualised care and potentially impact patient safety.

Approach to the Physiologically Challenging Endotracheal Intubation in the Intensive Care Unit

Endotracheal intubation for airway management is a common procedure in the ICU. Intubation may be difficult due to anatomic airway abnormalities but also due to physiologic derangements that predispose patients to cardiovascular collapse during the procedure. Results of studies demonstrate a high incidence of morbidity and mortality associated with airway management in the ICU. To reduce the likelihood of complications, medical teams must be well versed in the general principles of intubation and be prepared to manage physiologic derangements while securing the airway. In this review, we present relevant literature on the approach to endotracheal intubation in the ICU and provide pragmatic recommendations relevant to medical teams performing intubations in patients who are physiologically unstable.

Outcomes and Prognostic Factors of Pulmonary Hypertension Patients Undergoing Emergent Endotracheal Intubation

Background: Emergent endotracheal intubations (ETI) in pulmonary hypertension (PH) patients are associated with increased mortality. Post-intubation interventions that could increase survivability in this population have not been explored. We evaluate early clinical characteristics and complications following emergent endotracheal intubation and seek predictors of adverse outcomes during this post-intubation period. Methods: Retrospective cohort analysis of adult patients with groups 1 and 3 PH who underwent emergent intubation between 2005-2021 in medical and liver transplant ICUs at a tertiary medical center. PH patients were compared to non-PH patients, matched by Charlson Comorbidity Index. Primary outcomes were 24-h post-intubation and inpatient mortalities. Various 24-h post-intubation secondary outcomes were compared between PH and control cohorts. Results: We identified 48 PH and 110 non-PH patients. Pulmonary hypertension was not associated with increased 24-h mortality (OR 1.32, 95%CI 0.35-4.94, P = .18), but was associated with inpatient mortality (OR 4.03, 95%CI 1.29-12.5, P = .016) after intubation. Within 24 h post-intubation, PH patients experienced more frequent acute kidney injury (43.5% vs. 19.8%, P = .006) and required higher norepinephrine dosing equivalents (6.90 [0.13-10.6] mcg/kg/min, vs. 0.20 [0.10-2.03] mcg/kg/min, P = .037). Additionally, the median P/F ratio (PaO₂/FiO₂) was lower in PH patients (96.3 [58.9-201] vs. 233 [146-346] in non-PH, P = .001). Finally, a post-intubation increase in PaCO₂ was associated with mortality in the PH cohort (post-intubation change in PaCO₂ +5.14 ± 16.1 in non-survivors vs. -18.7 ± 28.0 in survivors, P = .007). Conclusions: Pulmonary hypertension was associated with worse outcomes after emergent endotracheal intubation than similar patients without PH. More importantly, our data suggest that the first 24 hours following intubation in the PH group represent a particularly vulnerable period that may determine long-term outcomes. Early post-intubation interventions may be key to improving survival in this population.

Management of the Difficult Airway

ABSTRACT

Airway management is a fundamental component of care during resuscitation of critically ill and injured children. In addition to predicted anatomic and physiologic differences in children compared with adults, certain conditions can predict potential difficulty during pediatric airway management. This review presents approaches to identifying pediatric patients in whom airway management is more likely to be difficult, and discusses strategies to address such challenges. These strategies include optimization of effective bag-mask ventilation, alternative approaches to laryngoscopy, use of adjunct airway devices, modifications to rapid sequence intubation, and performance of surgical airways in children. The importance of considering systems of care in preparing for potentially difficult pediatric airways is also discussed.

Risk factors associated with peri-intubation cardiac arrest in the emergency department

BACKGROUND

Peri-intubation cardiac arrest is an uncommon, serious complication following endotracheal intubation in the emergency department. Although several risk factors have been previously identified, this study aimed to comprehensively identify risk factors associated with peri-intubation cardiac arrest.

METHODS

This retrospective, nested case-control study conducted from January 1, 2016 to December 31, 2020 analyzed variables including demographic characteristics, triage, and pre-intubation vital signs, medications, and laboratory data. Univariate analysis and multivariable logistic regression models were used to compare clinical factors between the patients with peri-intubation cardiac arrest and patients without cardiac arrest.

RESULTS

Of the 6983 patients intubated during the study period, 5130 patients met the inclusion criteria; 92 (1.8%) patients met the criteria for peri-intubation cardiac arrest and 276 were age- and sex-matched to the control group. Before intubation, systolic blood pressure and diastolic blood pressure were lower (104 vs. 136.5 mmHg, p < 0.01; 59.5 vs. 78 mmHg, p < 0.01 respectively) and the shock index was higher in the patients with peri-intubation cardiac arrest than the control group (0.97 vs. 0.83, p < 0.0001). Cardiogenic pulmonary edema as an indication for intubation (adjusted odds ratio [aOR]: 5.921, 95% confidence interval [CI]: 1.044-33.57, p = 0.04), systolic blood pressure < 90 mmHg before intubation (aOR: 5.217, 95% CI: 1.484-18.34, p = 0.01), and elevated lactate levels (aOR: 1.012, 95% CI: 1.002-1.022, p = 0.01) were independent risk factors of peri-intubation cardiac arrest.

CONCLUSIONS

Patients with hypotension before intubation have a higher risk of peri-intubation cardiac arrest in the emergency department. Future studies are needed to evaluate the influence of resuscitation before intubation and establish airway management strategies to avoid serious complications.

Right heart failure: A narrative review for emergency clinicians

INTRODUCTION

Right heart failure (RHF) is a clinical syndrome with impaired right ventricular cardiac output due to a variety of etiologies including ischemia, elevated pulmonary arterial pressure, or volume overload. Emergency department (ED) patients with an acute RHF exacerbation can be diagnostically and therapeutically challenging to manage.

OBJECTIVE

This narrative review describes the pathophysiology of right ventricular dysfunction and pulmonary hypertension, the methods to diagnose RHF in the ED, and management strategies.

DISCUSSION

Right ventricular contraction normally occurs against a low pressure, highly compliant pulmonary vascular system. This physiology makes the right ventricle susceptible to acute changes in afterload, which can lead to RHF. Patients with acute RHF may present with an acute illness and have underlying chronic pulmonary hypertension due to left ventricular failure, pulmonary arterial hypertension, chronic lung conditions, thromboemboli, or idiopathic conditions. Patients can present with a variety of symptoms resulting from systemic edema and hemodynamic compromise. Evaluation with electrocardiogram, laboratory analysis, and imaging is necessary to evaluate cardiac function and end organ injury. Management focuses on treating the underlying condition, optimizing oxygenation and ventilation, treating arrhythmias, and understanding the patient's hemodynamics with bedside ultrasound. As RHF patients are preload dependent they may require fluid resuscitation or diuresis. Hypotension should be rapidly addressed with vasopressors. Cardiac contractility can be augmented with inotropes. Efforts should be made to support oxygenation while trying to avoid intubation if possible.

CONCLUSIONS

Emergency clinician understanding of this condition is important to diagnose and treat this life-threatening cardiopulmonary disorder.

Predictive value of difficult airway identifiers for intubation-related complications in the emergency department

OBJECTIVES

The Airway Alert banner at our institution alerts physicians to patients with the potential for a difficult intubation. Difficult airway guidelines can reduce intubation complications in the operating room, but little research has been done in the emergency department (ED). We hypothesize that patients meeting criteria for the banner will have a more difficult intubation and increased complications.

METHODS

Patients greater than 18 years old who presented to the ED for any complaint and required intubation were reviewed from January 2015 to January 2020 and divided into those meeting criteria for a difficult airway ("criteria cohort") and those who did not ("non-criteria cohort"). Past medical history and details of the intubation were collected.

RESULTS

The mean number of attempts for intubation was 1.60 in the criteria cohort and 1.36 in the non-criteria cohort (P > .05). The mean grade of view was 1.73 and 1.39, respectively (P < .05). The average size of endotracheal tube was 7.50 and 7.74 in the criteria and non-criteria cohorts (P < .05). The use of adjuncts was 28.6% and 12.5%, respectively (P < .01). The average number of intubation attempts and complication rate did not differ significantly.

CONCLUSIONS

Intubations in patients meeting criteria for the banner are associated with a more difficult view, use of smaller endotracheal tube, and increased use of adjuncts, but not with a significantly higher rate of complications or attempts. Physicians should prepare with additional endotracheal tube sizes, adjuncts, and a plan for secondary strategies in these patients.

LEVEL OF EVIDENCE

2b.

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

BACKGROUND

The administration of sedation and neuromuscular blockade to facilitate extraglottic device (EGD) placement is known as rapid sequence airway (RSA). In the emergency department (ED), EGDs are used largely as rescue devices. In select patients, there may be significant advantages to using EGDs over laryngoscopy as the primary airway device in the ED.

OBJECTIVE

Our study sought to describe the practice of RSA in the ED, including rates of successful oxygenation, ventilation, and complications from EGD use.

METHODS

We identified patients in the ED between 2007 and 2017 who underwent RSA with the LMA® Fastrach™ (hereafter termed ILMA; Teleflex Medical Europe Ltd., Athlone, Ireland) placed as the first definitive airway management device. A trained abstractor performed chart and video review of the cases to determine patient characteristics, physician use of the ILMA, indication for ILMA placement, success of oxygenation and ventilation, success of intubation, and complications related to the device.

RESULTS

During the study period, 94 patients underwent RSA with the ILMA. Of those, 93 (99%) were successfully oxygenated and ventilated, and when intubation was attempted, 89% were able to be intubated through the ILMA. The incidence of vomiting and aspiration was 1% and 3%, respectively. There were 30 different attending physicians who supervised RSA and the median number was 2 per physician in the 10-year study period.

CONCLUSION

The practice of RSA with the ILMA in the ED is associated with a high rate of successful oxygenation, ventilation, and intubation with infrequent complications, even when performed by physicians with few experiences in the approach.

Cardiac Arrest in Flight: A Retrospective Chart Review of 92 Patients Transported by a Critical Care Air Medical Service

OBJECTIVE

The purpose of this study was to describe the incidence, characteristics, and outcomes of cardiac arrest in the air medical environment so that we can begin to understand predictors of in-flight cardiac arrest and identify opportunities to improve care.

METHODS

This retrospective observational study was undertaken at Airlift Northwest from 2013 to 2017. Descriptive statistics of adult patients with medical and traumatic etiologies of cardiac arrest were analyzed and compared.

RESULTS

Of the 13,915 adult patients transported during the study period, fewer than 1% (N = 92) had a cardiac arrest during transport. Of those, 42% in the overall cohort had return of spontaneous circulation on arrival at the destination hospital. Medical etiologies of cardiac arrest were more common than traumatic (65% vs. 35%), more likely to have an initial shockable rhythm (30% vs. 3%, P = .004), and more frequently arrived at the receiving hospital with return of spontaneous circulation (57% vs. 31%, P = .03). Rearrest in transport occurred frequently (39%). Most patients were hypotensive before cardiac arrest, and peri-intubation cardiac arrest occurred in 12% of patients.

CONCLUSION

Cardiac arrest during air medical transport is a rare event that requires a high level of critical care to treat refractory cardiac arrests, hemodynamic instability, and airway compromise.