Study objective
Angioedema is an uncommon but important cause of airway obstruction. Emergency airway management of angioedema is difficult. We seek to describe the course and outcomes of emergency airway management for severe angioedema in our institution.
Methods
We performed a retrospective, observational study of all intubations for angioedema performed in an urban academic emergency department (ED) between November 2007 and June 2015. We performed a structured review of video recordings of each intubation. We identified the methods of airway management, the success of each method, and the outcomes and complications of the effort.
Results
We identified 52 patients with angioedema who were intubated in the ED; 7 were excluded because of missing videos, leaving 45 patients in the analysis. Median time from arrival to the ED to the first intubation attempt was 33 minutes (interquartile range 17 to 79 minutes). Nasotracheal intubation was the most common first method (33/45; 73%), followed by video laryngoscopy (7/45; 16%). Two patients required attempts at more invasive airway procedures (retrograde intubation and cricothyrotomy). The intubating laryngeal mask airway was used as a rescue method 5 times after failure of multiple methods, with successful oxygenation, ventilation, and intubation through the laryngeal mask airway in all 5 patients. All patients were successfully intubated.
Conclusion
In this series of ED patients who were intubated because of angioedema, emergency physicians used a range of methods to successfully manage the airway. These observations provide key lessons for the emergency airway management of these critical patients.
Introduction
Background
Hospitalization for angioedema has increased since the introduction of angiotensin-converting enzyme (ACE) inhibitors for the treatment of hypertension. There are as many as 108,000 emergency department (ED) visits annually for angioedema. It can lead to critical airway obstruction and the need for intubation.
What is already known on this topic
Airway management in acute angioedema is difficult.
What question this study addressed
How do emergency physicians manage acute angioedema airway obstruction?
What this study adds to our knowledge
In this descriptive series of 45 emergency department (ED) patients with acute angioedema airway obstruction, emergency physicians used a range of techniques to successfully manage the airway, with only one case requiring a surgical procedure.
How this is relevant to clinical practice
This large series illustrates successful strategies for acute angioedema airway management in the ED.
Importance
The intubation of a patient with severe angioedema can be extremely difficult because of swelling and distortion of airway anatomy, as well as pooling of airway secretions. Although described for cases outside of the ED, there are few descriptions of the methods, success rates, and complications of emergency airway management of angioedema in the ED.
Goals of This Investigation
We sought to characterize the methods, course, and outcomes of emergency airway management for patients treated for severe angioedema in our institution.
Materials and Methods
Study Design
We performed a retrospective, observational study, using video review as our primary method of data collection. This study was approved by our local institutional review board.
Setting
This study was conducted in Hennepin County Medical Center, a high-volume urban Level I trauma center treating approximately 100,000 patients per year. The ED is the setting for approximately 1,000 intubations per year. Emergency physicians manage all airways in our ED. Senior emergency medicine residents (postgraduate year 3 or higher) perform the majority of intubations under the supervision of the attending emergency physician. During the study period, there was no protocol for patients with difficult airways or angioedema.
Selection of Participants
Using the electronic medical record system (Epic Systems, Verona, WI), we identified all adults older than 17 years and with an ED or hospital diagnosis of angioedema ( International Classification of Diseases, Ninth Revision code 995.1) who underwent intubation in the ED between November 2007 and June 2015.
Methods of Measurement
We performed a structured review of resuscitation room videos recorded for each patient case. Critically ill or injured patients receive care in a 4-bay stabilization room. Each bay has 3 ceiling-mounted video cameras activated by motion sensors. Automated software combines the video streams with output from the patient cardiac and vital sign monitor, as well as audio recording of the room. The videos are stored on a secure database and are used for peer review and quality assurance purposes.
Both authors independently reviewed all selected videos, recording observations on a structured data collection form. Data points were defined by both investigators a priori, with refinement after review of the first 3 videos. One investigator (B.E.D.) recorded all data entry into Excel (version 14.0; Microsoft, Redmond, WA). Both investigators resolved discrepancies by consensus, including rereview of the relevant videos.
The medical record was used to identify patient demographics, ACE-inhibitor use, medications administered in the ED, and ED course before patient placement in the resuscitation bay.
Outcome Measures
Collected data included patient demographics, medications administered to facilitate intubation, the use of fiberoptic laryngoscopy before intubation, the course and methods of intubation, and complications of intubation. Elapsed times included time from ED arrival to start of intubation attempt, the duration of the first method, and time from the first attempt until successful intubation.
An intubation method was defined as the use of a single intubation approach (eg, blind nasal intubation, fiberoptic nasal intubation), without an intervening change to a different approach, regardless of the number of discrete attempts with that method. We defined the start of an airway attempt as the point at which the airway equipment (laryngoscope blade, oral intubating airway, endotracheal tube, or fiberoptic scope) entered the mouth or nose. We defined the end of an airway attempt as the point at which all airway equipment was removed from the patient, the method was changed (eg, from blind to fiberoptic nasal intubation), or the endotracheal tube was attached to a bag-valve device after successful intubation.
A patient was considered to have ACE inhibitor angioedema if the discharge summary stated that an ACE inhibitor was the most likely cause of angioedema. We were unable to assess the location and severity of angioedema because the overhead videos did not allow a detailed assessment of intraoral swelling, images from the video laryngoscopes were not routinely recorded, and descriptions in the medical record were not sufficiently detailed for most patients. Defined complications included hypoxemia (SpO 2 less than 90% and SpO 2 less than 90% for more than 60 seconds), esophageal intubation, epistaxis, vomiting, and hypotension (systolic blood pressure less than 90 mm Hg). Esophageal intubation was defined as advancement of the endotracheal tube into the esophagus with subsequent performance of bag-valve-mask ventilation before removal; if the endotracheal tube was passed into the esophagus during an attempt without bag-valve-mask ventilation, it was not considered to be an esophageal intubation. Epistaxis was defined as visible bleeding from either naris. We defined aspiration pneumonia as an infiltrate on chest radiography within 24 hours of admission that was believed by the treating physician to be a result of aspiration.
If a data point was unavailable or unclear from the video, it was considered to be missing for that subject.
Primary Data Analysis
We excluded all patients with missing videos. We analyzed the data with descriptive techniques. We used Stata (version 12.1; StataCorp, College Station, TX) for all data analyses.
Materials and Methods
Study Design
We performed a retrospective, observational study, using video review as our primary method of data collection. This study was approved by our local institutional review board.
Setting
This study was conducted in Hennepin County Medical Center, a high-volume urban Level I trauma center treating approximately 100,000 patients per year. The ED is the setting for approximately 1,000 intubations per year. Emergency physicians manage all airways in our ED. Senior emergency medicine residents (postgraduate year 3 or higher) perform the majority of intubations under the supervision of the attending emergency physician. During the study period, there was no protocol for patients with difficult airways or angioedema.
Selection of Participants
Using the electronic medical record system (Epic Systems, Verona, WI), we identified all adults older than 17 years and with an ED or hospital diagnosis of angioedema ( International Classification of Diseases, Ninth Revision code 995.1) who underwent intubation in the ED between November 2007 and June 2015.
Methods of Measurement
We performed a structured review of resuscitation room videos recorded for each patient case. Critically ill or injured patients receive care in a 4-bay stabilization room. Each bay has 3 ceiling-mounted video cameras activated by motion sensors. Automated software combines the video streams with output from the patient cardiac and vital sign monitor, as well as audio recording of the room. The videos are stored on a secure database and are used for peer review and quality assurance purposes.
Both authors independently reviewed all selected videos, recording observations on a structured data collection form. Data points were defined by both investigators a priori, with refinement after review of the first 3 videos. One investigator (B.E.D.) recorded all data entry into Excel (version 14.0; Microsoft, Redmond, WA). Both investigators resolved discrepancies by consensus, including rereview of the relevant videos.
The medical record was used to identify patient demographics, ACE-inhibitor use, medications administered in the ED, and ED course before patient placement in the resuscitation bay.
Outcome Measures
Collected data included patient demographics, medications administered to facilitate intubation, the use of fiberoptic laryngoscopy before intubation, the course and methods of intubation, and complications of intubation. Elapsed times included time from ED arrival to start of intubation attempt, the duration of the first method, and time from the first attempt until successful intubation.
An intubation method was defined as the use of a single intubation approach (eg, blind nasal intubation, fiberoptic nasal intubation), without an intervening change to a different approach, regardless of the number of discrete attempts with that method. We defined the start of an airway attempt as the point at which the airway equipment (laryngoscope blade, oral intubating airway, endotracheal tube, or fiberoptic scope) entered the mouth or nose. We defined the end of an airway attempt as the point at which all airway equipment was removed from the patient, the method was changed (eg, from blind to fiberoptic nasal intubation), or the endotracheal tube was attached to a bag-valve device after successful intubation.
A patient was considered to have ACE inhibitor angioedema if the discharge summary stated that an ACE inhibitor was the most likely cause of angioedema. We were unable to assess the location and severity of angioedema because the overhead videos did not allow a detailed assessment of intraoral swelling, images from the video laryngoscopes were not routinely recorded, and descriptions in the medical record were not sufficiently detailed for most patients. Defined complications included hypoxemia (SpO 2 less than 90% and SpO 2 less than 90% for more than 60 seconds), esophageal intubation, epistaxis, vomiting, and hypotension (systolic blood pressure less than 90 mm Hg). Esophageal intubation was defined as advancement of the endotracheal tube into the esophagus with subsequent performance of bag-valve-mask ventilation before removal; if the endotracheal tube was passed into the esophagus during an attempt without bag-valve-mask ventilation, it was not considered to be an esophageal intubation. Epistaxis was defined as visible bleeding from either naris. We defined aspiration pneumonia as an infiltrate on chest radiography within 24 hours of admission that was believed by the treating physician to be a result of aspiration.
If a data point was unavailable or unclear from the video, it was considered to be missing for that subject.
Primary Data Analysis
We excluded all patients with missing videos. We analyzed the data with descriptive techniques. We used Stata (version 12.1; StataCorp, College Station, TX) for all data analyses.
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