ORIGINAL ARTICLE
Two Hundred Sixty Pediatric Emergency Airway
Encounters by Air Transport Personnel
A Report of the Air Transport Emergency Airway Management
(NEAR VI: ‘‘A-TEAM’’) Project
William Wallace Tollefsen, MD,*Þþ Calvin A. Brown, III, MD,*§ Kelly L. Cox, MD,||
and Ron M. Walls, MD*§
Background: Effective airway management is the cornerstone of
resuscitative efforts for any critically ill or injured patient. The role and
safety of pediatric prehospital intubation is controversial, particularly
after prior research has shown varying degrees of intubation success.
We report a series of consecutive prehospital pediatric intubations performed by air-transport providers.
Methods: We retrospectively reviewed intubation flight records from
an 89-rotorcraft, multistate emergency flight service during the time
period from January 1, 2007, to December 31, 2009. All patients younger than 15 years were included in our analysis. We characterized patient, flight, and operator demographics; intubation methods; success
rates; rescue techniques; and adverse events with descriptive statistics.
We report proportions with 95% confidence intervals and differences
between groups with Fisher exact and W2 tests; P G 0.05 was considered
significant.
Results: Two hundred sixty pediatric intubations were performed
consisting of 88 medical (33.8%) and 172 trauma (66.2%) cases; 98.8%
(n = 257) underwent an orotracheal intubation attempt as the first
method. First-pass intubation success was 78.6% (n = 202), and intubation was ultimately successful in 95.7% (n = 246) of cases. Medical
and trauma intubations had similar success rates (98% vs 95%, Fisher
exact test P = 0.3412). There was no difference in intubation success
between age groups (W2 = 0.26, P = 0.88). Three patients were managed
primarily with an extraglottic device. Rescue techniques were used in
11 encounters (4.2%), all of which were successful. Cricothyrotomy
was performed twice, both successful.
Conclusions: Prehospital pediatric intubation performed by airtransport providers, using rapid sequence intubation protocols, is highly
successful. This effect on patient outcome requires further study.
Key Words: prehospital, helicopter, intubation
(Pediatr Emer Care 2013;29: 963Y968)
O
ut-of-hospital tracheal intubation is an accepted practice;
however, there is wide variability in tracheal intubation
performance by prehospital personnel. Prior research on paramedic intubation performance and patient outcomes after prehospital intubation has yielded mixed results.1Y6 Study in
From the *Department of Emergency Medicine, Brigham and Women’s
Hospital; †Harvard-Affiliated Emergency Medicine Residency;‡Department
of Emergency Medicine, University of Massachusetts, Worcester; §Division of
Emergency Medicine, Harvard Medical School, Boston, MA; and ||Department
of Emergency Medicine, University of Illinois, Peoria, IL.
Disclosure: Dr Cox is an employee of Air-Evac EMS, Inc. The other
authors declare no conflict of interest.
Reprints: William Wallace Tollefsen, MD, 75 Francis St, NH-236A,
Boston, MA 02115 (e-mail: [email protected]).
This study was supported by a research grant from Air-Evac EMS, Inc.
Copyright * 2013 by Lippincott Williams & Wilkins
ISSN: 0749-5161
Pediatric Emergency Care
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Volume 29, Number 9, September 2013
pediatric populations has demonstrated similar findings.7Y9 In
addition, some evidence suggests prehospital use of bag-valvemask ventilation may be equivalent to endotracheal intubation
for hypoxic and hypopneic children.9 Given this, some agencies are no longer including pediatric tracheal intubation as part
of a prehospital airway protocol. Difficulties with pediatric
prehospital intubations can stem from low intubation volume,
environmental constraints, anatomical variations with age, and
inadequate training. Adult intubation performance and patient
outcomes for helicopter emergency medical services (EMS)
providers have shown better results and improved survival
compared with ground personnel.6,10 Pediatric prehospital intubation in this select group of providers, however, has been
underreported. We report a consecutive series of pediatric intubations performed within an 89-rotorcraft, multistate transport system (Air-Evac EMS, Ltd) to characterize methods,
success rates, and rescue techniques when intubation is performed by flight paramedics and nurses, using rapid sequence
intubation (RSI) airway management protocols.
METHODS
Study Design
This is a retrospective analysis of consecutive intubations
performed by flight paramedics and nurses. Institutional review
board approval was obtained both at the University of IllinoisY
Peoria and at Brigham and Women’s Hospital (Harvard Medical
School) before analysis. Data analysis followed conventions
established for the National Emergency Airway Registry.
Setting
Intubations were performed by personnel from a large airmedical transport company (Air-Evac EMS), based in West
Plains, Mo. At the time of data collection, the company operated 89 long-range (206L) helicopters out of 85 air-medical
bases throughout the central part of the United States (Fig. 1).
Air-Evac transports to more than 1000 hospitals and records
an average of 26,000 flights per year including both interfacility transfers and on-scene flights. Most crews operate from
stations in rural settings and are not based out of urban or
academic medical centers. All providers underwent quarterly
training consisting of seminars on airway assessment, difficult airway management, and RSI under the instruction of regional medical directors. In addition, case-based skills sessions,
utilizing neonatal and pediatric METI ECS simulators, were
required that focused on intubation technique and difficult airway management. In addition, extraglottic device (EGD) and
needle cricothyrotomy techniques were practiced every 3 months.
Paramedics and flight nurses had an average of 12 years of
experience and performed more than 25 airway procedures
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FIGURE 1. Coverage May for Air-Evac EMS, Inc.
annually through a combination of field and simulated intubations. Pediatric airway management was guided by standard
intubation protocols that were reviewed and approved, annually,
by the senior medical director. Indications for prehospital pediatric intubation included oxygenation or ventilation failure,
inadequate airway protection, and predicted airway deterioration before or during transport. Protocols outlined the use of
pretreatment drugs, induction agents, and neuromuscular blockers for RSI, sedation-facilitated intubation, and algorithms for
crash and failed airway management. Accepted weight-based
drug doses were used during airway management.
Selection of Participants
All pediatric patients younger than 15 years who underwent at least 1 airway maneuver from January 1, 2007, to
December 31, 2009, were included in our analysis.
Methods of Measurement
Each encounter was categorized as either a medical or
trauma intubation based on the clinical and scene information. After an assessment by flight personnel and indications
for intubation were met, standard airway management protocols were followed. A difficult airway assessment was done,
whenever possible, by each operator before administration of
medication, and if appropriate for neuromuscular blockers,
RSI was performed. The operator evaluated mouth opening,
cervical spine mobility, mandible and tongue size, and location
of the thyroid cartilage before airway intervention. This approach has been used successfully to predict difficult direct
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laryngoscopy in emergency department patients.11 Orotracheal
RSI was performed by direct laryngoscopy if the airway was
not predicted to be difficult. An EGD (Combitube, Covidien,
Mansfield, MA, laryngeal mask airway [LMA], or laryngeal
tube) was used as the initial airway maneuver if the patient
was thought to be too difficult to safely receive neuromuscular blockade. Extraglottic devices placed as the first planned
method of airway control occurred with sedation only. Rare,
in-flight cardiopulmonary arrests with a crash airway were managed with immediate direct laryngoscopy, without RSI medications, followed by EGD placement if laryngoscopy failed. A
failed airway was defined in 2 ways: a failed intubation attempt in
combination with persistent hypoxia (oxygen saturation G90%)
despite maximal supplemental oxygen and assisted ventilations or
3 failed intubation attempts by the flight nurse or paramedic.12
Failed airways were managed with either an EGD (LMA, laryngeal tube, or Combitube), continued bag-mask ventilation, or
surgical airway if the patient could not be intubated or ventilated
by other means. Malleable stylets were used routinely. Video laryngoscopes were not available. The operator completed a contemporaneous electronic flight record and standardized intubation
report following each intubation. Procedural entries for intubation
had a demand function on the electronic flight record and could
not be skipped. Recorded variables included patient age, sex, estimated weight, flight classification, protocol and drugs used,
initial airway management maneuver, number of intubation attempts, intubation success, and use of rescue devices. An intubation attempt was defined as insertion of any laryngoscope blade
with passage of an endotracheal tube beyond the patient’s lips.
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Pediatric Emergency Care
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Volume 29, Number 9, September 2013
Pediatric Air Transport Intubations
FIGURE 2. Breakdown of airway management encounters.
Confirmation of endotracheal tube placement was done by auscultation and colorimetric end-tidal CO2 detection. Successful
endotracheal intubation was defined by tube passage, resulting in chest rise and color change on a qualitative end-tidal CO2
detector. Vital signs were noted to be ‘‘stable’’ or ‘‘unstable’’ both
before and after intubation, but specific values were not recorded
in the registry. Intubation reports were monitored for completeness by each regional medical director with a reporting compliance of 100%.
Data Collection and Processing
During or immediately after each flight, operators recorded all intubation details onto a structured data form. Data
were reviewed for completeness and entered by the medical
director and nurse educator into the company’s main database
(SQL database; Microsoft Access, Redmond, Wash). Data were
then imported into a spreadsheet (Microsoft Excel, Redmond,
Wash) for analysis. Structured queries were performed to retrieve relevant data with regard to intubation method, success,
attempts, rescue techniques, and the use of surgical airways.
were head injury (n = 64) and seizure (n = 26), respectively.
The mean patient age was 7.33 years. One hundred three
(39.6%) were female, and 157 (60.4%) were male.
Figure 2 depicts methods chosen, failed intubation encounters, and the rescue methods used; 98.8% (n = 257) of
the 260 patients underwent an orotracheal intubation attempt
as the first method, all using RSI. Intubation was successful on
first attempt 78.6% (n = 202) of the time and was ultimately
successful in 95.7% (n = 246) of patients. Of successful intubations, 95.9% (n = 236) were completed in 2 or fewer attempts (Fig. 3). There was no difference in intubation success
between medical and trauma patients (98% vs 95%, Fisher exact test P = 0.3412). In addition, there was no difference in intubation success between patients in age groups 0 to 2, 3 to 7,
and 8 to 14 years (W2 = 0.26, P = 0.88). Age-stratified success
rates are presented in Table 1. Three patients (1.1%) were
managed primarily with an EGD as the first method chosen
without an antecedent intubation attempt; all were successfully
Primary Data Analysis
We present descriptive data and Fisher exact and W2 tests
for binary comparisons, with P G 0.05 considered significant.
We performed all analyses with SAS 9.12 (SAS Institute,
Cary, NC).
RESULTS
During the 3-year study period, 4871 intubations were
performed within the Air-Evac system including 260 pediatric
intubations. Of pediatric intubations, 88 (33.8%) were performed for medical indications, and 172 (66.2%) were for
trauma. The most common indications for pediatric intubation
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FIGURE 3. Success rate per attempt number.
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TABLE 1. Success by Age Group
Age
0Y2 y
3Y7 y
8Y14 y
Total
Success
Yes
Success
No
Success
Rate
Total
53
78
115
246
2
3
6
11
96.4%
96.3%
95.0%
95.7%
55
81
121
257
oxygenated. Eleven patients were not successfully intubated.
Of these, 7 were successfully managed with an LMA and 2
with a Combitube. Rescue cricothyrotomy was performed in
2 patients, aged 2 (needle cricothyrotomy) and 14 years (open
[surgical] cricothyrotomy). Both were successful. There were
no reports of a patient death due to a failed airway.
DISCUSSION
Out-of-hospital airway management remains a necessary
lifesaving procedure for critically ill and injured children, yet
heterogeneous results regarding prehospital intubations, the
paucity of prehospital pediatric intubation literature, and the
feasibility of prolonged bag-and-mask ventilation in lieu of
tracheal intubation leave the extent of prehospital pediatric airway management up for debate.9 Tracheal intubation is a highrisk procedure that requires specialized training, practice,
knowledge of airway anatomy, human physiology, pharmacology, and plans for rescue should intubation fail. Even gardenvariety intubations represent a high-risk situation for every
patient, especially when neuromuscular blockade is used. Airmedical teams often take care of the most severely compromised pediatric patients for whom expert airway management
may have a direct impact on outcome.7Y9,13,14 For our group of
operators, prehospital pediatric airway management is most often
accomplished with tracheal intubation by direct laryngoscopy
using RSI, showing acceptable first-pass success rates and high
ultimate success rates. Air-medical intubation success rates in
studies including both adult and pediatric patients, using RSI
protocols, have demonstrated intubation success rates as high as
95%.15Y20 Our study showing 95.7% success confirms these
findings and suggests it extends to pediatric populations. Performance may be typical of other air-medical programs with similar operator characteristics.
Significant anatomic differences exists among patients
younger than 3 years. This can make intubation more challenging for neonates and very young children. Subgroup analysis of children aged 0 to 2, 3 to 7, and 8 to 14 years showed
similar intubation success rates. Although our number of failed
intubations is small, rescue methods, including placement of
EGDs and surgical airway techniques, were successful 100%
of the time.
Early investigations of out-of-hospital pediatric intubation
success by ground providers have shown varying results, but
as many as 43% of prehospital intubations may be unsuccessful.21 This inconsistency has many contributing factors but has
been linked, in part, to minimal airway management requirements for paramedic certification and skill degradation because
of infrequent field intubations.22,23 Procedural accomplishment is associated with repetition, and paramedics in highvolume settings or those with greater access to simulation or
operating room experience have shown higher rates of intubation success.24 The baseline skill set of intubators in our
study was high. Air-Evac provides an extensive airway training
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program for new employees and maintains skills through regular
training sessions, all with strict oversight by regional medical directors. In our study group, the average paramedic and flight
nurse had more airway management experience than what is
typically seen for ground paramedics.23 Like other rarely performed, high-risk procedures, experience and simulation training are likely going to play a prominent role in maintaining
skills.25Y30 Our findings suggest that prehospital providers, when
provided adequate intubation experience supplemented by simulation training, are highly skilled and successful with emergency
airway management in pediatric populations. This has implications for all EMS companies as they evaluate ongoing paramedic education and skills maintenance.
Eleven patients (4.2%) were not intubated and required
rescue airway maneuvers. Although this number is small, any
failed airway is concerning, given the possibility of prolonged
hypoxia. In our study, all patients except 2 had successful rescue with an EGD, most commonly an LMA. Surgical airways
were performed successfully on the remaining 2 patients. These
findings indicate that backup management plans can be enacted efficiently and successfully in our study group. Introduction of video laryngoscopy for pediatric intubation in this
system might further help to reduce the failure rate to zero,
the desired level.
LIMITATIONS
Our study has some important limitations. First, these intubations were performed by advanced paramedics and flight
nurses within a high-volume air-transport company, and our
results represent what operators with a similar training and intubation volume might achieve. These results may not be generalizable to traditional paramedics working in other settings
or with lower annual intubation volume. Second, self-reported
data have intrinsic limitations, and underreporting of poorly
performed intubations including those with multiple failed attempts and adverse events is possible. Close compliance monitoring by regional medical directors and mandatory reporting
fields for intubation in the electronic flight record limits the
possibility of selective reporting. The structured data form was
originally designed for internal, administrative purposes and
was not created with a developed research protocol in mind.
This has introduced nonstandard definitions and variables into
our data pool and has limited our ability to perform certain
analyses. For future studies, operational definitions can be clarified during prospective collection. First, the definition used
for tracheal intubation attempt required insertion of a tracheal
tube while the most widely used definition of intubation attempt simply requires insertion of the laryngoscope blade beyond the teeth. Therefore, it is impossible to tell whether the
patients we reported as being primarily managed with an EGD
as the first airway maneuver actually had a direct laryngoscopic attempt first. This would bias our results toward better
first-pass intubation success. However, because that number
was small (n = 3), success outcomes would have remained virtually unchanged. In addition, many data points that would have
added and additional level of understanding were not collected.
Vital signs surrounding intubation were noted to be ‘‘stable’’
or ‘‘not stable,’’ but specific values were not recorded. We also
cannot make comparisons stratified by the medications used.
With the exception of pretreatment agents, medications used
during intubation were documented in the registry as drug
classes instead of specific agents. In other words, if RSI was
performed, then succinylcholine or rocuronium could have been
used at standard doses and that would have been an acceptable
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Pediatric Emergency Care
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Volume 29, Number 9, September 2013
entry for ‘‘paralytic used’’ without knowing which agent was
administered. Finally, prehospital airway studies often use destination tube confirmation as a measure of validating successful
tracheal intubation. This was not recorded, and therefore an
overestimation of intubation success within our sample is
possible.31Y34 All tubes, however, were verified with end-tidal
CO2 detection, in addition to auscultation and observation of
chest rise. In addition, waveform capnography was a routine
part of the postintubation care during transport, making the
chance of an unrecognized misplaced tube very low. There were
no reports of patient death due to a failed airway. Patients
intubated by Air-Evac personnel but not flown because of instability or ongoing cardiopulmonary resuscitation in the field
were not included in our analysis because a transport flight record was not generated for these encounters. Certainly, this
population had poor outcomes, and some may have died as a
result of failed airway management. Although this is possible,
the likelihood that this number is large enough to have a
meaningful impact on overall success is small. Nevertheless,
this biases our findings toward better performance.
This group of advanced-level providers underwent advanced simulation airway training multiple times per year as
part of routine competency checks, and the effect this extra
training has on final performance above that obtained from reallife experience is difficult to gauge. Finally, patients were not
followed longitudinally in the hospital, and final functional or
survival outcomes were not recorded. How our results translate
to patient survival and neurologic function requires further
study.
CONCLUSIONS
In this high-volume air-transport agency, skilled prehospital providers, using RSI protocols, exhibited high pediatric
intubation success rates, modest first-pass success rates, and
successful application of rescue methods including use of
EGDs and surgical techniques. These data may be used to better define performance standards for air-medical providers performing pediatric tracheal intubation.
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