The role of an Anesthesiology curriculum at improving bagmask ventilation and intubation success rates of Emergency
Medicine residents: A prospective descriptive study
Hassan Soleimanpour1§, Changiz Gholipouri2*, Jafar Rahimi Panahi3*, Rouzbeh
Rajaei Ghafouri4*, Robab Mehdizadeh Esfanjani 5*.
§
1 . Corresponding author : Assistant professor of Anesthesiology, MD. Emergency Medicine Department, Tabriz
University of Medical Sciences, Daneshgah Street, Tabriz-51664, I.R Iran.
Tel: +989141164134 Fax:+984113352078 Email: h_mofid1357@yahoo.com or h.soleimanpour@gmail.com
2*. Associate professor of Surgery, MD. Emergency Medicine Department, Tabriz University of Medical Sciences,
Iran.
Email: c_gholipour@yahoo.com
3*. Associate professor of Anesthesiology, MD. Anesthesiology Department, Tabriz University of Medical
Sciences, Iran.
Email: jrjafar72@gmail.com
4*. Resident of Emergency medicine, MD (PGY3). Emergency Medicine Department ,Tabriz University of
Medical Sciences, Iran.
Email: Rozbehrajaei@yahoo.com
5*. MSc St1, Department of Statistics, Tehran North Branch, Islamic Azad University, Tehran, Iran.
Email: mehdizadeh18@yahoo.com
§
Corresponding author
*These authors contributed equally to this work
Abstract
Background: Rapid and safe airway management is paramount to the successful
management of critically ill and injured patients in the emergency department. The
purpose of our study was to determine success rates of bag-mask ventilation and
tracheal intubations performed by emergency medicine residents, before and after an
anesthesiology curriculum.
Methods: A prospective descriptive study was conducted at Nikoukari Hospital, a
teaching hospital in Tabriz, Iran. A total of 18 emergency medicine residents (Post
Graduate Year 1) received traditional intubation and bag-mask ventilation instruction
for 36 hours, as well as mannequin practice, in a skill lab. Then the same group
trained in airway management in an operating room for 1 month, part of an
Anesthesiology curriculum. Residents were asked to ventilate and intubate 18 patients
(Mallampati class I and ASA class I and II) in the operating room, before and after
this curriculum. The intubation was considered to be successful when it occurred on
the first attempt within 20 seconds. Successful bag-mask ventilation was defined by
an increase in ETCo2 to 20 mm Hg and back to baseline with 3 L/min fresh gas flow
and the adjustable pressure limiting valve at 20 cm H2O. An attending
Anesthesiologist confirmed the endotracheal intubation by direct laryngoscopy and
capnography and was always present in the operating room during the induction of
anesthesia. Success rates were recorded and compared by using McNemar test in
SPSS 15.
Results: Before educational intervention in operating room, the participants had an
intubation success rate of 27.7% (CI 0.07- 0.49) and the successful bag-mask
ventilation was 16.6% (CI 0-0.34). After educational intervention in operating room
Residents had an intubation success rate of 83.3% (CI 0.66-1) and successful bagmask ventilation was 88.8% (CI 0.73-1). The difference in intubation success rates
and successful bag-mask ventilation before and after intervention were statistically
significant, (P= 0.002 and P=0.0004 respectively).
Conclusions: Emergency medicine residents’ success rate in airway management
improved significantly after completing an Anesthesiology rotation, Anesthesiology
rotations should be an essential component for emergency medicine training programs
and such collateral curriculums should focus on the acquisition of skills in airway
management.
Key words: Education, Curriculum, Anesthesiology, Emergency Medicine
Background: Emergency Medicine is a complex and dynamic specialty that has
many interfaces, both in practice and in skills with other specialty areas. Rapid and
safe control of the airway is paramount to the successful management of critically ill
and injured patients in the Emergency Department (ED).
Effective airway management is the central part of emergency resuscitation and
many see it as an undisputable core skill for emergency physicians (EPs).1 However,
an early study on ED intubations reported an alarmingly high complication rate for
endotracheal intubations.2
Trainees must be taught the assessment and airway management of a critically ill
patient. This includes decision making and accepting responsibility.3
In recognition of this, the Emergency Medicine Faculty have identified that all EPs
will need to acquire the necessary skills to manage a patient’s airway for the initial 30
minutes after admission. In some instances this will require the administration of
drugs to facilitate tracheal intubation safely.3
Finally, it is important not to try to turn EPs into anesthetists, but instead equip them
with the skills they need for their own environment and the problems they face.4
The current basic skills, listed in trainees’ logbooks are insufficient. All of this must
mean closer cooperation between the two emergency medicine and anesthesiology
specialties, starting at collegiate and extending down to departmental level.3
As concurrent failure of tracheal intubation and mask ventilation may ultimately
result in death or brain damage, these two basic techniques are the most important that
an anesthetist learns. Instead of learning the use of a simple face mask and tracheal
tube, today’s trainee is faced with an ever increasing number of airway devices and
techniques.5
Although there are numerous opportunities to learn outside the operating theatre,
airway management trainees must be given the opportunity to practice maneuvers in a
controlled setting.
An Anesthesiology rotation is an important component of Emergency Medicine
training that should focus on the acquisition of airway skills. Consideration should be
given to the development of a set of specific objectives to assist planning training
programs and monitoring progress.6
For the past 25 years, higher specialist trainees in Accident and Emergency
Medicine in the United Kingdom (UK) have been required to complete a minimum
three month secondment in anesthesia and intensive care. In the early days of training
in Accident and Emergency Medicine, the goal was to orient trainees who were
predominantly from medical and surgical backgrounds to the concepts of anesthesia
and specifically to train them in basic and advanced airway management skills.7
The most important places for anesthetic training are the ward, the operating theatre
and the intensive care unit, not the classroom and the library. The influence of clinical
teachers as role models for students cannot be underestimated.8
Good anesthesia teachers combine enthusiasm, willingness to teach and an "inquiry"
approach.9
Graham has described the training requirements for higher specialist trainees in
Emergency Medicine (box 1).7
Although trainees have an opportunity for the development of specific learning
objectives for airway management during this period in the skill lab and operating
room, our research is based on two most important skills in airway management.
The aim of this study was to determine success rates of bag-mask ventilation and
tracheal intubation performed by Emergency Medicine residents, before and after an
Anesthesiology curriculum.
Methods: A prospective descriptive study was conducted at Nikoukari Hospital, a
teaching hospital in Tabriz, Iran.
Our emergency medicine residents were trained in a skills lab on dummies and were
then asked to bag mask ventilate and intubate patients in operating room before and
after an anesthesiology training program. They asked to perform the procedure as
part of their normal training program.
There is a mandatory 1-month rotation in Anesthesia during the first year of the
Emergency Medicine residency (EMR-1). During this month, the EMR-1s learn
airway management and perform intubations on stable patients in the operating room.
Anesthesiology curriculum had been approved in our university for emergency
residents during their residency program and they must attend in this rotation.
Furthermore all the ED residents who take part curriculum are eligible for bag-mask
ventilation and endotracheal intubation, since they already passed necessary training
in skill lab and got certificate.
In this study, a total of 18 EMR-1s received traditional instruction about orotracheal
intubation and bag-mask ventilation in the Skill Laboratory (Skill Lab), using
mannequin-based simulators, for a 36-hour period. The training program in skill lab
includes a period of theoretical instruction that EMR-1s received training in
orotracheal intubation and bag-mask ventilation, using Power Point software and
video-based training. The residents were then asked to bag-mask ventilate and
intubate the mannequins for at least 20 times, as hand-on training. The movements
required to successfully perform these procedures were instructed by an attending
anesthesiologist, as well as theoretical instruction. The theoretical and hand-on
training portions in this 30-hours course were approximately equal. All of participants
passed a certification exam.
Then the same group trained in airway management in operating room for a 1-month
period, as part of an anesthesiology rotation. During this period, EMR-1s received an
extensive didactic review of airway management, simple airway maneuvers, bagvalve–mask ventilation and oral intubation. The rotation also include the basic skills
of airway assessment, mask ventilation, tracheal intubation and airway decision
making.
They were asked to bag-mask ventilate and intubate 36 adult patients (18-52 years
old) in operating room, before and after this 1-month anesthesiology rotation. Every
resident performed both procedures on 2 patients.
The selected patients had Mallampati class I and ASA class I and II. The exclusion
criteria were: presence of beard, lack of teeth, facial anomalies, having a nasogastric
tube, morbid obesity and a history of snoring. These patients presented to operating
room for elective ophthalmic surgery. Our patients were aware that they are present in
a teaching hospital where the study was performing and they asked for consent before
admitting. On the other hand, because of our study has been designed for description
efficacy of anesthesiology curriculum and we did not do any intervention on the
routine training program; ethical approval was not required for our study.
For all intubations, patients were connected to a cardiac monitor, an automated blood
pressure monitor, pulse-oximeter and capnography. An attending anesthesiologist
supervised the process all of the time.
All patients were hydrated preoperatively with Ringer's Lactate solution 10 mL.kg-1.
After pre-oxygenation for three minutes and premedication with midazolam 0.02
mg.kg-1 and fentanyl 1.0 µg.kg-1, anesthesia was induced with propofol (2 mg.kg-1)
and atracurium (0.5 mg/kg).
Once the patients became unconscious, as judged by loss of response to command
and loss of eyelash reflex, mask ventilation was initiated.
The total fresh gas flow (FGF) on the anesthetic machine was set at 3L/min and the
adjustable pressure limiting (APL) valve at 20 cm H2o. A standard circle circuit and 2
L bag were used.
Achieving adequate tidal volume with bag-mask ventilation requires a tight mask
seal and appropriate compression of the bag.10
The end point for successful bag–mask ventilation was defined as an ETco2 trace
increasing to 20 mm Hg and back to baseline. If this was achieved at total fresh gas
flow of 3 L/min and APL valve at 20 cm H2o, bag–mask ventilation was considered to
be successful as the primary outcome. If it was not achieved, a protocol was followed
to ensure adequate bag–mask ventilation. This protocol that was defined as a
secondary outcome included increasing the FGF to 6 L/min, closure the APL valve to
30 cm H2o, use of the oxygen flush device and use of a two-person technique
(resident uses 2 hands to secure the mask while an assistant squeezes the bag).11
After 3 minutes the trachea was intubated with an appropriate endotracheal tube. An
intubation attempt was defined as placement of the laryngoscope into the patient’s
mouth, even if no attempt was made to pass an endotracheal tube.12
The intubation was considered to be successful when was completed on the first
attempt and within 20 seconds. This time starts when the blade was placed in the
mouth and end of procedure was considered when the balloon was inflated. When the
time exceeded 20 seconds, the procedure was aborted and intubation was performed
by the supervising anesthesiologist.
The same attending anesthesiologist was always present in the operating room
during the procedures. He has direct responsibility for all intubations performed in the
operating room and has the discretion to determine which resident performs the
ventilation and intubation and how the method was used.
To confirm tracheal intubation, direct laryngoscopy by the attending anesthesiologist
and a capnography (end-tidal carbon dioxide monitor) were used in all instances,
along with inspection and auscultation of the chest and epigastrium immediately after
intubation. He also recorded the time and success rate of intubation and successful
bag-mask ventilation.
Success rates in both bag-mask ventilation and endotracheal intubation were
recorded and compared before and after anesthesiology rotation.
The results were analyzed using SPSS 15 and compared by using McNemar and
marginal homogeneity test.
Results: There were 18 EMR-1s who performed both bag-mask ventilation and
endotracheal intubation on 36 patients at the start and end of the anesthesiology
rotation. All of patients were male with mean age of 37. Before the anesthesiology
rotation the participants had successful bag-mask ventilation rate of 6 of 36 (95%
confidence interval= 0% – 34%) and intubation success rate of 10 of 36 (95%
confidence interval = 7% – 49%). After the rotation, successful bag-mask ventilation
had been reported in 32 of 36 cases (95% confidence interval= 73% –100%) and
successful intubation in 30 of 36 (95% confidence interval= 66% – 100%) cases
(Figures 1&2).
The difference in successful bag-mask ventilation and endotracheal intubation before
and after the rotation were statistically significant, P=0.0004 and P=0.002
respectively.
Thirty of 36 residents, who were unsuccessful in bag-mask ventilation, had to ensure
adequate ventilation by using ancillary techniques. The failure numbers decreased to
only 4 after intervention (Tables 1&2). The use of ancillary techniques to produce
adequate bag-mask ventilation was reduced after the Anesthesiology rotation and
there was a statistically significant difference before and after the rotation (P= 0.001).
The average time spent for successful endotracheal intubation was 18.6 ± 1.67
seconds before the Anesthesiology rotation. This value decreased to 13.6 ± 1.34
seconds at the end of the rotation in the same group (P= 0.043).
Discussion: With the development of emergency medicine as a recognized medical
specialty, emergency airway management has become an essential skill for
emergency physicians. There has been remarkably little literature describing the
airway management skills of emergency physicians. We undertook this study to
determine the role of a 1-month anesthesiology rotation at improving EMR-1s airway
management skills. The only set of specific objectives for an anesthesiology rotation
by an emergency medicine trainee has been published with reference to training in the
United States of America.13
Assessment of the airway constitutes one of the most important aspects of airway
management. It is unclear what constitutes an acceptable minimum training in airway
assessment. Reports of management of the difficult airway consistently refer to the
difficulties of its predicting it despite using multiple accepted methods of assessment.
It is obviously important to recognize signs of a potentially difficult intubation early
in resuscitation, but the emergency physician must remain aware that unexpected
difficulties with intubation will occasionally occur.7
Amarasinghe et al have identified the core components of an Anesthesiology
curriculum for emergency medicine trainees. They collected and ranked the skills
judged to be most useful on an Anesthesiology rotation. The results demonstrated that
the most important skills to be learned on an Anesthesiology rotation are orotracheal
intubation, bag–mask ventilation, jaw thrust/chin lift maneuver and use of oral and
nasal airways.6
According to the results of Amarasinghe’s study, our research focused on
assessment of the two most important and highly useful airway management skills,
bag-mask ventilation and orotracheal intubation.
Our study showed that residents, who received traditional instruction about airway
management in the skills lab, using mannequin-based simulators, could not manage
the patient airway ideally. They had difficulties ventilating and intubating patients
with relatively easy airways in the operating room setting, although all of participants
passed a certification exam. Because of significant acquisition of airway management
skills after human-based instruction, we believe it is necessary to use this method in
addition to traditional mannequin-based training.
It has recently been suggested that future training of United Kingdom emergency
medicine specialists should include a one year anesthesia and critical care rotation,
involving six months of full time anesthesia followed by six months of full time
critical care.14 Another study showed that the Anesthesiology rotation is an essential
part of Emergency Medicine training and that the optimal duration is approximately 6
months, preferably in the first two years of advanced training.6
It seems that, despite the rotation’s efficacy on acquisition of airway management
skills, its length in our department may not be enough and should be extended. It will
also be important in the future to carefully study the effects of increased length and
quality of training for emergency physicians on the success and failure rates for
airway management in the Emergency Department (ED) as performed by residents.
It must also be remembered that the acquisition of anesthesiology-related knowledge
and skills is not confined to an anesthesiology rotation. In fact, many of these may be
learned better in other settings. For example, the pharmacology knowledge related to
this area is an important part of the primary examination curriculum. Intubation of
trauma and unstable patients may be best learned in the Emergency Department (ED)
under appropriate supervision, because these patients are different from those
encountered in elective anesthetic practice.6
It is widely accepted that endotracheal intubation in the emergency room is
significantly more hazardous and associated with an increased rate of difficult
intubation and failed intubation than that in the operating room.15
A difficult airway is not uncommon in the emergency setting. There is no specific
training program in the curriculum for trainees to develop difficult airway
management skills.
Maintenance of skills in emergency airway management is also a subject of
considerable debate presently. There is no objective scientific data to support a
minimum requirement of numbers of emergency or rapid sequence intubations (RSI)
to be performed by emergency physicians (or indeed Anesthetists) to maintain
competency in this area.
The figures from the Trauma Audit Research Network suggest a maximum of
approximately 6 RSIs per month, per department (based on an average of 68,000
patients per year), which, if staffed by four consultants in emergency medicine, will
equate to 1–2 RSIs per consultant per month. The Scottish Trauma Audit Group data
also suggest that the individual consultant in emergency medicine would be likely to
be involved in two to three RSIs per month.7 Due to the presence of a large number of
patients to our ED (near 6000 patients each month); the individual skills maintenance
will not be difficult for the practicing residents in emergency medicine.
This study has some limitations that should be considered when interpreting the
results. Our sample size was small and suboptimal. Further prospective studies are
needed to be done in larger sizes to validate the role of such rotations.
Another limitation of this study is that complications were not assessed. There is
certainly the potential for selection bias that could be responsible for the differences
noted in these rates. Also, study was held on patients with relatively easy airways,
raising the possibility that the results are not generalizable.
Other limitations:

Single site

Small number of participants at a single site

Results are not completely unpredictable given the instruction was 30 hours
vs. 1 month

Do not know who many raters there were, or whether there was strong
interpreter reliability

No control group
We did not determine adequate numbers of attempts to achieve reasonably consistent
skills in bag-mask ventilation or endotracheal intubation.
In the US, several studies have reported on the requirements and experience of their
residents in Emergency Medicine. Although it is difficult to be clear on exact numbers
and accepting that there will always be variations between people, it would seem that
novice anesthesiology residents require 80 or more intubations to achieve reasonably
consistent skills in endotracheal intubation.7
Hayden and Panacek reported that the mean number of intubations per trainee was
75 (95% confidence intervals 62 to 87); this is over a three year residency in
emergency medicine in a US setting.16
More studies should be carried out to determine the number of endotracheal
intubations required to achieve an acceptable level of procedural competency.
Conclusions: Since, Emergency Medicine residents’ success rate in airway
management improved after rotating on an anesthesiology rotation; anesthesiology
rotations should be a mandatory component of Emergency Medicine training
programs. We believe that a standardized theoretical instruction program in
combination with a practical anesthesiology rotation improves the skills of airway
management in Emergency Medicine residents. Airway management training is a
continuous process that should begin with theoretical instruction, continue in the skills
lab and operating theatre and end in the ED. All of the above mentioned steps should
be supervised by attending of Anesthesiology and/or Emergency Medicine.
Competing interests
The author(s) declare that they have no competing interests.
Authors' contributions
The authors were involved in patient management or writing of the manuscript.
Acknowledgements
We thank Dr.Terry Kowalenko, MD, Clinical Associate Professor, Department of
Emergency Medicine ,University of Michigan. Actually, We don’t know how we
could express our deep gratitude because of her comment on our paper. They were
very instructive and helpful for us. We will be deeply and always proud to remind
having her guidance in scientific issues as well as in research ethics.
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