A prospective descriptive study was conducted at Nikoukari Hospital - a teaching hospital located in Tabriz, Iran.
Our EMRs were trained in a skills lab on dummies and were then asked to bag-mask ventilate, and intubate patients in the operating room before and after an additional anesthesiology training program. They were asked to perform the procedures as part of their normal training program.
The anesthesiology curriculum had already been approved by our university for emergency residents as part of their residency program, which they were obliged to attend.
It should be mentioned that there is a mandatory one-month rotation in anesthesia during the first year of the EM residency (EMR-1). During this one month period, the EMR-1s learn airway management and perform orotracheal intubations on stable patients in the operating room.
Although our study was designed to describe the efficacy of the anesthesiology curriculum and it was not an interventional study; ethical approval was obtained. Furthermore, all the ED residents who took part in the curriculum were already qualified in bag-mask ventilation and orotracheal intubation, since they had already passed the required training courses in the Skills Laboratory and attained their certificates.
A total number of 18 EMR-1s received traditional instruction about orotracheal intubation and bag-mask ventilation in the skills lab, using mannequin-based simulators for a period of 36 hours. The training program in the skills lab included a course of theoretical instruction that EMR-1s received regarding orotracheal intubation and bag-mask ventilation. Power Point software and video-based methods were employed in the program. As hands-on training, the residents were then asked to bag-mask, ventilate, and intubate the mannequins for at least 20 times. The steps required in performing these procedures successfully were instructed by an attending anesthesiologist, who also dealt with the theoretical aspects. The theoretical and hands-on training portions in this 36-hour course were approximately equal. All of the participants passed a qualification exam.
As part of an anesthesiology rotation, the same group was trained in airway management in an operating room over a one-month period. During this period, EMR-1s received an extensive didactic review of airway management, simple airway maneuvers as well as bag-mask ventilation and orotracheal intubation. The rotation also included the basic skills of airway assessment, mask ventilation, orotracheal intubation and airway decision-making. In order to pass the curriculum successfully and as their hands-on training, the residents needed to bag-mask, ventilate and intubate at least 50 patients in the operating room.
In our research, the residents were asked to bag-mask, ventilate, and intubate 36 adult patients (18-52 year-olds) in the operating room both before and after the one-month anesthesiology rotation. Each resident performed both procedures on 2 patients.
The selected patients had Mallampati class I and ASA class I and II. The exclusion criteria were: 1 - presence of beard, 2 - edentulousness, 3 - facial anomalies, 4 - having a nasogastric tube, 5 - morbid obesity and a history of snoring. Patients undergoing elective ophthalmic surgery were aware of attending a teaching hospital and they willingly participated in this medical study.
Written informed consents were obtained from the patients before admission with an understanding that there would be students working on their cases as part of an ongoing experiment since Nikookari Hospital is a teaching hospital.
For all intubations, patients were connected to cardiac monitors, automated blood pressure monitors, pulse-oximeters and capnography monitors. An attending anesthesiologist supervised the procedures at all times.
All patients were hydrated preoperatively with Ringer's Lactate solution 10 mL.kg-1. After pre-oxygenation for 3 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).
When 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 3 L/min and the adjustable pressure limiting (APL) valve at 20 cm H2
O. A standard circle circuit and 2 L bags were used. In applying bag-mask ventilation tight mask seal and appropriate compression of the bag was taken into account [8
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 a total fresh gas flow of 3 L/min and an APL valve at 20 cm H2
O, bag-mask ventilation was considered to be successful as the primary outcome. If this was not achieved, it was then mandatory to use ancillary techniques to ensure adequate bag-mask ventilation. These techniques were defined as a secondary outcome and included the increasing of FGF to 6 L/min, closure of the APL valve to 30 cm H2
O, and use of the oxygen flush device and two-person technique (the resident using two hands to secure the mask while an assistant squeezing the bag) [9
After 3 minutes the trachea was intubated with an appropriate size orotracheal tube.
A successful orotracheal intubation was firstly confirmsed by direct laryngoscopy, secondly by chest rise and auscultation and finally by capnography. The intubation was also considered successful when it was performed on the first attempt and within 20 seconds. Intubation and bag-mask ventilation success rates were recorded by the supervising anesthesiologist. The time period needed for intubation was defined as the time from the cessation of bag-mask ventilation to the time of the confirmation of successful tracheal tube placement which was also recorded by the same supervising anesthesiologist [10
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 throughout the procedures. He had direct responsibility for all intubations performed in the operating room and had the discretion to determine which resident perform the ventilation and intubation and which method be used.
Success rates in both bag-mask ventilation and orotracheal intubation were recorded and compared both before and after anesthesiology rotation.
The data were analyzed using SPPS version 15. Nominal scale data were reported as absolute and relative frequency and continuous scale data were reported as mean ± SD. To detect differences between before and after education, data were analyzed by McNemar and marginal homogeneity tests for nominal variables. To compare continuous variables, paired t-test we used. P < 0.05 was considered to be statistically significant. The total census of the ED residents was included since the department was newly established and this made the sample size of the study rather small.