Exploration of Partial Task and Variable Priority Training for Anesthesia Residents to Improve Management of Adverse Respiratory Events: Preliminary Results

Introduction: Part task training (PTT) focuses on dividing complex tasks into small components followed by intensive, concentrated training on each individual component. The goal of PTT is to reduce the magnitude of processing demands when performing multiple complex tasks simultaneously by developing levels of automaticity. Variable priority training (VPT) focuses on optimal distribution of attention when performing multiple tasks simultaneously. The goal of VPT is to allow resource allocation to be priority driven. The aim of this study was to explore how PTT and VPT implemented over a twelve month period would improve first year anesthesiology residents’ management of simulated adverse respiratory events when compared to conventional training methods. We hypothesized that participants with PTT and VPT would complete more critical evaluation and treatment tasks for simulated adverse respiratory events than those with standard training.

Methods: Ten first year University of Utah anesthesia residents were enrolled and randomly assigned to two groups. Residents in the control group received conventional didactic and simulation training, which included five 90 minute simulation sessions and forty 45 minute “grand rounds” didactic sessions throughout the year in addition to clinical training in the operating room. Residents in the experimental group received five 90 minute simulation sessions that emphasized VPT, fifteen 45 minute didactic PTT sessions and twenty-five 45 minute traditional “grand rounds” didactic part-task training sessions in addition to clinical training in the OR. Students were assessed for competency on the management of adverse respiratory events prior to and after the twelve month training period. Six simulations, three adult and three pediatric were used to test the participants before and after training (See Table 1). The order of simulations administered to the participant were randomized. During each simulation, investigators observed the simulations via a video feed and completed case report forms (e.g., Table 2) that indicated the time in which monitoring and treatment tasks were completed by the resident. After each simulation, the resident answered questionnaires, including a NASA-TLX self-assessment of workload.

Noah Syroid, Diane Tyler, Lazarre Ogden, Jlia White, Frank Drews, David Strayer, Wesley Mortensen, Micheal Malan, Eddie Lu, Joshua Larsen, Jason Poulson, Santosh Balakrishnan, Srinath Lingutla, Dwayne Westenskow, Ken Johnson

Departments of Anesthesiology, Cognitive Psychology, and Biomedical Engineering. University of Utah School of Medicine, SLC, UT

Table 2: Example case report form for Adult Scenario 2a (bronchospasm), which was completed by study investigators.

Table 1: Description of simulated scenarios used to assess the effects of PTT and VPT.

Scenario Description

Adult 1 (A1)

A 50 year old 5’10” 100kg female presents for an elective laparoscopic cholecystectomy. The critical problem is an unanticipated difficult airway following induction. The subject will play the role of the attending anesthesiologist. There will be a resident anesthesiologist. Following an intravenous induction, mask ventilation will be possible, but difficult allowing enough ventilation to keep the pulse oximeter reading between 85 and 88%. Intubation will be impossible. After laryngoscopy and failed intubation, the anesthesia resident will ask to be excused. If not ventilated, the patient’s pulse oximeter reading will drop to 70%.

Adult 2(A2a,b)

A 40 year old 6’3” 100kg male is under general anesthesia for repair of a left distal tibia and fibula fracture that he sustained in skiing accident four days ago. This simulation has two life threatening critical problems. The first is a bronchospasm (Scenario A2a) that occurs following extubation and emergence and the second is the development of a pneumothorax (Scenario A2b) following re-intubation. In this scenario, the subject will be asked to wake the patient up after surgery and extubate the patient. Following extubation, the patient will begin to cough, hemoglobin oxygenation will rapidly decline, and mask ventilation will be difficult. He will require aggressive treatment of his bronchospasm that will include re-intubation. Once reintubated, the patient will develop a left sided pneumothorax

Adult 3(A3)

A 77 year old 5’10” 65kg male presents for a cardioversion. The critical problem is aspiration following an intravenous induction. In this scenario, the subject will be asked to perform an intravenous sedation for a cardioversion in an elderly patient with multiple medical problems. Following sedation, the patient will vomit and aspirate non particulate emesis and develop hypoxia. The patient will require aggressive ventilation therapy and other adjuncts to restore hemoglobin oxygenation

Peds 1(P1)

A 7 year old 3’6” 22 kg male presents for an eye exam under anesthesia. The critical problem is an esophageal intubation in a pediatric patient. The subject will play the role of the attending and an actor will play the role of the anesthesia resident. The child will start out crying. A mask induction will be planned. The resident will induce with sevoflurane. The anesthesia resident will place the endotracheal tube in the esophagus and claim that he saw it go through the cords and place the patient on the ventilator. The anesthesia resident will then complain of severe light headedness and leave the scenario. Following induction, the patient’s hemoglobin oxygenation will rapidly decline of not ventilated. The patient will require endotracheal intubation to restore hemoglobin oxygenation.

Peds 2(P2)

A 9 year old 3’0” 20kg male presents for an elective tonsillectomy for recurrent streptococcal throat infections. The critical problem is the development of a laryngospasm and bronchospasm during a mask induction with sevoflurane. The subject will play the role of the anesthesia attending. An anesthesia resident will be present. The child will start out crying. A mask induction will be performed by the anesthesia resident. The resident will induce with sevoflurane while the circulating nurse will attempt to place an intravenous line. Intravenous line placement will be unsuccessful. The resident will become faint and need to leave the room, leaving the study subject to finish the induction. During induction, the patient’s hemoglobin oxygenation will rapidly decline. The bronchospasm will persist despite intubation and require additional therapy to break.

Peds 3(P3)

An 8 year old 4’0” 42 kg male presents for an appendectomy. The critical problem is inadequate ventilation because of faulty ventilator circuit tubing. In this scenario, the subject will be the anesthesia attending. An actor will be the anesthesia resident. The anesthesia resident will induce with mask sevoflurane. The circulating nurse will place the IV. Once the IV is in, the anesthesia resident will ask the subject to administer mivacurium (6 mg or 3 ml). Following induction, the anesthesia resident will state that he feels light headed and is worried he will pass out. He will then leave the scenario. Following induction, the patient’s hemoglobin oxygenation will rapidly decline. He will require aggressive ventilation to restore hemoglobin oxygenation.

Results: A repeated measures ANOVA indicated no main effect of training (VPT/PTT) with regard to managing the simulated adverse respiratory events. One-tailed t-tests indicate that the adult difficult airway (t=1.9, df=7, p<0.05) and bronchospasm simulations (t=2.0, df=7, p=0.05) were statistically significant and trending towards significance respectively with regard to the change in the number of tasks completed from pre-training to post-training assessment (Figure 1).  In addition, when investigating only the post-training results, bronchospasm was also significant (t=2.15, df =7, p<0.05, see Figure 2). Figure 3 summarizes the results of the NASA-TLX, collapsed across all scenarios.

Discussion: The preliminary results indicate that resident curriculum that incorporates PTT and VPT as part of their education may be able to complete a greater number of relevant monitoring and treatment tasks when managing simulated adverse respiratory events. A second year of study with additional first-year residents is required to better elucidate the effects of PTT and VPT.  

Critical Time Points (Segment One): TREATMENT:

Time to extubation Calls for help

Time to desaturation (SpO2 < 90%) Suction oral airway

Attempt manual ventilation

Administer intravenous epinephrine

ABC/Physical Exam: Administer subcutaneous terbutaline

Ausculates pulmonary fields Administer lidocaine

Detects decreased breath sounds with wheezing Administer ketamine

Administer sedative hypnotic and muscle relaxant

PHYSIOLOGIC DATA Laryngoscopy and intubate (Inflate cuff)

Recognize low SpO2 Administer appropriate inhaler (minimum 4 puffs)

Recognize tachycardia Use inhaler circuit adapter

Recognize low end tidal CO2 Administer inhalation agent

MECHANICAL DATA: OUTCOMES:

Detects high peak airway pressure Time to restore oxygenation (SpO2 > 90%)

Detects low tidal volume Time to restore ventilation (ETCO2 b/w 35 and 45)

DIAGNOSIS:

Time to recognizing severe bronchospasm

Critical Time Points (Segment One): TREATMENT:

Time to extubation Calls for help

Time to desaturation (SpO2 < 90%) Suction oral airway

Attempt manual ventilation

Administer intravenous epinephrine

ABC/Physical Exam: Administer subcutaneous terbutaline

Ausculates pulmonary fields Administer lidocaine

Detects decreased breath sounds with wheezing Administer ketamine

Administer sedative hypnotic and muscle relaxant

PHYSIOLOGIC DATA Laryngoscopy and intubate (Inflate cuff)

Recognize low SpO2 Administer appropriate inhaler (minimum 4 puffs)

Recognize tachycardia Use inhaler circuit adapter

Recognize low end tidal CO2 Administer inhalation agent

MECHANICAL DATA: OUTCOMES:

Detects high peak airway pressure Time to restore oxygenation (SpO2 > 90%)

Detects low tidal volume Time to restore ventilation (ETCO2 b/w 35 and 45)

DIAGNOSIS:

Time to recognizing severe bronchospasm0

2

4

6

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10

12

14

16

18Control (Standard Training) Experimental (VPT/PTT)

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Figure 1: Average change for the number of tasks completed with regard to the pre-training and post-training assessments

Figure 2: Average number of tasks completed, post-training assessment only.

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0

2

4

6

8

10

12Control (Standard Training) Experimental (PTT/VPT)

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0

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34

5

67

89

10Control Experimental (VPT/PTT)

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Figure 3: Results of the NASA-TLX post-simulation questionnaire

Study supported by the Anesthesia Patient Safety Foundation, Indianapolis, IN

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