Scenario - Airway Drill 1
From WickedSim
Contents |
A relatively simple airway scenario
This scenario is also available as a PDF [1] but we strongly recommend that you download the zipped folder [2] containing the scenarios and view them using SimMan software!
This was one of our first attempts and is an inelegant scenario. We assume you've loaded the scenario AirwayDrill1.sce as described in our page Introducing SimMan Programming. (You may wish to drag the right margin of the SimMan window to enlarge it, as things tend to be a bit cramped. Drag it until the dotted margin on the right is visible). Let's now explore the scenario --- on later pages, we'll see how we can improve on this clumsy initial attempt.
The basic idea is as follows:
* A young patient with a throat pack left in becomes progressively more hypoxic and distressed; * Bag/mask ventilation with oxygen will delay deterioration; * Can't ventilate at 3 minutes; * The person being assessed must detect the glottic obstruction; * As this is a basic, introductory scenario, the mannequin will cough at 7 minutes, prompting the facilitator to end the scenario without undue distress!
Use the vertical scroll bar on the right to move around the scenario. Although it looks intimidating, see how we have an Initial State box, from which everything else flows. At this stage don't worry about the contents of the boxes, but see how there are two ways of linking boxes:
1. An oblique line joining the bottom of the source box with the top of the destination 2. A tab below the box which contains the name of the box 'joined to'!
Each state has a name. Note that you can alter this name by simply double-clicking on it (Try this, you won't break anything).
See how we've "linked in" a comment box called Explanatory Notes. It's good to have a lot of commentary on your scenarios, unfortunately SimMan is somewhat limited in what it allows. You can place a comment in any box by clicking on the Actions button on the left with an exclamation mark, and then clicking on the box you want to drop the comment into. The comment is always in the same place --- last in line! Once there is a comment in a box, double click it to edit it. Scenario editor will generally stuff up the formatting of long comments, making them difficult to read.
Examine a state in more detail
Look at the Initial State. We've dragged a whole lot of patient parameters from the left Actions section into this box. You might wish to double click on some of these to get a feel for how they are configured. This part is simple.
But how did we obtain the START SCENARIO action which links to the next state, the one we've called Central State?
Specifying an action
If you Alt+Tab to the main SimMan window and load and run AirwayDrill1.sce, you'll find that the START SCENARIO action appears in the Miscellaneous section near the bottom right corner of the screen. Clicking on it will move us to the central state.
We create our customised START SCENARIO action as follows. In the Scenario Editor we click on the Edit tab and then on Edit Event Menus. A vast menu will pop up. This contains many Laerdal-defined events. The main problem with using these events would seem to be the hierarchical menu structures (especially if you're driving your SimMan from a PDA), although you can drag the Laerdal events around at will. We will often create our own events. You can too --- right click on the Event Menu, and simply Add an Event.
Especially in the Medication section, you may first wish to collapse all of the menus. You probably also want to hide all of the default medication, first minimising everything (Click on the [-] tabs, and then right click to Hide all in folder).
Before you move from the Initial State to the Central State, note one more thing. We set the Patient Time to 07:00 within the initial state. This becomes important later.
Trends
Within the main SimMan console, click on START SCENARIO to see how you move to the central state. In particular, note how the trend hypoxiadrill1 starts up once we enter this state. What is a trend, and how do we set one up? Let's go back to the Scenario Editor and investigate trends...
Look at the Central State box. SimMan might conceivably have squished up this box, in which case it will have a scroll bar on the right, which you can use to locate the line which reads:
Start trend(stop others): hypoxiadrill1 (Start: 0min)
If you double click on this line, you'll open up a Trends box which allows you to modify such trends. To examine this trend further, click on hypoxiadrill1 in the Trends box, and then on the [Edit] button in the top right corner.
See how a Trend Editor opens up. You can play around with the trends, dragging the current points on the curves, or clicking to create your own points which you can then drag around. This trend editor is actually fairly user-friendly, but note that there are important limitations. Values are generally not percentages but absolute numbers. You will find that occasionally this approach discombobulates you, but generally you can fiddle the trends to make things look reasonable! (It's probably very wise NOT to play with the Infusion option at this stage).
Moving around
Let's now examine the states leading from the Central State. If you look at the tabs and links at the bottom of the Central State, there are three options:
1. Oxygen is administered 2. The airway is cleared 3. The mysterious "PT=0:00"
It should be obvious that clearing the airway will take us to the 'final state' where the airway is cleared, and the patient recovers. Less obvious is that 'oxygen' takes us to the Hudson mask state (Later on we will look at defects in the current scenario, and how we can improve it). And "PT=0:00" is still obscure, so let's investigate this strange option further.
Patient time
Double click on the "PT=0:00" tab at the bottom of the Central State and a box will pop up. It should be obvious that 'Time in frame' continuously examines how long somebody has been in the current frame, but what about 'Patient time (PT)'?
Recall that in our initial state we set the patient time to seven minutes. Once we set the patient time, a counter starts counting down. We can subsequently test the counter, and respond based on the value in the counter. When the time counts down to a particular value, we can initiate an action.
In this simple scenario, we initiate a cough when the PT counts down from 7 min to 0 minutes, prompting the facilitator to end the scenario!
Why this scenario is clumsy
You can see several 'problems' with our current scenario:
1. There are lots of clumsy boxes and links, creating confusion in the mind
of anyone reading the scenario
2. The 'Oxygen' tab is used in two different ways, causing further confusion
3. The whole scenario appears rather artificial
On our next page, Airway Drill 1A we find out how to clarify and improve our scenario!
