Page 51 - JSOM Fall 2019

FIGURE 7 Medical error in tourniquet placement as a function of APPENDIX 1 Card to Aid Tourniquet Placement
user experience.

A type of error was charted cumulatively by use number, a surrogate This card is 3 × 5 inches and is to help first-aid providers estimate
of user experience. Variable error is a computed measure of inconsis- accurately the distance to place the tourniquet from the wound. The
tency in movement outcome and is the variability of a subject’s (user’s) card illustrates the wound on the left side, the blue tourniquet is on the
performances about the mean value for that subject. Variable error right, the beige limb is horizontal, and the fingers are gauging the gap.
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can be reported for each use or for all uses. To assess performance Four fingers are situated as if the reader uses a left hand to estimate the
over time, we used a cumulative mean, which is a way of representing gap width with the fingers extended and laid near or on the limb. The
a learning curve. small finger is left and its left border is placed adjacent to the wound.
The index finger is right and its right border is at the target point,
FIGURE 8 Classification of tourniquet placement. which is on the minimum gap line between the wound and tourniquet.
The tourniquet is placed at the upper edge of the optimal zone. The
line is red when off-target by being either too close or too far from the
wound, and the line is green in the middle zone, by being on-target
at 2–3 inches. The line is anchored at the wound on the left, and the
origin is the reference or 0 point. In creating the diagram, the actual
user had his hand on the manikin, penciled an outline of the fingers,
measured the distances, and adjusted his practice to fit four fingers to
target the point in the middle of the 1-inch–wide zone. By trial and
error in sliding the fingers to hover over the gap, this outline became
the best fit, because it targeted the midpoint more reliably. The user
discarded his previous practice of using three fingers at the proximal
interphalangeal joint because of the excess risk of missing the target.

within these slide statements complex or hidden and may fo-
cus only on “above” because “2 to 3 inches” looks boring.
Tourniquet placement is categorized by how surface anatomy relates Furthering the distraction problem, the rest of the 116-word
to the external wound edge. Highest placement is at the buttocks slide and its 153-word script is an avalanche of other informa-
(gluteal fold) or armpit (deltoid-biceps fold) of the injured limb. This tion. Further impairing attention, there is no image—no gap
placement is common in tactical situations during care under fire
and is often called “high and tight,” after a nickname for a military map to help viewers understand what “2 to 3” is intended
haircut. Civilian and military caregivers also sometimes see this place- to mean. Of the two edges of the tourniquet, if the edge far-
ment used in inappropriate situations, and such placement routinely is ther from the wound covers but does not go past the 2-inch
corrected by replacement to 2–3 inches or by removal. Placement >3 line, is it placed okay? No, because the referent is the nearer
inches and less than highest is a common training error or when cloth- edge which is too close at a half inch from the wound (2 − 1.5
ing or objects interfere with placement; extra tissue is at ischemic risk
unnecessarily. Placement 2–3 inches is optimal. Placement <2 inches is = 0.5).
too close to the wound and risks uncontrolled bleeding if the wound
had hidden parts under the tourniquet. Placement atop the external Besides students, instructors may also be surprised by unearth-
wound has similar risk. Placement below the wound risks death as a ing what “2 to 3 inches” means. Some instructors who taught
result of uncontrolled bleeding. Placement on an uninjured limb has
occurred in chaotic caregiving and is often detected and corrected by learners to gauge that distance with their fingers have relayed to
the first medic to routinely assess the situation. Because placement 2–3 us that despite being instructors, they have never gauged their
inches relates to the wound, when the tourniquet overrides the 2–3- own fingers to know where they are held 2 inches wide or 3
inch zone and is placed in the <2-inch zone, such a placement is an inches wide. When asked, some instructors said they had not
error. When tourniquets overlay only the 3-inch location of the 2–3- thought about putting any gauging guidance into operation for
inch zone, such placement is categorized as 2–3 inches. One should
not cross the 2-inch line. teaching or caregiving but continued to utter the words in the
bulleted statement on slide 27. These instructors had no plan to
check, to learn, or to develop their own understanding or teach-
in turn, eventually affected the understanding of the learner. ing skills. To understand what “2 to 3 inches” meant to first-aid
The gap map was one tool to elicit changes in understanding. providers, we asked them how wide the placement zone was.
The major finding is relevant to the first minor finding because Their answers varied (e.g., 1 inch, 2 inches, 2–3 inches), and
in the Bleeding Control presentation slide 27 also nests an idea they questioned “is this math?” Being impatient for their efforts
of “above” relative to the wound. The word “above” is a lay to excavate meaning, we redirected their attention by develop-
word for “proximal,” and the slide’s script notes that “Above ing a cue in the form of a card—a template for self-gauging
the bleeding site” means farther up on the arm or leg and not one’s fingers (Appendix 1). In a contest for attention, a gap map
on top of the wound. A learner may not find the meanings aids one dig up a buried treasure: learned meaning.

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