Key Questioning and Determinant Selection
Scripted questions, narrowing answers
Once a protocol is selected, the EMD works through that protocol's Key Questions in the order written. Each answer narrows the field of possible determinants; the questions are not a menu to be sampled. Listen for the answers that describe status - conscious or not, breathing or not - because status questions usually carry the largest jump in response level.
How a determinant is built
A determinant has three parts: the protocol number, the Determinant Level, and the descriptor number (for example, 6-D-2). The levels run from Omega (lowest, often a referral or non-emergency response) through Alpha, Bravo, Charlie, Delta, to Echo (highest, used for cardiac arrest and similarly time-critical presentations). The level is set by the most severe finding among the key questions and status answers - not by the average, and not by the caller's tone of voice.
Traps
Common errors: stopping the key questions early because the caller sounds calm; asking unscripted questions and acting on the answers; letting a reassuring answer override a contradictory high-level one; missing that gasping or agonal breathing counts as ineffective breathing rather than breathing; confusing "not alert" with "alert"; and failing to ask the additional questions a second patient on scene requires. Another trap is treating the first determinant reached as final when a later key question reveals something worse.
Rule of thumb: the most severe answer wins, and when key questions cannot be answered at all, err toward the higher determinant rather than the lower one. It is always safer to over-respond than to under-respond.