I would have to strongly disagree with you there, jones58. The zebra analogy is traditionally stated as, "When you hear hoofbeats, think 'horse', not 'zebra.'" It is used to discourage medical students, in particular, from wildly extrapolating from common symptoms to arrive at rarely-seen and unlikely diagnoses. I'm afraid your instructor didn't do you or your classmates any favors by presenting it as meaning precisely the opposite of its accepted usage.
Shopgirl, I don't know that I have the skills to teach you or anyone critical thinking--although I think my CT skills are exemplary now, I certainly didn't have them in school, and consequently sometimes I missed the obvious. I think my CT skills came when I started in ICU, where the emphasis is very much about triage, and anticipating/preparing for or heading off the "worst-case scenario."
It helps me to think in algorithmic terms. If pt has X
symptom(s), what are the most common causes of this? Do any of those causes coincide with what I know about my patient's history/condition/meds? What is the likely outcome? What is the worst
-case outcome? What do I need to do to ensure this condition is properly diagnosed, ruled out, treated and the worst outcome avoided?
Think of things in terms of: If_____, then______.
my patient has a low potassium, then some likely causes are
: his high NG output/extra dose of Lasix he received today/failure to continue his daily home potassium supplement when he was admitted to the hospital.
Most serious consequence would be
: malignant cardiac dysrhythmias.
Steps I therefore need to take to avoid this outcome include
: reporting abnormal labs immediately to PMD, sugesting reinstituting daily K+ supplement, suggest additional dose now with repeat labs; monitor NG/urine output closely; monitor VS closely.
Just an example, but you get the idea. Hope that was helpful. Good luck!