HSRT Deductive Reasoning Application 2

Question 1

Premise 1: All patients with serum sodium below 125 mEq/L require urgent intervention. Premise 2: Mr. Ortega's serum sodium is 121 mEq/L. What follows deductively?

Accepted Answer

Mr. Ortega requires urgent intervention

Answer

Mr. Ortega may require urgent intervention depending on his symptoms

Answer

Mr. Ortega's sodium is critically low only if he is symptomatic

Answer

Additional tests are needed before any conclusion can be drawn

Question 2

A clinical protocol states: 'No patient on anticoagulation therapy should receive intramuscular injections.' The nurse knows that Mrs. Lee is on warfarin. What deductively follows?

Accepted Answer

Mrs. Lee should not receive intramuscular injections

Answer

Mrs. Lee should receive subcutaneous injections instead, but only after consulting a physician

Answer

The rule applies only to high-dose warfarin patients

Answer

Mrs. Lee can receive IM injections if no other route is available

Question 3

From the premises: 'All community-acquired pneumonias should be treated with empiric antibiotics within 4 hours of diagnosis' and 'Patient X was diagnosed with community-acquired pneumonia at 10:00 AM,' which deductive conclusion is valid?

Accepted Answer

Patient X should receive empiric antibiotics no later than 2:00 PM

Answer

Patient X should receive empiric antibiotics if his oxygen saturation drops below 90%

Answer

Patient X may wait for culture results before starting antibiotics

Answer

Patient X requires antibiotics only if he is immunocompromised

Question 4

A medical student is presented with the following argument: 'If a patient is in anaphylactic shock, epinephrine is indicated. This patient is not in anaphylactic shock. Therefore, epinephrine is not indicated.' Is this deductively valid?

Accepted Answer

No — this is the fallacy of denying the antecedent; epinephrine may be indicated for other reasons

Answer

Yes — the argument correctly identifies when epinephrine is and is not needed

Answer

Yes — the absence of anaphylaxis logically excludes all indications for epinephrine

Answer

No — the argument contains a false premise about anaphylaxis treatment

Question 5

A physical therapist deduces: 'All patients with a Berg Balance Scale score below 45 are at high fall risk. Ms. Chen scored 38. Therefore Ms. Chen is at high fall risk.' This argument is BEST characterized as:

Accepted Answer

Deductively valid — the conclusion follows necessarily from the premises if they are true

Answer

Inductively strong — the conclusion is probably true given the premises

Answer

Invalid — the Berg Balance Scale is not a perfect predictor

Answer

Circular — the conclusion restates one of the premises

Question 6

Premise: 'If a medication has a narrow therapeutic index, plasma level monitoring is required.' Medication Y has a narrow therapeutic index. A pharmacist concludes that plasma level monitoring is required for Medication Y. This inference is:

Accepted Answer

Modus ponens — a valid deductive argument affirming the antecedent

Answer

Modus tollens — a valid deductive argument denying the consequent

Answer

Affirming the consequent — an invalid deductive form

Answer

Inductive generalization — a probable conclusion from observed cases