Answer to Question 1
A
As the heart rate increases, ventricular filling decreases, and cardiac output and renal perfusion decrease. Tachycardia does not elevate blood pressure. Jugular vein distension and shortness of breath occur with fluid volume overload.
Answer to Question 2
D
Beta-lactamases are enzymes that cleave the beta-lactam ring and render the PCN inactive. This resistance is common with organisms that cause ear infections. Amoxicillin is a broad-spectrum antibiotic. A three-layer cell envelope occurs in gram-negative bacteria. Some bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA), develop PBPs with a low affinity for penicillins. MRSA is not a common cause of otitis media.