Answer to Question 1
A
A patient who is obese usually has reduced ventilatory capacity because of the upward pressure against the diaphragm caused by an enlarged abdomen. There is also an increased risk for aspiration during the administration of anesthesia. The recumbent and supine positions required on the operating bed (table) for surgery further limit a patient's ventilation. The increased workload of the heart and atherosclerotic blood vessels often results in compromised cardiovascular function. Because of these physiological changes, patients who are obese often have difficulty resuming normal physical activity after surgery. Hypertension, coronary artery disease, type 2 diabetes mellitus, and heart failure are common in this population. They are also more susceptible to developing embolism, atelectasis, and pneumonia after surgery than patients who are not obese.
Answer to Question 2
D
Fluids that have the same osmolality as normal blood are called isotonic. Intravenous (IV) solutions are hypertonic, isotonic, or hypotonic. Isotonic solutions such as 0.9 sodium chloride (same osmolality as normal blood) expand the body's extracellular fluid volume without causing water to shift in or out of cells. Infusion of hypertonic intravenous solutions (more concentrated than normal blood), such as 3 sodium chloride, pulls fluid from cells by osmosis, causing them to shrink. Physiologically hypotonic solutions (less concentrated than normal blood after they are infused) move water from the extracellular compartment into the cells by osmosis, causing them to swell.