Final answer:
The appropriate cuff size for measuring blood pressure is vital for accurate readings, so measuring arm circumference and selecting a cuff whose bladder covers 80% of the circumference is essential.
Step-by-step explanation:
When a medical assistant is preparing to measure a patient’s blood pressure, selecting the appropriate cuff size is critical to ensure accurate readings. If the cuff is too small, the blood pressure reading may artificially inflate due to excessive constriction. Conversely, if the cuff is too large, the reading may be lower than the patient's actual blood pressure. To determine the correct cuff size, the medical assistant should compare the width of the cuff to the circumference of the patient’s arm. The bladder of the cuff should cover 80% of the arm circumference for adults. Such considerations help to prevent measurement errors and ensure that blood pressure is measured accurately and safely.