Final answer:
The sphygmomanometer cuff size is critical for accurate blood pressure measurements. The bladder length should be 80% of the arm's circumference, and the width should be 40%. Correct cuff size and proper placement at heart level help ensure valid readings.
Step-by-step explanation:
The appropriate size of a sphygmomanometer cuff is based on the patient's arm circumference. For accurate blood pressure measurements, the bladder length of the sphygmomanometer should be about 80% of the arm's circumference, and the width should be approximately 40%. This ensures that the cuff can inflate adequately to compress the artery and accurately reflect the arterial blood pressure without being too loose or excessively tight, which could skew the readings.
It's crucial for medical technicians to select the correct cuff size when preparing to measure a patient's blood pressure using a sphygmomanometer to avoid the potential for incorrect measurements which could lead to misdiagnosis or improper treatment. When the cuff is placed on a patient's upper arm, it should be at the same level as the heart to reflect the central blood pressure properly, which will affect the blood flow detected below the cuff.