unit 31 sphygmomanometer gauges. basic principles of reading sphygmomanometer gauges a...
TRANSCRIPT
Basic Principles of Reading Sphygmomanometer Gauges
• A sphygmomanometer is an instrument calibrated for measuring blood pressure (BP) in millimeters (mm) of mercury (Hg).
• There are two main types of sphygmomanometer gauges, mercury and aneroid.
Basic Principles of Reading Sphygmomanometer Gauges
• The mercury sphygmomanometer as shown on the next slide has a long column of mercury. – Each line on the gauge represents two millimeters of
mercury (mm Hg). If it is calibrated correctly, the level of mercury should be at zero when viewed at eye level.
– Because blood pressure is recorded as the pressure drops in the gauge, it is best to learn to read the gauge in a backward direction.
Basic Principles of Reading Sphygmomanometer Gauges
• The aneroid sphygmomanometer gauge as shown on the next slide does not have a column of mercury. It is calibrated equivalent to mm Hg, and each line represents 2 mm Hg. – Note that long lines represent a multiple of 10.
• Because readings are recorded as the pressure drops, it is best to learn to read the gauge in a backward direction.
Basic Principles of Recording Blood Pressure
• Blood pressure (BP) is a measurement of the pressure that the blood exerts on the walls of the arteries during the various stages of heart activity.
• There are two types of BP measurements: systolic and diastolic.
Basic Principles of Recording Blood Pressure
• Systolic pressure occurs in the walls of the arteries when the left ventricle of the heart is contracting and pushing blood into the arteries. – A normal range for systolic pressure is 100 to 120 mm
Hg.
• Diastolic pressure is the constant pressure in the walls of the arteries when the left ventricle of the heart is at rest, or between contractions. – A normal range for diastolic pressure is 60 to 80 mm Hg.
Sphygmomanometer Gauges
• Example: On the aneroid sphygmomanometer gauge shown on the next slide (calibrated equivalent to mm Hg; each line represents 2 mm Hg), a reading 4 lines below 160 would be what?
Sphygmomanometer Gauges
– A reading 4 lines below the 160 mark equals:
160 – 2 – 2 – 2 – 2
= 152 mm Hg
- The correct reading would be 152 mm Hg.
Practical Problem
• When using an aneroid sphygmomanometer as shown on the next slide, what is the correct reading 2 lines below the 120 mark?