- Slides: 12
Blood Pressure • Force exerted on the walls of the artery. Created by the pulsing blood under pressure of the heart. • BP = CO x R • Systolic- Peak and maximum pressure of ejection of blood from the heart into the aorta. This is the top number. • Diastolic- The minimal pressure remaining the heart when the heart relaxes. This is the bottom number. • Recorded as a ratio Ex. 120/80
Equipment for BP Sphygmomanometer Stethoscope
Measuring BP • Pulse pressure- Difference between the systolic and diastolic. ( 120/80 – Pulse pressure 40) • Size matters-False high if cuff too small, false low if cuff is too loose • Don’t take BP on arm with IV, sling, surgery, mastectomy, renal dialysis shunt, etc.
Electronic BP Readings • Easy to use • Does not count respirations • Do not use for patients with irregular pulse
Alternative Sites • Use popliteal artery • Place bladder of cuff on posterior part of leg
Measuring BP • Cuff must be appropriate size • Cuff should be snug, not loose • Do not put stethoscope under cuff ( place cuff 1 -2 inches above elbow)
Measuring BP • Pt should be sitting or lying with arm at the level of the heart • Distinguish Korotkoff sounds (sounds heard when taking BP) from artifact • Make mental note of systolic and diastolic numbers
Measuring BP • If unsure of reading, wait 30 seconds and recheck-if unsure, have someone else check with you • Loosen cuff even if to be checked q 15 minutes • Make sure all air is out cuff before applying
Factors Affecting BP • • • Exercise-increases Fluids (IV or PO) -increases Blood Transfusions- increases PAIN-increases Hemorrhage –decrease RACE-Blacks and Hispanics more prone increase • Age • Heredity-increased chance if immediate family history
Alterations in Blood Pressure • • • Hypertension – Most common alteration in BP Most often asymptomatic Characterized by persistently elevated BP Noted when diastolic is greater than 90 mm/Hg and systolic is greater than 140 mm/Hg Optimal BP for 18 y/o and older is less than 120/80 mm/Hg
Alterations in Blood Pressure • When systolic blood pressure falls to 90 or below. • Orthostatic (Postural) Hypotension- Occurs when a normotensive person develops symptoms and low blood pressure when rising to an upright position.