Measuring and Recording Blood Pressure
Health Science Technology
Mrs. J. Hanna, RN
Blood Pressure-BP
• Measurement of pressure that the blood exerts on the artery walls during the various stages of heart activity.
• Measured in mmHg on instrument called a sphygmomanometer. (blood pressure cuff)
Two types of BP
• Systolic-top#-first beat heard
• Diastolic-bottom #-last beats
heard
Systolic Pressure
• Systolic pressure occurs in artery walls when the L ventricle of the heart is contracting and pushing blood into the arteries.
• Normal systolic reading is 120 mmHg
• Normal range is 100-140 mmHg
Diastolic Blood Pressure
• Diastolic pressure-constant pressure in artery walls when L ventricle of heart is at rest or between contractions.
• Volume of blood in arteries has decreased.
• Normal reading: 80mm/Hg
• Normal range: 60-90 mm/Hg
Pulse Pressure
• Difference between systolic and diastolic pressure
• Normal range in adults is 30 to 50 mm/Hg.
• Example: Systolic pressure is 120 mm/Hg and diastolic pressure is 80 mm/Hg, the pulse pressure is 40 mm/Hg. (120-80=40)
HYPERTENSION
• High blood pressure
• When pressures are greater than
140 mm/Hg systolic and 90 mm/Hg
diastolic
Common Causes: stress, anxiety, kidney disease, aging, high-salt intake, thyroid deficiency, and vascular conditions.
HYPOTENSION
• Low blood pressure when pressures are less than 100 mm/Hg systolic and
60 mm/Hg diastolic.
Common Causes: heart failure, hemorrhage, dehydration, depression, severe burns.
Orthostatic Hypotension
• Postural hypotension-occurs when there is a sudden drop in both systolic and diastolic pressure.
• This occurs when the individual moves from a lying to a sitting or standing position.
• Caused by inability of blood vessels to compensate quickly to the change in position.
Various Factors Influences BP Readings
• Force of heartbeat
• Resistance of the arterial system
• Elasticity of the arteries
• Volume of the blood in arteries
Various Factors CausingIncreased BP
1. excitement, anxiety, nervous tension
2. Exercise and eating
3. smoking
Various Factors Causing Decreased BP
• Rest or sleep
• Depressant drugs
• Shock
• Excessive loss of blood
• Fasting
Factor that may cause changes
• Lying down
• Sitting position
• Standing position
Recording BP
• Record as a fraction.
• Systolic is the top number
• Diastolic is the bottom number
• 120/80
Two main types of sphygmomanometers
• Mercury sphygmomanometer-has long column of mercury
• Each mark represents 2 mmHg.
• Aneroid has round gauge
• Cuff deflated=zero for accuracy
• *Electronic types used in healthcare facilities.
Recommendations
• AHA-American Heart Assn. recommends pt. sit quietly for @ least 5 min. before taking BP.
• AHA recommends that two readings be taken, averaged, with a minimum wait of 30 seconds between readings.
• Pt. seated or lying comfortably with forearm supported on flat surface.
Procedure
• Cuff appropriate size for pt.
• Arm free of restrictive clothing
• Deflated cuff should be placed on arm with center of cuff directly over the brachial artery.
• Lower edge of cuff should be 1-1 ½ inches above the bend of the elbow.
Rest of the procedure
• Final point-accuracy in placing stethoscope bell or diaphragm directly over the brachial artery at the antecubital area (bend in the elbow).
• Hold securely but with slight pressure.
• NEVER DISCUSS ANY READING OR VS READING WITH A PT/RESIDENT!
Do not use
• Arm with IV
• Arm with paralysis
Reflection
• Your resident’s blood pressure is 186/110.
• Discuss with a partner what this means and what your next step would be.
• Explore some of the questions you might want to ask the resident if he were at home or at a community event.