Measuring and Recording Blood Pressure

Health Science Technology

Nursing

Mrs. J. Hodge, 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 90mm/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

• Arm on the side of a Mastectomy