Blood Pressure Assessment

Health Science

Rationale• Health care workers are

responsible for the accurate assessment of vital signs.

• This includes blood pressure readings.

Objectives• Upon completion of this

lesson, the student will be able to:

• Accurately measure adult blood pressure

• Evaluate a peer using check-off

Definition of Blood Pressure• The measurement of the force of blood against artery walls.–The force comes from the pumping of the heart.

–If arteries are hardened or narrowed, this force might be increased, to pump the blood throughout the body.

Measurement

• Measurement is done by listening for two sounds with a stethoscope – the first sound and the change in sound / or in some instances, the last sound.

First sound….• The first sound is called

the systolic blood pressure.

• It measures the pressure in an artery when the heart is contracting (during the beat).

• This will be the higher number.

The change or second sound…….• The change in sound / or last

sound heard is the diastolic blood pressure.

• It measures the pressure in the artery when the heart relaxes between contractions.

• It will be the lower of the two numbers.

Units of measurement• The units of measurement

are in millimeters of mercury. (mmHg)

• The top number (systolic) is charted first, then the bottom number (diastolic).

• 120/80 is an example of a blood pressure and this would be in mm Hg.

• When a patient’s blood pressure is higher than normal, this is called hypertension.

• When a patient’s blood pressure is lower than normal, and the patient is symptomatic, this is called hypotension.

Blood pressure valuesB/P Category Systolic Diastolic

Normal less than 120 and less than 80

Prehypertension 120 – 139 or 80 - 89

Hypertension (Stage 1)

140 – 159 or 90 - 99

Hypertension (Stage 2)

160 or higher or 100 or higher

Hypertensive Crisis (Emergency Care Needed)

Higher than 180

or Higher than 110

Low Blood Pressure (Hypotension)• Optimal blood pressure is less

than 120/80 mm Hg. Within certain limits, the lower your blood pressure reading is, the better. There is no specific number at which day-to-day blood pressure is considered too low, as long as no symptoms of trouble are present.

Symptoms of Hypotension• Dizziness or lightheadedness• Fainting (called syncope)• Dehydration and unusual thirst• Lack of concentration• Blurred vision• Nausea / Fatigue• Cold, clammy, pale skin• Rapid, shallow breathing• Depression

Dehydration and Hypotension• Dehydration can sometimes

cause blood pressure to drop. However, dehydration does not automatically signal low blood pressure. Fever, vomiting, severe diarrhea, overuse of diuretics and strenuous exercise can all lead to dehydration, a potentially serious condition in which your body loses more water than you take in.

• Even mild dehydration (a loss of as little as 1 percent to 2 percent of body weight), can cause weakness, dizziness and fatigue.

Hypertension

• Hypertension is called the “silent killer” because there are often no symptoms. Hypertension is blood pressure above 140/90.

• Some people might experience headache, pressure in the head, ringing in the ears, a general feeling of malaise.

• Continued B/P elevation over time may result in a Cerebral Vascular Accident (stroke).

• Contributing factors: overweight, emotional upset, family history, high salt diet, pain, illness, medications.

Hypertension

• High blood pressure directly increases the risk of coronary heart disease (which leads to heart attack), and stroke, especially along with other risk factors.

• High blood pressure can occur in children or adults.

• It is particularly prevalent in African Americans, middle-aged and elderly people, obese people and heavy drinkers.

• People with diabetes, gout or kidney disease have hypertension more often.

• There is a simple, quick painless test to detect high blood pressure:

• High blood pressure risk calculator on the American Heart Association website.

Instruments for taking a B/P

• Blood pressure cuff / sphygmomanometer

• This must fit the arm properly. The width of the cuff should approximately equal the width of the upper arm.

• The gauge should be calibrated and the needle should be on 0.

Instruments………

• The other piece of equipment would be a stethoscope.

• The stethoscope should be well fitting and clean.

Procedure for taking a B/P• Person should be

comfortably seated or lying down.

• Should have rested for 10-15 minutes prior to the reading.

• Arms that are paralyzed, injured, have an IV or shunt should not be used.

• Electronic blood pressure equipment can be used; the type used most often in the hospital setting is the Dyna-map.

• Excess air should be squeezed out of the cuff.

• Cuff should be placed snugly on the upper arm.

• Gauge should be easily visualized.

• Valve should be closed, but easily able to be opened.

• There are two techniques for obtaining the pressure:

• Find the radial pulse. Pump cuff till pulse no longer is palpated. Then pump another 30mm Hg higher. Place diaphragm of stethoscope on brachial artery about ½ to 1 inch above the elbow. Release the valve and listen for the two measurements, slowly deflating the cuff.

• Find brachial artery and put diaphragm over the site. Pump cuff to 120 mmHg and listen for the heart beat. If it is heard, pump another 30 mmHg and listen again.

• When the pulse is no longer heard, then pump another 30 mm Hg and slowly deflate, listening for the two measurements.

• If the reading is uncertain, wait 30 seconds to 1 minute before re-measuring.

• Record the reading and report any abnormalities. If the B/P reading is outside of the normal limits, retake it before reporting the value to a supervisor to be certain of accuracy.