Resting BP Measurement

Measures the maximum pressure (systolic) and the lowest pressure (diastolic) made by the beating of the heart. The systolic pressure is the maximum pressure in an artery at the moment when the heart is beating and pumping blood through the body. The diastolic pressure is the lowest pressure in an artery in the moments between beats when the heart is resting. The non-invasive ausculatory method is one of the most common ways of monitoring a subject's blood pressure.

Seat the client in a quiet room for at least 5 min. Subject should have not had intake of caffeine and nicotine at least 30 min prior Clients bare arm should be resting on a table so that the middle of the arm is at the level of the heart

Estimate/measure the circumference of the arm using anthropometric tape – At the midpoint between the acromion process of the shoulder and the olecranon process of the elbow The bladder of the cuff should encircle 80% of an adult arm or 100% of a child’s arm

Palpate the brachial artery pulse on the anteromedial aspect of the arm below the belly of the biceps brachii and 2-3 cm above the antecubital fossa Wrap the deflated cuff firmly around the upper arm so the midline of the cuff is over the brachial artery pulse The lower edge should be approx. 2.5 cm above the antecubital fossa

If the cuff is too loose, BP will be overestimated Avoid placing the cuff over clothing; and if the shirtsleeve is rolled up, make certain it is not occluding the circulation Position the manometer so that the center of the mercury column or dial is at eye level and the cuff’s tubing is not overlapping or obstructed

Locate and palpate the radial pulse Close the valve of the BP unit completely and inflate the cuff to 70 mmHg Then slowly increase the pressure in 10 mmHg increments while palpating the radial pulse and note when the pulse disappears (estimate of systolic BP)

Partially open the valve Release the pressure at a rate of 2-3 mmHg/sec. – Note when the pulse reappears (estimate of diastolic BP) Fully open the valve to release the pressure of the cuff

The estimate of systolic BP from the palpatory method is used to determine how much the cuff needs to be inflated for measuring BP by means of ausculatory technique. In this way you can avoid under/over inflating the cuff for clients with low or high BPs.

Position the earpieces of the stethoscope so that they are aligned with the auditory canals Place the head (bell) of the stethoscope over the brachial pulse – about 1 cm superior and medial to the antecubital fossa Make certain the entire head of the stethoscope is contacting the skin

To avoid extraneous noise, do not place any part of the head of the stethoscope underneath the cuff Close the valve and quickly and steadily inflate the cuff pressure to mmHg above the estimated systolic pressure previously determined by palpation

Partially open the valve to slowly release the pressure at a rate of 2 to 3 mmHg/sec. – Note, when you hear the first sharp thud caused by the sudden rush of blood as the artery opens This is known as Korotkoff sound and corresponds to the systolic pressure (Phase I)

Continue reducing the pressure slowly (no more than 2mmHg/sec.) – Noting when the metallic tapping sound become muffled (Phase IV diastolic pressure) – And when the sound disappears (Phase V diastolic pressure) Typically Phase V is used as the index of diastolic pressure Phase IV = ‘change in tone’ During rhythmic exercise, Phase V pressure tends to decrease because of reduction of peripheral resistance

After noting the Phase V pressure, continue deflating the cuff for at least 10 mmHg, making certain that no additional sounds are heard Then rapidly and completely deflate the cuff

The Korotkoff sounds The Korotkoff sounds are the sounds heard through the stethoscope as the pressure cuff deflates. The sounds are first heard when the cuff pressure equals the systolic pressure, and cease to be heard once the cuff has deflated past the diastolic pressure. It is generally accepted that there are five phases of Korotkoff sounds. Each phase is characterized by the volume and quality of sound heard. The figure below illustrates these phases. In this example, the systolic and diastolic pressures are 120mmHg and 80mmHg respectively.

Record all three BP values (Phase I, IV, and V) to the nearest 2mmHg Wait at least 30 seconds, then repeat the measurement Use the average of the two measurements for each of the three values

Orthostatic (postural) hypotension is a sudden and extreme fall in blood pressure that occurs when a person stands up or is in an upright position. Standing causes 500 to 700 ml of blood to pool in the legs Thus, there is less blood for the heart to pump. This results in a decreased BP.

Baroreceptors sense this decrease in blood pressure. Counteract BPΔ by triggering the heart to beat faster and pump more blood in order to stabilize the blood pressure. Increased sympathetic activity Decreased parasympathetic activity Normal BP response moving to standing is a small reduction in SBP and a small increase in DBP. This imbalance lasts only for a few seconds as it adjusts to the new posture.

Large changes in SBP associated with increased risk of CVD Orthostatic when a person stands. It occurs within three minutes of standing. Caused by abnormal blood pressure regulation

Symptoms of orthostatic hypotension: Light-headed or dizzy after standing up from a lying or sitting position lasting a few seconds to minutes. Other symptoms include blurring of vision, loss of consciousness (syncope), and falls. More common with aging (1/3 non-free living older adults affected).

Mean arterial pressure Avg arterial pressure during one cardiac cycle Minimum: 60 Average: Ischemia: <60 MAP = DBP + (1/3 (SBP – DBP)) MAP is regional (upper / lower body).