(1) To obtain an accurate blood pressure reading, you will need a
stethoscope, a blood pressure cuff, and a sphygmomanometer. Be sure that the patient is
relaxed and use a cuff that is not more than 20 percent wider than the diameter of the
patient's limb and long enough to completely encircle it. If the patient is very obese, it may
be necessary to use a thigh cuff on his arm. If possible, take the blood pressure in two
positions, supine or seated and standing. Wrap the cuff around the arm so that it is about
one inch above the bend of the elbow. Palpate the brachial artery and place the
diaphragm of the stethoscope over the artery below, but not underneath, the cuff. Inflate
the cuff 30 to 40mmHg above the point at which the last sound is heard. Release the
pressure slowly. Observe the pressure readings on the manometer and relate these to the
sounds heard through the stethoscope. The systolic pressure is the point where the first
tapping sound is heard. The diastolic pressure is the point where the sound disappears.
(2) Take the peripheral pulses with the patient in the supine position, using
your index and middle finger. Palpate the apical, radial, dorsalis pedis, and posterior tibial
pulses. The posterior tibial pulse is palpable behind and below the protuberance on the
inside of the ankle. See figure 4-2 for arterial pulse sites.
(3) Several heart sounds can be heard by auscultation (see figure 6-7). The
first two heart sounds are produced by closure of the valves of the heart. The first heart
sound (S1) occurs when the ventricles have been sufficiently filled and the right and left
atrioventricular (A-V) valves close. S1 is heard as one dull, low-pitched sound. After the
ventricles empty their blood into the aorta and pulmonary arteries, the semilunar valves
close, producing the second heart sound (S2). The second heart sound is shorter and has
a higher pitch than S1. The two sounds occur within one second or less, depending on
the heart rate. Systole is the period in which the ventricles are contracted. It begins with
the first heart sound and ends at the second heart sound. Diastole is the period in which
the ventricles are relaxed. Normally no sounds are heard during this period. The two
heart sounds are audible anywhere in the region over the heart, but are best heard over
specific valve areas. Rhythm is the pattern of the heartbeats and the intervals between
the beats. It may be regular or irregular. Normally, equal time elapses between
heartbeats. Any deviation from the normal pattern is arrhythmia. Murmurs, produced by
turbulent blood flow, may occur at any cardiac auscultation site. The volume of blood flow,
the force of the contraction, and the degree of valve compromise all contribute to murmur
quality. Descriptive terms are used to give the murmur character. Murmurs are
"whooshing" sounds. Although the mitral sound is usually loudest, a stenotic mitral valve
that moves very little may produce a muffled sound.
MD0906
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