Page 253 - Cardiac Nursing

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C HAPTER 1 0 / History Taking and Physical Examination 229
pressure enables the listener to hear the alternating weaker sounds setting. However, if the patient takes his or her own blood pres-
produced by the ectopic impulses as well. sure, readings may be elevated because of the isometric exercise
Pulsus alternans, indicative of severe organic heart disease and required to inflate the cuff and because of the concentration nec-
left heart failure, also is manifested by alternating strong and weak essary. Newer devices for home use inflate the cuff automatically
pulses but with a regular cadence. Pulsus alternans can occur with and some maintain a record of recent measurements. Many fire
ectopic bigeminal rhythms that are interpolated rather than pre- stations and hospital auxiliaries provide blood pressure measure-
mature, but, in this instance, it does not necessarily indicate severe ment as a community service. Alternately, a fully automated
organic heart disease. system that measures blood pressure at preset intervals over the
Because pulse cycle length changes constantly in atrial fibrilla- 24-hour period may be used.
tion, both systolic and diastolic blood pressures must be approxi- Pseudohypertension. Misleadingly high systolic blood pres-
mated. 24 For systolic blood pressure, average a series of readings sure values may be obtained in older adults because of excessive
(three to five) of phase I pressures. For diastolic blood pressure, av- vascular stiffness. Pseudohypertension should be suspected in the
28
erage the pressure readings obtained in phase IV and phase V. presence of high systolic blood pressure values and the absence of
Atrioventricular dissociation can be detected during ausculta- target organ damage. To confirm suspected pseudohypertension,
tion of blood pressure. Examples of rhythms with atrioventricular inflate the cuff above systolic pressure and palpate the radial artery.
dissociation include ventricular tachycardia, high-grade or complete Presence of a palpable, pulseless radial artery provides additional
atrioventricular block, and asynchronous ventricular pacing. In atri- evidence of pseudohypertension.
oventricular dissociation, an occasional, well-timed atrial contrac-
tion contributes to diastolic ventricular filling. This “atrial kick”
augments the stroke volume for that beat. As the cuff bladder is Peripheral Vascular System
deflated, phase I sounds periodically are increased.
Adequacy of both arterial and venous circulation is assessed when
Clinical Shock. In shock states associated with reduced car- examining the extremities. Always make arm-to-arm and leg-
diac output and elevated systemic vascular resistance, Korotkoff to-leg comparisons. Careful examination of the lower extremities
sounds may not be generated in the periphery. Direct measure- is impossible without removing shoes and stockings.
ment of blood pressure may be required to manage these critically
ill patients. When indirect cuff measurements are compared with Inspection and Palpation
direct (femoral arterial) pressure measurements, direct pressures are Inspection and palpation are the primary techniques used in ex-
higher than auscultated pressures. In hypotensive states, when di- amining the peripheral vasculature (see “Bruits” section). Observe
rect measurement of blood pressure is not feasible, Doppler ultra- and compare (right to left) size, temperature, symmetry, swelling,
sound may provide a more reliable indirect measurement of systolic venous pattern, pigmentation, scars, and ulcers. Palpate the su-
blood pressure than the auscultatory method. Place the Doppler perficial lymph nodes, noting their size, consistency, discreteness,
probe (with conducting gel) over the patient’s artery. As in auscul- and any tenderness.
tatory measurement, inflate the cuff and listen for the arterial sig-
nal as the bladder is deflated. Cuff widths of 50% of the arm cir- Clubbing
cumference have been recommended for the Doppler technique. 24 Clubbing is a pathologic sign that is defined as focal enlargement
of the terminal phalanges. Two diagnostic findings are present in
Obesity. Cuff size and bladder size frequently are too small for clubbing: change in the angle between the base of the nail and the
use in the obese patient. If a proper-sized cuff cannot be used, ap- phalangeal skin, and “floating” nails. When viewed from the side,
ply a standard cuff to the forearm 13 cm from the elbow and aus- the base angle normally is less than 180 degrees and the distal pha-
cultate the radial artery to obtain the blood pressure measurement.
langeal diameter is less than the interphalangeal diameter. In club-
Thigh Blood Pressure Measurement. Blood pressures are bing, the base angle becomes 195 degrees or greater and the distal
measured in the thigh if the arms cannot be used or to confirm or phalangeal diameter becomes greater than the interphalangeal di-
rule out certain conditions that alter circulation, such as coarcta- ameter (Fig. 10-15). 29 Floating nails can be detected by palpating
tion of the aorta or dissecting aortic aneurysm. the base of the nail while moving the tip of the nail. Rather than
For thigh blood pressure measurement, use a cuff and bladder a firm anchor, the base of the nail appears to float or move under
that are both longer and wider than an arm cuff. Recommenda- the palpating finger. Clubbing may develop in a variety of condi-
tions for the exact sizes of the thigh cuff and bladder have not tions, including congenital heart disease and lung abscess; its
been made. With the patient in the prone position, apply the cause is unknown.
compression bladder over the posterior aspect of the mid-thigh.
Place the stethoscope over the artery in the popliteal fossa and aus- Arterial Circulation
cultate in the same manner as described previously. If the patient Adequacy of peripheral arterial circulation is assessed by arterial
is unable to tolerate the prone position, have the patient remain pulse; skin color, temperature, and moistness; and capillary refill
supine with the knee slightly flexed. Apply the stethoscope over time. Pulse-wave analysis and skin color are described earlier in
the popliteal artery. When cuffs of the correct size are used for this chapter under the “Arterial Pulse” and the “Head” section, re-
both arms and legs, pressures should vary by only a few millime- spectively.
ters of mercury. (The arm cuff, incorrectly used on the thigh, pro-
Temperature and Moistness. Temperature and moistness
duces a falsely high value.)
are controlled by the autonomic nervous system. Normally, hands
Community Blood Pressure Readings. Blood pressures and feet are warm and dry. Under stress, the periphery may be
taken in the patient’s home may provide a better indication of cool and moist. In cardiogenic shock, skin becomes cold and
basal blood pressure than those obtained in an office or clinic clammy.