chapter 1 vital signs copyright © the mcgraw-hill companies, inc

Chapter 1Vital Signs

Copyright © The McGraw-Hill Companies, Inc.

Copyright © The McGraw-Hill Companies, Inc. Chapter 92

Blood Pressure

Blood pressure (BP) is the pressure or tension exerted on the arterial walls as blood pulsates through them.

Systolic blood pressure (SBP) – pressure exerted on the arteries during the contraction phase of the heartbeat. Maximum blood pressure is exerted on the walls of arteries when the left ventricles of the heart pushes blood through the aortic valve into the aortas during contraction, the highest pressure thus called systolic pressure.


Diastolic blood pressure (DBP) – the resting pressure on the arteries as the heart relaxes between contractions.

Diastolic pressure, then, is the lower pressure present at all times within the arteries. The differences between the two called the pulse pressure

Chapter 93


Factors affecting Blood Pressure

Age; the pressure rises with age, reaching a peak at the onset of puberty, and then tend to decline.

Exercise; physical activity increases the cardiac output and hence in blood pressure; thus 20-30 minutes of rest following exercise is indicated before the resting blood pressure can reliably assessed.


Stress; stimulation of the nervous system increases cardiac output and vasoconstriction of the arterioles, however severe pain can decrease blood pressure greatly by inhibiting the vasomotor center and provide vasodilatation

Race (African American males over 35 years have higher BP than European American males)

Gender; after puberty, female usually have lower blood pressure than males at the same age. After menopause the female has higher blood pressure than males


Medications Obesity; predispose to high blood pressure Diurnal variations; pressure is usually lowest

early in the morning when metabolic rate is low. Disease process; any condition affecting the

cardiac output, blood volume, blood viscosity, and compliance of the arteries has a direct effect on the blood pressure.


Blood Pressure (cont.)

Expected Blood Pressure Values– Expected SBP – 100 to 140 mm Hg.– Expected DBP – 60 to 90 mm Hg.– Hypotension – when the blood pressure

drops below expected levels. – Hypertension – high blood pressure.– Prehypertension – classified by the

American Heart Association as SBP 120 to 139 mm Hg or DBP 80 to 89 mm Hg.


Hypertension

Hypertension; an abnormally high blood pressure, over 140mm Hg systolic and 90 mm Hg diastolic.

Factors associated with hypertension Thickening of the arterial walls, which reduces

the size of the arterial lumen Elasticity of the arteries Lifestyle as cigarette smoking


Obesity Lack of physical exercise High blood cholesterol level Continued exposure to stress


Hypotension; blood pressure below normal that is systolic reading between 85-110mm Hg. It occurs as a result of peripheral vasodilatation in which blood leaves the central body organs especially the brain and moves to the periphery

Factors associated with hypotension Analgesics Bleeding Severe burn Dehydration.



Sites for Blood Pressure Assessment– Brachial – taken on the upper arm;

most common site.– Radial – taken on the lower arm;

possible site for infants or clients who have very large upper arms.

– Popliteal – taken on the thigh.– Dorsalis pedis and posterior tibial –

taken on the lower leg.


Equipments used to assess pulse and blood pressure

Stethoscope; is used to auscultated and assess body sounds including the apical pulse and the blood pressure

Sphygmomanometer; is used to assess blood pressure consist of cuff, good selection of the cuff in order to obtain accurate blood pressure.



Equipment for Measuring Blood Pressure– Blood pressure is measured using a

sphygmomanometer, also called a BP cuff, or cuff.


Equipment for Measuring Blood Pressure

– Types of Sphygmomanometers Mercury – has a calibrated glass

tube containing mercury. Aneroid – has a calibrated dial

with a needle that points to numbers on the face of the dial.

Electronic – uses a digital display and usually includes the pulse rate.


Mercury

Aneroid

Electronic


Blood pressure sites

Assessing the blood pressure on a client’s thigh is indicated in these situations:– The blood pressure can not be measured on either arm due

to burn or other trauma– The blood pressure on one thigh is to be compared with the

blood pressure in the other thigh


Blood pressure is not measured on a particular clients’ limb in the following situations:

1) Avoid having blood [pressure in injured or an area with cast

2) The client has had removal of axilla lymph node on that site

3) The client has intravenous line in that limb

4) The client has an arteriovenous fistula for dialysis in that limb

chapter 1 vital signs copyright © the mcgraw-hill companies, inc

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