VITAL SIGNS1

These are indices of health, or signposts in determining client’s condition. This is also known as cardinal signs and it includes body temperature, pulse, respirations, and blood pressure. These signs have to be looked at in total, to monitor the functions of the body.

Different considerations in Taking Vital signs

1)      The frequency of taking TPR and BP depends upon the condition of the client and the policy of the institution.

2)      The procedure should be explained to the client before taking his TPR and BP.

3)      Obtain baseline data.

1. BODY TEMPERATURE

Factors that Affect Body Temperature

  1. Age

The infant is greatly influenced by the temperature of the environment and must be protected from extreme changes. Children’s temperature continue to be more labile than those of adults until puberty. Elderly people are at risk of hypothermia for variety of reasons. Such as lack of central heating, inadequate diet, loss of subcutaneous fat, lack of activity, and reduced thermoregulatory efficiency.

  1. Diurnal variations (circadian rhythms)

This refers to the sleep – wake rhythm of the body, a pattern that varies slightly from person to person. Body temperature normally changes throughout the day, varying as much as 1.0C between the early morning and the late afternoon.

  1. Exercise

Hard work or strenuous exercise can increase body temperature.

  1. Hormones

Women usually experience more hormone fluctuations than men do. Progesterone secretion at the time of ovulation raises body temperature above basal temperature.

  1. Stress

Stimulation of the SNS can increase the production of epinephrine and norepinephrine, thereby increasing metabolic activity and heat production.

  1. Environment

Extremes in environmental temperatures can affect a person’s temperature regulatory systems.

Common Sites for Measuring BT

  1. Oral

This is the most accessible and convenient. However, because of the mercury in glass thermometer, this is contraindicated for children under 6 years and clients who are confused or who have convulsive disorder.

  1. Rectal

This is considered the most accurate. However, it is inconvenient and more unpleasant for client. It is contraindicated for clients who are undergoing rectal surgery or have diarrhea or diseases of the rectum.

  1. Axillary

This is the safest and most noninvasive. It is the preferred site for measuring temperature in newborns because there was no possibility of rectal perforation.

  1. Tympanic membrane

This is readily accessible and reflects the core temperature. The tympanic has an abundant arterial blood supply, primarily from branches of the external carotid artery. The noninvasive infrared thermometers are now used for this purpose.

Nursing Interventions for Clients with fever (Fund. Of Nursing, Kozier, et al.)

  1. Monitor vital signs.
  2. Assess skin color and temperature.
  3. Monitor white blood cell count, hematocrit value, and other pertinent laboratory records.
  4. Remove excess blankets when the client feels warm, but provide extra warmth when the client feels chilled.
  5. Provide adequate food and fluids to meet the increased metabolic demands and prevent dehydration, if health permits. Clients who sweat profusely can become dehydrated.
  6. Measure intake and output.
  7. Maintain prescribed intravenous fluids.
  8. Reduce physical activity to limit heat producing, especially the flush stage.
  9. Administer antipyretics as ordered.
  10. Provide oral hygiene to keep the mucous membranes moist. They can become dry and cracked because of excessive fluid loss.
  11. Provide a tepid sponge bath to increase heat loss through conduction.
  12. Provide dry clothing and bed linens to increase heat loss through conduction.

2. Pulse

            This is a wave of blood created by contraction of the left ventricle of the heart. The heart is a pulsating pump, and the blood enters the arteries with each heartbeat, causing pressure pulses or pulse waves. Generally, the pulse wave represents the stroke volume and the compliance of the arteries.

            Stroke volume is the amount of blood that enters the arteries with each contraction in a healthy adult.

            Compliance of the arteries is their ability to contract and expand. When a person’s arteries lose their distensibility, greater pressure is required to pump the blood into the arteries.

            Peripheral pulse is the pulse located in the periphery of the body, for example in the foot, hand and neck. Apical pulse is a central pulse. It is located at the apex of the heart.

Factors Affecting Pulse Rate

  1. Age

As age increases, the pulse rate gradually decreases.

  1. Sex

After puberty, the average male’s pulse rate is slightly lower than the female’s.

  1. Exercise

Pulse rate normally increases with activity.

  1. Fever

The pulse rate increases in response to the lowered blood pressure that results from peripheral vasodilation associated with elevated body temperature, and because of the increased metabolic rate.

  1. Medications

Some medications decrease the pulse rate, and others increase it.

  1. Hemorrhage

Loss of blood from the vascular system normally increases pulse rate.

  1. Stress

In response to stress, sympathetic nervous stimulation increases the overall activity of the heart. Stress increases the rate as well as the force of the heartbeat.

  1. Position changes

When a person assumes a sitting or standing position, blood usually pools in dependent vessels of the venous system. Pooling results in a transient decrease in the venous blood return to the heart and a subsequent reduction in blood pressure reduction in blood pressure and increase in the heart rate.

 

 

Characteristics of Normal Pulse

  1. Rate

This is the number of pulse beats per minute (70 – 80 beats/min in the adult). An excessively fast heart rate (100 beats/min) is referred to as tachycardia. A heart rate in the adult of 60 beats/minute or less is called bradycardia.

  1. Pulse rhythm

This is the pattern of the beats and the intervals between the beats. Equal time elapses between beats of a normal pulse. A pulse with an irregular rhythm is referred to as a dysrhythmia or arrhythmia. It may consist of random, irregular beats or a predictable pattern of irregular beats.

  1. Pulse volume

This is also called the pulse strength or amplitude. It refers to the force of blood with each beat. It can range from absent to bounding. A normal pulse can be felt with moderate pressure of the fingers and can be obliterated with greater pressure. A forceful or full blood volume that is obliterated only with difficulty is called a full or bounding pulse. A pulse that is readily obliterated with pressure from the fingers is referred to as weak, feeble, or thready. A pulse volume is usually measured on a scale 0 to 3.

Pulse Sites

  1. Temporal, where the temporal artery passes over the temporal bone of the head. The site is superior and lateral to the eye.
  2. Carotid, at the side of the neck below the lobe of the ear, where the carotid artery runs between the trachea and the sternocleidomastoid muscle.
  3. Apical, at the apex of the heart.
  4. Brachial, at the inner aspect of the biceps muscle of the arm (especially in infants) or medially in the antecubital space (elbow crease).
  5. Radial, where the radial artery runs along the radial bone, on the thumb site of the inner aspect of the wrist.
  6. Femoral, where the femoral artery passes alongside the inguinal ligament.
  7. Popliteal, where the popliteal artery passes behind the knee. This point is difficult to find, but it can be palpated if the client flexes the knee slightly.
  8. Poserior tibial, on the medial surface of the ankle where the posterior tibial artery passes behind the medial malleolus.
  9. Pedal (dorsalis pedis), where the dorsalis pedis artery passes over the bones of the foot. This artery can be palpated by feeling the dorsum of the foot on the imaginary line drawn from the middle of the ankle to the space between the big and second toes.

3. RESPIRATION

Assessing Respirations

            Resting respirations should be assessed when the client is at rest because exercise affects respirations, and increase their rate and depth as well. Respiration may also need to be assessed after exercise to identify the client’s tolerance to activity. Before assessing a client’s respirations, a nurse should be aware of:

v     The client’s normal breathing pattern.

v     The influence of the client’s health problems on respirations.

v     Any medications or therapies that might affect respirations.

v     The relationship of the client’s respirations to cardiovascular function.

Characteristics of Normal Respiration

  1. Respiratory rate

This is described in breaths per minute. A healthy adult normally takes between 15 and 20 breaths per minute. Breathing that is normal in rate is eupnea. Abnormally slow respirations are referred to as bradypnea, and abnormally fast respirations are called tachypnea or polypnea.

  1. Depth

This can be established by watching the movement of the chest. It is generally described as normal, deep, or shallow.

  1. Respiratory rhythm or pattern

This refers to the regularity of the expirations and the inspirations. Normally, respirations are evenly spaced. Respiratory rhythm can be described as regular or irregular.

  1. Respiratory quality or character

This refers to those aspects of breathing that are different from normal, effortless breathing. It includes:

  1. Amount of effort a client must exert to breathe. Usually, breathing does not require noticeable effort.
  2. The sound of breathing. Normal breathing is silent, but a number of abnormal sounds such as a wheeze are obvious to the nurse’s ear.

4. BLOOD PRESSURE

            This is the force exerted by the blood against a vessel wall. Arterial blood pressure is a measure of the pressure exerted by the blood as it flows through the arties. There are two blood pressure measures:

  1. Systolic pressure. This is the pressure of the blood because of contraction of the ventricles, which is the height of the blood wave.
  2. Diastolic pressure. This is the pressure when the ventricles are at rest. It is the lower pressure present at all times within the arteries.

Pulse pressure is the difference between the diastolic and systolic pressures.

            Blood pressure is measured in millimeters of mercury (mm Hg) and recorded as a fraction. The systolic pressure is written over the diastolic pressure. The average blood pressure of a healthy adult is 120/80 mm Hg. A number of conditions are reflected by changes in blood pressure. The most common is hypertension, an abnormally high blood pressure. Hypotension is an abnormally low blood pressure below 100min Hg systolic.

Physiology of Arterial Blood Pressure

1)      Pumping action of the heart

Cardiac output is the volume of blood pumped into the arteries by the heart. When the pumping action of the heart is weak, less blood is pumped into arteries, and the blood pressure decreases. When the heart’s pumping action is strong and the volume of blood pumped into the circulation increases, the blood pressure increases. Cardiac output increases with fever and exercise.

2)      Peripheral Vascular Resistance

This can increase blood pressure. The diastolic pressure is especially affected. The following are factors that create resistance in the arterial system:

a.       Size of the arterioles and capillaries. This determines in great part the peripheral resistance to the blood in the body pressure, whereas decreased vasoconstriction lowers the blood pressure.

b.      Compliance of the arteries. The arteries contain smooth muscles that permit them to contract, thus decreasing their compliance (distensibility). The major factor reducing arterial compliance is pathologic change affecting the arterial walls. The elastic and muscular tissues of the arteries are replaced with fibrous tissues. The condition, most common in middle-aged and elderly adults, is known as arteriosclerosis.

c.       Viscosity of the blood.

3)      Blood volume. When the blood volume decreases, the blood pressure decreases because of decreased fluid in the arteries. Conversely, when the volume increase, the blood pressure increases because of the greater fluid volume within the circulatory system.

4)      Blood viscosity. This is a physical property that results from friction of molecules in a fluid. The blood pressure is higher when the blood is highly viscous, that is, when the proportion of RBC’s to the blood plasma is high. This ratio is referred to as the hematocrit is more than 60 to 65%

Factors Affecting Blood Pressure

1.)      Age. Newborn have a mean systolic pressure of 78mmHg. The pressure rises with age. The pressure rises with age, reaching a peak at the onset of puberty, and then tends to decline somewhat.

2.)      Exercise. Physical activity increase both the cardiac output and hence the blood pressure. Thus, a rest of 20 to 30 minutes is indicated before the blood pressure can be readily assessed.

3.)      Stress. Stimulation of the sympathetic nervous system increase cardiac output and vasoconstriction of the arterioles, thus increasing the blood pressure.

4.)      Race. African – American males over 35 years have higher blood pressure than European – American males of the same age.

5.)      Obesity. Pressure is generally higher in some overweight and obese people than in people of normal weight.

6.)      Sex. After puberty, females usually have lower blood pressures than males of the same age; this difference is thought to be due to hormonal variations. After menopause, women generally have higher blood pressures than before.

7.)      Medications. Many medications may increase or decrease the blood pressure; nurses should be aware of the specific medications a client is receiving and consider their possible impact when interpreting blood pressure readings.

8.)      Diurnal variations. Pressure is usually lowest early in the morning, when the metabolic rate is lowest, then rises throughout the day and peaks in the late afternoon or early evening.

9.)      Disease process. Any conditions affecting the cardiac output, viscosity, and or compliance of the arteries have a direct effect on the blood pressure.

Common Errors in Blood Pressure Assessment

 
Error Effect 
Bladder cuff too narrow Erroneously high
Bladder cuff too wide Erroneously high
Arm unsupported  Erroneously high
Insufficient rest before the assessment Erroneously high
repeating assessment too quickly Erroneously high
Cuff wrapped too loosely or unevenly    Erroneously high
Deflating cuff too quickly Erroneously low systolic and high diastolic reading
Deflating cuff too slowly Erroneously high diastolic reading
Failure to use the same arm consistently Inconsistent measurements
Arm above level of the heart Erroneously low
Assessing immediately after a meal or while client smokes Erroneously high
Failure to identify auscultatory gap pressure Erroneously low systolic pressure and erroneously low diastolic

 

Auscultatory gap is the temporary disappearance of sounds normally haerd over the brachial artery when the cuff pressure is high and the reappearance of the sounds at a lower level.

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