Knowledge of the factors influencing vital signs assists in

determining and evaluating abnormal values.

Vital signs provide a basis for evaluating response to

nursing interventions.

Measure vital signs when the patient is

inactive and the environment is controlled for comfort.

Nurses help patients maintain

body temperature by initiating interventions that promote heat loss, production, or conservation.

A fever is one of the normal

defense mechanisms of the body.

Measurement of temperature using the temporal artery is the

least invasive, most accurate method of obtaining core temperature.

Respiratory assessment includes determining the

effectiveness of ventilation, perfusion, and diffusion.

Assessment of respiration involves observing

ventilatory movements through the respiratory cycle.

Variables affecting ventilation, perfusion, and diffusion influence

oxygen saturation.

To assess cardiac function, it is easy to measure pulse rate and rhythm using the

radial or apical pulses.

Hypertension is diagnosed only after an average of

readings made during two or more subsequent visits reveals an elevated BP.

Improper selection and application of the BP measurement cuff results

in errors in BP measurement.

Changes in one vital sign often influence

characteristics of the other vital signs.

Afebrile – p 445

When the fever “breaks”, without fever

Antipyretics – p 452

substance or procedure that reduces fever

Auscultatory gap – P 463

disappearance of sound when obtaining a blood pressure; typically occurs between the first and second Korotkoff sounds.

Blood pressure – p 458

is the force exerted on the walls of an artery by the pulsing blood under pressure from the heart. Blood flows throughout the circulatory system because of pressure changes.

Bradycardia – p 455

slower than normal heart rate; heart contracts fewer than 60 times/min

Cardiac output – p 452 (CO)

Volume of blood expelled the ventricles of the heart, equal to the amount of blood ejected at each beat multiplied by the number of beats in the period of time used for computation (usually 1 minute).

Celsius – p 447

also known as centigrade, is a scale and unit of measurement for temperature.

Diastolic pressure – p 458

?Pertaining to diastole, or the blood pressure at the instant of maximum cardiac relaxation

Diffusion – p 458

movement of molecules from an area of high concentration to one of lower concentration

Dysrhythmia – p 455

Deviation from the normal pattern of the heartbeat

Eupnea – p 456

normal respirations that are quiet, effortless, and rhythmical

Fahrenheit – p 447

denotes temperature scale in which 32 degrees is the freezing point of water and 212 degrees is the boiling point of water at sea level.

Febrile – p 445

hypothalamus set point drops, initiating heat loss responses. The skin becomes warm and flushed because of vasodilation. Diaphoresis assists in evaporative heat loss.

Fever – p 445

occurs because heat-loss mechanisms are unable to keep pace with excessive heat production, resulting in an abnormal rise in body temperature.

Fever of unknown origin (FUO) – p 445

fever with undetermined cause

Frostbite – p 446

occurs when the body is exposed to subnormal temperatures. Ice crystals form inside the cell, and permanent circulatory and tissue damage occurs.

Heat exhaustion – p 446

occurs when profuse diaphoresis results in excess water and electrolyte loss. Caused by environmental heat exposure. First aid includes transporting him or her to a cooler environment and restoring fluid and electrolyte balance.

Heatstroke – p 446

a body temperature of 40° C (104° F) or more (Lewis, 2007). Heatstroke is a dangerous heat emergency with a high mortality rate.

Heatstroke exhibits signs and symptoms of fluid volume deficit

(see chapter 41)

Heatstroke - Patients at risk include the

very young or very old and those who have cardiovascular disease, hypothyroidism, diabetes, or alcoholism. Also at risk are those who take medications that decrease the ability of the body to lose heat (e.g., phenothiazines, anticholinergics, diuretics, amphetamines, and beta-adrenergic receptor antagonists) and those who exercise or work strenuously (e.g., athletes, construction workers, and farmers).

Signs and symptoms of heatstroke include

giddiness, confusion, delirium, excess thirst, nausea, muscle cramps, visual disturbances, and even incontinence. Vital signs reveal a body temperature sometimes as high as 45° C (113° F), with an increase in heart rate (HR) and lowering of BP. The most important sign of heatstroke is hot, dry skin. Victims of heatstroke do not sweat because of severe electrolyte loss and hypothalamic malfunction. If the condition progresses, the patient with heatstroke becomes unconscious, with fixed, nonreactive pupils. Permanent neurological damage occurs unless cooling measures are rapidly started.

Hematocrit – p 459

percentage of red blood cells in the blood, determines blood viscosity. When hematocrit rises and blood flow slows, arterial BP increases. The heart contacts more forcefully to move the viscous blood through the circulatory system.

Hypertension – p 460

disorder chacterized by an elevated blood pressure exceeding 120/80 mm Hg.

Hyperthermia – p 446

an elevated body temperature related to the inability of the body to promote heat loss or reduced heat production.

Hypotension – p 461

abnormal lowering of blood pressure that is inadequate for normal perfusion and oxygenation of tissues.

Hypothermia – p 446

Abnormal lowering of body temperature below 35 degrees C, or 95 degrees F, usually caused by prolonged exposure to cold.

Hypoxemia – p 456

Arterial blood oxygen level less than 60 mm HG; low oxygen level in the blood

Malignant hyperthermia – p 446

a hereditary condition of uncontrolled heat production that occurs when susceptible people receive certain anesthetic drugs.

Orthostatic hypotension – p 461

Abnormally low blood pressure occurring when a person stands

Oxygen saturation – p 457

amount of hemoglobin fully saturated with oxygen, given as a percent value.

Perfusion – p 456

the distribution of red blood cells to and from the pulmonary capillaries

Postural hypotension – p 461

abnormally low bp occurring when individual assumes the standing posture; also called orthostatic hypotension

Pulse deficit – p 455

condition that exists when the radial pulse is less than the ventricular rate as auscultated at the apex or seen on an electrocardiogram. The condition indicates a lack of peripheral perfusion for some of the heart contractions.

Pulse pressure – p 459

Difference between the systolic and diastolic pressures normally 30 to 40 mm Hg.

Pyrexia – p 445

abnormal elevation of the temperature of the body above 37° C (98.6° F) because of disease; same as fever.

Pyrogens – p 445

bacteria and viruses

Sphygmomanometer – p 461

device for measuring the arterial blood pressure that consists of an arm or leg cuff with an air bladder connected to a tube, a bulb for pumping air into the bladder, and a gauge for indicating the amount of air pressure being exerted against the artery.

Systolic pressure – p 458

pertaining to or resulting from ventricular contraction

Tachycardia – p 454

rapid heart rate ranging between 100 and 150 beats/min

Ventilation – p 456

Respiratory process by which gases are moved into and out of the lungs.

Vital signs – p 441

are the most frequent measurements obtained by health care providers.

What are the most frequent Vital Signs obtained by health care providers

Vital Signs - temperature, pulse, blood pressure (BP), respiratory rate, and oxygen saturation.

Temperature, pulse, blood pressure (BP), respiratory rate, and oxygen saturation are indicators of health status, these measures indicate the

effectiveness of circulatory, respiratory, neural, and endocrine body functions.

The fifth vital sign that is frequently measured with the others (see Chapter 43) is

pain (which is a subjective symptom)

Measurement of vital signs provides data to determine a

patient's usual state of health (baseline data).

What can cause vital signs to change

temperature of the environment, the patient's physical exertion, and the effects of illness cause vital signs to change, sometimes outside an acceptable range.

Assessment of vital signs provides data to

identify nursing diagnoses, implement planned interventions, and evaluate outcomes of care.

An alteration in vital signs signals a change in

physiological function and the need for medical or nursing intervention.

Vital signs are a quick and efficient way of

monitoring a patient's condition or identifying problems and evaluating his or her response to intervention.

When you learn the physiological variables influencing vital signs and recognize the relationship of their changes to other physical assessment findings, you can

make precise determinations about a patient's health problems.

Vital signs and other physiological measurements are the basis for

clinical decision making and problem solving.

Box 29-1 Vital Signs -

Acceptable Ranges for Adults - Temperature Range, Respirations, average oral/tympanic, Average rectal , Average axillary, Blood Pressure Pulse Average, Pulse pressure Temperature Range: 36° to 38° C (96.8° to 100.4° F), Respirations : 12 to 20 breaths/min, average oral/tympanic : 37° C (98.6° F), Average rectal : 37.5° C, (99.5° F), Average axillary : 36.5° C (97.7° F), Blood Pressure Pulse Average : <120/<80 mm Hg, Pulse pressure : 30 to 50 mm Hg, 60 to 100 beats/min

Box 29-2 When to Measure Vital Signs (1)

• On admission to a health care facility, • When assessing a patient during home care visits, • In a hospital on a routine schedule according to the health care provider's order or hospital standards of practice, • Before and after a surgical procedure or invasive diagnostic procedure, • Before, during, and after a transfusion of blood products,

Box 29-2 When to Measure Vital Signs (2)

• Before, during, and after a transfusion of blood products, • Before, during, and after the administration of medication or therapies that affect cardiovascular, respiratory, or temperature-control functions, • When a patient's general physical condition changes (e.g., loss of consciousness or increased intensity of pain),

Box 29-2 When to Measure Vital Signs (3)

• Before and after nursing interventions influencing a vital sign (e.g., before a patient previously on bed rest ambulates or before a patient performs range-of-motion exercises), • When a patient reports nonspecific symptoms of physical distress (e.g., feeling “funny” or “different”)

Core temperature – p 442

Temperature of the deep tissues (keeps relatively constant no matter the environmental conditional and physical activity. The measurement of body temperature aims to obtain a representative average temperature of core body tissues. Sites reflecting core temperatures are more reliable indicators of body temperature than those reflecting surface temperatures.

The site of temperature measurements are

oral, rectal, axillary, tympanic membrane, temporal artery, esophageal, pulmonary artery, or even urinary bladder. It is one factor that determines a patient's temperature. For healthy young adults the average oral temperature is 37° C (98.6° F), but normal temperatures are different for different people.

Thermoregulation – p 446

Physiological and behavioral mechanisms regulate the balance between heat lost and heat produced. Has Neural and Vascular control.

Hypothalamus controls

body temperature like a thermostat in the house.

Anterior hypothalamus controls

heat loss

Posterior hypothalamus controls

heat production

Mechanisms of heat loss include

sweating, vasodilation(widening) of blood vessels reduces blood flow to the skin and extremities. Compensatory heat production is stimulated through voluntary muscle contraction and muscle shivering.

When disease or trauma to the hypothalamus or spinal cord occurs then

vasoconstriction is ineffective in preventing heat loss shivering occurs.

Basal metabolic rate (BMR) – p 443

Basal metabolism accounts for the heat produced by the body at absolute rest. The average BMR depends on the body surface area.

What hormones affect the BMR by promoting the breakdown of body glucose and fat.

Thyroid hormones.

When thyroid homrones are secreted

the BMR can increase 100% above normal

The absence of thyroid hormones reduces the BMR by

half, causing a decrease in heat production.

The _______ sex hormone ____ increases BMR. _____ have a higher BMR then _____.

Male, testosterone, Men, women

BMR ______ during activity, sometimes causing heat production to increase up to ___ times normal.

Increases, 50

Shivering – p 443

an involuntary body responds to temperature differences in the body.

Shivering increases heat production up to 4-5 times, it helps to

equalize the body temperature, and then ceases.

In vulnerable patients shivering seriously drains energy sources causing

further physiological deterioration.

Nonshivering thermogenesis – p 443

occurs primarily in neonates. Because neonates cannot shiver, a limited amount of vascular brown tissue, present at birth, is metabolized for heat production.

Heat loss and heat production occurs at the same time due to

skin structure and exposure to the environment .

Heat loss is through

radiation, conduction, convection, and evaporation.

Radiation – p 443

the transfer of heat from the surface of one object to the surface of another without direct contact between the two.

As much as ___% of the human body radiates heat to the environment.

85

___________ vasodilation increases blood flow from the internal organs to the skin to increase ________ heat loss.

Peripheral, radiant

Peripheral _________ minimizes heat loss.

Vasoconstriction

___________ increases as the temperature difference between the objects increase, but if the environment is warmer than the skin, the body ________ heat through radiation.

Radiation, absorbs

Radiation heat loss can be considerable during ________ when the skin is subjected to a cool environment.

Surgery

The patient's position enhances radiation heat loss (e.g., _________exposes a greater radiating surface area, and lying in a ________ position minimizes heat radiation).

standing, fetal

Conduction – p 443

is the transfer of heat from one object to another with direct contact. Solids, liquids, gases conduct heat through contact.

Convection – p 444

The transfer of heat away by air movement (e.g. a fan promotes heat loss through convection). Convective heat loss increases when moistened skin comes into contact with slightly moving air.

Evaporation – p 444

is the transfer of heat energy when a liquid is changed to a gas. The body continuously loses heat by evaporation (sweat).

During physical exercise over ___% of the heat that is produced is lost.

80%

Approximately ______ to ______mL a day evaporates from the skin and lungs.

600, 900

When body temperature rises the ________ hypothalamus signals the _______ glands to release sweat through tiny ducts on the skins surface.

anterior, sweat

Diaphoresis – p 444

visible perspiration primarily occurring on the forehead and upper thorax, although you can see it in other places on the body.

Skin controls body temperature like

a radiator controls engine temperature, heated blood flows through the body to the outer surface where it cools off, repeating the cycle.

The degree of vasoconstriction determines the

amount of blood flow and heat loss to the skin.

If the core temp is too high the hypothalamus inhibits

vasoconstriction, as a result blood vessels dilated so that more blood reaches the surface to cool. Like on a hot humid day the blood vessels in the hands are dilated.