Chapter 19: Vital Signs

Three Stages of Fever:

(1) Initial phase (febrile episode or onset): the period when body temperature is rising but has not yet reached the new set point; the person usually feels chilly and generally uncomfortable and may shiver (2) Second phase (course): the period when the body temperature reaches its maximum (set point) and remains fairly constant at the new higher level; the person is flushed and feels warm and dry (can last a few days to a few weeks) (3) Third phase (defervescence or crisis): the period when the temperature returns to normal; the person feels warm and appears flushed in response to vasodilation; diaphoresis occurs, which assists with heat loss by evaporation--commonly referred to as the fever's *"breaking"*

Average Temperature, Pulse, Respiration, and Blood Pressure by Age

*NEWBORNS: -Temperature (AXILLARY): 98.2°F (36.8°C) -Pulse: 130 (80-180) beats/min -Respiration: 40-90 breaths/min -Blood Pressure: 80/40 mm Hg *1-3 YEARS: -Temperature (RECTAL): 99.9°F (37.7°C) -Pulse: 110 (80-150) beats/min -Respiration: 20-40 breaths/min -Blood Pressure: 98/64 mm Hg *6-8 YEARS: -Temperature (ORAL): 98.6°F (37°C) -Pulse: 95 (75-115) beats/min -Respiration: 20-25 breaths/min -Blood Pressure: 102/56 mm Hg *10 YEARS: -Temperature (ORAL): 98.6°F (37°C) -Pulse: 90 (70-100) beats/min -Respiration: 17-22 breaths/min -Blood Pressure: 110/58 mm Hg *TEEN: -Temperature (ORAL): 98.6°F (37°C) -Pulse: 80 (55-105) beats/min -Respiration: 15-20 breaths/min -Blood Pressure: 110/70 mm Hg *ADULT: -Temperature (ORAL): 98°F (36.7°C) -Pulse: 80 (60-100) beats/min -Respiration: 12-20 breaths/min -Blood Pressure: <120/80 mm Hg *ADULT OLDER THAN 70: -Temperature (ORAL): 95°F to 96.8°F (35°C to 36°C) -Pulse: 80 (60-100) beats/min -Respiration: 12-20 breaths/min -Blood Pressure: 120/80 up to 160/95 mm Hg

Respiration: Pain

-Acute pain causes an increase in respiratory rate but a decrease in depth

Blood Pressure: Diseases

-Diseases that affect the circulatory system or any of the major organs of the body may affect BP

When you assess respiration, it is important to assess for clinical signs of ____ and _____

-Oxygenation; perfusion

Respiration: Position

-Standing maximizes respiratory depth; lying flat reduces respiratory depth -Slumping (sitting with shoulders forward, and the back curved in a C shape) prevents chest expansion, which impedes breathing

Use the Apical Site when:

-The radial pulse is weak or irregular -The rate is less than 60 beats/min or greater than 100 beats/min -The patient is taking cardiac medications (e.g., digitalis) -The patient is an infant or is a child up to age 3 (because peripheral pulses may be difficult to palpate)

Conduction

-Transfer of heat from a warm to a cool surface by direct contact -Example: sitting on a cold metal chair. The body transfers heat to the chair and warms it

Temperature Site: Temporal Artery

Advantages: -Most accurate representation of core temperature -No discomfort -Safe; can be used even for those who cannot follow instructions (e.g., infants) -Less prone to error -Fast (about 3 seconds) Disadvantages: -Requires special scanning thermometer -Any covering (hat, hair, etc.) presents heat and causes the reading to be falsely high

When a client's VS vary from their baseline, ______

Assess and document them more frequently. Perhaps every 5 to 15 minutes

To keep the body temperature constant, the body must balance _____

Heat production and heat loss

You can usually palpate only the _____ pressure

Systolic

Heat Stroke

- Temperature: above 103°F (above 39.4°C) -Symptoms: rapid, strong pulse; throbbing headache; delirium; confusion; impaired judgement; lethargy; red, hot dry skin; dizziness; seizures; and coma

Korotkoff Sounds

-1st sound: Systolic BP -2nd sound: occurs as you further deflate the cuff. It is a soft, swishing sound caused by blood turbulence -3rd sounds: begins midway through the BP and is a sharp, rhythmic tapping sound -4th sound: like the 3rd sound, but softer and fading -5th sound: Diastolic BP; silence

Blood Pressure: Family History

-A family history of hypertension markedly increases the likelihood of an individual's developing hypertension

Cough

-A forceful or violent expulsion of air during expiration -May be constant (occurring frequently and consistently) or intermittent (occurring occasionally) -If secretions are expectorated (coughed up), the cough is PRODUCTIVE; if no secretions are produced, the cough is NONPRODUCTIVE/DRY -A HACKING COUGH is a series of dry cough that occur together, whereas a WHOOPING COUGH is a sudden, periodic cough that ends with a whooping sound on inspiration -Coughs may be symptoms of allergic reactions, lung disease, respiratory infection, or heart conditions

Respiration: Developmental Level

-A newborn's respiratory rate usually ranges from 40 to 60 breaths/min -The rate gradually decreases until it reaches the normal adult rate of 12 to 20 breaths/min. The respiratory rate decreases slightly in older adults

Pulse Oximetry

-A noninvasive method of monitoring oxygenation with a device that measures OXYGEN SATURATION (an indication of the oxygen being carries by hemoglobin in the arterial blood) -The oximeter emits light, and a photosensor placed on the client's finger or earlobe measures the light passing through the site and calculate a pulse saturation that is a good estimate of arterial oxygen saturation -The only risk in pulse oximetry is that clinicians may become overdependent on it or trust erroneous readings; do not neglect the other aspects of holistic respiratory assessment

Hypertension

-A persistently higher than normal BP -Major cause of illness and death in the United States -Diagnosed when BP is higher than 140 mm Hg systolic or above 90 mm Hg diastolic on 2 or more separate occasions -*Prehypertension* is a BP reading of 120 to 139 mm Hg systolic or 80 to 89 mm Hg diastolic obtained with 2 readings taken 6 minutes apart with the patient sitting -The Joint National Committee's latest guidelines recommend that even prehypertension be treated by lifestyle modifications to prevent coronary artery disease

Fever (Pyrexia)

-A temperature above the person's usual range of normal -Occurs in response to pyrogens (fever-producing substances); when bacteria or other foreign substances invade the body, they stimulate phagocytes, which ingest the invaders and secrete pyrogens; pyrogens induce secretions of prostaglandins (substances that reset [set point] the hypothalamic thermostat at a higher temperature); -A person with a fever is said to be *febrile*; one without fever is *afebrile* -A single high reading may not indicate fever; you need several readings at different times of the day, as well as the person's usual normal reading

Blood Pressure: Race

-African Americans have a higher rate of hypertension than do European Americans, and they have a higher incidence of complications and hypertension-related death

Pulse Site: Dorsalis Pedis

-Also called "pedal pulse" and "posterior tibial arteries" -For assessing peripheral circulation (feet and legs)

Core Temperature

-An adult's normal internal temperature -Ranges from 97°F to 100.8°F (36.1° C to 38.2°C) -Usually not convenient to measure -Typically 1°F to 2°F (0.6°C to 1.2°C) higher than surface (skin) temperatures -Examples: rectal and tympanic membrane measurements

Blood Pressure: Developmental Stage

-An average newborn has a systolic BP of about 40 mm Hg; it increases gradually throughout childhood -A childhood or adolescent's BP depends on body size; a smaller child or adolescent has a lower blood pressure than does a larger child -Both systolic and diastolic BP continue to increase with age as a result of decreased arterial compliance

Blood Pressure (BP)

-An important indicator of overall cardiovascular health, is the pressure of the blood as it is forced against arterial walls during cardiac contraction -Adequate blood pressure is essential for healthy tissue perfusion -Measured in mm Hg and is recorded as systolic pressure over diastolic pressure

Cardiac Function

-An increase of cardiac output causes an increase in BP; a decrease in cardiac output causes a decrease in BP -Conditions that increase cardiac output by increasing stroke volume include: -Increased blood volume (e.g., occurs during pregnancy) -More forceful contraction of the ventricles (e.g., as occurs during exercise) -Conditions that decrease cardiac output by decreasing stroke volume include: -Dehydration -Active bleeding -Damage to the heart -A rapid heart rate

Two methods that measure oxygen and carbon dioxide blood levels:

-Arterial blood gas (ABG) sampling -Pulse oximetry

Blood Pressure: Obesity

-As a rule, obesity increases BP; this increase is related to the additional vascular supply required to perfuse the large body mass and the resultant increase in peripheral resistance

What site should be used when assessing blood pressure?

-Avoid assessing blood pressure in an arm that has an IV device, renal dialysis fistula, or skin graft; that is paralyzed, diseased, or has extensive trauma; that has a cast or dressings; or that is on the same side of breast or shoulder surgery -In these and similar instance, you can use the forearm, thigh, or calf -Systolic pressure may be 20 to 30 mmHg higher in the lower extremities than the arms, but diastolic pressure are similar -Forearm and upper arm reading may not be interchangeable

Bloop Pressure: Body Position

-BP is higher when a person is standing than when they are sitting or lying down -Readings are higher if taken with the client's arm above heart level or if the arm is unsupported at the client's side -Seated readings are higher if the client's feet are dangling rather than resting on the floor or if the legs are crossed at the knees

You cannot reliably convert temperatures mathematically ______

-Between sites *When you measure a temp., record the value you obtain and the site used*

Behavioral Control of Temperature

-Body temperature is under our voluntary control -Examples: when people feel cool, they turn up the thermostat, put on more clothing, or move to a warmer place. When they feel too warm, they can turn on an air conditioner, remove some clothing, or take a cool shower

Blood pressure regulation is influenced by 3 factors:

-Cardiac function -Peripheral vascular resistance -Blood volume

Respiration: Medications

-Central nervous system depressants, such as morphine or general anesthetics, cause slow, deeper respirations -Caffeine and atropine can cause shallow, fast breathing

Respiration: Smoking

-Chronic smoking increases resting respiratory rate as a result of changes in airway compliance (elasticity)

If a peripheral pulse is absent or weak, it may be because _____

-Circulation is compromised in that extremity -PALLOR: refers to the paleness of the skin in one area when compared to another part of the body -CYANOSIS: a bluish or grayish discoloration of the skin due to the deficient oxygen in the blood

What factors influence respiration?

-Developmental level -Exercise -Pain -Stress -Smoking -Fever -Hemoglobin -Disease -Medications -Position

What factors influence pulse rate?

-Developmental level -Gender -Exercise -Food -Stress -Fever -Disease -Blood loss -Position Changes -Medications

Factors that influence blood pressure

-Developmental stage -Gender -Family history -Lifestyle -Exercise -Body position -Stress -Pain -Race -Obesity -Diurnal Variations -Medications -Diseases

Hypotension

-Diagnosed when systolic BP is less than 100 mm Hg - A low BP is usually not considered a problem; however, further evaluation is always called for if the client is also experiencing dizziness, fatigue, concentration problems, activity intolerance, or shortness of breath, or; the low blood pressure is of sudden onset

Primary/Essential Hypertension

-Diagnosed when there is no known cause for the increase -Accounts for at least 90% of all cases of hypertension

Blood pressure may be assessed directly or indirectly:

-Direct method: a catheter is threaded into an artery under sterile conditions and attached to tubing that is connected to an electronic monitoring system; the pressure us constantly displayed as a waveform on the monitor screen; although this method is very accurate, its used is confined to critical care areas and surgery because of the risk of arterial blood loss -Indirect method: most common method (noninvasive); an accurate estimate of arterial BP that can be performed in any clinical or community setting

Arterial Blood Gas (ABG) Sampling

-Directly measures the partial pressures of the gases in the arterial blood: oxygen and carbon dioxide and blood pH -This method requires the puncture of an artery followed by laboratory testing of the sample -It provides comprehensive data, but it is invasive, painful, time consuming, and relatively expensive

Pulse: Disease

-Diseases, such as heart disease, hyperthyroidism, respiratory diseases, and infections, are generally associated with increased pulse rates -Hypothyroidism is associated with decreased pulse rates

Expiration

-Expulsion of air from the lungs -When the diaphragm and thoracic muscles relax, the chest cavity decreases in size, and the lungs recoil, forcing air from the lungs until the pressure within the lungs again reaches atmospheric pressure -Expiration is passive and normally takes 2-3 seconds

Blood Pressure: Stress

-Fear, worry, excitement, and other stressors cause BP to rise sharply because of sympathetic nervous system stimulation -Example: "white-coat hypertension;" occurs when a patient's BP is elevated in the physician's office or clinic

Hyperpyrexia

-Fever above 105.8°F (41.0°C) -Dangerous and requires intervention

Pulse Site: Radial Artery

-For routine assessment of vital signs -The most commonly used site because it is easily found and readily accessible

Blood Pressure: Diurnal Variations

-Generally, BP varies according to the person's daily schedule and routines -BP is lower while the person is sleeping and when they first gets up, rising during the day and dropping again toward bedtime

Piloerection

-Hairs standing on end -Not an important heat-conserving mechanism in humans

Pulse: Gender

-In general, adult women have a slightly higher pulse rate than do adult men

Commonly used frequencies of assessing vital signs

-In the hospital: once every 4 to 8 hours -In the home health setting: at each visit -In the clinic: at each visit -In skilled nursing facilities (convalescent hospitals): weekly to monthly

Hypoxia

-Inadequate cellular oxygenation -Signs include: pallor or cyanosis, restlessness, apprehension, confusion, dizziness, fatigue, decreased level of consciousness, tachycardia, tachypnea, and changes in blood pressure -When evaluating cyanosis, the tongue and oral mucosa are the best indicators of hypoxia

Chemical Respiration

-Includes: (1) External respiration: the exchange of oxygen and carbon dioxide between the alveoli and the pulmonary blood supply (2) Gas transport: the transport of these gases throughout the body (3) Internal respiration: the exchange of these gases between the capillaries and body tissue cells

Blood Pressure: Lifestyle

-Increased sodium consumption, smoking, and consumption of three or more alcoholic drinks per day have been shown to elevate BP -Caffeine may raise BP for a short while after ingestion, but it has no long-term effect on the BP

Pulse: Food

-Ingestion of a meal causes a slight increase in pulse rate for several hours

Mechanical Respiration

-Involve the active movement of air into and out of the respiratory system; known as PULMONARY VENTILATION (breathing)

Hyperthermia

-Is diagnosed when a person's body temperature is *above normal* -Defining characteristics: convulsions, flushed skin, tachycardia, tachypnea, and warmth to touch -Can result in heat exhaustion or heat stroke

Hypothermia

-Is diagnosed when a person's body temperature is *below normal* -Defining characteristics: cool skin, cyanotic nailbeds, elevated blood pressure, pallor, piloerection, shivering, slow capillary refill, and tachycardia -Rewarm a patient who is severely hypothermic gradually to prevent complications, such as shock or dysrhythmias (abnormal heartbeats) and to ensure core, as well as surface, warming -*Don't use electric blankets; vasoconstricted skin burns easily* -*Don't apply pulse oximetry probes to a vasoconstricted finger*

Blood Pressure: Medications

-Many medications alter BP -This effect may be intended, as with antihypertensive medications, or unintended, such as the drop in BP that often results when a client receives pain medication -Many over-the-counter preparations, herbal products, and illicit drugs can affect BP

Vital Signs: Average Normal Findings for Adults

-Mean Adult Temperature: 1. Oral: 98°F (36.7°C) 2. Rectal: 98.6°F (37°C) -Pulse 1. Normal Range: 60-100 beats/min 2. Average: 80 beats/min -Respirations 1. Normal Range: 12-20 breaths/min -Blood Pressure 1. Normal Range: Systolic: 100-119 mm Hg Diastolic: 60-80 mm Hg 2. Prehypertensive: Systolic: 120-139 mm Hg Diastolic: 80-89 mm Hg 3. Average: 110/70 mm Hg

Pulse: Exercise

-Muscle activity normally increases the pulse rate -After exercise, a well-conditioned heart returns to normal more quickly than does a non conditioned heart -People who are well-conditioned have lower heart rates, both before and during exercise, than do those who are not

Respiration: Exercise

-Muscular activity causes a temporary increase in respiratory rate and depth so as to increase oxygen availability to the tissue and to rid the body of excess carbon dioxide

Pulse: Developmental Level

-Newborns have a rapid pulse rate -The rate stabilizes in childhood and gradually slows through old age

Frequency is determined by:

-Nursing judgement -Client's condition -Physician's orders -Facility standards

Orthostatic (postural) Hypotension

-Occurs when a person's BP drops suddenly on moving from a lying position to a sitting or standing position -Joint National Committee definition: a decrease of 10 mm Hg in standing BP when associated with dizziness and/or fainting -Most likely to occur in older adults, pregnant women, clients on prolonged bed rest, and clients with decreased blood volume (e.g., from dehydration or recent blood loss

Hyperventilation

-Occurs when rapid and deep breathing result in excess loss of carbon dioxide (hypocapnia) -A client who is hyperventilating may complain of feeling lightheaded and tingly -Cause of hyperventilation include anxiety, infection, shock, hypoxia, drugs, diabetes mellitus, or acid-base imbalance

Hypoventilation

-Occurs when the rate and depth of respirations are decreased and carbon dioxide is retained or alveolar ventilation is compromised -May be related to chronic obstructive pulmonary failure, or other conditions that result in decreased respirations

Common occasions for assessing vital signs

-On admission to the hospital -For inpatients, at the beginning of a shift -At a visit to the healthcare provider's office or clinic -Before, during, and after surgery or certain procedures -To monitor the effects of certain medications or activities -Whenever the patient's condition changes

Blood Pressure: Pain

-Pain often causes the BP to increase. However, severe or prolonged pain can significantly decrease BP

Blood Pressure: Exercise

-Physical fitness has been shown to reduce BP in many individuals; however, muscular exertion temporarily increases BP as a result of increased heart rate and cardiac output -You should wait 30 minutes before you asses the BP of someone who has been physically active

Respiration: Stress

-Psychological stress, such as anxiety or fear, may markedly influence respiration as a result of sympathetic stimulation -The most common change is an increase in rate

Respiratory Effort

-Refers to the degree of work required to breathe -Normal breathing is effortless -When diseases such as asthma or pneumonia are present, the person must work harder to breathe -Increased effort with breathing is called DYSPNEA, or labored breathing; it is uncomfortable for the client and frequently produces fatigue and fear -ORTHOPNEA is difficulty or inability to breathe when in a horizontal position

Breath Sounds

-Requires a stethoscope to listen -Normal respirations are quiet -Abnormal (adventitious) sounds include: (1) WHEEZES: high-pitched, continuous musical sounds, usually heard on expiration. They are caused by narrowing of the airways; can often be heard without a stethoscope (2) RHONCHI: low-pitched, continuous gurgling sounds caused by secretions in the large airways; they often clear with coughing (3) CRACKLES: caused by fluid in the alveoli; they are discontinuous sounds usually heard on inspiration, but they may be he heard throughout the respiratory cycle; they may be high-pitched, popping sounds or low-pitched, bubbling sounds, and they have been described as being similar to the sound made by running strands of hair together with the fingertips (4) STRIDOR: a piercing, high-pitched sound that is heard without a stethoscope, primarily during inspiration, in infants who are experiencing respiratory distress or in someone with an obstructed airway (5) STERTOR: refers to labored breathing that produces a snoring sounds, common with mouth breathing due to nasal congestion; the "death rattle" is a type of stertorous breathing

Respiration: Hemoglobin

-Respiratory rate and depth increase as a result of anemia (reduced hemoglobin), sickle cell anemia (abnormally shaped RBC's), and high altitudes -When hemoglobin is decreased or abnormal, the rate and depth of respirations, as well as the heart rate, may increase to maintain adequate tissue oxygenation -High altitudes inhibit the binding of oxygen to hemoglobin and trigger similar compensation efforts

Respiratory Rhythm

-Rhythm is assess simply as regular or irregular -Generally, the period between each respiratory cycle is the same, and there is a regular breathing pattern -Infant breathing rhythms are more likely to be irregular than adult rhythms -An abnormal breathing pattern may indicate other healthcare problems and deserves further assessment

Pulse: Blood loss

-Small blood loss is generally well tolerated and produces only a temporary increase in pulse rate -Theoretically, a large blood loss stimulates the sympathetic nervous system, bringing about an increase in pulse rate to compensate for the decreased blood volume -Stable pulse and blood pressure alone do not ensure that there has been no blood loss

Pulse: Position Changes

-Standing and sitting positions generally cause a temporary increase in pulse rate as a result of blood pooling in the veins of the feet and legs -This decreases blood return to the heart, decreasing blood pressure and subsequently increasing heart rate

Pulse: Medications

-Stimulant drugs (e.g., epinephrine) increase pulse rate -Cardiotonics (e.g., digitalis) and opioids (e.g., narcotic analgesics) or sedative drugs decrease pulse rate

Respiratory Depth

-TIDAL VOLUME is the amount of air taken in on inspiration (about 300 to 500 mL) -Described as DEEP (taking in a very large volume of air and fully expanding one's chest or abdomen), SHALLOW (when the chest barely rises and is difficult to observe, or NORMAL (between shallow and deep)

The most frequent measurements obtained in healthcare include:

-Temperature -Pulse -Respiration -Blood pressure -Oxygen saturation

Heat Exhaustion

-Temperature: 98.6°F to 103°F (37°C to 39.4°C) -Warning signs: weakness, nausea, vomiting, syncope, tachycardia, tachypnea, muscle aches, headache, diaphoresis (heavy sweating), and flushed skin

Pulse Sites

-Temporal -Carotid -Brachial -Radial -Femoral -Popliteal -Posterior tibial -Dorsalis pedis

Temperature Sites

-Temporal artery -Rectal -Oral -Axillary -Tympanic membrane -Skin

Blood Pressure: Gender

-The average BP for men is slightly higher than that for women of comparable age -After menopause, a women's BP tends to increase, possibly due to a decrease in estrogen

Body Temperature

-The degree of heat maintained by the body -It is the difference between heat produced by the body and heat lost to the environment

Pulse Pressure

-The difference between the systolic and diastolic pressures -Generally, the pulse pressure should be no greater than 1/3 of the systolic pressure

Respiration

-The exchange of oxygen and carbon dioxide in the body -The process of respiration has 2 aspects: mechanical and chemical

Diastolic Pressure

-The minimum pressure exerted against arterial walls, between cardiac contractions when the heart is at rest

Respiratory Rate

-The number of times a person breathes (or completes a cycle of inhalation and exhalation) within 1 full minute -You can observe respirations by: placing your hand on the client's chest or observing the number of times the client's chest or abdomen rises and falls; placing your stethoscope on the client's chest and counting the number of inhalation and exhalation cycles

Pulse Rhythm

-The pattern of intervals between heartbeats -Dysrhythmia: abnormal rhythm -Regularly irregular: an irregular rhythm that forms a pattern -Irregularly irregular: an unpredictable rhythm

Systolic Pressure

-The peak pressure exerted against arterial walls as the ventricle contract and eject blood

Pulse: Fever

-The pulse rate tends to increase about 10 beats/min for each degree Fahrenheit of temperature elevation -The reasons are that: (1) the metabolic rate increases (2) the body attempts to compensate for the decrease in blood pressure produced by the peripheral vasodilation that occurs with fever

Pulse Quality

-The quality of a pulse is assessed by determining the pulse volume and bilateral equality of pulses -PULSE VOLUME: the amount of force produced by the blood pulsing through the arteries 0--Absent: pulse cannot be felt 1--Weak (thready): pulse is barely felt and can be easily obliterated by pressing with the fingers 2--Normal quality: pulse is easily palpated, not weak or bounding 3--Bounding or full: pulse is easily felt with little pressure; not easily obliterated

Respiration: Disease

-The rate of breathing may be increased or decreased by various diseases -For example: brainstem injuries and increased intracranial pressure may interfere with the respiratory center, inhibiting respirations or altering respiratory rhythm

Inspiration

-The ribs move upward from midline, the diaphragm move downward and out, and the abdominal organs move downward and forward, expanding the thorax in all directions -As expansion causes airway pressure to decrease below atmospheric pressure, air moves into and expands the lungs -Normally takes 1-1.5 seconds

Convection

-Transfer of heat through currents of air or water -Example: A/C unit or vent

Respiration: Fever

-When heart rate increases because of fever, respiratory rate also increases -For every 1°F (0.6°C) the temperature rises, the respiratory rate may increase up to 4 breaths/min

Pulse Site: Brachial Artery

-When performing CPR of infants -When obtaining blood pressure

Pulse Site: Carotid Artery

-When performing CPR of inpatient adults and for assessing circulation to the brain -Palpate (lightly) only one side of the neck at a time to avoid interrupting circulation to the head

Increasing Body Temperature

-When sensors in the hypothalamus detect cold, they send out impulses to increase heat production and reduce heat loss -To produce heat, the body responds by shivering and releasing epinephrine, which increases metabolism -Two mechanisms reduce heat loss: *vasoconstriction* and *piloerection*

When is it best to count a person's respirations?

-When the client is unaware, because people can control their breathing rate

Obtaining a baseline is important because _____

1. A change in vital signs may be caused by a diseased state, the effect of therapies, or merely by changes in activity and environment 2. There are normal variations in vital signs among individuals

Temperature Site: Rectal

Advantages: -Accurately represents core (internal body temperature) -Use for clients who are unable to follow directions for oral temperature monitoring, or in situations where accuracy is crucial Disadvantages: -Most clients find this method objectionable or embarrassing -*Not recommended as the first choice of site because of the risk of injury to the rectal mucosa* -Requires special positioning of the client -Does not reflect changes in core temperature as rapidly as the oral method -Presence of stool may cause inaccurate reading Contraindications: -Clients who may be injured by the method (e.g., clients who have a rectal disease, severe diarrhea, or rectal surgery; newborns, whose rectal mucosa is fragile) -Clients with cardiac surgery and some heart conditions because it can slow the heart rate by stimulating the vagus nerve -Clients with hemorrhoids -Immunosuppressed clients or those with clotting disorders

Temperature Site: Tympanic Membrane

Advantages: -Fast (2-5 seconds) -Can be used for children and for uncooperative or unconscious clients Disadvantages: -Requires a special thermometer; expensive purchase -More variable than oral or rectal sites -Must be carefully positioned to ensure accuracy; prone to caregiver measurement errors -Presence of cerumen (earwax) may affect accuracy -Significant differences have been found between readings in left and right ear of same patient -Risk of injury to tympanic membrane if not positioned carefully to avoid touching it -May be uncomfortable for the client -Chemical thermometers (skin temps.) have been found to be more accurate and reliable than tympanic membrane instruments -Hearing aids must be removed Contraindications: -Clients who have had recent ear surgery -Contraindicated in the presence of ear infection

Temperature Site: Axillary

Advantages: -Safe -Easy to use -Can be used for children and for uncooperative or unconscious clients -Recommended over rectal site for routine measurements Disadvantages: -Not reflective of core temperature -Considered one of the least accurate sites -Diaphoresis (sweating) can affect the reading -Thermometer may need to be left in place for a long time (8 min. if glass) Contraindications: -Clients who are perspiring heavily -Does not accurately diagnose fever. If fever is suspected, confirm with measurement from another route

Temperature Site: Skin (e.g., forehead)

Advantages: -Safe, convenient -Easy to use for nonprofessionals -Can be used when other sites are contraindicated -Inexpensive (chemical paper or tape is used) Disadvantages: -Forehead skin temp. is generally 28°-48°F (18°-28°C) less than core temp; if marked deviations in skin temps. are detected, the readings must be confirmed via a more reliable route Contraindications: -Should not be used when accurate, reliable readings are required (e.g., in the presence of hypothermia or heat stroke) -Accurate and reliable when obtained with an infrared skin thermometer

Temperature Site: Oral

Advantages: -Simple, convenient -Comfortable for most patients -Safe for adults and for children who are old enough to follow simple directions Disadvantages: -Glass thermometers can break if bitten -Slow; requires up to 8 minutes to ensure accurate reading (if it's glass thermometer) -Patient must keep mouth closed for several minutes (glass thermometers) -Eating, drinking (e.g., ice water, hot tea), and smoking in the 30 minutes before measurement affect the accuracy of the reading -Bradypnea may create false temperature elevations Contraindications: -Clients who cannot cooperate with the instructions or who might be injured (e.g., infants and small children; patients who have had oral surgery, breathe through the mouth, have chills, or are confused or unconscious)

The ______ pulse is the most accurate of the pulses

Apical

Which artery is usually used when assessing blood pressure?

Brachial artery

Vasoconstriction

Conserves heat by shunting blood away from the periphery (where heat is lost) to the core of the body, where blood is warmed

Pulse Site: Popliteal Artery

For assessing circulation to the lower leg

Variations in temperature, pulse, respirations, or blood pressure are indicators of a person's state of _____

Health and function of the body systems

The primary stimulus for breathing is the _____

Level of carbon dioxide tension in the blood

Radiation

Loss of heat through electromagnetic waves emitting from surfaces that are warmer than the surrounding air

Apical Site Location (Adult)

On the anterior chest at 3 inches (8 cm) or less to the left of the sternum, at the 4th, 5th, or 6th intercostal space at the midclavicular line

Surface (Skin) Temperatures

Oral and axillary measurements

Pulse: Stress

Stress triggers the fight-or-flight sympathetic nervous system response, which increases both pulse rate and strength of the heart contractions (stroke volume)

Vital Signs

Suggests assessment of vital or critical physiological functions

Pulse changes are _____ not _____

Symptoms; problems

Perfusion

The continuous supply of oxygenated blood to all body cells

Thermoregulation

The process of maintaining a stable temperature

The choice of pulse site depends on ______

The reason for assessing the pulse and/or the accessibility of a site

Pulse

The rhythmic expansion of an artery produced when a bolus of oxygenated blood is forced into it by contraction of the heart

How is Heat Produced in the Body?

Through the interaction of 3 factors: metabolism, the movement of skeletal muscles, and nonshivering thermogenesis

Pulse Site: Femoral Artery

To determine circulation to the legs, in cases of cardiac arrest, and for children

Evaporation

Water is converted to vapor and lost from the skin (as perspirations) or the mucous membranes (through the breath)

Pulse Site: Temporal Artery

When assessing circulation to the head or when other sites are not easily accessible

Decreasing Body Temperature

When heat sensors in the hypothalamus are stimulated, they send out impulses to mechanisms that inhibit heat production and activate sweating and peripheral *vasodilation* to cool the body