measuring vital sign

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CHAPTER 21CHAPTER 21

Measuring Vital SignsMeasuring Vital Signs

CHAPTER 21CHAPTER 21

Measuring Vital SignsMeasuring Vital Signs




Production of Body HeatProduction of Body HeatProduction of Body HeatProduction of Body Heat

� Heat is a by-product of normal body metabolism

� As metabolism increases, heat increases.

� When the body is invaded by pathogens, thebody elevates the temperature to elevate thebasal metabolic rate in an effort to destroypathogens.




Factors Affecting Body Heat ProductionFactors Affecting Body Heat ProductionFactors Affecting Body Heat ProductionFactors Affecting Body Heat Production

(«Cont¶d)

� Other hormones affecting metabolic rate:

Epinephrine

Norepinephrine Testosterone

� Men have a higher BMR than women because of testosterone.

� Voluntary muscle movement causes increasedheat production.

� Shivering can increase heat production up to fivetimes normal.




Body Temperature RegulationBody Temperature RegulationBody Temperature RegulationBody Temperature Regulation

� Hypothalamus acts as the thermostat to controlbody temperature.

� Pyrogens may increase the thermostat¶s set point(pyrexia).

� A decrease in body temperature results inperipheral vasoconstriction and shivering.

� An increase in body temperature results inperipheral vasodilatation and diaphoresis.

(Cont¶d«)




Body Temperature RegulationBody Temperature RegulationBody Temperature RegulationBody Temperature Regulation

(«Cont¶d)

� Heat loss occurs through the skin¶s exposure tothe environment through:

Radiation

Conduction

Convection

Evaporation

� Heat being lost by evaporation results in 800-mLloss of water each day.




Body Temperature MeasurementsBody Temperature MeasurementsBody Temperature MeasurementsBody Temperature Measurements

� Temperature measurements vary depending onsite used.

� Rectal temperatures are approximately1° F higher than oral temperatures.

� Axillary temperatures are approximately1° F lower than oral temperatures.

� Tympanic membrane measurementapproximates core body temperature.

(Cont¶d«)




Body Temperature MeasurementsBody Temperature MeasurementsBody Temperature MeasurementsBody Temperature Measurements

(«Cont¶d)

� Other factors affecting temperaturemeasurements:

Time of day

Environmental temperature

Age of the patient

Physical exercise

Menstrual cycle or stress Eating, drinking, mouth-breathing




PyrexiaPyrexiaPyrexiaPyrexia

Temperature higher than 100.2° F

� Pyrexia (fever) occurs when normal regulationmechanisms cannot keep up with heat producedby the body.

� Pyrogens such as bacteria cause an increasedbody temperature.

� Diaphoresis is excessive sweat production in aneffort to cool the body.




Nursing Interventions to Reduce Fever Nursing Interventions to Reduce Fever Nursing Interventions to Reduce Fever Nursing Interventions to Reduce Fever

� Increase patient¶s fluid intake

� Lower room temperature

� Increase the rate of circulating air

� Remove excessive clothing or bed covers� Control or reduce the amount of body activity

� Provide sponge bath or cooling blanket

� Antipyretics (ASA, acetaminophen)




HypothermiaHypothermiaHypothermiaHypothermia

Body temperature lower than 94° F

� People at risk for hypothermia:

Infants

Surgical patients in the operating room

Elderly exposed to cold for prolonged periods

People exposed to extreme cold weather

People exposed to cold water immersion




PulsePulsePulsePulse

� Pulse is produced by cardiac contractionscausing a pressure wave against the walls of arteries

� Cardiac contractions are normally initiated by the

sinoatrial node.� Each contraction propels 60 to 70 mL of blood

into the aorta (stroke volume).

� Stroke volume affects pulse character.

� Stroke volume x heart rate = Cardiac output(approximately 5 L/min for the average adult)

(Cont¶d«)





(«Cont¶d)

� Normally found by palpation or by auscultation

� Strength is determined by force of cardiaccontraction and circulating volume.

� Rate is affected by fever, pain, hypoxia, anxiety,exercise and cardiac disease

� Rate does not normally change with age, butarrythmias are common in the elderly.

(Cont¶d«)





(«Cont¶d)

Common pulse points:

� Radial artery in the wrist at the base of the thumb

� Temporal artery just in front of the ear � Carotid artery on the front side of the neck

� Femoral artery in the groin

� Apical pulse over the apex of the heart

� Popliteal pulse just behind the knee� Pedal pulse




Factors Affecting Pulse RateFactors Affecting Pulse RateFactors Affecting Pulse RateFactors Affecting Pulse Rate

� Age� Body build and size

� Blood pressure

� Drugs� Emotions

� Blood loss

� Exercise

� Increased body temperature� Pain

� Hypoxia




RespirationsRespirationsRespirationsRespirations

� An involuntary autonomic function� Controlled by respiratory center in the pons and

medulla in the brainstem

� Triggered by increased levels of CO2 or serumhydrogen ion concentration or by decreasedlevels of O2

� Organs of respiration

Nose, pharynx, larynx, trachea, bronchi, lungs

(Cont¶d«)




RespirationsRespirationsRespirationsRespirations

(«Cont¶d)

� Respiratory center works with feedbackmechanisms.

� The carotid body receptors alter rate and depth of respiration based on CO2 content of the blood.

� O2 and CO2 are diffused across capillaries in thelungs to maintain normal O2, CO2 and H+ levels.




Terms Used to Describe RespirationsTerms Used to Describe RespirationsTerms Used to Describe RespirationsTerms Used to Describe Respirations

� Eupnea� Dyspnea

� Tachypnea

� Hyperventilation� Cheyne-Stokes

� Apnea

� Kussmaul¶s

� Biot¶s




Blood PressureBlood PressureBlood PressureBlood Pressure

The pressure exerted on the arterial walls by thepumping action of the heart

� Affected by the condition of the vascular bed,circulating blood volume, and

cardiac output

� Changes with aging are normal

(Cont¶d«)





(«Cont¶d)

� Systolic pressure: The pressure exerted on thearterial wall during cardiac contraction

� Diastolic Pressure: The pressure exerted on thearterial wall between contractions

� Blood pressure is affected by cardiac output.

� Blood pressure increases with increases incirculating blood volume.

(Cont¶d«)





(«Cont¶d)

� If blood volume decreases beyond the vascular beds ability to compensate, blood pressure maydecrease.

Causes

� Dehydration

� Hemorrhage

� Vasoconstriction and vasodilatation alter blood

pressure to compensate for changes incirculating volume.




Changes in Vital Signs Occurring withChanges in Vital Signs Occurring with

AgingAging

Changes in Vital Signs Occurring withChanges in Vital Signs Occurring with

AgingAging

� Temperature: Heat loss may lead to hypothermiain the elderly.

� Lower metabolic rate may also result inhypothermia in the elderly.

� Respiratory rates may vary with decreases in vitalcapacity in the elderly.

� Systolic and diastolic blood pressure may risewith hardening of the arteries.




PainPainPainPain

� Pain is recognized by the JCAHO as the fifth vitalsign.

� Assessment should include:

Location

Intensity

Character

Frequency

Duration

� Pain should be measured using a standardizedpain scale.

measuring vital sign

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