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Chapter 29: Vital Signs

Most frequenttemperature, pulse, blood pressure (BP), respiratory rate, oxygen

saturation, pain

Acceptable ranges for adults

Temp 36-38*C, 96.8-100.4*F Respirations 12-20 breaths/min Pulse 60-100 beats/min Blood Pressure

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o Conductionthe transfer of heat from one object to another with directcontact (when warm skin touches a cool object)

o Convectiontransfer of heat away by air movement (promoted by a fan)o Evaporationthe transfer of heat energy when a liquid is changed to a gas

(evaporation of sweat)

oDiaphoresisvisible perspiration primarily occurring on the forehead andupper thorax

Skin regulates temp through insulation, vasocontriction, & temp sensationo Internal organs produce heat, blood flows from organs to surface, allowing

the heat to transfer to the surface of the skin and lost in the enviroment

keeping the body at a safe temp

Factors affecting Tempo Age

Infants temp control mechanisms are immatureresponddrastically to changes in environment

Older adult has narrower range (avg36*C 96.8*F)o

Exercise, stress, environmento Hormone levelsaffects women during menstrual cycle & menopauseo Feverpyrexiawhen heat loss mechanisms cant keep pace w excessive

heat production

Pyrogensbacteria/viruses that increase body temp Febrilewith fever Afebrilewithout fever FUOfever of unknown originfever w undetermined cause Antipyreticsmedications used to reduce fever

o Hyperthermiaelevated body temp related to the inability of the body topromote heat loss or reduce heat production (results from an overload ofthermoregulatory mechanisms)

Malignant hyperthermiahereditary condition of uncontrolledheat production when receiving certain anesthetic drugs

o Heat stroke 40*C 104*Fprolonged exposure to high environmentaltemp that overwhelms heat loss mechanisms of the body

o Heat exhaustionoccurs when profuse diaphoresis results in excess waterand electrolyte loss

o Hypothermiacaused by heat loss during prolonged exposure to cold thatoverwhelms the bodys ability to produce heat

Pulse

The palpable bounding of blood flow noted at various points in the body Electrical impulses originate from SA node, travel through heart muscle, stimulate

cardiac contraction. 60-70mL of blood enter aorta with each ventricular

contraction (stroke volume). Stroke volume ejection, walls of aorta distend and apulse wave is sent traveling through distal ends of arteries

Pulse rate = pulsing sensations/1 minute Cardiac output = volume of blood pumped by heart during 1 minute

o = heart rate x stroke volume Assessing the pulse

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o Typically use radial artery If abnormal or inaccessible assess apical pulse

o Apical rateuse stethoscope Always review baseline before measuring a pulse (for comparison) Tachycardiaelevated, above 100 beats/min Bradycardiaslow, below 60 beats/min Pulse deficitan inefficient contraction of the heart that fails to transmit a pulse

wave to the peripheral pulse site (the difference between radial and apical rates)

Dysrhythmiaan abnormal rhythymo ECG, holter monitor, telemetry monitored are ordered to document

dysrhythmia

Strength0 (absent), +1(barely palpable) +2 (normal/expected), +3 (full, strong),+4 (bounding)

Assess radial pulses on both sides for equality Normal heart rates

o Infant 120-160o Toddler 90-140o Preschooler 80-110

o School age 75-100o Adolescent 60-90o Adult 60-100

Respiration

Survival depends on ability of O2 to reach cells and CO2 to be removed fromcells

Ventilationmovement of gases in and out of the lungs Diffusionmovement of oxygen and carbon dioxide between the alveoli and

RBC

Perfusionthe distribution of RBCs to and from pulmonary capillaries Hypoxemialow levels of arterial O2 Inspirationactive processdiaphragm contracts Expirationpassive processdiaphragm relaxes Eupneanormal breathing When assessing respirationsdo NOT let the patient know because it may alter

their breathing

o Assess the rate, depth, and rhythm

Normal (breaths/min)

o Newborn 35-40o Infant (6mos) 30-50o Toddler (2 yrs) 25-32o Child 20-30o Adolescent 16-20o Adult 12-20

Oxygen Saturationevaluates processes of diffusion and perfusion

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o The percent of hemoglobin that is bound with oxygen in the arteries(SaO2)

o Normal 95%-100%o Measured by pulse oximeter

Blood Pressure

The force exerted on the walls of an artery by the pulsing blood under pressurefrom the heart.

Blood moves from area of high pressure to one of low pressure Systemic, arterial BPgood indicator of cardiovascular health Systolic pressurepeak of maximum pressure when ejection occurs Diastolic pressurewhen the ventricles relax, the blood remaining in the arteries

exert this pressure. Minimal pressure exerted against the arterial walls at all times

Reported as systolic/diastolic (ex 120/80) mm Hg Difference between systolic and diastolic is Pulse Pressure Physiology of arterial blood pressure

o Cardiac output rises, more blood pumped against walls, BP increaseso Changes in HR occur faster than blood volume/muscle contractibilitya

rapid or significant increase in HR will decrease filling time of heart andreduce BP

o As peripheral resistance rises, BP rises. As vessels dilate and resistancefalls, BP drops

o Increase in blood volume, more pressure, higher BP. Decrease in volume(hemorrhage, dehydration) BP drops.

o Hematocritpercentage of RBC in blooddetermines viscositythickness of blood.

Hematocrit rises, BP increases.o Systolic pressure is more significantly elevated than diastolic pressure as a

result of reduced arterial elasticity

Factors influencing blood pressureo Age, stress, ethnicity, gender, daily variation, medications, activity and

weight, smoking

Average optimal blood pressureo Newborn 40 (mean)o 1 month 85/54o 1 year 95/65o 6 years 105/65

o 10-13 years 110/65o 14-17 years 119/75o 18+ years 140o Most common change in BP and often asymptomatico Associated with thickening and loss of elasticity in arterial walls

Hypotension (low BP)o Present when systolic BP falls to 90 mm Hgo Occurs because of dilation of the arteries in the vascular bed, loss of

substantial amount of blood, or failure of heart muscle to pump adequately

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o Pallor, skin mottling, clamminess, confusion, inc HRo Orthostatic hypotension aka postural hypotensionwhen a normotensive

person develops symptoms and low BP when rising to an upright position

Use sphygmomanometer and stethoscope Size of the cuff is importanttoo big/too small can give incorrect numbers Best environment is a quiet room, with comfortable temp Take BP in both arms and compare (ask) patients normal Phase 1sharp thump (systolic pressure) Phase 2a blowing or whooshing sound Phase 3a crisp intense tapping Phase 4a softer blowing sound that fades Phase 5silence (diastolic pressure) Can also use ultrasonic stethoscope or palpation (indirect measurement) when

patient has weakened arterial pulse

Electronic blood pressure devices are also usedmore sensitive to outsideinterference and susceptible to error

Patients are able to keep track of their own BP at home with electronic devicesthat start with the push of a button

o Also have machines in pharmacies and other storesPages 469-484 have step by step instructions to take vital signs