Transcript Chapter 24

Chapter 24
Vital Signs
Vital Signs
 Temperature
 Pulse
 Respiration
 Blood Pressure
 Pain
Temperature
 Heat Production
 Heat Loss
Temperature
 Core Temperature
 Surface Temperature
Variations in Body
Temperature
 Factors Affecting Body Temperature
 Circadian Rhythms
 Age and Sex
 Environmental Temperature
 Hypothermia – low body temperature
 Hyperthermia – high body
temperature
Normal Body Temperature
 Varies 0.3 to 0.6 degrees C (0.51.0 degrees F).
 Afebrile – a person with a normal
body temperature
Increased Body
Temperature
 Pyrexia (fever) –Febrile – a person with an
increased body temperature.
 Hyperpyrexia – a high fever, usually above 41
degrees C (105.8 degrees F).
 Hyperthermia- differs from pyrexia – hypothalamic
set point is not changed, but in extreme heat
exposure or excessive heat production, the
mechanisms that control body temp are ineffective.
 Neurogenic fever – result of damage to the
hypothalamus from intracranial trauma, intracranial
bleeding, or increased intracranial pressure.
Physical Effects of Increased
Body Temperature
 Loss of appetite, headache,
hot, dry skin, flushed face,
thirst, and general malaise.
 Young children may experience
delirium or seizures
 Assess for potentially
dangerous manifestations of a
fever, such as dehydration,
decreased urinary output, and
rapid heart rate.
 Methods of reducing
Decreased Body
Temperature
 Hypothermia – body temp below the
lower limit of normal.
 Death may occur when temp falls
below 34 degrees C (93.2 degrees F).
Assessing Temperature
 Equipment
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Electronic and Digital Thermometers
Tympanic Membrane Thermometer
Glass thermometer
Disposable Single-Use Thermometers
Temporal Artery Thermometer
Automated Monitoring Devices
Temperature
 Routes
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Oral most common
Rectal
Axillary
Tympanic
 Always record site when recording
temperature.
Pulse
 Throbbing sensation that can be
palpated over a peripheral artery or
auscultated (listened to ) over the
apex of the heart.
 Results as a wave of blood is
pumped into the arterial circulation
by the contraction of the left
ventricle.
Pulse Physiology
 Pulse regulated by the ANS through the
cardiac SA node (pacemaker).
 Parasympathetic stimulation via the vagus
nerve decreases the HR, and sympathetic
stimulation increased the HR and force of
contraction.
 Pulse rate is the number of pulsations felt over
a peripheral artery or heard over the apex of
the heart in 1 minute.
Variations in Pulse Rate
 Pulse Rate
 Normal range 60 – 100
 Increased to 100 – 180 Tachycardia
 Decreased below 60 Bradycardia
Variations in Pulse
Amplitude and Quality
 Pulse Amplitude and Quality
 Quality of pulse in terms of its fullness and reflects
the strength of left ventricular contraction.
 Assessed by the feel of the blood flow through the
vessel.
 Amplitude is normally strong in areas where an
artery can be palpated.
 Absent (0), Thready (1+), Weak (2+), Normal (3+),
Bounding (4+)
Variations in Pulse
Rhythm
 Pulse Rhythm
 The pattern of the pulsations and the pauses
between them.
 Normally regular
 Irregular pattern of heartbeats - dysrhythmia
Assessing the Pulse
 Palpating peripheral arteries or by
auscultating the apical pulse with a
stethoscope.
 Equipment
 Stethoscope
Sites and Methods of
Assessing the Pulse
 Peripheral Arterial Pulses – place the middle three
fingers over the artery and lightly compress the artery
so pulsations can by felt and counted.
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Temporal
Carotid – during emergency situations
Brachial – used for infants who have had a cardiac arrest
Radial – most commonly used in children and adults
Femoral
Popliteal
Posterior tibial
Dorsalis pedis
Pulse
 Apical Pulse
 Apical-Radial Pulse
Respirations
 Pulmonary ventilation (or breathing) is movement of air
in and out of the lungs; inspiration (or inhalation) is the
act of breathing in, and expiration ( or exhalation) is the
act of breathing out.
 External respiration is the exchange of oxygen and
carbon dioxide between the alveoli of the lungs and the
circulating blood through diffusion.
 Internal respiration is the exchange of oxygen and
carbon dioxide between the circulating blood and
tissue cells.
Respiration Physiology
 Rate and depth of breathing can change
in response to body demands.
 Increase in carbon dioxide is the most
powerful respiratory stimulant, causing
an increase in respiratory depth and rate.
 The cerebral cortex of the brain allows
voluntary control of breathing.
Variations in Respiratory
Rate and Depth
 Normally smooth, effortless, and without
conscious effort.
 Factors Affecting Respiration
 Respiratory Rate (12 to 20 times each minute)
 Normal – eupnea (1 resp to 4 heartbeats)
 Increased – tachypnea – occurs inresponse
to the increased metabolic rate during fever
(pyrexia).
 Decreased – bradypnea – occurs in some
pathologic conditions.
Respiratory Depth and
Rhythm
 Normally from shallow to deep.
 Apnea – no breathing
 If lasts longer than 4 to 6 minutes, brain
damage and death might occur.
 Dyspnea – difficult or labored breathing
Assessing Respirations
 Rate, Depth, and Rhythm by inspection
(observing and listening) or by listening with
the stethoscope.
 Monitoring arterial blood gas results and using
a pulse oximeter to determine oxygenation of
blood.
 Depth – assessed by observing the degree of
excursion or movement in the chest wall.
 Rhythm
Alterations in Respirations
 Bradypnea - <10 rate reg but abn slow.
 Tachypnea - > 24 rate reg but abn rapid.
 Hyperpnea – resp labored, increase in
depth, increase in rate > 20 (occurs
normal in exercise).
 Apnea – respirations cease for several
second. Persistent cessation results in
respiratory arrest.
Alterations in Respirations
 Hyperventilation – increased rate and depth
 Hypoventilation – decreased rate and depth;
irregular
 Cheyne-Stokes Respirations – Alternating
periods of deep, rapid breathing followed by
periods of apnea.
 Kussmauls’s Respirations – abnormally
deep; regular and increase in rate.
 Biolt’s Respirations – varying depth and rate
of breathing, followed by periods of apnea.
Oxygen Saturation
 Measures diffusion and perfusion.
 95% - 100% - % of hemoglobin that is
bound with oxygen in the arteries is the
% of saturation of hemoglobin (SaO2).
 Pulse oximeter – indirect measurement
 Interferance with Light Transmission
Reduction of Arterial
Pulsations
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PVD
Hypothermia
Pharmocological vasoconstrictors
Decreased Cardiac Output and
Hypotension
 Peripheral Edema
 Tight Probe
Blood Pressure
 The force of the blood against arterial walls.
 Maximum blood pressure is exerted on the
walls of arteries when the left ventricle of the
heart pushes blood through the aortic valve
into the aorta at the beginning of systole.
 Pressure rises as the ventricle contracts and
falls as the heart relaxes.
 This continuous contraction and relaxation of
the left ventricle creates a pressure wave that
is transmitted through the arterial system.
Blood Pressure
 Systolic pressure (numerator) – the highest
pressure
 Diastolic pressure (denominator) – the lowest
pressure
 Pulse pressure – the difference between
Systolic and Diastolic pressure.
 Measured in millimeters of mercury (mm Hg)
and recorded as a fraction. (Example 120/80 –
systolic 120, diastolic 80, pulse pressure 40)
Compliance
 Arteries have a considerable quantity of elastic
tissue that allows them to stretch and distend.
 Constant state of pressure in arteries which
offers the resistance.
 Elasticity of walls + resistance of the arterioles
= maintain normal blood pressure.
 With age, walls of arterioles less elastic,
decreased ability to stretch and dilate.
Ultimately limits adequate blood flow and
contributes to rising pressure.
Neural and Humoral
Mechanisms
 ANS mediates control mechanisms that function to
maintain short-term regulation of BP
 Hormones and humoral mechanisms regulate BP
 Renin-angiotensin-aldosterone system controls
vasoconstriction to increase peripheral vascular
resistance and also increases sodium and water
retention bythe kidneys to increase circulatory fluid
volume – increased BP
 ADH 0 Antidiuretic hormone – vasopressin- is release
from the posterior pituitary when stimulated by
decreased blood volume and blood pressure, or by an
increased osmolarity of the blood – water is retained to
increase circulatory fluid volume - increase BP
Cardiac Output
 Stroke Volume – quantity of blood forced
out of the left ventricle with each contraction
 Cardiac Output is the amount of blood
pumped per minute, and averages from
3.5L to 8.0 L/min in a healthy adult.
 CO = SV X HR
 Increases during exercise, decreases
during sleep.
 Varies depending on body size and
metabolic needs.
 Increased CO – arteries distend more,
increased BP.
 Decreased CO – BP falls
Variations in Blood
Pressure
 Factors Affection BP
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Age
Circadian rhythm
Sex
Food Intake
Exercise
Weight
Emotional state
Body position
Race
Drugs/Medications
Increased Blood Pressure
 Hypertension – BP is above normal for a sustained
period
 Most common health problems in adults and the
leading cause of cardiovascular disorders.
 Primary or essential HTN – without know cause.
 Secondary HTN – with know pathology.
 Major risk factor for heart disease, and most imp risk
factor for stroke.
 “Silent Killer”
 Few symptoms beyond the HTN; 22 million don’t know
Risk Factors for HTN
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Family history
Sedentary lifestyle
Obesity
Continual stress
HIGH RISK FACTORS
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Cigarette smoking
Alcohol consumption
High salt intake
High-fat, high-calorie diet
Twice as common in African Americans
as in Americans of European descent.
Treatment of HTN
 Medications
 Antihypertensive medication
 Diuretics – to decrease fluid volume.
 Beta-adrenergic blockers – to block
sympathetic stimulation and decrease
cardiac output.
 Vasodilators and calcium channel
blockers – to relax smooth muscles of
arterioles and decrease peripheral
vascular resistance.
 ACE inhibitors – to prevent
vasoconstriction by angiotensin II and
decrease circulatory fluid volume by
reducing aldosterone production.
Lifestyle Changes
 Low-calorie, low-fat diet
 Losing excess weight and
maintaining weight loss
 Limiting alcohol intake
 Eliminating smoking
 Reducing salt intake
 Regular physical activity
Decreased Blood Pressure
 Hypotension – below-normal BP
 Orthostatic hypotension (Postural
Hypotension) – low BP
Assessing Blood Pressure
 Equipment
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Sphygmonmanometer
Noninvasive BP monitors
Doppler Ultrasound
Direct Electronic Measurement
Assessment Sites and
Methods
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Korotkoff Sounds
Assessing a Brachial Artery BP
Assessing a Popliteal Artery BP
Palpating the BP
Blood Pressure Assessment
Errors and Contributing
Causes
 See Table 24-11 on page 554.