Ch 31 Vital Signs: PnP 494 – 527 (Dirk)
Guidelines for measuring vital signs
Box 31-1 Vital signs: acceptable ranges for adults
Guidelines for vital sign measurement
-
Unregulated staff can measure vitals, but nurse is responsible for interpretations
Use equipment that is appropriate for size and age of client
Select equipment based on condition
Minimize environmental factors that can affect vitals
Use organized step by step process
Follow guidelines set in box 31-2 to decide frequency of vital assessment
Use vitals measurements to determine indications for prescribed medication administration
Measure vital measurements against client usual vitals from medical history or therapy
o Verify changes from normal
Develop a teaching plan to instruct client or caregiver in vital sign assessment and the
significance of findings
Body Temperature
Physiology
Difference between the amount of heat produced by body and heat lost to environment
Regulation
Thermoregulation - Balance between heat lost and produced, regulated by physiological and
behavioural mechanisms
Neural and vascular control
Hypothalamus controls body temperature (thermostat)
Heat production
Heat produced by from metabolism, food as energy source
 Activity and thyroid hormones can increase metabolism thus heat
production
 Shivering increases heat
 Non-shivering theromogenesis – newborns vasoconstrict bloodvessels,
to increase heat (started by release of norepinephrine)
Heat loss
Radiation
 Transfer of heat from surface of one object to another (direct contact not
needed); increased by removing clothes
Conduction

Heat loss through direct contact (when touching a cooler object, you cool down)
Convection
 Transfer of heat moved away by air
Evaporation
 Transfer of heat when energy is changed into a gas (heat loss by evaporation,
after, sweating)
Diaporesis
 Visible perspiration
Skin temperature regulation
Vasodilation – blood vessels near skin increase in diameter, more heat loss through skin
Vasoconstriction – blood vessels near decrease in diameter, less heat loss through skin
Behavioral control (in controlling body temp)
Person’s ability to control body temp depends on:
1.
2.
3.
4.
The degree of extreme temp
The person’s ability to sense comfortability/uncomfortability
Thought processes or emotions
Person’s ability or mobility to add or remove clothes
Factors affecting body temperature
1. Age
o Newborns lose 30% heat through head
o Puberty is when we are able to regulate body heat better
o Older people have a harder time keeping core temp up.
2. Exercise
o Requires an increase in metabolism during activity, heat production is by product of
exercise
3. Hormone levels
o During menstruation, progersterone is released which drops body temp
o During menopause body temp rises for short periods due to hot flashes
4. Circadian rhythms
o Body temp lowest at 1-4am and slowly rise throughout the day
5. Stress
o
Stress increase body temp
6. Environment
o External factor
7. Temperature alterations – temperature outside normal ranges
Fever – excessive heat loss (problem if above 39 degrees C); fever occur when fighting
infection
Pyrexia – bacteria cause rise in body temp from triggering immune response;
hypothalamus creates new lower se point; person experiences chills even though body
temp is rising
Febrile episode = fever; afebrile = when fever breaks
Hyperthermia
Body temp that is elevated as a result of the body’s inability to promote heat loss (overload of body’s
thermoregulatory system)
Heatstroke – prolonged exposure to high temperature that overwhelm body’s heat loss mechanism
- Warning sign: hot, dry skin
Heat exhaustion
During profuse diaphoresis (excess water and electrolyte loss)
Hypothermia
Heat loss during prolonged exposure to cold, overwhelms body’s abilty to produce heat, can be gradual;
as temp falls below 34 degrees, hr, resp rate and bp fall; if continues cardiac dysrhythmia
Frostbite
Ice crystals forming inside cells can result in permanent circulatory and tissue damage
Nursing Process and Thermoregulation:
Assessment:
Sites:
Sites of temperature measurement (oral, rectal, axillary, tympanic membrane, temporal artery,
esophageal, pulmonary artery, and urinary bladder (ranges from 36-38 degrees celcius)
Rectal .05 deg C higher
Oral .05 deg C lower
Thermometers:
Electronic, disposable, glass-mercury, chemical strip thermometers
Boxes and Tables:
Box 31-1 Vital Signs: Acceptable ranges for adults (494)
Box 31-2 When to measure Vital signs (495)
Box 31-3 Sites of measurement of Core and Surface Temperature (495)
Table 31-1 Classification of Hypothermia (498)
Skill 31-1 Measuring Body temp (499-503)
Box 31-4 Advantages and Disadvantages of Select Tempature measurement Sites (504)
Box 31-5 Measurement of Temporatal artery temperature (505)