Week 2 Flashcards
Why are vital signs important ?
They determine a baseline for future assessments
what are the guidelines for vital sign measurements ?
1) unregulated care providers may measure the vital sigs and the nurse responsible has to interpret and act on these measurements
2) use equipment that is functional and appropriate for the size and age of the patient
3) select equipment based on the persons conditions and characteristics
4) minimize environmental factors that may affect vital signs
5) use an organized step by step approach
6) approach patient in calm, caring manner while demonstrating profiency
7) use vital signs to determine indications for prescribed medication administration
8) Analyze vital sign measurement results
9) when vital signs appear abnormal, have another nurse take the vital signs
10) involve in the patient/and or caregiver in the vital sign assessment and finding
What is core temperature ?
temperatures of structures deep within the body
what do temperature control mechanisms do?
They keep the core temperature constant
normal body temperature range
36C to 38C - body surface temperatures fluctuate depending on blood flow to the skin and amount if heat lost to the external environment
thermoegulation
the balance between heat lost and heat produced
what is the role of the hypothalamus ?
To control body temperature - it sense changes in the body temperature - when its too hot the nerve cells in the anterior hypothalamus go above the set point, impulses are then sent to reduce body temp - the posterior hypothalamus senses the temp is below the set point then impulses are sent to increase the body temp
what is a set point
A comfortable temperature
which part of the hypothalamus recognize an increase in body temp above set point
the anterior hypothalamus
which part of the hypothalamus recognizes a decrease in body temp below the set point
the posterior hypothalamus
what mechanisms are used to increase body temp
Vasoconstriction of blood vessels to decrease flow to skin and the extremities - muscle shivering
what mechanisms are used to decrease body temperature when its too high
sweating, vasodilation, inhibition of heat production
Which process produces heat ?
metabolism - as metabolism increases more heat is produced and when metabolism decreases heat production decreases
when does heat production occur ?
rest, voluntary movement, involuntary shivering, non-shivering thermogenesis
Basal metabolic rate
heat produced at absolute rest
which hormone affects BMR ? how does it affect BMR?
the thyroid hormone affects bmr by promoting the breakdown of body glucose and fat
male sex hormone
testosterone increases BMR- men have a higher BMR than women
Exercise
exercise increases BMR and heat production
Shivering
is an involuntary body movement - significant energy is required for shivering which increases body temp - this heat equalizes body temperatures
Why are babies and older individuals at risk for hypothermia
they are less likely to generate heat via shivering or preserve heat via vasoconstriction which puts them at risk for hypothermia
Non shivering thermogenesis
main source of heat generation in newborns - sympathetic nerve ending release norepinephrine to respond to chilling which stimulates fat metabolism in richly vascularized brown adipose tissue to produce internal heat that is then conducted to the surface
how is heat lost
conduction, evaporation, convection, radiation
Radiation
transfer of heat from the surface of one object to the surface of another without direct contact - radiation increases as the temp difference increases - if the environment is hotter than person we absorb heat - radiation can increase through removing clothing patients position enhances radiation - standing more SA to radiate heat - fetal position covered by something decreases heat
Conduction
transfer of heat from direct contact - touch colder surface you will lose heat - touch a hotter surface the body gains heat
Convection
transfer of heat away from body by air movement
Evaporation
transfer of heat when liquid is changed to gas - sweat
Diaphoresis
visible perspiration which occurs primarily on the forehead and upper thorax - excess evaporation can cause skin scaling and itching, as well as drying of the nares and pharynx
what determines a persons ability to control body temperature
1) the degree of temp extreme 2) the persons ability to sense feeling comfortable or uncomfortable 3) though processes or emotions 4)the persons mobility or ability to remove or add clothes
Factors affecting body temperature ?
1) age - infants lose 30% of there heat from there heads - temp regulation is unstable until children hit puberty
2) exercise
3) hormone level - women have greater body fluctuations than men - progesterone increases body temp - menopause causes hot flashes which is caused the instability of the vasomotor controls
4) Circadian Rhythm - lowest between 0100 and 0400 hours - body temp rises steadily to about 1800 hours then declines back down to early morning levels
5) stress
6) environment (poikilothermia - depends on the level of the injury, high cervical injuries have a greater loss of ability to regulate temperature
7) temperature alterations ( Fever or pyrexia - the heat loss mechanisms cannot keep up with the rise in body temp - below 39C its ok) - pyrogens can cause a rise in body temperature - pyrogens are antigens, triggering the immune system responses - during the period the person may experience chills and shivers even though body temp is rising - once the chill phase subsides a new set point of high temp is achieved - the person feels dry and warm - once the pyrogens are removed the third phase of febrile (showing symptoms of fever) occurs (white blood production is stimulated, increased temp decreases iron in blood plasma which suppresses bacteria growth ) - when the fever breaks someone becomes afebrile (not showing symptoms of fever)
why are fever patterns important ?
helps with making diagnosis - fever pattern differ depending on the pyrogen - fever of unknown pyrogen refers to a fever that does not have a determined cause
risks of fever
during fever cellular metabolism increases ad oxygen consumption rises - energy use increases due to increase in metabolism - increases metabolism required an increase in oxygen - risks of myocardial hypoxia produces angina (chest pain) - cerebral hypoxia produces confusion - oxygen therapy may be needed - water loss is excessive which causes dehydration
hyperthermia
body temperature that is elevated as a result of the body inability to promote heat loss or reduce heat production which results from an overload of the body’s thermoregulatory mechanisms
Heatstroke
prolonged exposure to the sun or high environmental temperatures can overwhelm the bodies heat loss mechanisms - people old, very young, alcoholism, spinal cord injury, diabetes, cardiovascular disease, hypothyroidism - symptoms are confusion, delirium, excess thirst, nausea, muscle cramps, visual disturbances, giddiness, hot dry skin, vital signs as high as 45C increase HR and low BP
Heat Exhaustion
profuse diaphoresis results in excessive water and electrolyte loss - fluid volume deficit
Hypothermia
heat loss prolonged exposure to cold overwhelms body’s ability to produce heat - loss of memory, depression, poor judgement, uncontrollable shivering - severe hypothermia causes death - 35C or less
Frostbite
ice crystals form inside cells can result in circulatory and tissue damage (earlobes, tip of the nose, fingers, and toes) white, waxy, firm to touch, loss of sensation
where are core temperatures measured ?
pulmonary artery, esophagus, urinary bladder
intermittent temperatures are measured from ?
mouth, rectum, tympanic membrane
Types of thermometers
1) electronic thermometer
2) clinical strip thermometers - remove after 60sec tend to overestimate
3) glass thermometers
during acute care, how may a health care provider try t0 intervene ?
the healthcare provider may try to find the cause by isolating the pyrogen via lab analysis - once the lab results are available the prescribed healthcare provider with give the correct antibiotics for the pyrogen
What happens when children get fevers ?
children usually get fevers from viruses - they immature temperature control mechanisms - febrile seizures are uncommon for children older than 6 years of age - children are also at risk of losing large amounts of water in proportion to there BW
what medications can be given to decrease fever ?
Antipyretics example:
nonsteroidal (acetaminophen, salicylates, indomethacin, and ketorolac) by increasing heat loss
corticosteroids reduce heat production
nonpahrmalogical methods would be via conduction, evaporation, convection, or radiation (hypothermia blankets, tepid sponge baths, bathing with alcohol water solution, ice packs, cooling fans)
what are the solution for heatstroke ?
moving patient to cooler environment - reducing clothing - placing cool wet towels over skin -
what are the solutions for hypothermia ?
removing wet clothes, wrapping patient in blanket, forced air warming blankets, placed under blanket next to warm person in non healthcare setting, drink hot liquids - keep patients head covered
AVOID ALCOHOL AND CAFFIENE
stroke volume
60 to 70 ml of blood enters the aorta with each ventricular contraction
what happens with each stroke volume ejection ?
blood is pushed out of the heart - the walls of the aorta distend - this creates a pulse wave which reaches the peripheral arteries
Pulse Rate
is the number of pulsing sensations occurring in one minute
Cardiac output
the volume of blood pumped by the heart during 1 minute
how do you determine how much ml of blood is pumped out of the heart per minute ?
beats per minute (pulse rate) x stroke volume (ex: 70bpm x 70ml = 4900 ml per min)
As heart rate increase…..
the heart has less time to fill - without a change in stroke volume - bp decreases
as the heart slows….
filling time increases - blood pressure increases
which artery is mainly used for the assessment of pulse ?
Radial artery - when a patient suddenly worsen the carotid artery is used - if the radial pulse cannot be used then the apical pulse can be assessed
when should apical pulse be assessed ?
when patient takes medication that affects heart rate - apical pulse is more accurate assessment of cardiac function - infants an young children the apical or brachial pulse should be checked
heart sounds to focus on….
a normal slow rate (S) is low pitched and dull “lub” - higher pitched and shorter “dub” - count the number of lub dubs
Tachycardia
abnormally fast heart rate, more than 100bpm