VITAL SIGNS2
v Provide excellent clues to the physiological functioning of the body.
v Alteration in body fxn are reflected in the body temp, pulse, respirations and blood pressure.
v These data provide part of the baseline info from which plan of care is developed.
v Any change from normal is considered to be an indication of the person’s state of health.
v Also called Cardinal Signs.
Heat – producing & Heat – losing Mechanisms
v Heat production: most body heat is produced by the oxidation of foods, the rate at which it is produced is called METABOLIC RATE.
Heat Loss:
v Radiation
v Conduction
v Convection
v Evaporation
Pre – optic area of the HYPOTHALAMUS
v Temperature regulator; thermostat
v Receives input from temp receptors in the skin & mucous membranes (peripheral thermoreceptors) & internal structures (central thermoreceptors)
* if blood temp increases, neurons of the pre – optic area fire nerve if it decreases.
Heat Promoting Centers
v VASOCONSTRICTION
= Less blood flow from the internal organs to the skin = less heat transfer from the internal organs to the skin = increases internal body temp
v SYMPATHETIC STIMULATION
= stimulation of sympathetic nerves leading to the adrenal medulla = secretes epinephrine & norepinephrine = Increases cellular metabolism = increases heat production
v SKELETAL MUSCLES
= stimulation of part of the brain that increases muscle tone (stretch reflex + contraction of muscles = SHIVERING) = heat production
v THYROXINE = increases metabolism = increase in body temp
Body Temperature Abnormalities
v FEVER/hyperthermia/hyperpyrexia
– An abnormally high temp mainly results from infection from bacteria (& their toxins) & viruses. (stimulates prostaglandin secretion)
Other causes: heart attacks, tumors, tissue destruction by x – ray, surgery or trauma & rxns to vaccines.
v HEAT CRAMPS AND HEAT EXHAUSTION
– Due to fluid & electrolyte loss
v HEAT STROKE
v HYPOTHERMIA
The THERMOMETER
v A glass clinical thermometer is most commonly used to measure body temperature.
It has 2 parts:
BULB – contains mercury which expands when exposed to heat & rise in the stem
STEM – is calibrated in degrees of Celcius or Fahrenheit
Sites for Obtaining Body Temperature
v ORAL – most common site (3 or 7 to 10minutes)
C.I. : unconscious, irrational, seizure – prone patients and infants & young children, those who breath through their mouth or for those with diseases/sugery of their mouth or nose.
v RECTAL – most accurate, used when obtaining an oral temp is contraindicated (2 to 3 minutes)
C.I. : rectal surgery, diarrhea, other diseases of the rectum, certain heart diseases.
v AXILLARY – used when both oral & rectal are not accessible. Commonly used site (10minutes or more)
