Elizabeth A. Bruderle
College of Nursing
Last Updated: Thursday, February 13, 2003

Vital Signs

Independent nursing function

Nurse has ultimate responsibility for accuracy:

Temperature, Pulse, Respirations, Blood Pressure (T. P. R., BP) are assessed and interpreted together.

Nurse must consider patient's normal pattern in relation to standard values/range.


When to assess? determined by routine, physician’s orders, and/or nurse’s clinical judgment.

On admission: baseline data
Beginning of each shift
Change in patient's status
Before/after invasive procedures
Before/after certain medications
Before/after nursing interventions

Body Temperature

Definition: Heat of body measured in degrees; indicates relationship between heat production and heat loss.

Core body temperature

Surface temperature

Normal adult range: 96.6-99.3; afebrile
Pyrexia/Hyperpyrexia: febrile



Heat Production: metabolism, muscle activity, hormones, pyrexia

Heat Loss: radiation, conduction, convection, evaporation

Regulation: Skin & Central Nervous System (Hypothalamus)

Factors Affecting Temperature: age, circadian rhythm, stress, gender, environmental extremes


Assessing Body Temperature: Site and Method must be consistent; be sure to record site selected.

Methods: glass, electronic, temperature sensitive tape, automated monitoring

Sites: Selection based on nurse's assessment of patient

Oral, Rectal, Axillary, Tympanic Membrane (ear)


Definition: Wave of blood that can be palpated at major arteries. Produced by contraction of left ventricle.

Cardiac Output: Amount of blood pumped per minute.

Stroke Volume: Amount of blood pumped into aorta with each ventricular contraction, approx. 70cc.

CO = SV x Beats per Minute

What is your Cardiac Output?


Regulation of Pulse: Involuntary

Autonomic Nervous System (ANS)

Sympathetic & Parasympathetic

Sinoatrial node (SA): Pacemaker

Factors Affecting Pulse: age, gender, exercise, fever, medications, hemorrhage, stress, pain, position change


Assessing Pulse

Rate (beats/min.): Bradycardia, Tachycardia

Rhythm (pattern of beats): Sinus Rhythm versus Dysrhythmia

Volume/strength/amplitude: scale 0-+4

Alternative assessment techniques:

Stethoscope for apical pulse at apex of heart: AHR



Definition: Process through which oxygen is inhaled and carbon dioxide is exhaled.


CNS control: Cerebral Cortex (voluntary); Brainstem (involuntary)

Mechanical and Chemical Factors: Muscle activity and Blood gas levels

Critical Factor: Level of carbon dioxide in arterial blood


Factors Affecting Respirations: age, exercise, stress, fever, medications, pulmonary diseases

Assessing Respirations

Rate: apnea, bradypnea, tachypnea,

Depth: deep, shallow

Rhythm/pattern: regular, irregular

Quality: quiet, labored

Blood Pressure

Definition: Measure of pressure/force exerted by the blood as it moves through the arteries; moves in waves consistent with the pumping action of the heart.

Terms: Korotkoff sounds, systolic, diastolic, pulse pressure, hypertension, hypotension, orthostatic hypotension


Hemodynamic factors Circulating blood volume Cardiac output Peripheral resistance Blood viscosity

Factors that affect blood pressure:

age, sex, race, obesity, exercise, stress, pain, circadian rhythm, cardiovascular/renal disease

Assessing Blood Pressure

Cuff size

Too small: False high reading (pressure not transmitted evenly to artery).

Too large: False low reading (pressure directed to a large surface area)

Auscultatory Gap

Estimated Systolic