Vital Signs: Temperature and Measurement

• Vital signs are measurements of the body's basic functions.
• Normal vital signs change with age, sex, weight, exercise tolerance, and overall health.
• The five main vital signs usually monitored are body temperature, pulse rate, respiratory rate, blood pressure, and oxygen saturation.

Temperature

• The normal range of body temperature is between 36.7 to 37.2°C.
• To convert Fahrenheit to Celsius: C = (Fahrenheit temperature - 32) × 5/9

Alterations in Body Temperature

• Pyrexia, also known as hyperthermia or fever, is a body temperature above the usual range.
• Hyperpyrexia is a very high temperature, such as 41°C (105°F).
• Hypothermia is a core body temperature below the lower limit of normal.
• Frostbite is the freezing of the body's surface areas, like earlobes, fingers, and toes, in extremely low temperatures.

Types of Thermometers

• Electronic or digital thermometers are used to measure body temperature.
• Glass (mercury) thermometers are a traditional type.
• Paper thermometers are available.
• Tympanic membrane thermometers measure temperature in the ear.
• Non-contact infrared thermometers are used to measure temperature from a distance.

Sites for Assessing Body Temperature

• Orally: A common way to measure temperature with a typical reading of 37°C taken within 3-5 minutes. Oral cavity temperature is reliable when the thermometer is placed posteriorly into the sublingual pocket, close to the sublingual artery which tracks changes in core body temperature.
• Axillary: Considered a safe method; a typical temperature is 36°C + 0.5°C which taken in 10 minutes. Temperature is measured at the axilla by placing the thermometer in the central position and adducting the arm close to the chest wall. It is considered an unreliable site for estimating core body temperature because there are no main blood vessels around this area, therefore 0.5°C should be added to the reading.
• Rectal: Considered an accurate reading with a typical temperature of 37°C - 0.5°C taken within 2-3 minutes. Rectal temperature is the most accurate method for measuring the core temperature, and 0.5°C should be reduced to the actual reading.
• Tympanic Membrane: The tympanic thermometer senses reflected infrared emissions from the tympanic membrane through a probe placed in the external auditory canal. This method is quick.

Common Types of Fevers

• Intermittent Fever: Body temperature alternates at regular intervals between periods of fever and periods of normal temperatures.
• Remittent Fever: A wide range of temperature fluctuations occurs over a 24-hour period, with all temperatures being above normal.
• Constant Fever: Body temperature fluctuates minimally but always remains elevated.
• Relapsing Fever: Short febrile periods of a few days are interspersed with periods of 1 or 2 days of normal temperature.

Respiratory Rate

• Inspiration (inhalation) is the act of breathing in.
• Expiration (exhalation) is the act of breathing out.
• Respiration is the overall process of breathing.
• Respiratory rate is the number of breaths per minute.
• Normal respiratory rate ranges from 12-20 breaths per minute.

Characters of Respiratory Rate

• Bradypnea is a respiratory rate of 10 or fewer breaths per minute.
• Tachypnea is a respiratory rate greater than 24 breaths per minute.
• Apnea is the cessation of breathing.

Pulse Examination

• Key items include definition, examination technique, pulse sites, and comments on pulse characteristics.
• Pulse is derived from the Greek word meaning "move to and fro."
• Arterial pulse is a wave produced by cardiac systole traversing in the peripheral direction in the arterial tree.

Sites of Pulse Examination

• Sites include UL (Upper limb), Neck, LL (Lower limb), and Apical Pulse.

UL (Upper Limb) Pulse Sites

• Brachial artery.
• Radial artery.
• Ulnar artery.

Radial Pulse

• It is done with 3 fingers: index, middle, and ring fingers.
• The ring finger should be kept proximal to the heart.
• The index finger should be distal from the heart to obliterate the back flow from the ulnar artery, and light pressure should be applied to obliterate.
• All parameters of the pulse are judged by the middle finger.

How to Examine Radial Pulse

• Light pressure should be applied.
• Occlude the artery.
• Palpate the pulse.

Brachial Artery

• Patient's arm should rest with the elbow extended and palm up.
• Use the thumb of the opposite hand.
• Cup your hand under the patient's elbow.
• Feel the pulse just medial to the biceps tendon.

The Carotid (Common Carotid)

• The patient should lie down with the head of the bed elevated 30 degrees.
• Carotid pulsations may be visible just medial to the sternomastoid.
• Place your left thumb on the right carotid artery in the lower third of the neck at the level of the cricoid cartilage, just inside the medial border of the sternomastoid, and press posteriorly.
• Never press both carotids at the same time.

LL (Lower Limb) Pulsations

• Femoral.
• Popliteal.
• Anterior Tibial.
• Posterior Tibial.
• Dorsalis Pedis.

Dorsalis Pedis

• Feel the dorsum of the foot just lateral to the extensor tendon of the big toe.
• Tendons include the extensor hallucis longus and extensor digitorum longus.

Posterior Tibial

• Located behind the medial malleolous.

Comments on Pulse

• Rate: 60-100 bpm.
• Rhythm.
• Force, tension, volume.
• Character.
• Equality on both sides.
• Condition of arterial wall.
• Apex pulse ratio.

Pulse Rate

• Normal adult HR is 60-100 bpm.
• To count, measure for 15 seconds and multiply that number by four for regular pulses, or measure for one full minute for irregular pulses.
• Tachycardia is a heart rate in excess of 100 bpm in an adult.
• Bradycardia is a heart rate less than 60 bpm in an adult.

Rhythm

• Regularly regular indicates that pulse at regular intervals.
• Irregular at regular intervals indicates pulse comes irregularly.
• Irregularity is repeated irregularly at irregular intervals indicates that pulse comes irregularly at irregular intervals.

Pulse Volume

• Pulse volume is a measurement of the strength or amplitude of force exerted by the ejected blood against the arterial wall with each contraction.
• Can be characterized as Weak (thready and usually rapid), Normal (full, easily palpable), or Strong (bounding).

Equality on Both Sides

• Check if equality on both sides.