Body Temperature: Vital Signs

• Vital signs are measurements of basic body functions.
• Normal vital signs vary based on age, sex, weight, exercise tolerance, and overall health.
• The five main vital signs usually monitored include body temperature, pulse rate, respiratory rate, blood pressure, and oxygen saturation.

Temperature

• Normal oral body temperature ranges from 36.7 to 37.2 °C.
• Conversion from Fahrenheit to Celsius: C= (Fahrenheit Temperature - 32) × 5/9

Alterations in Body Temperature

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

Types of Thermometers

• Examples include: electronic (digital) thermometers, glass (mercury) thermometers, paper thermometers, tympanic membrane thermometers, and non-contact infrared thermometers.

Sites for Assessing Body Temperature

• Orally (common way): The oral cavity temperature is considered reliable when the thermometer is placed posteriorly into the sublingual pocket, around 37 C° and should be done for 3-5 minutes.
• The sublingual landmark is close to the sublingual artery, it tracks changes in core body temperature.
• Axillary (safe way): Temperature is measured at the axilla with thermometer in the central position, and adducting the arm close to the chest wall, around 36 C° + 0.5 C° and should be done for 10 minutes.
• This is considered to be an unreliable site for estimating core body temperature because there are few main blood vessels in the area; add 0.5°C to the reading.
• Rectal (accurate reading): 37 C° – 0.5 C° and should be done for 2 – 3 minutes.
• Rectal temperature is the most accurate method for measuring core temperature; reduce 0.5°C from the actual reading.
• Tympanic Membrane: Senses reflected infrared emissions from the tympanic membrane through a probe placed in the external auditory canal.
• This method is quick.

Respiratory Rate

• Inspiration (inhalation) is the act of breathing in.
• Expiration (exhalation) is the act of breathing out.
• The respiratory rate is the number of breaths per minute.
• A normal respiratory rate ranges from 12 to 20 breaths per minute.

Respiratory Rate Characteristics

• Bradypnea: A respiratory rate of 10 or fewer breaths per minute.
• Tachypnea: A respiratory rate greater than 24 breaths per minute.
• Apnea: Cessation of breathing.

Pulse Examination

• Pulse is a Greek word, meaning "move to and fro".
• Arterial pulse: A wave produced by cardiac systole traversing peripherally in the arterial tree.

Pulse Examination - Sites

• Upper Limb (UL)
• Neck
• Lower Limb (LL)
• Apical Pulse

UL Pulse Sites

• Brachial
• Radial
• Ulnar

Radial Pulse

• Performed with 3 fingers (index, middle, and ring).
• The ring finger should be kept proximal to the heart.
• The index finger to be distal from the heart to obliterate backflow from the ulnar artery, applying light pressure to obliterate it.
• Rest of the parameters of pulse are judged by the middle finger

How to Examine Pulse

• Uses light pressure when palpating.

Brachial Artery

• Rest the patient's arm with the elbow extended, palm up.
• Use the thumb of the opposite hand
• Cup hand under patient's elbow.
• Feel for the pulse just medial to the biceps tendon.

The Carotid (Common Carotid)

• The patient lies down with the head of the bed elevated 30 degrees
• Carotid pulsations may be visible just medial to the sternomastoid
• Place the 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 Pulsations

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

Comment on Pulses

• Rate
• Rhythm
• Force, Tension, Volume
• Character
• Equality on Both Sides
• Condition of Arterial Wall
• Apex Pulse Ratio

Pulse Rate

• Normal adult heart rate is between 60-100 beats per minute.
• To count a regular pulse, count for 15 seconds and multiply by four to calculate heart rate per minute.
• To count an irregular pulse count for one minute.
• Tachycardia: Heart rate in excess of 100 beats per minute in an adult.
• Bradycardia: Heart rate less than 60 beats per minute in an adult.

Pulse Rhythm

• Pulse rhythm can be regularly regular at regular intervals.
• Pulse rhythm can be irregular at regular intervals.
• Pulse rhythm can have irregularity repeated irregularly at irregular intervals.

Pulse Volume

• This is a measurement of the strength or amplitude of force exerted by the ejected blood against the arterial wall with each contraction
• Can be weak (thready and usually rapid or rapid).
• Can be normal (full, easily palpable).
• Can be strong (bounding).