Vital Signs, Temperature Measurement, and Cardiovascular Assessment in Nursing

Vital signs

Body temperature, pulse, respiratory rate, and blood pressure; oxygen saturation and pain assessment may also be included.

Why does the nurse measure vital signs?

To obtain baseline data, detect or monitor changes in health status, and monitor patients at risk for alterations in health.

What may be included with the four traditional vital signs?

Oxygen saturation and pain assessment.

Why is pain sometimes called the fifth vital sign?

The phrase was promoted in the late 1990s to increase awareness of pain assessment and treatment; however, concerns about overemphasis on pain treatment and opioid use led the AMA in 2016 to vote to stop using pain as the fifth vital sign.

Why is pain assessment essential?

Pain is subjective and personal and can affect every aspect of health and well-being; its perception and response vary with age, sex, culture, and developmental level.

What is core body temperature?

The temperature of the deep tissues of the body, such as the thorax and abdominal cavity; it remains relatively constant at about 37°C (98.6°F).

Why is surface body temperature unreliable for monitoring health status?

Surface temperature is affected by environmental factors because it reflects the temperature of the skin, subcutaneous tissues, and fat.

What regulates core body temperature?

Sensors in the hypothalamus regulate body temperature.

What happens when hypothalamic sensors detect heat?

The body decreases heat production and increases heat loss through mechanisms such as vasodilation and sweating.

What happens when hypothalamic sensors detect cold?

The body increases heat production and decreases heat loss through shivering, vasoconstriction, and inhibition of sweating.

How does age affect body temperature?

Infants are highly responsive to environmental temperature changes; children are more stable than infants but less stable than adolescents and adults; older adults are more sensitive to environmental temperature changes because of decreased thermoregulatory control and loss of subcutaneous fat.

When is core body temperature usually highest?

Between 8:00 p.m. and midnight.

When is core body temperature usually lowest?

Between 4:00 a.m. and 6:00 a.m.

How much can normal body temperature vary during the day?

It may vary by as much as 1°C (1.8°F) between its highest and lowest points.

How does strenuous exercise affect core temperature?

Strenuous exercise can increase core body temperature by as much as 2°C (5°F).

How does progesterone affect body temperature?

At ovulation, progesterone secretion raises core body temperature by about 0.35°C (0.5°F).

How does stress affect body temperature?

Stress can elevate temperature because increased epinephrine and norepinephrine increase metabolic activity and heat production.

What is hyperthermia?

An abnormally elevated body temperature, also called fever; it may occur with viral or bacterial infection or tissue breakdown after myocardial infarction, malignancy, surgery, or trauma.

What is hypothermia?

A decreased body temperature, usually resulting from prolonged exposure to cold.

What are the five routes for measuring core body temperature?

Oral, rectal, axillary, tympanic, and temporal artery.

Why are mercury thermometers no longer used clinically?

They can break and expose patients and healthcare workers to toxic mercury.

What type of thermometer are nurses most likely to use today?

An electronic thermometer, which provides an accurate reading in about 2 to 60 seconds.

What are the components of an electronic thermometer?

An electronic display unit, a probe, and disposable probe sheaths.

What is the oral route for temperature measurement?

A commonly used route that is accessible, accurate, and convenient.

How is an oral temperature measured?

Place the covered probe at the base of the tongue in either sublingual pocket, to the right or left of the frenulum, and instruct the patient to keep the lips tightly closed around the thermometer.

What color is the probe commonly used for oral temperature?

Blue.

When is a rectal temperature used?

When a patient is comatose, confused, having seizures, or unable to close the mouth.

What position should a patient be in for a rectal temperature?

Side-lying.

What precautions are used when taking a rectal temperature?

Use a pre-lubricated thermometer cover, disposable examination gloves, and insert the thermometer gently without forcing it.

How far is a rectal thermometer inserted in an infant?

Approximately 1.3 to 2.5 cm (0.5 to 1.0 inch).

How far is a rectal thermometer inserted in an adult?

Approximately 2.5 to 4 cm (1.0 to 1.5 inches).

What color is the probe commonly used for rectal temperature?

Red.

What is the axillary temperature route?

Temperature measurement in the axilla, or armpit.

What is an advantage of the axillary route?

It is the safest and least invasive method, especially for infants and young children.

What is a disadvantage of the axillary route?

It is considered the least accurate because probe positioning can vary.

How is an axillary temperature measured?

Place the thermometer in the axilla and have the patient hold the arm tightly across the chest to keep it in place.

How is a tympanic temperature measured?

An infrared electronic thermometer is gently placed at the opening of the ear canal without forcing it into or occluding the canal; the reading appears in about 2 seconds.

What are advantages of tympanic temperature measurement?

It is quick, accurate, comfortable, and noninvasive.

What is a temporal artery thermometer (TAT)?

A noninvasive infrared device used to measure body temperature.

How is a temporal artery temperature measured?

Place the TAT in the center of the forehead and move it in a straight line toward the temple into the hairline; then lift it and place the tip behind the earlobe while continuing the scan.

Why is the temporal artery thermometer used in a two-step process?

To improve accuracy by reducing the effect of diaphoresis and evaporative cooling on the temperature reading.

What can incorrect TAT technique cause?

Significantly inaccurate temperature readings.

What have studies found about TATs in children?

TATs correlate well with rectal temperatures and may be more accurate than tympanic and axillary temperatures in children.

What did studies find about TATs in acutely ill trauma patients?

TATs overestimated temperature compared with electronic oral thermometers and were not recommended for acutely ill hospitalized trauma patients in the cited study.

What did a study find about TATs in febrile cancer patients?

TATs were found to be unreliable for detecting fever in that population.

What did research show about tympanic temperatures from each ear?

No significant difference was found between temperatures from the two ears, indicating that checking one ear is sufficient.

What is stroke volume?

The amount of blood pumped from the heart with each heartbeat.

What creates a pulse?

The force of blood against arterial walls generates a wave of pressure that can be felt at various points in the body.

What is arterial compliance?

The ability of arteries to contract and expand.

What happens when arterial compliance is reduced?

The heart must exert more pressure to pump blood throughout the body.

What is the apical pulse?

The pulse felt at the apex of the heart.

What is a peripheral pulse?

A pulse felt in the body's periphery, such as the neck, wrist, or foot.

In a healthy patient, how does the peripheral pulse compare with the heartbeat?

The peripheral pulse rate is equivalent to the heartbeat.

Which peripheral pulse is most accessible in obese patients?

The radial pulse.

Why can the carotid pulse be difficult to assess in morbidly obese patients?

A short, thick neck can make the carotid pulse difficult to locate.

What device may be required to assess peripheral pulses in obese patients?

A Doppler device.

What does a Doppler device do?

It produces a swishing sound when blood flows through vessels by bouncing high-frequency ultrasound waves off circulating red blood cells.

How does age affect pulse rate?

Infants and children normally have higher pulse rates than teens and adults; after age 16, pulse averages about 70 beats/min in males and 75 beats/min in females.

How does sex affect adult pulse rate?

The average adult male pulse rate is slightly lower than the average adult female pulse rate.

How does exercise affect pulse rate?

Exercise normally increases pulse rate.

How does stress affect pulse rate?

Fear, anxiety, and stress increase heart rate and the force of the heartbeat.

How does fever affect pulse rate?

Fever causes peripheral vasodilation, which lowers systemic blood pressure and results in an increased pulse rate.

How does hemorrhage affect pulse rate?

Significant blood loss increases pulse rate.

How can medications affect pulse rate?

Some medications increase heart rate while others decrease it.

How can prolonged sitting or standing affect pulse rate?

Blood may pool in the veins, reducing venous return to the heart and temporarily lowering blood pressure and pulse rate.

How is the radial pulse assessed?

Place the pads of the first two or three fingers on the anterior wrist along the radius bone.

How long should a regular radial pulse be counted?

Count for 30 seconds and multiply by 2 to obtain beats per minute.

How long should an irregular radial pulse be counted?

Count for a full 60 seconds.

Why is a 30-second radial pulse count preferred over a 15-second count?

A 30-second count is more accurate, particularly when pulse rates are greater than 100 beats/min.

What is more accurate than a palpated radial pulse in an acutely ill patient?

An ECG heart rate measurement is more accurate, especially when tachycardia is present.

What four factors are assessed when measuring a pulse?

Rate, rhythm, force, and elasticity.

What is bradycardia?

A pulse rate less than 60 beats/min.

Can bradycardia occur normally?

Yes. A pulse below 60 beats/min may occur in a healthy, well-trained athlete.

What is tachycardia?

A pulse rate greater than 100 beats/min.

Can tachycardia occur in an otherwise healthy patient?

Yes. It may occur with anxiety or immediately after exercise.

What is a normal adult pulse rhythm?

A relatively constant rhythm with regular intervals between beats.

How is pulse force assessed?

By determining how much pressure must be exerted before the pulse is felt.

What is a full, bounding pulse?

A pulse that is difficult to obliterate; it may occur with fear, anxiety, exercise, or health alterations.

What is a weak, thready pulse?

A pulse that is easy to obliterate and may indicate health problems such as hemorrhage.

How is arterial elasticity assessed?

The nurse palpates along the radial artery in a proximal-to-distal direction.

What does a normal artery feel like?

Smooth, straight, and resilient.

What is the normal adult respiratory rate?

12 to 20 breaths per minute.

What does one complete respiratory cycle include?

One inspiration and one expiration.

How is respiratory rate normally measured in an adult?

Observe and count respirations for 30 seconds and multiply by 2.

When should respirations be counted for a full minute?

When irregularities or difficulty breathing are detected.

Why should the nurse avoid making the patient aware that respirations are being counted?

Awareness can cause the patient to consciously alter the breathing rate.

What position should the nurse use while counting respirations?

Maintain the same posture used when counting the radial pulse so the patient is less likely to realize respirations are being assessed.

What resting adult respiratory rate indicates illness?

A rate greater than 20 breaths/min.

What adult respiratory rate is considered a critical concern according to the cited evidence?

A respiratory rate greater than 24 breaths/min.

What factors can increase respiratory rate?

Exercise, stress, increased temperature, and increased altitude.

How can medications affect respiratory rate?

Some medications increase respiratory rate while others decrease it.

Why may obese patients have difficulty breathing?

Increased fatty tissue in the chest wall and abdomen can make respiration more difficult.

What position is most comfortable for obese patients during respiratory assessment?

A sitting position.

Why should obese patients be allowed time to recover after moving onto an examination table?

Exertion from moving can temporarily increase respiratory rate.

What is oxygen saturation (SpO2)?

The percentage of oxygen carried by hemoglobin.

What device measures oxygen saturation?

A pulse oximeter.

How does a pulse oximeter measure oxygen saturation?

A sensor and photodetector measure the light sent through and absorbed by oxygenated and deoxygenated hemoglobin.

Where is a pulse oximeter sensor usually placed?

On the patient's finger.

What oxygen saturation is considered normal in a healthy individual?

Approximately 97% to 99%.

What SpO2 level should be investigated further?

Less than 90%.