VITAL SIGNS
Introduction
The assessment of a patient’s vital signs provides you with invaluable information, and will
help you to identify time critical patients. Vital signs include the initial examination for
breathing and circulation, the blood pressure and the temperature.
You will learn how to assess an unconscious patient using the ABC (Airways, Breathing, and
Circulation) approach during your teaching on Managing a Cardiac Arrest (Semester 3). In a
patient who is alert and orientated, you would assess and record the following vital signs:
Pulse
Respiration
Body temperature
Blood pressure
Pulse
Blood is forced into the aorta and then the arteries when the left ventricle contracts. The
resulting pressure wave is transmitted through the arteries, and is felt as a pulse. An artery is
muscular, and it contracts and dilates along its entire length with each heart beat. A pulse is
most often palpated by compressing an artery against a bone.
Peripheral pulses are checked to assess blood flow to a limb, or the head, as well as to
assess heart rate, rhythm, character and volume.
In the absence of a pulse, the feeding artery should be examined; for example, if you are
unable to palpate a dorsalis pedis pulse, the popliteal artery may be compromised.
Diminished or absent pulses may be indicative of impaired blood flow and underlying
disease; this is why it is important for you to be able to examine the peripheral pulses as part
of the peripheral vascular examination.
You should be able to locate the arterial pulses listed below. Remember not to apply
excessive pressure when palpating for a pulse, you may occlude the artery and think that
there is no pulse.
Radial Pulse - Anterior to the distal third of the radius, lateral to the tendon of the flexor
carpi radialis muscle
Ulnar Pulse - Lateral to the tendon of the flexor carpi ulnaris, anterior to the distal third of
the ulna
Brachial Pulse - Antecubital fossa, medial to the insertion of the biceps tendon
Carotid Pulse - Palpate slightly beneath the anterior border of the sternocleidomastiod
muscle ant the level of the superior border of the thyroid cartilage
Aorta - Palpate in the vertical midline of abdomen above the umbilicus.
Femoral Pulse - Lay the patient flat. Palpate the femoral artery
halfway between the pubic tubercle and the anterior superior iliac
spine by using your index and middle fingers together, pointing
upwards and slightly medially
Popliteal Pulse - Using both hands, flex the knee slightly. Place
the thumbs on the front of the knee and palpate the popliteal
fossa with the fingers.
Practice Tip!
Remember not to apply
excessive pressure when
palpating for a pulse, you
may occlude the artery and
think that there is no pulse.
Posterior Tibialis - Palpate with the index and middle fingers
just posterior and inferior to the medial malleolus
Dorsalis Pedis - Between the bases of the 1st and 2nd
metatarsals, 1/3rd of the way down the dorsum of the foot, lateral to the extensor hallucis
tendon
Respiration
When assessing respiration you need to note both the respiratory rate and the
characteristics of respiration.
Normal respiration results in even movement of the ribcage and should be effortless,
automatic and regular, producing no noise or discomfort. An irregular breathing rhythm may
indicate the presence of injury or illness. Abnormal breathing may require effort or be
accompanied by pain or noises such as wheezing, rattling or stridor. Many of these changes
are characteristic of particular illnesses or problems.
The respiratory rate should be counted for a full minute. One respiration consists of one
inhalation and one exhalation. You should try to assess the respiratory rate without the
patient being aware of what you are doing or this can result in alteration of the rate and
depth of breathing.
Body Temperature
Core body temperature is maintained at about 37 C in an adult but can increase or decrease
with illness. It is important to be able to gain an accurate body temperature, as changes can
be important diagnostic indicators. For example, a collapse may be due to heat syncope, or
an elderly acutely confused person may be hypothermic.
The main sites for the measurement of body temperature are:
Oral – reading taken in the mouth, under the tongue
Tympanic – reading taken from the tympanic membrane
Rectal – reading taken from inside the rectum
Axillary – reading taken under the armpit, or between two folds of skin
Consideration must be given to the normal changes in body temperature that are observed
when comparing gender, time of day and age, as well as the temperature site.
You must ensure that when taking a temperature, there are no environmental factors which
will lead to an erroneous reading. Taking an oral temperature from a person who has just
swallowed hot coffee will give you a falsely high reading, as will taking a tympanic
temperature in the ear that the person was sleeping on.
Blood Pressure
Measurement of blood pressure is an important skill, and done correctly will provide you with
valuable diagnostic information. A person’s blood pressure is not static and undergoes
natural variation from one heartbeat to another and throughout the day. Blood pressure
also changes in response to stress, nutritional factors, drugs, illness, exercise, and changes
in posture. Hypertension refers to arterial pressure being abnormally high, as opposed to
hypotension when it is abnormally low.
Measurement of blood pressure includes the systolic pressure and the diastolic pressures. It
is written as systolic/diastolic, for example 112/76 mmHg (millimetres Mercury).
Blood pressure measurement is a skill you will need to practise, as a careful, precise
approach will ensure the reading is correct.
When taking a blood pressure, it is important that you consider environmental and positional
issues which may cause an erroneous reading. The environment and procedure should be
as stress free as possible, as blood pressure can vary depending on emotional states,
stress, position of the patient and the environment.
The sounds listened for whilst taking a blood pressure are called Korotkoff Sounds.