Vital Signs Measurement

• Vital sign measurement is crucial for assessing an individual's health status
• Vital signs reflect the body's physiologic condition and are essential for evaluating homeostatic balance

Learning Objectives

• Describe accurately how to measure vital signs including temperature, pulse, respiration, and blood pressure
• Know factors which can change vital sign measurements
• Know what equipment is needed to assess vital signs
• Recognise when different temperature assessment routes are needed
• Take and interpret the reading from vital signs measurements
• Record measured vital signs and any findings

Vital Signs

• Core vital signs include temperature, pulse rate, respiratory rate, and blood pressure
• Temperature reflects the body's hotness or coldness and the balance between heat production and loss
• Pulse rate indicates the heart's function and is measured in beats per minute (BPM)
• Respiration rate involves the intake of oxygen and removal of carbon dioxide
• Blood pressure measures the force exerted by the blood against artery walls

Purposes of Measuring Vital Signs

• Purpose is to create a base line data for a patient's condition
• Vital signs data is gatheredfor diagnostic purposes
• Vital signs data is gathered for therapeutic purposes

Equipment Needed

• Vital sign tray, stethoscope, sphygmomanometer, thermometer
• Second hand watch, red and blue pen, pencil
• Vital sign sheet, cotton swab in bowel, disposable gloves if available
• Dirty receiver kidney dish

Correct Times to Assess Vital Signs

• On admission to obtain baseline data
• When a client has a change in health status or reports symptoms like chest pain or fainting
• The timing is according to a nursing or medical order
• Before and after the administration of medications affecting respiratory rate or blood pressure
• Before and after surgery or an invasive diagnostic procedure
• Before and after any nursing intervention that could affect vital signs, e.g., ambulation
• According to hospital policy

Temperature

• Core temperature measures internal organs, remaining constant around 37°C with a range of 36.5-37.5°C
• Surface temperature measures skin, subcutaneous tissue, and fat cells; it fluctuates in response to the external environment and ranges between 20-40°C
• Normal body temperature, when taken orally, is around 37°C or 98.6°F

Alterations in Body Temperature

• Normal range is 36-38°C (96.8-100°F)
• Pyrexia, or fever, indicates a body temperature above normal ranges (38-41°C, or 100.4-105.8°F)
• Hyperpyrexia indicates a very high fever, such as 41°C, where temperatures exceeding 42°C can lead to death
• Hypothermia indicates a body temperature between 34-35°C, with temperatures below 34°C being fatal

Common Types of Fevers

• Intermittent fever fluctuates at regular intervals, alternating between periods of fever and normal or subnormal temperature
• Remittent fever involves a wide range of temperature fluctuation (more than 2°C) over 24 hours, all above normal
• Relapsing fever has short febrile periods of a few days interspersed with normal temperature days
• Constant fever means that body temperature fluctuates minimally but always remains above normal

Factors Affecting Body Temperature

• Age, diurnal variations, exercise, hormones, stress, and environment

Sites to Measure Temperature

• Oral, rectal, axillary, tympanic
• A thermometer is an instrument used to measure body temperature

Oral Temperature

• This involves placing a thermometer under the tongue
• The measurement reads about 0.65° less than a rectal reading
• The measurement reads about 0.65° greater than an axillary reading
• Thermometer needs to be held in place for 3-5 minutes
• The most common measurement site
• This measurement site is not suitable for unconscious patients, infants and children, and those with mouth sores or persistent cough

Oral Temperature Advantages and Disadvantages

• Oral temperature taking is easily accessible and comfortable
• Taking an oral temp may give a false reading if the person has consumed hot or cold food or drink
• Taking an oral temp may give a false reading if the person has smoked, wait for at least 10-15 minutes after eating or smoking

Oral Temperature Contraindications

• Patients who cannot follow instructions, children under 7, epileptic or mentally ill patients
• Unconscious patients, clients receiving oxygen, those with persistent cough, uncooperative patients or in severe pain
• Recent surgery of the mouth, nasal obstruction, nasal or gastric tubes in place

Rectal Temperature

• Obtained by inserting the thermometer into the rectum or anus
• Measurement is reliable and reflects the core body temperature
• The thermometer should be held in place for 3 to 5 minutes
• More accurate and reliable, being > 0.65°c (1°F) higher than oral
• Few factors influence the rectal reading
• Disadvantages are injury to the rectum, need for privacy
• Not appropriate for patients with diarrhoea & anal fissure

Rectal Temperature Contraindications

• Rectal or perennial surgery
• Fecal impaction
• Rectal infection
• Newborn infants

Axillary Temperature

• Safe and non-invasive
• Recommended for infants and children
• Disadvantages, long time (5-10 min)
• The least accurate and reliable because the temp obtained can be influenced by a number of factors, e.g. bathing & friction during cleaning
• The suitable route of choice for patients that cannot have their temperature measured by other routes

Tympanic Temperature

• Placed in to the client’s outer ear canal
• It reflects the core body temperature
• Readily accessible and permits rapid temperature readings, especially in pediatric or unconscious patients
• A very fast method, at 1 to 2 seconds
• Disadvantages are discomfort and the risk of injuring the membrane, cerumen (wax) can affect readings, right and left ear measurements may differ

Normal Temperature Ranges by Route

• Oral: 98.6°F / 37.0°C
• Tympanic: 99.6°F / 37.6°C
• Rectal: 99.6°F / 37.6°C
• Axillary: 97.6°F / 36.6°C

Pulse

• Pulse is a wave of blood created by the contraction of the left ventricle
• Pulse reflects the heartbeat
• Stroke volume and arterial wall compliance influence pulse rate
• Pulse rate is regulated by the autonomic nervous system

Pulse Types

• Peripheral Pulse is located in the periphery of the body e.g. in the foot, and or neck
• Apical Pulse (central pulse) is located at the apex of the heart
• Pulse rate is expressed in beats/minute (BPM)
• Pulse deficit is the difference between peripheral and apical pulse, which is usually zero

Pulse Assessments

• Pulse is assessed for rate (60-100bpm), rhythm (regularity or irregularity), volume,elasticity of arterial wall
• Pulse assessment is commonly assessed through feeling (palpation) and hearing (auscultation) using a stethoscope

Factors Affecting Pulse Rates

• The average pulse rate of an infant ranges from 100 to 160 BPM
• The normal range of the pulse in an adult is 60 to 100 BPM
• After puberty males PR is slightly lower than female

Autonomic Nervous System Activity

• Stimulation of the parasympathetic nervous system results in a decrease in pulse rate (PR)
• Stimulation of the sympathetic nervous system results in an increased pulse rate
• Sympathetic nervous system activation occurs in response to a variety of stimuli including pain ,anxiety ,exercise, Fever
• Other stimuli are ingestion of caffeinated beverages and change in intravascular volume

More Pulse Factors

• Exercise: PR increase
• Fever: increases PR in response to the lowered B/P that results from peripheral vasodilatation which causes increased metabolic rate
• Heat: increases PR as a compensatory mechanism
• Stress: increases the sympathetic nerve stimulation

Pulse Position Changes

• A sitting or standing position, blood usually pools in dependent vessels of the venous system
• A fall in blood return to heart and a subsequent decrease in systolic Blood Pressure increases heart rate

Medications Affecting Pulse

• Cardiac medication such as digoxin decreases heart rate
• Medications that decrease intravascular volume such as diuretics may increase pulse rate
• Atropine inhibits impulses to the heart from the parasympathetic nervous system, causing increased pulse rate
• Propranolol blocks sympathetic nervous system action resulting in decreased heart rate

Pulse Sites

• Carotid pulse is on the side of the neck below tube of the ear (where the carotid artery runs between the trachea and the sternocleidomastoid muscle)
• Temporal pulse is taken at temporal bone area
• Apical pulse is at the apex of the heart, often used for infants and children younger than 3 years
• Location in adults is left mid-clavicular line under the 4th, 5th, 6th intercostal space
• The Brachial pulse is at the inner aspect of the biceps muscle of the arm or medially in the antecubital space (elbow crease)
• The Radial pulse is on the thumb side of the inner aspect of the wrist, readily available and routinely used
• The Femoral pulse is along the inguinal ligament, and is used or in infants and children
• The Popliteal pulse is behind the knee and requires flexing the knee slightly
• The Posterior tibial pulse is on the medial surface of the ankle
• The Pedal (Dorsal Pedis) pulse is palpated by feeling the dorsum (upper surface) of foot

Pulse Palpation Method

• Pulse is commonly assessed by palpation (feeling) or auscultation (hearing)
• Palpation is undertaken using the middle 3 fingertips are used with moderate pressure for palpation of all pulses except apical
• Important features to assess in the pulse are; rate, rhythm, volume, and elasticity of the arterial wall

Pulse Rate

• Normal pulse rate is 60-100 b/min (80/min)
• Adult pulse rate greater than 100 BPM is called tachycardia
• Adult pulse rate less than 60 BPM is called bradycardia

Pulse Rhythm

• The pattern and interval between the beats where random or irregular beats indicates dysrhythmia
• Pulse volume is the force of blood with each beat
• A normal pulse can be felt with moderate pressure of the fingers
• A full or bounding pulse is forceful or full blood volume which the assessor will find difficult to eliminate through pressure
• A Weak, feeble pulse can readily be eliminated with pressure from the finger tips

Elasticity of Arterial Wall

• A healthy, normal artery feels straight, smooth, soft, easily bent
• Reflects the status of the client's vascular system

Measurement Tips

• If the pulse is regular, measure (count) for 30 seconds and multiply by 2
• If it is irregular count for 1 full minute
• Each heart beat consists of two sounds

Respiration

• Respiration rate (RR) is the act of breathing involving the intake of oxygen and removal of carbon dioxide
• Ventilation- refers to movement of air in and out of the lung
• Hyperventilation is a very deep, rapid respiration
• Hypoventilation is a very shallow respiration

Two Types of Breathing

• Costal (thoracic) is observed by the movement of the chest upward and downward, and commonly used for adults
• Diaphragmatic (abdominal) involves the contraction and relaxation of the diaphragm, observed through abdominal movement and is common for children

Factors Affecting Respiration

• Age, medications, stress, exercise, altitude, gender and fever

Respiration Assessments - What to Note

• The client should be at rest
• Assessed by watching the movement of the chest or abdomen
• Rate, rhythm, depth and any special characteristics of respiration

Respiration Rate

• Described in rate per minute (RPM)
• A healthy adult's RR is 15-20 breaths per minute, measured for a full minute, or just for 30 seconds if regular
• The younger the client, the higher the respiratory rate tends to be

Respiration Terms

• Eupnea is normal breathing rate and depth
• Bradypnea is slow respiration
• Tachypnea is fast breathing
• Apnea is temporary cessation of breathing

Average Respiratory Rates

• Newborn 30-80
• Early childhood 20-40
• Late childhood 15-25
• Adulthood-male 14-18
• Adult female 16-20

Rhythm and Depth

• Rhythm is the regularity of expiration and inspiration
• Normal breathing is automatic and effortless
• Depth is described as normal, deep or shallow
• Deep breathing is a large volume of air inhaled & exhaled, inflates most of the lungs
• Shallow breathing is exchange of a small volume of air minimal use of lung tissue

Blood pressure

• The force exerted by the blood against the walls of the arteries in which it is flowing
• It is expressed in terms of millimeters of mercury (mm of Hg)

Blood Pressure Types

• Systolic pressure, is the maximum of the pressure against the wall of the vessel following ventricular contraction
• Diastolic pressure is the minimum pressure of the blood against the walls of the vessels following closure of aortic valve (ventricular relaxation)

Blood Pressure Measurements

• BP is measured by using an instrument called Bp cuff (sphygmomanometer) & stethoscope
• The average normal value is 120/80mmHg for adults
• Brachial artery and popliteal artery are most commonly used
• Measurement involves securing the Bp cuff to the upper arm & thigh and placing the stethoscope on brachial artery in the antecubital space & popliteal artery at the back of the knee
• Pulse pressure is the difference between the systolic and diastolic pressure

Factors Affecting Blood Pressure

• Fever, Stress, Arteriosclerosis, Exposure to cold and Obesity
• Others include Hemorrhage, Low hematocrit, and External heat

Sites for Measuring Blood Pressure

• Upper arm, where the brachial artery lies (commonest site)
• Thigh, around the popliteal artery
• Forearm, measuring using radial artery
• Leg, measured using posterior tibial or dorsal pedis

Definitions of Normal Blood Pressure

• A persistently high Bp, measured greater than three times indicates hypertension
• A persistently less than normal range indicates hypotension
• Variations in blood pressure exist due to many influencing factors
• A single measurement may not be enough to confirm hypertension
• Secondary hypertension, known cause
• Primary or essential hypertension, unknown cause

Assessing Blood Pressure - What is the Purpose

• To obtain base line measure of arterial blood pressure for subsequent evaluation
• To determine the client’s homodynamic status
• To identify and monitor changes in blood pressure

Equipment Needed to Measure Blood Pressure

• Stethoscope
• Blood pressure cuff of the appropriate size
• Sphygmomanometer

Procedure to Measure BP

• Procedure explained to the patient, remove any light cloth from patient’s arm
• Ensure the client has not ingested caffeine, within 30 minutes prior to measurement
• Keep the patient on lying, sitting or standing position, placing the sphygmomanometer at the level of the heart with the arm supported, palm facing upwards
• Apply cuff snugly, 2.5cm above the antecubital space/fossa, at the level of the heart (for every cm the cuff sites above or below the level of the heart the BP varies by 0.8mmHg)
• Palpate the radial pulse, and inflate the cuff until this can no longer be felt to estimate systolic pressure
• Inflate cuff 30mmHg higher than estimated systolic pressure

Listening for Systolic and Diastolic Pressure

• Palpate the brachial artery and place the bell of the stethoscope over the site, then place the ear pieces on ear, then apply enough pressure to keep the stethoscope in place
• The bell of the stethoscope is designed to amplify or intensify frequencies which can be difficult to hear
• Deflate the cuff 2-4mmHg per second
• The first pulse heard is the systolic reading
• Continue to deflate until there is a "change in tone" to a muffled beat, this is the diastolic reading

After Taking Measurement

• Deflate & remove cuff roll neatly and replace
• Record the systolic and diastolic pressure on vital sing sheet and compare present reading with previous reading
• Report or treat any change
• Store all equipments safely
• Clean earpieces and bell of the stethoscope with antiseptic swab