Week 7 Nursing Flashcards
Body Temperature
▪ Body temperature is the heat of the human body.
▪ Core body temperature is normally within a range of 35.8 to 37.5\c
▪ Normal variations occur with age, health status & time of day
▪ Cellular metabolism requires a core temperature of 37.20c
▪ Normal body temperature is known as normothermia or euthermia
Body Temperature Physiology
▪ Heat Production
– Primary source of heat production is cellular metabolism
– Heat is produced as a by-product of cellular activities
– Hormones, muscle movement and exercise increase
temperature
▪ Heat Loss
– The skin is the primary site of heat loss from the body
– Blood vessels in the skin bring heat to the skins surface
– Surface heat escapes via the process of radiation,
convection, evaporation or conduction
Factors Affecting Body Temperature
▪ Body temperature may vary due to age, gender, stress,
environmental temperatures and surgery
▪ Circadian Rhythm
– Temperature is usually 0.60c lower in the morning than late afternoon and evening
▪ Age and Gender
– The very young, the old & infirm are more sensitive to temperature
changes in the environment
– During the menstruation cycle, progesterone secretion occurs with
ovulation - increases temperature 0.15-0.450c
▪ Environment
– Patients exposed to extremes of temperature may suffer from
hypothermia/hyperthermia
Temperature Assessment Sites
▪ Surface Temperature Sites
– Oral, axillary, forehead and temporal sites
▪ Core Temperature Sites
– Tympanic (eardrum) membrane (same blood supply as
the hypothalamus)
There are invasive sites for temperature checking
you will discuss later in the course
Pyrexia
▪ A person has an elevated core temperature above 38 degrees
▪ May occur as a response to tissue injury or trauma
▪ Patients may experience:
– Loss of appetite, headache, hot dry skin, flushed face, thirst, general malaise, fatigue, shivering and nausea/vomiting.
Pulse
▪ A wave of pressure through an artery wall that follows each contraction of the left ventricle of the heart.
▪ With every beat the heart pumps an amount of blood (stroke volume) into the ascending (then descending) aorta.
▪ Heart rate or pulse rate is the number of pulsation felt over a peripheral artery or auscultated over the apex of the heart in one (1) minute.
Pulse Physiology
▪ Volume- With each beat of the heart, a new volume of blood distends the aorta & spreads to smaller arteries in the peripheries
▪ Rhythm- Normal rhythm is regular. The pattern & time interval between pulsations is even is most people
▪ Arrhythmia/Dysrhythmia
– An irregular pattern of heartbeats is called an arrhythmia
▪ Rate - is assessed by counting the pulsations in 1 minute
Pulse rate is controlled by a group of specialised cells -
sinoatrial node (located in the upper right atrium)
▪ Tachycardia
– A rapid heart rate which can impact on cardiac output
– Occurs in adults when the pulse is more than 100 bpm
▪ Bradycardia
– A slow pulse rate can also impact upon cardiac output
– Occurs in adults when the pulse rate is below 60 bpm
Assessing Pulse
▪ Can be measured at any artery including these common sites:
▪ Radial
▪ Brachial
▪ Carotid
▪ Femoral
▪ Use the pads of your first three fingers lightly compress
the artery so pulsations can be felt and counted.
Assessment of Respirations
▪ Respiratory Rate
– RR should be measured for a full minute
– Ensure the patient is not aware you are counting their respirations
▪ Ventilatory Depth
– Depth is measured by the degree of excursion (movement) in the chest wall
– Ventilatory depth is described as normal, shallow or deep
– Indicates degree of respiratory effort
▪ Characteristics
– Refers to sounds that can be heard during respiration
– Crackles indicate fluid within the lung or collapse of alveoli
– Wheeze results from narrowing of the airways from inflammation/mucud
Factors Affecting Respiration Rate
▪ Exercise
▪ Temperature
▪ Emotions
▪ Medications\Drugs
▪ Haemorrhage
▪ Smoking
▪ Pulmonary Conditions
▪ Pain
▪ Neurological Damage
▪ Anaemia
Oxygen Saturation
▪ Blood flow through the pulmonary capillaries provides red blood cells (RBC) for oxygen attachment.
▪ RBC carry oxygen attached to haemoglobin molecules
through the left side of the heart to the peripheral arteries.
▪ The percentage of haemoglobin bound to oxygen in the
arteries is the saturation of haemoglobin (SaO2).
▪ Normal range is between 95-100%
▪ It’s very important to assess SaO2 – but assessing the
patient and how they are maintaining their saturation (eg.
Positioning) is also important!
Measuring Oxygen Saturation
▪ Oxygen saturation is measured using pulse oximetry - a
non-invasive method of measuring oxygen saturation.
* Pulse oximetry provides an estimation of arterial
oxygen saturation (Sp02).
* True arterial oxygen saturation must be obtained using
arterial blood gas analysis (Sa02).
▪ Pulse oximetry is effective when the Sa02 saturation is
within 70-100%, lower saturation will result in inaccurate
results.
Pulse Oximeter
▪ Pulse oximetry works by passing red and infrared light through the finger and capillary beds.
▪ The receiving probe detects the amount of red and infrared light that has not been absorbed by the blood
▪ Oxygen saturation (Sp02) detects pulsatile blood flow through the capillaries in the limb the oximeter is attached.
▪ Patients with chronic respiratory conditions may tolerate an oxygen saturation of between 88-94%.
Blood Pressure
▪ Blood pressure is the force (pressure) of the blood pushing
against the blood vessel wall.
▪ The strength of the pressure changes with the events that
occur during the normal cardiac cycle.
▪ BP is measured in millimetres of mercury (mmHg).
▪ It is a reflection of the relationship between cardiac output
and peripheral vascular resistance.
▪ BP is expressed as a ratio of the systolic pressure over the
diastolic pressure.
Systolic and Diastolic Blood Pressure
▪ There are two (2) blood pressure measurements:
– SYSTOLIC
▪ The higher pressure occurring during ventricular
contraction
– DIASTOLIC
▪ The lower pressure occurring during ventricular
relaxation
▪ Blood Pressure is usually expressed as 120/80mmHg and
is usually taken on the person’s right upper arm
– Need to indicate where BP was taken if not on right
upper arm.