Download Vital Signs Bp and SpO2

Vital Signs
Bp and SpO2
Marija Buttery 2010
BLOOD PRESSURE
BLOOD PRESSURE
•
Blood pressure is the measurement of force exerted by the
blood on the walls of the blood vessels as the heart contracts
and relaxes
•
Systolic – is the pressure of the blood exerted on the walls of
the vessels when the heart contracts
•
Diastolic – is the pressure of the blood exerted on the walls
of the vessels when the heart is relaxed.
•
For example Mr Harris’ Bp is 150/80 – 150(systolic) /
80(diastolic)
BLOOD PRESSURE
•
Blood pressure is measured in mmHg (millimetres of
mercury)
•
A rise or fall in blood pressure can cause significant
problems for the entire body
•
The pressure is what enables to blood to go from the heart
around the entire body then back to the heart
•
Where there is not enough blood pressure, parts of the
body will not be supplied with enough blood, oxygen and
nutrients.
•
Where the blood pressure is too high it puts a strain on all
the parts of the body.
BLOOD PRESSURE
•
Hypertension – elevated blood pressure
•
Hypotension – low blood pressure
•
There is also postural hypotension where the
blood pressure drops when the patient stands
Definitions and classification of BP levels
(measured in mm Hg) Heart Foundation 2004
Category
Systolic
Diastolic
Normal
90 - 120
60 - 80
High-normal
120 – 139
80 - 89
Grade 1 (mild)
140 – 159
90 - 99
Grade 2 (moderate)
160 – 179
100 - 109
Grade 3 (severe)
≥ 180
≥ 110
Blood Pressure (BP)

Measurement of cardiovascular
function

Force resulting from cardiac output
and peripheral vascular resistance

Indirectly measured with
sphygmomanometer and stethoscope
Blood Pressure

Systolic pressure/diastolic pressure

BP is an easily measured vital sign that
is a screening tool for identifying
hypertension

Hypertension is a silent disease, often
without symptoms, yet can be fatal
and/or cause significant morbidity
Blood Pressure

Hypertension:




Elevated systolic pressure only
Elevated diastolic pressure only
Elevated systolic and diastolic pressures
Which ever value is most out of range is used
to classify the degree of hypertension
Hypertension Facts (HT)

High BP is major risk for heart disease
and chief risk factor for:




Stroke
Congestive Heart Failure
Myocardial infarction (MI)
Can lead to kidney, liver and retinal
changes
Hypertension Facts (HT)

Lifestyle measures are a crucial part of treatment
 Lose excess weight
 Be physically active
 Limit alcoholic beverages
 Decrease salt intake
 Decrease fat intake - cholesterol
 Follow a heart-healthy eating plan
 Quit smoking
Conditions that increase BP






Stress – physical or emotional
Steroid therapy and other medications
Hypercholesterolemia
Diabetes mellitus
Renal disease
Hyperthyroidism
Risk Factors for HT






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Age
Obesity
Disease - diabetes
Lack of exercise
Smoking
Alcohol
Stress
Diet
Diagnosis of HT

Made after three readings on separate days
when all are elevated beyond normal

If you determine a reading that is abnormal:
 Report to RN, may need MO review
 Recheck after 5 minutes
 Assess patient for cause (e.g. stress, just
had a cigarette)
Hypotension

BP < 90/60 mm Hg
Orthostatic / postural hypotension
 Excessive fall in BP (> 20/10 mm Hg) on assuming
the upright position
 Gravitational stress
 Autonomic reflex
 Hypovolaemia
5 Factors Determine BP Level
1.
2.
3.
4.
5.
Cardiac output
Peripheral vascular resistance
Total blood volume
Viscosity of the blood
Compliance of the arterial wall
Factors Contributing to
Inaccurate BP Measurement
 Defective
equipment
 Faulty technique
 Clinical error
 Failure to consider patient
factors
Factors Contributing to Inaccurate
BP Measurement
Defective equipment

Inflating system, exhaust valve & tubing
without leaks

Cuff fabric should be intact so pressure is
distributed evenly

Adjust the “0” on Hg manometers
Factors Contributing to Inaccurate
BP Measurement
Faulty Technique




Incorrect positioning of the
patient/artery
Cuff size (too small or too big)
Not Applying cuff evenly, snugly
Placing stethoscope under the cuff
Factors Contributing to Inaccurate
BP Measurement
Clinician Error



Same as previous
Be sure to estimate systolic blood pressure
Refrain from rechecking repeatedly without
allowing for pressure equilibration
Patient Factors

Emotion, anger, anxiety, pain, frustration,
sudden noises, sedation, fever
Positioning the Bp Cuff

Cuff applied evenly, snugly with bottom edge about
1 inch above the antecubital fossa (elbow)

Valve tubing attached to the cuff should be placed
over the brachial arterial. Palpate the artery

It may be difficult to hear the BP sounds in an
obese patient, in the case of hypotension or if the
artery is very deep in a muscular person
Measuring the BP




Patient should be at rest
Position the patient so that the arm is at
the height of the heart
Remove any clothing that may be
restrictive
Estimate the systolic BP
Estimating the systolic BP

Palpate the radial artery (with index/middle finger)

Inflate the cuff to a pressure 20 mm Hg above the
point at which the radial pulsation disappears,
slowly release cuff whilst feeling for return of
pulse. Note the number - that is your palpable
systolic pressure

Deflate the cuff and wait a short time
Measuring the BP



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

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Place the diaphragm of the stethoscope
over the brachial artery
Close the valve of the pressure bulb
Inflate the cuff to the estimated point
Slowly release valve
Systolic pressure is when the first sound is
heard
Diastolic pressure is when the sound
disappears
Deflate the cuff & remove
YOU WILL NOT HEAR
THE BRACHIAL
ARTERY PULSE
UNTIL THE CUFF IS
INFLATED!!
Systolic and Diastolic Readings
Systolic
• Top number
• When the heart is
contracting
Diastolic
• Bottom number
• When the heart is
resting (or refilling)
110
75
S for Systolic
S for Squish!
Pulse Oximetry
Oximeter
SpO2
Sats
SaO2
Pulse Oximetry





A non invasive measurement of arterial blood
oxygen saturation
A Light Emitting Diode (LED) measures the
amount of oxygen on the haemoglobin (Hb)
Light waves are absorbed then reflected back by
oxygenated and deoxygenated Hb molecules
The light is processed by the oximeter, which
calculates the pulse oxygen saturation (Sp02).
It is recorded as a percentage
Inaccurate Readings

Can be caused by:

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Movement
False nails
Some red/dark nail polish
Direct sunlight
Hypotension
Peripheral vascular disease
Hypothermia
Oedema