Pulse oximetry is a noninvasive method to measure the oxygen saturation of hemoglobin in arterial blood and assess the oxygen delivery to tissues. A pulse oximeter indirectly monitors blood oxygen levels through the skin using light absorption properties of oxygenated and deoxygenated hemoglobin to calculate oxygen saturation. It is useful for continuously monitoring patients at risk for hypoxemia in settings like the ICU, operating room, and emergency department. While generally accurate, readings can be affected by factors like poor perfusion, dyshemoglobins, or excessive motion.

1. Pulse Oximetry
MR.J.G Sambad (M.Sc.Nursing-M.S.N)

2. Pulse Oximeter:
Pulse Oximeter used to measure oxygen
saturation in the body i.e how much of the
hemoglobin in the blood is carrying the
oxygen.

3. DEFINITION
IT IS A NON INVASIVE DEVICE USED TO MEASURE
BLOOD OXYGEN LEVELS AND CAN ALSO DISPLAY
HEART RATE.
A PULSE OXIMETER IS A MEDICAL DEVICE THAT
INDIRECTLY MONITORS THE OXYGEN SATURATION
OF A PATIENT'S BLOOD

4. PURPOSES OF PULSE OXYMETRY:
PULSE OXYMETERS MEASURE THE ARTERIAL
OXYGEN SATURATION OF HAEMOGLOBIN.
TO RELIEVE CYANOSIS BY DETECTING HYPOXIA
AND SEVEOUR RESPIRATORY FAILURE.
PULSE OXIMETERS MEASURE:
1. THE OXYGEN SATURATION OF HAEMOGLOBIN IN
ARTERIAL BLOOD
2. THE PULSE RATE - IN BEATS
PER MINUTE

5. Calculation:

6. FUNCTIONS
Q IT IS A SAFE AND SIMPLE METHOD OF ASSESSING
OXYGENATION.
Q IT IS NONINVASIVE.
Q ACCEPTABLE NORMAL RANGES ARE FROM 95 TO
100 PERCENT.
Q CONVENIENT ANDMEASUREMENT CAN BE
CONTINOUS.

7. Pulse Oximeters may be used in
patients:
Undergoing
surgical procedure
under general
anesthesia
Undergoing surgical
procedure under
conscious sedation

8. Pulse Oximeters may be used in
patients:  Emergency situations
like loss of
consciousness,
trauma etc.
 After surgery during
the recovery phase
• In the ICU, Pulse
Oximetry is used
extensively on
mechanically
ventilated patients

9. Pulse Oximeters may be used in
patients:
• Pulse Oximeters
are routinely used
in certain hospital
wards and in
casualty
departments for
immediate
assessment of
patients

10. Pulse Oximeter
reading may not be accurate
 Venous congestion (partial
obstruction of the veins) of
an arm or leg
 Reduced peripheral
pulsatile blood flow
 Bright overhead lights,
such as in an operating
theatre
 Shivering or significant,
repeated movement of the
sensor

11. Pulse Oximeter
reading may not be accurate:
• Nail varnish may cause
falsely low readings
with most pulse
Oximeters, especially
those colored blue or
black

12. The following won’t affect the
Pulse Oximeter reading:
Anemia Jaundice

13. OXIMETERS CONSIST OF
☺ PERIPHERAL PROBE
☺ A MICROPROCESSOR UNIT DISPLAYS A
WAVEFORM, THE OXYGEN SATURATION AND
THE PULSE RATE.
☺RED AND INFRARED
☺ LIGHT EMITERS DETECTOR
MOST OXIMETERS ALSO
HAVE AN AUDIBLE PULSE
TONE,

14. Operation:
Finger is placed in between the light source
and the light detector. Non absorbed light by
finger reaches at detector.
Light is emitted from light sources which
goes across the pulse oximeter probe and
reaches the light detector.

15. The amount of light absorbed depends
on three physical properties:
1. concentration of the light absorbing
substance.
2. length of the light path in the
absorbing substance
3. oxyhemoglobin and
deoxyhemoglobin
absorbs red and infrared light
differently

16. Property No.1
Amount of light absorbed is
proportional to the concentration of
the light absorbing substance.

17. Property No.2
Amount of light absorbed is proportional
to the length of the light path.

18. Property No.3
oxyhemoglobin absorbs more infrared
light than red light & deoxyhemoglobin
absorbs more red light than infrared light.

19. PRINCIPLES OF PULSE OXIMETRY TECHNOLOGY
AIT IS BASED ON THE RED AND INFRARED LIGHT
ABSORPTION CHARACTERISTICS OF OXYGENATED
AND DEOXYGENATED HEMOGLOBIN.
ARED LIGHT IS IN THE 600-750 NM WAVELENGTH
LIGHT BAND. INFRARED LIGHT IS IN THE 850-1000 NM
WAVELENGTH LIGHT BAND.

20. PULSE OXIMETRY WORKS BY PLACING A PULSATING
ARTERIOLAR VASCULAR BED BETWEEN A DUAL LIGHT
(RED AND INFRARED) SOURCE AND A
PHOTODETECTOR.
THE PHOTODETECTOR RECORDS THE RELATIVE
AMOUNT OF EACH COLOR ABSORBED BY ARTERIAL
BLOOD AND TRANSMITS THE DATA TO A MONITOR,
WHICH DISPLAYS THE INFORMATION WITH EACH
HEARTBEAT.

22. GENERALLY MEASURED ON:
 VARIOUS SITES LIKE
 THE FINGER
 TOE
 PINNA (TOP) OR LOBE OF THE EAR
 INFANTS - THE BRIDGE OF THE NOSE,FOOT OR
PALM OF THE HAND, THE BIG TOE OR THE THUMB.

24. TYPES OF OXIMETERS
Designs:
• Pulse Oximeter as part of an anesthetic
machine
• A portable desktop unit
• A finger/mobile pulse Oximeter

25. Pulse Oximeter as part of an
anesthetic machine

26. Pulse Oximeters (continue)
Desktop Finger/mobile

27. Types

28. ADVANTAGES
A PULSE OXIMETER IS USEFUL IN ANY SETTING
WHERE A PATIENT'S OXYGENATION IS UNSTABLE:
a INCLUDING INTENSIVE CARE UNITS (SICU, CTICU,
PICU, NICU.
a OPERATION THEATRE AND RECOVERY ROOMS.
a EMERGENCY OR CAUSALITY.
HOSPITAL WARD SETTINGS
AND DETERMINING THE EFFECTIVENESS OF NEED
FOR SUPPLEMENTAL OXYGEN

29. 1) OXIMETRY IS NOT A COMPLETE MEASURE OF
RESPIRATORY SUFFICIENCY.
A PATIENT SUFFERING FROM HYPOVENTILATION
(POOR GAS EXCHANGE IN THE LUNGS) GIVEN 100%
OXYGEN CAN HAVE EXCELLENT BLOOD OXYGEN
LEVELS WHILE STILL SUFFERING FROM RESPIRATORY
ACIDOSIS DUE TO EXCESSIVE CARBON DIOXIDE.
LIMITATIONS

30. 2) IT IS ALSO NOT A COMPLETE MEASURE OF
CIRCULATORY SUFFICIENCY
IF THERE IS INSUFFICIENT BLOODFLOW OR
INSUFFICIENT HEMOGLOBIN IN THE BLOOD
(ANEMIA), TISSUES CAN SUFFER HYPOXIA DESPITE
HIGH OXYGEN SATURATION IN THE BLOOD THAT
DOES ARRIVE

31. 3) A HIGHER LEVEL OF METHEMOGLOBIN WILL TEND
TO CAUSE A PULSE OXIMETER TO READ CLOSER TO
85% REGARDLESS OF THE TRUE LEVEL OF OXYGEN
SATURATION.
4) IT WILL NOT SHOW THE PCO2 AND ACID BASE
STATUS.
5) IT WILL NOT PROVIDE AN ABSOLUTE INDICATOR
OF HYPEROXIA.

32. INACCURATE RESULTS IN FOLLOWING CONDITIONS
EPOOR PERFUSION (PROCESS OF NUTRITIVE
DELIVERY OF ARTERIAL BLOOD TO A CAPILLARY BED
IN THE BIOLOGICAL TISSUE).
EDYSHAEMOGLOBIN
(OR)CARBOXYHEMOGLOBIN Is a stable complex of
carbon monoxide and hemoglobin that forms in red
blood cells when carbon monoxide is inhaled or
produced in normal metabolism.

33. EHYPER OXYGENATION
EARRHYTHMIA : it is An arrhythmia is a
disorder of the heart rate (pulse) or heart
rhythm, such as beating too fast (tachycardia),
too slow (bradycardia), or irregularly.
EEXCESSIVE AMBIENT LIGHT

34. A PULSE OXIMETER GIVES NO INFORMATION ON
ANY OF THESE OTHER VARIABLES
d THE OXYGEN CONTENT OF THE BLOOD.
d THE AMOUNT OF OXYGEN DISSOLVED IN THE BLOOD.
d THE RESPIRATORY RATE OR TIDAL VOLUME I.E.
VENTILATION.
d THE CARDIAC OUTPUT OR BLOOD PRESSURE.

35. PROVIDE THE PATIENT WITH A SIMPLE EXPLANATION
OF PULSE OXIMETRY AND ITS VALUE.
SELECT APPROPRIATE SENSOR PROBE FOR PATIENT’S
AGE, WEIGHT, CONDITION, DURATION OF PULSE
OXIMETRY MONITORING, AS WELL AS THE USE OF
BP CUFF, ARTERIAL CATHETER AND/OR PERIPHERAL
I.V. LINE.
NURSING RESPONSIBILITIES

36. REMOVE ANY NAIL POLISH FROM ANY DIGITS
WHICH WILL HAVE A SENSOR APPLIED AS IT
INTERFERES WITH LIGHT TRANSMISSION
IF IT SHOWS WRONG READING CHECK PATIENT’S BP
AND VITAL SIGNS FIRST – IF THEY ARE ACCEPTABLE
FOR PATIENT, THEN CHECK FOR THE FOLLOWING.
Bad Connection
Inadequate or Intermittent Blood Flow to Site
Equipment Malfunctions

37. AFTER USE:
 REMOVE SENSOR FROM MONITORING SITE.
 WASH SITE OFF WITH SOAP AND WATER.
 (DO NOT USE ALCOHOL).
DOCUMENTATION:
DOCUMENT PULSE OXIMETER READINGS (SAO2), SENSOR
PLACEMENT AND ALARM SETTINGS (CONTINUOUS MODE) ON
PATIENT CARE RECORD OR FLOWSHEET.

38. THANKYOU