SlideShare a Scribd company logo

Scientific Concept SpO2 of Pulse Oximeter

SpO2 stands for peripheral capillary oxygen saturation, an estimate of the amount of oxygen in the blood. More specifically, it is the percentage of oxygenated haemoglobin (haemoglobin containing oxygen) compared to the total amount of haemoglobin in the blood (oxygenated and non-oxygenated haemoglobin).SpO2 is an estimate of arterial oxygen saturation, or SaO2, which refers to the amount of oxygenated haemoglobin in the blood.

1 of 14
Download to read offline
SpO2 Monitoring
Contents
1 Introduction
1 What is SpO2?
How Does Pulse Oximetry Work?
SpO2 Sensors
Absorption at the Sensor Site
Oxyhemoglobin Dissociation Curve
5 How Do I Use SpO2?
Choosing a Sensor
7 Using SpO2
8 Considerations When Using Pulse Oximetry
8 Effects of Non-functional Hemoglobin on Oxygen Saturation
Measurements
Other Situations
Common Problems with Pulse Oximetry 13
Glossary
1111
Introduction
The body's need for oxygen is certain. Its availability at a tissue level is some-
times in doubt. Blood gas measurements provide critical information regarding
oxygenation, ventilation, and acid-base status.
However, these measurements only provide a snapshot of the patient's condition
taken at the time that the blood sample was drawn. It is well known that
oxygenation can change very quickly. In the absence of continuous oxygenation
monitoring, these changes may go undetected until it is too late.
Pulse oximeters measure blood oxygen saturation noninvasively and continu-
ously.
What is SpO2?
A blood-oxygen saturation reading indicates the percentage of hemoglobin
molecules in the arterial blood which are saturated with oxygen. Readings vary
from 0 to 100%. Normal readings in a healthy adult, however, range from 94% to
100%.
The term SpO2 means the SpO2 measurement determined by pulse oximetry. As
explained in the section "Considerations When Using Pulse Oximetry,” under
some circumstances pulse oximetry gives different readings, and the use of a
different term indicates this.
How Does Pulse Oximetry Work?
Within the SpO2 sensor, light emitting diodes shine red and infrared light
through the tissue. Most sensors work on extremities such as a finger, toe or ear.
The blood, tissue and bone at the application site absorb much of the light.
However, some light passes through the extremity. A light-sensitive detector
opposite the light source receives it.
SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts
2222
SpO2 Sensors
Most sensors work on extremities such as a finger, toe or ear. The sensor mea-
sures the amount of red and infrared light received by the detector and calculates
the amount absorbed. Much of it is absorbed by tissue, bone and venous blood,
but these amounts do not change dramatically over short periods of time.
3333
The amount of arterial blood does change over short periods of time due to
pulsation (although there is some constant level of arterial blood). Because the
arterial blood is usually the only light absorbing component which is changing
over short periods of time, it can be isolated from the other components.
SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts
4444
Absorption at the Sensor Site
The amount of light received by the detector indicates the amount of oxygen
bound to the hemoglobin in the blood. Oxygenated hemoglobin (oxyhemoglobin
or HbO2) absorbs more infrared light than red light. Deoxygenated hemoglobin
(Hb) absorbs more red light than infrared light. By comparing the amounts of red
and infrared light received, the instrument can calculate the SpO2 reading.
Oxyhemoglobin Dissociation Curve
You may have used oxygen partial pressure (PaO2) to judge oxygen saturation.
SpO2 is related to PaO2 in a complex way, as shown in Figure 3, the Oxyhe-
moglobin Dissociation Curve.
At very high SpO2 levels, PaO2 values can vary widely without producing a
significant change in SpO2 levels. Because of this, SpO2 readings cannot be used
to warn of high PaO2 levels.
Many variables can affect hemoglobin’s affinity for oxygen, and thus the position
of the curve. Decreasing concentrations of hydrogen ions, PaCO2 and 2,3 DPG,
increase hemoglobin’s affinity for oxygen and shift the curve to the left.
TimeTimeTimeTime
Figure 2: AbsorptionAbsorption due to:Absorption due to:Absorption due to:Absorption due to:
pulsepulsepulsepulse----added volume ofadded volume ofadded volume ofadded volume of
arterial bloodarterial bloodarterial bloodarterial blood ---------------------------- >>>>
arterial bloodarterial bloodarterial bloodarterial blood -------------------------------------------------------------------------------------------------------- >>>>
venous bloodvenous bloodvenous bloodvenous blood -------------------------------------------------------------------------------------------------------- >>>>

Recommended

Pulseoximetry
PulseoximetryPulseoximetry
Pulseoximetrydrriyas03
 
How Pulse oximeter works- Principle and Limitations I SpO2 I Respiratory Phys...
How Pulse oximeter works- Principle and Limitations I SpO2 I Respiratory Phys...How Pulse oximeter works- Principle and Limitations I SpO2 I Respiratory Phys...
How Pulse oximeter works- Principle and Limitations I SpO2 I Respiratory Phys...HM Learnings
 

More Related Content

What's hot (19)

Pulse Oxymetry
Pulse OxymetryPulse Oxymetry
Pulse Oxymetry
 
Pulse oximeter
Pulse  oximeterPulse  oximeter
Pulse oximeter
 
Pediatrics - Pulse Oximetry and Clubbing (concise)
Pediatrics - Pulse Oximetry and Clubbing (concise)Pediatrics - Pulse Oximetry and Clubbing (concise)
Pediatrics - Pulse Oximetry and Clubbing (concise)
 
Pulse oximeter
Pulse oximeterPulse oximeter
Pulse oximeter
 
Pulse oximeter
Pulse oximeterPulse oximeter
Pulse oximeter
 
pulse oximetry final
pulse oximetry finalpulse oximetry final
pulse oximetry final
 
Oximeter
OximeterOximeter
Oximeter
 
Pulse oximetry
Pulse oximetryPulse oximetry
Pulse oximetry
 
Pulse oximetry journal
Pulse oximetry journalPulse oximetry journal
Pulse oximetry journal
 
Pulse Oximetry
Pulse OximetryPulse Oximetry
Pulse Oximetry
 
Pulse oximetry slidefinal abc
Pulse oximetry slidefinal abcPulse oximetry slidefinal abc
Pulse oximetry slidefinal abc
 
medicalbulkbuy India Pvt. Ltd. | SlideShare
 medicalbulkbuy India Pvt. Ltd. | SlideShare medicalbulkbuy India Pvt. Ltd. | SlideShare
medicalbulkbuy India Pvt. Ltd. | SlideShare
 
Pulse oximeter
Pulse oximeterPulse oximeter
Pulse oximeter
 
Pulse oximeter – how does it work and how can it be used in home care?
Pulse oximeter – how does it work and how can it be used in home care?Pulse oximeter – how does it work and how can it be used in home care?
Pulse oximeter – how does it work and how can it be used in home care?
 
Pulse oximetry & capnography
Pulse oximetry & capnographyPulse oximetry & capnography
Pulse oximetry & capnography
 
Spo2 ppt
Spo2 pptSpo2 ppt
Spo2 ppt
 
PULSE OXIMETRY
PULSE OXIMETRYPULSE OXIMETRY
PULSE OXIMETRY
 
Pulse oximetry capnography
Pulse oximetry capnography Pulse oximetry capnography
Pulse oximetry capnography
 
Pulse oximeter
Pulse oximeterPulse oximeter
Pulse oximeter
 

Viewers also liked

CVA cerebrovascular accidant - History taking and OSCE
CVA cerebrovascular accidant - History taking and OSCECVA cerebrovascular accidant - History taking and OSCE
CVA cerebrovascular accidant - History taking and OSCEMohamed Eisam Elhag
 
Importance of breathing_Pranayama.ppt
Importance of breathing_Pranayama.pptImportance of breathing_Pranayama.ppt
Importance of breathing_Pranayama.pptShama
 
Cerebrovascular disease (CVA / Stroke)
Cerebrovascular disease (CVA / Stroke)Cerebrovascular disease (CVA / Stroke)
Cerebrovascular disease (CVA / Stroke)Richard Brown
 
Ppt on unemployment
Ppt on unemploymentPpt on unemployment
Ppt on unemploymentmanav500
 

Viewers also liked (7)

EtCO2 Linkedin
EtCO2 LinkedinEtCO2 Linkedin
EtCO2 Linkedin
 
CVA cerebrovascular accidant - History taking and OSCE
CVA cerebrovascular accidant - History taking and OSCECVA cerebrovascular accidant - History taking and OSCE
CVA cerebrovascular accidant - History taking and OSCE
 
KHÍ MÁU ĐỘNG MẠCH
KHÍ MÁU ĐỘNG MẠCHKHÍ MÁU ĐỘNG MẠCH
KHÍ MÁU ĐỘNG MẠCH
 
03 capnography
03 capnography03 capnography
03 capnography
 
Importance of breathing_Pranayama.ppt
Importance of breathing_Pranayama.pptImportance of breathing_Pranayama.ppt
Importance of breathing_Pranayama.ppt
 
Cerebrovascular disease (CVA / Stroke)
Cerebrovascular disease (CVA / Stroke)Cerebrovascular disease (CVA / Stroke)
Cerebrovascular disease (CVA / Stroke)
 
Ppt on unemployment
Ppt on unemploymentPpt on unemployment
Ppt on unemployment
 

Similar to Scientific Concept SpO2 of Pulse Oximeter

Similar to Scientific Concept SpO2 of Pulse Oximeter (20)

Pulseox[1]
Pulseox[1]Pulseox[1]
Pulseox[1]
 
ABG by DJ
ABG by DJABG by DJ
ABG by DJ
 
PULSE OXIMETRY.pptx
PULSE OXIMETRY.pptxPULSE OXIMETRY.pptx
PULSE OXIMETRY.pptx
 
Moderate sedation monitoring
Moderate sedation monitoring Moderate sedation monitoring
Moderate sedation monitoring
 
Arterial Blood Gases
Arterial Blood GasesArterial Blood Gases
Arterial Blood Gases
 
Anesthesia 5th year, 6th & 7th lectures (Dr. Gona)
Anesthesia 5th year, 6th & 7th lectures (Dr. Gona)Anesthesia 5th year, 6th & 7th lectures (Dr. Gona)
Anesthesia 5th year, 6th & 7th lectures (Dr. Gona)
 
Monitoring Modality in anesthesia
Monitoring Modality  in anesthesiaMonitoring Modality  in anesthesia
Monitoring Modality in anesthesia
 
Pulse oximetry
Pulse oximetryPulse oximetry
Pulse oximetry
 
IRJET- The Multiphysiological Parameter Monitoring System
IRJET-  	  The Multiphysiological Parameter Monitoring SystemIRJET-  	  The Multiphysiological Parameter Monitoring System
IRJET- The Multiphysiological Parameter Monitoring System
 
Respiratory monitoring
Respiratory monitoringRespiratory monitoring
Respiratory monitoring
 
Pulse oximetry
Pulse oximetryPulse oximetry
Pulse oximetry
 
EMS: the tools we use
EMS: the tools we useEMS: the tools we use
EMS: the tools we use
 
ABG for ICU Clinical PhARMACIST
ABG for ICU Clinical PhARMACIST ABG for ICU Clinical PhARMACIST
ABG for ICU Clinical PhARMACIST
 
Arterial Blood Gas Analysis Toufiqur Rahman
Arterial Blood Gas Analysis Toufiqur RahmanArterial Blood Gas Analysis Toufiqur Rahman
Arterial Blood Gas Analysis Toufiqur Rahman
 
Pulse Oxymetry , Inspired & Expired Gas Monitoring
Pulse Oxymetry ,  Inspired & Expired Gas MonitoringPulse Oxymetry ,  Inspired & Expired Gas Monitoring
Pulse Oxymetry , Inspired & Expired Gas Monitoring
 
Abg interpretation
Abg interpretationAbg interpretation
Abg interpretation
 
Oxygen reserve index
Oxygen reserve indexOxygen reserve index
Oxygen reserve index
 
Ppt0000002
Ppt0000002Ppt0000002
Ppt0000002
 
An Introduction To Surgical Icu
An Introduction To Surgical IcuAn Introduction To Surgical Icu
An Introduction To Surgical Icu
 
Arterial blood gas
Arterial blood gasArterial blood gas
Arterial blood gas
 

More from Gurin Products, LLC

Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...
Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...
Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...Gurin Products, LLC
 
Liztek PSS-100 Portable Wireless Bluetooth Speaker
Liztek PSS-100 Portable Wireless Bluetooth SpeakerLiztek PSS-100 Portable Wireless Bluetooth Speaker
Liztek PSS-100 Portable Wireless Bluetooth SpeakerGurin Products, LLC
 
Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...
Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...
Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...Gurin Products, LLC
 
Liztek USB 3.0 to HDMI Video Graphics Adapter Card
Liztek USB 3.0 to HDMI Video Graphics Adapter CardLiztek USB 3.0 to HDMI Video Graphics Adapter Card
Liztek USB 3.0 to HDMI Video Graphics Adapter CardGurin Products, LLC
 
Santamedical SM-240 OLED Finger Pulse Oximeter
Santamedical SM-240 OLED Finger Pulse OximeterSantamedical SM-240 OLED Finger Pulse Oximeter
Santamedical SM-240 OLED Finger Pulse OximeterGurin Products, LLC
 
Santamedical SM-230 OLED Finger Pulse Oximeter
Santamedical SM-230 OLED Finger Pulse OximeterSantamedical SM-230 OLED Finger Pulse Oximeter
Santamedical SM-230 OLED Finger Pulse OximeterGurin Products, LLC
 
Santamedical SM-220 Finger Pulse Oximeter
Santamedical SM-220 Finger Pulse OximeterSantamedical SM-220 Finger Pulse Oximeter
Santamedical SM-220 Finger Pulse OximeterGurin Products, LLC
 
SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer
SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer
SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer Gurin Products, LLC
 
2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...
2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...
2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...Gurin Products, LLC
 
Gurin Portable Ultrasonic Massager
Gurin Portable Ultrasonic MassagerGurin Portable Ultrasonic Massager
Gurin Portable Ultrasonic MassagerGurin Products, LLC
 
Bpm 165 w blood pressure monitor
Bpm 165 w blood pressure monitorBpm 165 w blood pressure monitor
Bpm 165 w blood pressure monitorGurin Products, LLC
 

More from Gurin Products, LLC (20)

HDD docking station
HDD docking stationHDD docking station
HDD docking station
 
Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...
Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...
Liztek USB 3.0 Universal Docking Station, Dual Monitor, for Laptop, Ultrabook...
 
Liztek PSS-100 Portable Wireless Bluetooth Speaker
Liztek PSS-100 Portable Wireless Bluetooth SpeakerLiztek PSS-100 Portable Wireless Bluetooth Speaker
Liztek PSS-100 Portable Wireless Bluetooth Speaker
 
Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...
Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...
Liztek HDDT2BS Dual Bay USB 3.0 Super Speed to 2.5 and 3.5 inch SATA Hard Dis...
 
Liztek USB 3.0 to HDMI Video Graphics Adapter Card
Liztek USB 3.0 to HDMI Video Graphics Adapter CardLiztek USB 3.0 to HDMI Video Graphics Adapter Card
Liztek USB 3.0 to HDMI Video Graphics Adapter Card
 
Gurin steam inhaler
Gurin steam inhalerGurin steam inhaler
Gurin steam inhaler
 
Gurin Steam Inhaler
Gurin Steam InhalerGurin Steam Inhaler
Gurin Steam Inhaler
 
Santamedical SM-240 OLED Finger Pulse Oximeter
Santamedical SM-240 OLED Finger Pulse OximeterSantamedical SM-240 OLED Finger Pulse Oximeter
Santamedical SM-240 OLED Finger Pulse Oximeter
 
Santamedical SM-230 OLED Finger Pulse Oximeter
Santamedical SM-230 OLED Finger Pulse OximeterSantamedical SM-230 OLED Finger Pulse Oximeter
Santamedical SM-230 OLED Finger Pulse Oximeter
 
Santamedical SM-220 Finger Pulse Oximeter
Santamedical SM-220 Finger Pulse OximeterSantamedical SM-220 Finger Pulse Oximeter
Santamedical SM-220 Finger Pulse Oximeter
 
Sm 165 pulse oximeter
Sm 165 pulse oximeterSm 165 pulse oximeter
Sm 165 pulse oximeter
 
Sm 110 pulse oximeter
Sm 110 pulse oximeterSm 110 pulse oximeter
Sm 110 pulse oximeter
 
Pulse oximeter
Pulse oximeterPulse oximeter
Pulse oximeter
 
Ry230 thermometer
Ry230 thermometerRy230 thermometer
Ry230 thermometer
 
SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer
SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer
SantaMedical Professional Clinical Large LCD Non-Contact Infrared Thermometer
 
2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...
2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...
2-in-1 Professional Clinical RY210 Large LCD Non-contact Infrared Thermometer...
 
Gurin Portable Ultrasonic Massager
Gurin Portable Ultrasonic MassagerGurin Portable Ultrasonic Massager
Gurin Portable Ultrasonic Massager
 
Hair straightener
Hair straightenerHair straightener
Hair straightener
 
Ga 2800 d multi adapter card
Ga 2800 d multi adapter cardGa 2800 d multi adapter card
Ga 2800 d multi adapter card
 
Bpm 165 w blood pressure monitor
Bpm 165 w blood pressure monitorBpm 165 w blood pressure monitor
Bpm 165 w blood pressure monitor
 

Recently uploaded

Poliomyelitis.pptx Department of Physiotherapy, SHUATS, Prayagraj
Poliomyelitis.pptx Department of Physiotherapy, SHUATS, PrayagrajPoliomyelitis.pptx Department of Physiotherapy, SHUATS, Prayagraj
Poliomyelitis.pptx Department of Physiotherapy, SHUATS, PrayagrajSurabhi Srivastava
 
Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...
Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...
Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...Abhinav S
 
Seminario biología molecular Kevin Duque
Seminario biología molecular Kevin DuqueSeminario biología molecular Kevin Duque
Seminario biología molecular Kevin Duquekevinestebanduque
 
Impact of Early Pregnancy---Lecture-2024
Impact of Early Pregnancy---Lecture-2024Impact of Early Pregnancy---Lecture-2024
Impact of Early Pregnancy---Lecture-2024ERWINPEJI2
 
Finger Clubbing by Dr. Samuel2 Alawode.pptx
Finger Clubbing by Dr. Samuel2 Alawode.pptxFinger Clubbing by Dr. Samuel2 Alawode.pptx
Finger Clubbing by Dr. Samuel2 Alawode.pptxAlawode Samuel2
 
Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...
Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...
Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...Golden Helix
 
Influenza.pptx Department of Physiotherapy, SHUATS, Prayagraj
Influenza.pptx Department of Physiotherapy, SHUATS, PrayagrajInfluenza.pptx Department of Physiotherapy, SHUATS, Prayagraj
Influenza.pptx Department of Physiotherapy, SHUATS, PrayagrajSurabhi Srivastava
 
Staphylococcus.ppt.........ali.rasool.badr
Staphylococcus.ppt.........ali.rasool.badrStaphylococcus.ppt.........ali.rasool.badr
Staphylococcus.ppt.........ali.rasool.badrssuser06f49d
 
A complete guide to the Human Digestive System
A complete guide to the Human Digestive SystemA complete guide to the Human Digestive System
A complete guide to the Human Digestive Systemantoneymichael992
 
Measles.pptx Department of Physiotherapy, SHUATS, Prayagraj
Measles.pptx Department of Physiotherapy, SHUATS, PrayagrajMeasles.pptx Department of Physiotherapy, SHUATS, Prayagraj
Measles.pptx Department of Physiotherapy, SHUATS, PrayagrajSurabhi Srivastava
 
PTERYGIUM ,clinical picture and its management.pptx
PTERYGIUM ,clinical picture and its management.pptxPTERYGIUM ,clinical picture and its management.pptx
PTERYGIUM ,clinical picture and its management.pptxvideosfildr
 
Macquarie Neurosurgery Journal Club 2022 PPT
Macquarie Neurosurgery Journal Club 2022 PPTMacquarie Neurosurgery Journal Club 2022 PPT
Macquarie Neurosurgery Journal Club 2022 PPTMQ_Library
 
(DENGUE).pptx Department of Physiotherapy, SHUATS, Prayagraj
(DENGUE).pptx Department of Physiotherapy, SHUATS, Prayagraj(DENGUE).pptx Department of Physiotherapy, SHUATS, Prayagraj
(DENGUE).pptx Department of Physiotherapy, SHUATS, PrayagrajSurabhi Srivastava
 
Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...
Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...
Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...Subrata Roy
 
Anesthesia Implications in cannabis Users.pptx
Anesthesia Implications in cannabis Users.pptxAnesthesia Implications in cannabis Users.pptx
Anesthesia Implications in cannabis Users.pptxhrowshan
 
Dasha vidha Pareeksha.pptx Dr Akshay Shetty
Dasha vidha Pareeksha.pptx Dr Akshay ShettyDasha vidha Pareeksha.pptx Dr Akshay Shetty
Dasha vidha Pareeksha.pptx Dr Akshay ShettyAkshay Shetty
 
Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]
Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]
Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]Brian Peacock
 
RADIATION THERAPY IN BILIARY TRACT CANCER
RADIATION THERAPY IN BILIARY TRACT CANCERRADIATION THERAPY IN BILIARY TRACT CANCER
RADIATION THERAPY IN BILIARY TRACT CANCERKanhu Charan
 
KOSHTA CONCEPT IN AYURVEDA BY VIJAY R K
KOSHTA CONCEPT IN AYURVEDA  BY  VIJAY R KKOSHTA CONCEPT IN AYURVEDA  BY  VIJAY R K
KOSHTA CONCEPT IN AYURVEDA BY VIJAY R Kvinaykumarrkumabar
 

Recently uploaded (20)

Poliomyelitis.pptx Department of Physiotherapy, SHUATS, Prayagraj
Poliomyelitis.pptx Department of Physiotherapy, SHUATS, PrayagrajPoliomyelitis.pptx Department of Physiotherapy, SHUATS, Prayagraj
Poliomyelitis.pptx Department of Physiotherapy, SHUATS, Prayagraj
 
Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...
Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...
Circulatory shock Cardiogenic Shock Hypovolemic Shock Sepsis, Septic Shock an...
 
Seminario biología molecular Kevin Duque
Seminario biología molecular Kevin DuqueSeminario biología molecular Kevin Duque
Seminario biología molecular Kevin Duque
 
Impact of Early Pregnancy---Lecture-2024
Impact of Early Pregnancy---Lecture-2024Impact of Early Pregnancy---Lecture-2024
Impact of Early Pregnancy---Lecture-2024
 
Finger Clubbing by Dr. Samuel2 Alawode.pptx
Finger Clubbing by Dr. Samuel2 Alawode.pptxFinger Clubbing by Dr. Samuel2 Alawode.pptx
Finger Clubbing by Dr. Samuel2 Alawode.pptx
 
Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...
Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...
Analyzing Performance of the Twist Exome with CNV Backbone at Various Probe D...
 
Influenza.pptx Department of Physiotherapy, SHUATS, Prayagraj
Influenza.pptx Department of Physiotherapy, SHUATS, PrayagrajInfluenza.pptx Department of Physiotherapy, SHUATS, Prayagraj
Influenza.pptx Department of Physiotherapy, SHUATS, Prayagraj
 
Staphylococcus.ppt.........ali.rasool.badr
Staphylococcus.ppt.........ali.rasool.badrStaphylococcus.ppt.........ali.rasool.badr
Staphylococcus.ppt.........ali.rasool.badr
 
A complete guide to the Human Digestive System
A complete guide to the Human Digestive SystemA complete guide to the Human Digestive System
A complete guide to the Human Digestive System
 
Measles.pptx Department of Physiotherapy, SHUATS, Prayagraj
Measles.pptx Department of Physiotherapy, SHUATS, PrayagrajMeasles.pptx Department of Physiotherapy, SHUATS, Prayagraj
Measles.pptx Department of Physiotherapy, SHUATS, Prayagraj
 
PTERYGIUM ,clinical picture and its management.pptx
PTERYGIUM ,clinical picture and its management.pptxPTERYGIUM ,clinical picture and its management.pptx
PTERYGIUM ,clinical picture and its management.pptx
 
Macquarie Neurosurgery Journal Club 2022 PPT
Macquarie Neurosurgery Journal Club 2022 PPTMacquarie Neurosurgery Journal Club 2022 PPT
Macquarie Neurosurgery Journal Club 2022 PPT
 
(DENGUE).pptx Department of Physiotherapy, SHUATS, Prayagraj
(DENGUE).pptx Department of Physiotherapy, SHUATS, Prayagraj(DENGUE).pptx Department of Physiotherapy, SHUATS, Prayagraj
(DENGUE).pptx Department of Physiotherapy, SHUATS, Prayagraj
 
Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...
Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...
Work-role of Radiation Therapists in the Consequences of Adaptive Radiotherap...
 
Anesthesia Implications in cannabis Users.pptx
Anesthesia Implications in cannabis Users.pptxAnesthesia Implications in cannabis Users.pptx
Anesthesia Implications in cannabis Users.pptx
 
Dasha vidha Pareeksha.pptx Dr Akshay Shetty
Dasha vidha Pareeksha.pptx Dr Akshay ShettyDasha vidha Pareeksha.pptx Dr Akshay Shetty
Dasha vidha Pareeksha.pptx Dr Akshay Shetty
 
Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]
Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]
Psychedelic Interventions for Neurological Conditions [NAN 2022 Poster]
 
RADIATION THERAPY IN BILIARY TRACT CANCER
RADIATION THERAPY IN BILIARY TRACT CANCERRADIATION THERAPY IN BILIARY TRACT CANCER
RADIATION THERAPY IN BILIARY TRACT CANCER
 
KOSHTA CONCEPT IN AYURVEDA BY VIJAY R K
KOSHTA CONCEPT IN AYURVEDA  BY  VIJAY R KKOSHTA CONCEPT IN AYURVEDA  BY  VIJAY R K
KOSHTA CONCEPT IN AYURVEDA BY VIJAY R K
 
A rare case of Omental & Fibroid Torsion
A rare case of Omental & Fibroid TorsionA rare case of Omental & Fibroid Torsion
A rare case of Omental & Fibroid Torsion
 

Scientific Concept SpO2 of Pulse Oximeter

  • 2. Contents 1 Introduction 1 What is SpO2? How Does Pulse Oximetry Work? SpO2 Sensors Absorption at the Sensor Site Oxyhemoglobin Dissociation Curve 5 How Do I Use SpO2? Choosing a Sensor 7 Using SpO2 8 Considerations When Using Pulse Oximetry 8 Effects of Non-functional Hemoglobin on Oxygen Saturation Measurements Other Situations Common Problems with Pulse Oximetry 13 Glossary
  • 3. 1111 Introduction The body's need for oxygen is certain. Its availability at a tissue level is some- times in doubt. Blood gas measurements provide critical information regarding oxygenation, ventilation, and acid-base status. However, these measurements only provide a snapshot of the patient's condition taken at the time that the blood sample was drawn. It is well known that oxygenation can change very quickly. In the absence of continuous oxygenation monitoring, these changes may go undetected until it is too late. Pulse oximeters measure blood oxygen saturation noninvasively and continu- ously. What is SpO2? A blood-oxygen saturation reading indicates the percentage of hemoglobin molecules in the arterial blood which are saturated with oxygen. Readings vary from 0 to 100%. Normal readings in a healthy adult, however, range from 94% to 100%. The term SpO2 means the SpO2 measurement determined by pulse oximetry. As explained in the section "Considerations When Using Pulse Oximetry,” under some circumstances pulse oximetry gives different readings, and the use of a different term indicates this. How Does Pulse Oximetry Work? Within the SpO2 sensor, light emitting diodes shine red and infrared light through the tissue. Most sensors work on extremities such as a finger, toe or ear. The blood, tissue and bone at the application site absorb much of the light. However, some light passes through the extremity. A light-sensitive detector opposite the light source receives it.
  • 4. SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts 2222 SpO2 Sensors Most sensors work on extremities such as a finger, toe or ear. The sensor mea- sures the amount of red and infrared light received by the detector and calculates the amount absorbed. Much of it is absorbed by tissue, bone and venous blood, but these amounts do not change dramatically over short periods of time.
  • 5. 3333 The amount of arterial blood does change over short periods of time due to pulsation (although there is some constant level of arterial blood). Because the arterial blood is usually the only light absorbing component which is changing over short periods of time, it can be isolated from the other components.
  • 6. SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts 4444 Absorption at the Sensor Site The amount of light received by the detector indicates the amount of oxygen bound to the hemoglobin in the blood. Oxygenated hemoglobin (oxyhemoglobin or HbO2) absorbs more infrared light than red light. Deoxygenated hemoglobin (Hb) absorbs more red light than infrared light. By comparing the amounts of red and infrared light received, the instrument can calculate the SpO2 reading. Oxyhemoglobin Dissociation Curve You may have used oxygen partial pressure (PaO2) to judge oxygen saturation. SpO2 is related to PaO2 in a complex way, as shown in Figure 3, the Oxyhe- moglobin Dissociation Curve. At very high SpO2 levels, PaO2 values can vary widely without producing a significant change in SpO2 levels. Because of this, SpO2 readings cannot be used to warn of high PaO2 levels. Many variables can affect hemoglobin’s affinity for oxygen, and thus the position of the curve. Decreasing concentrations of hydrogen ions, PaCO2 and 2,3 DPG, increase hemoglobin’s affinity for oxygen and shift the curve to the left. TimeTimeTimeTime Figure 2: AbsorptionAbsorption due to:Absorption due to:Absorption due to:Absorption due to: pulsepulsepulsepulse----added volume ofadded volume ofadded volume ofadded volume of arterial bloodarterial bloodarterial bloodarterial blood ---------------------------- >>>> arterial bloodarterial bloodarterial bloodarterial blood -------------------------------------------------------------------------------------------------------- >>>> venous bloodvenous bloodvenous bloodvenous blood -------------------------------------------------------------------------------------------------------- >>>>
  • 7. SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts 5555 An increase in the variables shifts the curve to the right. Fetal hemoglobin, which binds more readily with oxygen than adult hemoglobin, also affects the curve, as does temperature. The relationship between SpO2 and PaO2 is not simple, so judging one mea- surement from the other should only be attempted with caution. Using pulse oximetry is fairly simple. Many questions may be answered by referring to your instrument’s InstructionsforUse. How Do I Use SpO2? Choosing a Sensor There are some general guidelines to choosing the right sensor. The ideal application site has good perfusion, does not generate movement artifact, is comfortable for the patient and allows easy application. The size of the application site determines what size sensor to use. The age of the Figure 3: Oxyhemoglobin Dissociation Curve 100%100%100%100% 0 Partial Pressure of Oxygen0 Partial Pressure of Oxygen0 Partial Pressure of Oxygen0 Partial Pressure of Oxygen (mmHG)(mmHG)(mmHG)(mmHG) 100100100100
  • 8. 6666 patient is not a factor. If a sensor is too big or too small, the light emitting diode and the light detector may not line up. This could cause a false reading or an alarm. If a finger sensor is too large, it may slip partway off so that the light source partly covers the finger. This condition, called optical bypass, causes incorrect readings. If a finger is inserted too far into the sensor it may be squeezed by the sensor, which causes venous pulsation. The pulse oximeter recognizes arterial blood only by its pulsing motion, so in this case it also measures venous blood. This causes readings which are falsely low. Figure 4: Pediatric Finger Sensor
  • 9. 7777 Using SpO2 Because pulse oximetry provides continuous monitoring and is noninvasive, it may be useful in several clinical situations. Surgery and Post Anesthetic Care Units Since pulse oximetry provides a means of continuously assessing of the oxygenation of the patient, many require it. If ventilation fails, an alarm sounds. Additionally, SpO2 is noninvasive so it is safer and more pleasant for the patient than invasive methods of oxygen analysis. Neonatal Care and NICU Blood-oxygen saturation levels taken immediately after birth, preferably on the right hand, (within five minutes) are a good guide to the neonate's general state of health. Levels below 75% may indicate abnormalities. Together with Apgar scores, blood- oxygen saturation readings are very useful. Both too little or too much oxygen is dangerous for the neonate, particularly for the premature neonate. Oxygen partial pressure (PaO2) is most critical for the neonate. Although blood- oxygen saturation and PaO2 are related, there are too many other factors involved to convert easily between the two measurements. Refer to the “Oxyhemoglobin Dissociation Curve” on page 3 for more details. Emergency Care In emergent care situations, both in and out of the hospital, patients may need ECG monitoring, SpO2 monitoring, pacing and defibrillation at a moment's notice. Noninvasive Transcutaneous Pacing Pulse oximetry, as integrated into Philips’ defibrillator/monitors, provides a tool to help determine whether pacing is effective. You can use the SpO2 measurements in addition to the patient's ECG signal as shown on the monitor to verify that mechanical capture has been achieved. When the patient is being successfully paced, the pulse rate derived from the pulse oximeter, the ECG heart rate derived from the ECG monitor and the pacing rate should all be about the same. In addition, there should be signs of improved cardiac
  • 10. SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts 8888 output. Recorded strips provide a printed record of SpO2 measurements and SpO2 alarm violations during pacing. Considerations When Using Pulse Oximetry Blood oxygen saturation is a measure of the amount of oxygen carried by hemoglobin in the blood stream. It is usually expressed as a percentage rather than an absolute reading. Pulse oximeters define this percentage in a different way than other instruments. These subtle, but important differences, are described in the following section. Effects of Non-functional Hemoglobin on Oxygen Saturation Measurements In order to judge a patient’s condition, ideally you would like to have blood oxygen saturation expressed as a percentage of the total hemoglobin that is saturated with oxygen. Under many circumstances, that is the reading you get from pulse oximeters. However, if the patient has a large amount of nonfunctional hemoglobin, the reading is not accurate. Non-functional hemoglobin is defined as hemoglobin which is incapable of carrying oxygen, but does include carboxyhemoglobin (HbCO) and methemoglobin (METHb). Functional hemoglobin is defined as hemoglobin capable of carrying oxygen. It includes oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb). In other words, the ideal blood saturation measurement is: HbO-, 100 ¥----------------------------- 2 ------------------------ Hb + HbO2 + HbCO + METHb + other non-functioning hemoglobins where Hb is hemoglobin, HbO2 is oxygenated hemoglobin, HbCO is carbox- yhemoglobin, and METHb is methemoglobin. This is also referred to as frac- tional saturation. Pulse oximeters usually assume there are no non-functioning hemoglobins in the
  • 11. 9999 arterial blood and measure the blood oxygen saturation as: HbO 100 ¥ ----- — Hb + HbO2 When the amount of non-functioning hemoglobin (represented above by HbCO + METHHb + other non-functioning hemoglobins) is very small, both readings are nearly the same. When the patient has large amounts of non-functioning hemoglobin, these measurements vary widely. Several situations can lead to such large amounts of non-functioning hemoglobin. Carbon monoxide poisoning and even heavy smoking increase the amount of carboxyhemoglobin, a non-functioning hemoglobin. Other Situations Pulse oximetry is a very useful technology, but there are situations where you must be careful in applying it. Keep the following in mind when you use a pulse oximeter. Anemia Damage to red blood cells may cause anemia, a lack of red blood cells and thus hemoglobin in the blood. An anemic patient may not have enough functioning hemoglobin in the blood to oxygenate the tissues. The small amount of functioning hemoglobin in the blood may be well saturated with oxygen, so the patient may have a normal SpO2 reading, but the patient may not have enough oxygen going to the tissues. Dyes Some surgical procedures, especially in cardiology and urology, call for the injection of dyes into the blood in order to trace blood flow. These dyes affect light transmission through the blood. They directly influence the pulse oximeter and lead to wrong readings. If the patient’s blood contains any of the following dyes, you cannot use pulse oximetry to measure oxygenation: • Methylene blue
  • 12. SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts 10101010 • Indiocyanine green • Indiocarmine Bilirubin, a breakdown product from red blood cells, does not affect readings from pulse oximeters. Perfusion SpO2 is always measured at one of the body’s peripheral sites: a finger, toe or ear. The site chosen for the SpO2 measurement must be adequately perfused with blood. Shock The body reduces blood supply to the limbs and extremities as a response to injury, or even the fear of injury, to maintain the blood supply to vital organs even in the event of severe blood loss. Because of this reduced perfusion, pulse oximeters may give misleading readings on patients in severe shock. Hypothermia The body reduces the heat lost by the skin by constricting the peripheral blood vessels. Cold is a common problem, often seen with car accident victims and patients undergoing brain or open heart surgery during which body temperature is lowered. Cold also causes shivering, which can lead to movement artifacts. Common Problems with Pulse Oximetry Although a pulse oximeter is easy to use, there are common problems associated with the use of oximeters. Light Interference Sometimes external light sources may cause inaccurate readings. If you suspect that a light may be causing interference, try covering the site with an opaque material and see if the reading changes. If so, keep the site covered. Movement Artifacts Movement artifacts, such as shivering, have been overcome with the latest SpO2 algorithms, such as Philips FAST-SpO2. However, unusually strong movement may cause movement artifact in the pulse. Apply the sensor to a less susceptible site if
  • 13. 11111111 possible. Sensor application The sensor should fit the application site snugly. If it is too tight, it might cause venous pulsation. If it is too loose, the light issuing from the emitters may not pass completely through the site and may cause erroneous readings. If adhesive sensors are not the right size, the emitter and detector may not line up correctly. Make sure you use the correct sensor for the patient to get the most accurate reading. Inadequate Blood Flow Blood pressure cuffs, tight clothing or restraints may interfere with blood flow. Use another application site or loosen clothing. Nail Polish Some nail polish and false fingernails may cause false readings. If possible, switch to an unpolished nail, or consider another application site. Glossary Blood-oxygen Saturation The amount of oxygen bound to hemoglobin in the blood, expressed as a percentage. Functioning Hemoglobin Hemoglobin which is capable of carrying oxygen. Functioning hemoglobin includes oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb). Movement Artifacts Motion of the blood caused by patient motion instead of pulsation. Non-functioning Hemoglobin Hemoglobin which is not capable of carrying oxygen. Non-functioning hemoglobin includes carboxyhemoglobin (HbCO) and methemoglobin (METHb). Pulse Oximetry The technique of measuring oxyhemoglobin saturation by shining red and infrared light through a peripheral site, such as a finger, toe, or nose. SaO2 A measurement of oxygen saturation in arterial blood.
  • 14. SpOSpOSpOSpO2 ConceptsConceptsConceptsConcepts 12121212 SpO2 Oxygen saturation in arterial blood as measured by a pulse oximeter. SaO2 and SpO2 readings differ because pulse oximetry measures the oxygen saturation of only functional hemoglobin. SaO2 readings indicate the saturation of both functional and nonfunctional hemoglobin.