What is Pulse oximeter ?
Pulse oximeters are medical devices that monitor the level of oxygen in a patient’s blood.
It is a small clip like device which attaches to body parts like finger , toes or ear.
A pulse oximeter consists of the monitor containing the batteries and display, and the probe that senses the pulse.
What does a pulse oximeter measure ?
1.Oxygen saturation in blood (SpO2) : It is amount of oxygen level present in blood
2.Heart rate or pulse (PR) in beats per minute.
Additionally , some oximeters display a pulse waveform or indicator that shows the strength of the pulse being detected.
Practical use of pulse-oximeter :
1.Turn the pulse oximeter on , it will go through internal calibration and checks.
2. When used on a finger or toe, make sure the area is clean. Remove any nail varnish.
3. Position the device carefully , make sure it fits easily without being too loose or too tight.
4. Allow several seconds for the pulse oximeter to detect the pulse and calculate the oxygen saturation.
5. Once the unit has detected a good pulse, the oxygen saturation and pulse rate will be displayed.
6. Adjust the sound of the audible pulse beep to a comfortable level – never use on silent.
7. Always make sure the alarms are on.
What it means if no signal obtained on pulse-oximeter ?
1.Check if the probe or device is correctly positioned . Try putting it on another finger or toe . Even you can check it on other person to make sure probe is working properly.
2.No signal also obtained in conditions like
a) Low Blood pressure : In severe dehydration , cardiac problems , septic shock etc.
b) When patient limb is cold : gentle rubbing the finger may restore signal.
When we get Alarms on pulse-oximeter ?
1 . SpO2 or oxygen saturation is low ( <90 %)
2. Pulse not detected.
3. Pulse is high. ( > 100 / min )
4. Pulse is low ( <60 / min )
What is normal SpO2 and pulse rate in healthy adults ?
Normal SpO2 in healthy adults is 95 %-100 %.
Normal pulse rate in adults is 60 to 100 per minute.
(Note : Some patients have lower baseline SpO2 ( 90 %) like obesity , cardiac problems , chronic smoker , COPD , lung problems , sleep apnea etc.)
What can interfere with pulse-oximeter readings ?
1. Bright light can interfere with pulse oximeter readings , shield the probe from direct light.
2. Shivering will make it difficult for probe to pick up readings.
3. Very weak pulse as in low Blood pressure due to cardiac problems or septic shock or severe dehydration.
4. Cold peripheral limbs.
What is the cost of pulse-oximeter in india ?
A pulse oximeter costs between Rs 1,000 to 3,000. You can buy it here in the ad given below.
How can pulse-oximeter help in Covid 19 ?
Silent hypoxia (deprivation of oxygen at the tissue level) has emerged as a major cause of death in COVID-19 patients.
Usually, when your oxygen falls below 95%, you will have symptoms, breathlessness, a feeling of discomfort certainly.
Now, in COVID-19, for some reason, that is not happening. Patients are not feeling the drop in oxygen levels at all until they are dangerously low. When they finally land up in hospital, they sometimes have a SpO2 of 80% or 75%, and are in respiratory distress.
If the oxygen saturation drops to less than 92 per cent, it requires hospital evaluation with Chest X ray or CT scan.
Current guidelines say that Covid-19 patients have to be admitted to hospitals if their oxygen saturation drops to 90% or below.
Pulse oximeter can help you in monitoring your oxygen saturation daily and can guide you when to get medical care. According to Hindustan times report , Experts too have recommended the use of this relatively cheap device at home that can forewarn you about any impending crisis.