Oxygen Administration (1/8)

What percentage of oxygen is carried in atmospheric air?

21%

What percentage of oxygen does a nasal cannula provide? How many liters per minute?

24%-44% 1-6lpm

What percentage of oxygen does a non-rebreather mask provide? How many liters per minute?

70%-90% 10-15lpm

Steps to Use a Non-Rebreather Mask

1. Connect tubing to oxygen regulator

2. Set flow to 10-15lpm

3. Cover one way valve in the mask with finger until the bag fully inflates

4. Place mask over patient’s nose and mouth and secure by tightening the strap

5. Monitor the bag and ensure that it is always inflated

   1. Increase oxygen so that it remains inflated

Steps to Using a Nasal Cannula

1. Connect tubing to regulator and set flow rate to 1-6lpm

   1. Note: Higher flow rates are less comfortable

2. Place the prongs in the patient’s nose face down and loop tubing around their ears

3. Adjust plastic slider closer to neck as needed

What three things does a pulse oximeter display?

Peripheral Oxygen Saturation (SpO2): The percentage of hemoglobin oxygen binding sites that are bound to oxygen

Pulse Rate: Number of pulses traveling through the vasculature per minute (generally = HR)

Photoplethysmograph (“pleth”): Waveform tracing the pulse ox reading over time

What is a normal SpO2 reading?

94%-99% at sea level

• altitude and COPD can change this baseline

What does a well-defined “pleth” wave vs. a poorly defined “pleth” wave tell you?

Well defined:

• Good blood flow to the finger and accurate SpO2

Ill-defined:

• Poor perfusion or sensor dysfunction

• SpO2 readings with bad pleth waves are often extremely low

How does a Pulse Oximeter Work?

The light source emits a red and an infrared wavelength of light. The red light is preferentially absorbed by hemoglobin, and the infrared is preferentially absorbed by the oxyhemoglobin. The sensor detects the percentage of light absorbed over time.

What causes an inaccurate pulse ox reading?

• Hypoperfusion: often caused by shock or thermoregulatory vasoconstriction

  • In healthy patients, this can happen because of cold environments

• Movement: Such as shivering

• Fingernail Polish: Red nail polish disrupts the sensor’s readings causing extremely low readings

• Carbon Monoxide (CO) Poisoning: Binds to hemoglobin stronger than oxygen can

  • The pulse ox will mistake carboxyhemoglobin as oxyhemoglobin and cause extremely high readings

Other than the finger, where can you place a pulse ox and what kind would you use?

Adhesive Pulse Ox: Wrapped around fingers, earlobes, feet (in infants), or other translucent body parts

• Use on patients with poor peripheral circulation or those who are disoriented and will remove a finger pulse ox

Clip Pulse Ox: Clips to a patient’s earlobe

• Rarely used in EMS

What happens if you administer oxygen when you shouldn’t?

Hyperoxia: high levels of oxygen causing vasoconstriction and oxidative stress

What are the Sp02 reading percentages for each type of supplemental oxygen?

None: 94%-100%

Nasal Cannula: 80%-93%

Non-rebreather mask: <80%

What do you do when a patient’s oxygen level has climbed back up to be >94%?

Titrate back down so that you don’t cause hyperoxia

How do you determine the amount of oxygen to give if you are getting inaccurate pulse-ox readings?

Determine based on level of respiratory distress.

• For mild respiratory distress, use a nasal cannula

• For severe respiratory distress, use a non-rebreather mask

What conditions should be treated with a non-rebreather regardless of Sp02?

Carbon Monoxide Poisoning

Cyanide Poisoning

Severe Shock

What Sp02 should a COPD (chronic obstructive pulmonary disease) patient be titrated to?

88%-92%

Going higher has been shown to cause them harm

How do you treat someone with anemia (oxygen)?

Benefit from low-flow oxygen if they have SEVERE anemia