Low Flow vs High Flow Oxygen: Difference and Comparison

Oxygen therapy is used medically where oxygen is given to the patient if he or she is suffering from a low flow of oxygen, i.e. hypoxia etc. Oxygen therapy is also given to maintain the flow of oxygen in the body when anaesthesia is induced.

Oxygen is required in the human body for cellular metabolism. If the concentration of oxygen increases in the body, then it may lead to the toxicity of oxygen, and the person may suffer from respiratory failure and lung damage.

Using oxygen for medical use was started in 1917. Since then, it has been the most common treatment in the world. Low Flow Oxygen Therapy and High Flow Oxygen Therapy are the two types.

Key Takeaways

  1. Low-flow oxygen therapy delivers a lower, fixed rate of oxygen, while high-flow oxygen therapy provides a higher, adjustable rate of oxygen delivery.
  2. High-flow oxygen therapy suits patients with high oxygen demand or unstable breathing patterns. In contrast, low-flow therapy is appropriate for patients with stable breathing and lower oxygen requirements.
  3. High-flow systems can provide better humidification and maintain more consistent oxygen concentrations than low-flow systems.

Low Flow vs High Flow Oxygen

Low-flow oxygen refers to a kind of delivery method that provides a relatively low amount of oxygen, up to six liters per minute. High-flow oxygen delivers a higher amount of oxygen, up to 60 litters per minute, and can also warm and humidify the air.

Low Flow vs High Flow

Low Flow of oxygen means when a person requires oxygen at a lower concentration. Such people only require oxygen for inhaling slightly more than their lungs can do.

Low flow oxygen can be provided using several types of equipment and devices depending upon the follow, requirement of the patients etc.

When a patient is supplied oxygen at a lower flow rate, it means that oxygen flows from 0 to 15 litres per minute. Usually, low flow oxygen is provided using face masks, nasal cannula, partial rebreathing masks etc.

High Flow Oxygen means that the flow rate of oxygen is higher than the normal rate of the oxygen therapy. Here the patients are critically ill or are suffering from serious respiratory problems.

That is why high flow is needed. High flow oxygen therapy means that oxygen supplied here becomes the breathing support system of the patient. Nasal Prongs are used to give oxygen.

Continuously oxygen needs to be provided in the humidified form so that the person can breathe. Before giving high flow oxygen therapy, some tests like blood tests and chest X-rays are done to see how well the lungs are working.

Comparison Table

Parameters of ComparisonLow Flow OxygenHigh Flow Oxygen
Flow rate0 to 15 litres50 to 60 litres
Types of Devices Nasal cannula, Simple masks, Reservoir masks, Partial Rebreather, and Non-Rebreather.Nebulizer, Ventilators, Oxygen Tents, Aerosol masks, Tracheostomy Collars.
ConditionsProvided to those who are stable.Provided to those who have respiratory requirements.
RisksNasal Irritation, skin rash, frostbite, fire connected to devices etc.Nasal Prongs may get blocked.
PreparationClinical history of the patients and illness is checked.Blood Tests and Chest X-rays.

What is Low Flow Oxygen?

When the low flow oxygen is required to supply to the patients. Before giving oxygen therapy. The first illness and clinical history of the patient need to be checked. After that, low flow can be provided.

Many of the patients don’t require the pure oxygen that is provided during serious respiratory problems. In Low flow, patients require inhaled oxygen in slightly more amounts.

There are many devices through which it can be given. Nasal cannula, Face masks are the most common types of devices used during low flow.

In a nasal cannula, a thin tube having two nozzles are inserted inside the nostrils of the person. The nasal cannula provides oxygen in the concentration of 24 to 40%. Oxygen is provided at 1 to 6 litres per minute (LPM) through it.

In the face mask, the oxygen concentration is 35 to 55%. The flow of the oxygen is at 5 to 10 LPM. A partial rebreather can be used instead of face masks when there is a shortage of oxygen. A partial rebreather consists of a reservoir bag.

It supplies oxygen at the rate of 5 to 15 LPM at a concentration of 40 to 70%. The advantage of using low flow oxygen therapy is that it provides comfortability to the patient and make them feel at ease.

To ensure that oxygen is provided properly, masks and cannula should fit properly.

What is High Flow Oxygen?

While preparing high flow oxygen, blood tests and chest X rays are done to check whether lungs are working. If traditional oxygen therapy doesn’t do anything, then only high flow oxygen is provided.

When the therapy is done, you are positioned on a bed, supported with pillows. Then nasal prongs are fitted that supplies oxygen. It is secured with an elastic string that goes around the head.

The oxygen flow rate is set, and the patient receives the oxygen. They are asked to breathe in and out through the nose. It is a non-invasive therapy.

It means that it doesn’t break the skin. Very few risks are involved in high flow oxygen therapy. Nasal prongs may be blocked if there is a lot of mucous.

High flow oxygen therapy is needed when there is a severe respiratory problem like Acute heart failure, Asthma, Bronchiectasis, Pneumonia, Lung cancer, Pulmonary oedema, Acute Respiratory Distress Syndrome (ARDS), Chest trauma etc.

The benefit of high flow oxygen is that it provides better clearance of fluids due to humidified air, it becomes easier to eat and drink during therapy, better to tolerate, more comfortable, less dryness of mouth, easier to communicate with patients, airway inflammation is reduced etc.

Main Differences Between Low Flow and High Flow Oxygen

  1. Low Flow provides oxygen at the rate of 0 to 15 litres per minute. High Flow oxygen provides oxygen at the rate of 50 to 50 litres per minute.
  2. Types of devices used in Low flow are Nasal cannula, Simple masks, Reservoir masks, Partial Rebreather, and Non-Rebreather. Types of devices used in High flow oxygen are Nebulizer, Ventilators, Oxygen Tents, Aerosol masks, Tracheostomy Collars.
  3. Low flow oxygen is provided to those patients who are stable and have FiO2 levels are not crucial. High Flow Oxygen is provided to those who have respiratory requirements.
  4. Risks involved in low flow are Nasal Irritation, skin rash, frostbite, fire connected to devices etc. Risks involved in high flow oxygen is that Nasal Prongs may get blocked.
  5. Before supplying low flow, the clinical history of the patients and illness is checked. Before supplying high flow oxygen, blood tests and chest x-rays are done to see whether lungs are working properly or not.
References
  1. http://rc.rcjournal.com/content/50/5/604.short
  2. https://www.sciencedirect.com/science/article/pii/S0012369216576612

Last Updated : 08 July, 2023

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