Non-rebreather mask is the NRBM Full Form. Non-rebreather masks are masks which supply air to the patient. A mechanical ventilator provides an artificial breath for a patient whose breathing has ceased or is inadequate or insufficient.
They work by blowing high-pressure gas into the lungs to inflate them, allow drainage of fluid and increased oxygenation of blood in pulmonary capillaries. This opens up collapsed alveoli prevents atelectasis decreases inspiratory muscle fatigue, and enhances carbon dioxide elimination. They are typically used to help patients who have respiratory problems such as asthma , congestive heart failure COPD , pneumonia, emphysema bronchitis, chronic obstructive pulmonary disease (COPD) acute respiratory distress syndrome (ARDS), other lung diseases or unconsciousness.
Non-rebreather masks are frequently used in emergency medicine, critical care, anesthesia, airway management, oxygen therapy and neonatology. They are sometimes used in cardiopulmonary resuscitation and can be placed over the nose or the mouth of a patient who is not breathing, or is only able to breathe in an inadequate amount of air. They deliver high concentrations of oxygen gas (about 90%) and are generally disposable.
There are three main types of non-rebreather masks:
Non-rebreather masks may also be used during cardiopulmonary resuscitation. A bag valve mask has a reservoir bag that is squeezed by the rescuer to force air into the lungs. The reservoir bag provides positive pressure ventilation even if the patient’s mouth is opened wide, because it contains a one-way valve which prevents exhaled breath from flowing back into the bag. In contrast, a standard face mask does not have this one way valve, as thealed breath will flow out through the open space between the mask and the patient’s face.
An incomplete non-rebreather mask is one that can be used without being completely sealed, for example during brief patient assessment or an urgent situation where only high flow oxygen are needed. It has a one-way valve which prevents exhaled breath from entering the demand valve of the reservoir bag, but does not have a check valve against inbound air (the check valves may cause resistance to inspiration). They can provide up to 15 L/min of high concentration oxygen outflow through the delivery tube and into the patients’ lungs, with each inhalation delivering up to 60% carbon dioxide back into the mask. This is useful in situations such as traffic accidents when it is necessary to ventilate the patient’s lungs quickly without having to spend time finding an alternative airway. They are not suitable for extended periods of use, as they do not protect against oxygen depletion or carbon dioxide poisoning.
There are three main types of incomplete masks:
A complete non-rebreather mask is one that comprises both a demand valve and reservoir bag. It has full one way valves preventing exhaled breath from entering either into the bag or back into the atmosphere (the check valves may be located within these two components). When properly fitted, it can provide up to 15 L/min of high concentration oxygen outflow through the delivery tube and into the patients’ lungs with each inhalation delivering up to 100% carbon dioxide back into the mask. This is useful in situations such as cardiac arrest and respiratory failure where it is necessary to deliver a high flow of oxygen and allow carbon dioxide elimination in order to keep up blood pressure, heart rate and prevent death.
There are two main types of complete masks:
A bag-valve mask (BVM) with an oxygen reservoir may be used without a nonrebreather mask when there is breathing but no airway protection needed, such as in cases where the patient has already been intubated or during cardiopulmonary resuscitation when chest compressions are being performed. They connect directly to inspiratory positive airway pressure devices (e.g., ambu bags). BVM can also be used as an alternative to non-rebreather masks, as they provide very similar performance. The main advantage of BVMs is that they do not cover the nose and mouth like a mask does, thus allowing the patient who was not intubated to continue breathing through their own (albeit congested) nose and mouth; this may make it easier for them to resume spontaneous breathing once the emergency has passed.
The World Health Organization has designed guidelines for oxygen therapy in healthcare facilities such as hospitals or ambulances where advanced life support takes place. Their recommendations state that anaesthesia providers should “first attach a reservoir bag and flow meter; then adjust to give 100% O without any mandatory ventilation requirement” if no other factors prevent it. Oxygen flow rates should be 4-6 liters per minute in order to maximize the number of patients who can receive oxygen simultaneously. If flow rates are too low, then demand valves may not provide enough oxygen flow and there is a risk that life-threatening hypoxia could occur because patients will still require some breathing effort to stay alive (i.e., their respiratory system does not fully relax when given high concentrations of oxygen).
If higher oxygen flow rates are needed, such as during CPR or severe respiratory distress, BVMs with reservoir bags should be used instead. They deliver up to 15 litres per minute in an open system and allow airway pressure release ventilation which is useful in cases where chest compressions need to be performed in addition to rescue breathing. The World Health Organization has said the following:
When invasive or non-invasive ventilation equipment is not available and oxygen flow rates need to be increased (such as during CPR), a bag-valve mask with an oxygen reservoir should be used. It allows airway pressure release ventilation, which can also help patients who are experiencing respiratory failure by releasing the pressures caused by the obstruction of their chest or abdomen during breathing efforts. During rescue breathing, its one way valve prevents exhaled breath from entering back into the bag while fresh gas flows in through an attached tube at all times – this does not happen with other types of BVMs where there are two separate tubes for both inhalation and exhalation that are clamped shut when the patient is “bagged” due to their one-way design.
Oxygen masks are sometimes used on the faces of patients with severe facial burns, or after certain types of plastic surgery, in order to prevent atelectasis (collapse of lung tissue) and pneumonia caused by inhalation of dried mucus secretions that collect in the oropharynx during episodes of unconsciousness. Patients may be intubated (tracheal intubation) prior to treatment with oxygen via a mask because they are unable to maintain adequate airflow through an airway on their own; this helps them breathe without assistance during the early stages of treatment. For example, people recovering from anesthesia often require assistance upon awakening before they regain enough muscle strength to turn their heads or lift their arms.