What is a Ventilator? How Does it Work and How to Use It
A ventilator is one of the most important pieces of equipment doctors have at their disposal. You've probably heard a lot about ventilators recently, as they have been used extensively during the coronavirus pandemic to treat patients with severe cases of COVID-19. In essence, they are used as life support to help patients in ICU who are struggling to breathe and those who have lost the ability to breathe, ventilators have saved hundreds of thousands of lives over the years.
Understanding the basic principles of artificial ventilation, and learning what happens when someone is on a ventilator, will help to prepare you for going on a ventilator yourself. If you’re supporting a loved one who’s on ventilation or about to go on ventilation, getting an idea of what a ventilator is used for can be even more important.
What is a Ventilator?
Modern ventilators are precisely engineered pieces of medical equipment. Used in virtually every major hospital in the world, they can help patients through severe illness, surgery and paralysis.
The primary function of a ventilator is to breathe - or support breathing – for patients who have lost the ability to respirate themselves. Ventilator support helps patients to breathe by gently forcing air into their lungs using a breathing tube inserted into the windpipe. The patient’s body then expels the air naturally. Some ventilators help patients to exhale as well as inhale.
Patients going into surgery under general anesthesia are often put on mechanical ventilators because surgical drugs and procedures can interfere with the breathing process. Being on a ventilator will ensure that the patient is able to get enough oxygen into their system throughout the operation.
In intensive care units, ventilators are used to help patients who are struggling to breathe because of an illness or accident that causes acute respiratory distress syndrome (ARDS) or pneumothorax (collapsed lung). Taking over the breathing function for a patient can give their body time to rest and help them along the road to recovery. It can also give doctors time to try new medications, assess the condition of the patient and create effective treatment plans.
How is Ventilation Measured?
In a clinical setting, ventilation is measured as minute ventilation. It is calculated by multiplying the respiratory rate (RR) by tidal volume (Vt). This calculation shows how regularly a patient is breathing and how much air they are able to inhale with each breath.
Doctors will monitor both the respiratory rate and tidal volume of a patient's lungs while they are on a ventilator. They will also monitor the oxygen levels and carbon dioxide saturation of the patient’s blood in order to ensure they are breathing as they should.
Types of Ventilators
There are various types of ventilators available to treat patients with different needs. Medical professionals will assess a patient, their condition, prognosis and treatment plan before deciding which type of ventilation is most suitable.
· Invasive Ventilation
Invasive ventilation is when a tube is inserted into a patient’s mouth (endotracheal) or throat (tracheostomy) to help them breathe. This tube is attached to the ventilator which uses intermittent positive pressure to gently force air into the patient's lungs.
· CPAP and BiPAP
CPAP ventilators use continuous positive pressure to help patients maintain their breathing. CPAP machines administer pressure via a mask rather than an endotracheal or tracheostomy tube. This makes them a non-invasive ventilation option. BiPAP machines offer patients pressure relief between breaths to help them exhale.
· Nasal Ventilation
Nasal ventilation is a type of non-invasive ventilation. It is often used to provide domiciliary nocturnal ventilatory support in patients with chest wall disorders, neuromuscular disease and chronic obstructive lung disease (COPD).
Like a CPAP machine, nasal ventilation works by the delivery of positive pressure to the airway. Nasal ventilation generally uses intermittent pressure to allow the patient to exhale naturally.
How Does a Ventilator Work?
For many years, ventilators and breathing machines used negative pressure to help a patient breathe. When the body is exposed to negative pressure, it causes the thorax to expand and air to be drawn into the lungs. The most famous example of negative pressure ventilation is probably the Iron Lung, a groundbreaking machine that saved the lives of thousands of children affected by polio.
Today, most ventilators use positive pressure to help patients breathe. These ventilators push oxygen into a patient’s airway via a mask or endotracheal or tracheostomy tube. The positive pressure causes air to flow into the lungs until the ventilator breath ends. Often, oxygen is added to the air supply to ensure the patient’s levels of oxygen in the blood reach the correct level.
Unless it’s an emergency situation, endotracheal and tracheostomy tubes are inserted while the patient is under general anaesthetic. Endotracheal tubes enter the patient’s airway via the mouth while tracheostomy tubes are inserted into the throat or trachea. Tracheostomy tubes are generally used when a patient requires long periods of ventilation.
Both endotracheal and tracheostomy tubes are a type of invasive ventilation. In some cases, a non-invasive method of ventilation will be more appropriate. This delivers positive pressure to the airway via a mask. This type of ventilation increases gas exchange and reduces the amount of effort it takes for a patient to breathe.
What is the Difference Between a Medical Respirator and a Ventilator?
A respirator is a masklike device, usually made of gauze, worn over the nose and mouth to prevent the inhalation of noxious substances. Health professionals wear respirator face masks to filter out virus particles so they aren’t exposed to infection when treating patients. Respirators also help to prevent the wearer from passing on any infections they may have to their patients.
Unlike ventilators, respirations don’t push air into the lungs or aid breathing. They are purely used as personal protective equipment to prevent infection and injury.
What is the Difference Between a Medical Ventilator and a CPAP Machine?
Medical ventilators work via a tube inserted into the neck or mouth of the patient, usually for critical care in ICU settings. They use short ‘breaths’ of positive pressure to gently force air into the lungs and effectively breathe for the patient.
CPAP machines, while a type of ventilator, work very differently. CPAP stands for Continuous Positive Airway Pressure. When a patient is using a CPAP machine, they will have a face mask over their nose and mouth. The machine then applies continuous pressure to their airway via the mask in order to help them breathe.
CPAP machines are used by individuals to treat conditions such as obstructive sleep apnea as prescribed by a respiratory therapist. Using a CPAP machine at night prevents patients with obstructive sleep apnea from experiencing breathing difficulties as they sleep.
What is a BiPAP Ventilator?
BiPAP and CPAP machines are closely related. They both use a face mask to administer positive pressure and both are non-invasive treatment options. However, unlike CPAP machines which provide a constant flow of positive pressure, BiPAP machines offer pressure relief as the patient exhales. This can make it easier, and more comfortable, for patients to expel air from their lungs.
How Long Can You Be on a Ventilator?
Mechanical ventilation is used as a last resort, and medical professionals will try to discontinue ventilation as soon as is safely possible. This is because there are a number of health risks associated with long term ventilation. These include:
- Ventilator-associated pneumonia
- Sinus infection
- Blood clots
- Lung injury
- Damage to vocal cords
The process of taking a patient off of ventilation is called weaning. When a patient is being weaned, doctors will carry out spontaneous breathing trials. During these trials, the patient will attempt to breathe with reduced or no ventilator support.
When a patient is undergoing breathing trials, they are always closely monitored by a team of medical professionals. If a patient has been on a ventilator for a long time, it may take more than one attempt to wean them from ventilation.
Can a Person Recover From a Ventilator?
A lot of people who are put on a ventilator will go on to recover from their illness, accident or operation. Mechanical ventilation gives the body a chance to rest and heal. However, as a lot of people put on a ventilator are seriously ill, there will always be a percentage of patients who are unable to recover following ventilation.
Is it Painful Being on a Ventilator?
In most cases, the endotracheal or tracheostomy tubes used for ventilation are inserted when a patient is under general anaesthetic. This means the patient won’t experience any pain during the procedure. Once the tube is in place, it may cause a little discomfort. Patients will often be prescribed sedative and analgesic medications in order to make them more comfortable.
Patients who are on invasive ventilation can’t talk and their movement is very restricted. They also can’t eat and so receive nutrients via an IV or through nasogastric feeding. Some patients who require long term ventilation may be able to use a portable machine. This will give them more freedom of movement and greater independence.
What is the Price of a Medical Ventilator?
The cost of a medical ventilator will vary depending on its make, model and capabilities. Good quality ventilators are available for around $8,500. A range of accessories and replacement parts are available for most ventilators to help equipment last longer and work efficiently.
Where to Buy a Ventilator
Ventilators are available to purchase from recognised medical equipment supply stores. As ventilators are essential pieces of life-saving equipment, they should only ever be sourced from trusted retailers.