What is mechanical ventilation?

Mechanical ventilation is a treatment to help a person breathe when they find it difficult or are unable to breathe on their own. A mechanical ventilator pushes airflow into the patient’s lungs to help them breathe.
Mechanical ventilation may be
- Invasive ventilation with a tube inserted into the patient’s airway, performed in the intensive care unit in the hospital.
- Noninvasive ventilation that can be used at home by people with respiratory difficulties.
Does mechanical ventilation treat COVID-19 coronavirus?
Mechanical ventilation is part of the arsenal of supportive care clinicians use for COVID-19 coronavirus disease patients with the most severe lung symptoms.
A COVID-19 infection can cause fluids and mucus in the lungs that block oxygenation of lung tissue. Mechanical ventilation can help support COVID-19 patients breathing until their immune system and treatment can clear the infection and proper lung function is restored.
Public health experts fear there is a shortage of mechanical ventilation machines in the U.S. considering the coronavirus pandemic.
What are the different types of mechanical ventilation?
Mechanical ventilation first came into use in 1929. The two types of mechanical ventilation are
- Positive-pressure ventilation: pushes the air into the lungs.
- Negative-pressure ventilation: sucks the air into the lungs by making the chest expand and contract.
Negative-pressure ventilation
The early ventilators were negative-pressure ventilators. Negative pressure ventilation is very little in use now.
- Iron lung: The first mechanical ventilator, a metal cylinder which enveloped the patient completely up to the neck.
- Chest cuirass: A small shell which can be strapped to the patient’s chest to create the negative pressure.
Positive-pressure ventilation
Positive-pressure ventilators were developed in the early 1950s to treat polio patients with respiratory paralysis. These ventilators blow the air into the patient’s lungs through a tube. They may be invasive or noninvasive.
Invasive ventilation
- Endotracheal intubation: the tube is inserted into the patient’s airway (trachea) through the mouth or nose.
- Tracheostomy: the tube is inserted through a hole made into the airway.
Noninvasive ventilation
Noninvasive mechanical ventilators come with masks and can be used at home. The three kinds are
- Continuous positive airway pressure (CPAP): delivers constant and steady air pressure.
- Autotitrating (adjustable) positive airway pressure (APAP): changes air pressure according to the breathing pattern.
- Bilevel positive airway pressure (BiPAP): delivers air with different pressures for inhalation and exhalation.
How does a mechanical ventilator work?
Negative-pressure ventilation
Iron Lung
The iron lung of the past forces the chest cavity to expand and contract by adjusting the air pressure inside a chamber that envelops the body up to the neck, . A vacuum pump creates a negative pressure in the iron lung’s chamber which makes the patient’s chest expand, drawing air in. When the negative pressure releases, the patient’s chest recoils, and air pushes out.
The negative pressure created in the chamber affected the stomach and heart as well, which was a problem with the iron lung. The iron lung ventilator also curtailed the patient’s mobility and made caregiving difficult.
Cuirass
Cuirass, developed later, is a small form-fitted shell with a bladder, strapped to a patient’s chest. Cuirass applies negative pressure to stimulate the chest to expand and contract. Cuirass is used in very few situations today. It is a suitable option for patients with neuromuscular disorders, but it cannot be used for patients lying down.
Positive-pressure ventilation
Currently positive pressure ventilation is the common form of mechanical ventilation in hospitals. The positive-pressure ventilators push the air into the patient’s airway. The ventilator continually blows and stops in regular preset cycles enabling the lungs to receive oxygen and expel carbon dioxide. Positive-pressure ventilators may be
- Volume-controlled: delivers a preset volume of air into the patient’s trachea even if it entails high airway pressure. When the flow is stopped the chest recoils and expels the air out.
- Pressure-controlled: delivers air till the airway pressure limit is reached and the valve opens to expel air. The volume of air delivered may vary depending on the airway resistance and lung capacity.
- Dual control: these combine the advantages of volume control and pressure control and deliver airflow based on the requirement and response of the patient.
Why is a mechanical ventilator used?
The mechanical ventilator does the work of a patient’s breathing so their body can rest and recover. Mechanical ventilators are used:
- As short-term respiratory assistance in surgeries
- For longer periods in critically ill patients
- At home by people who have difficulty breathing normally
In the last two decades several new modes of mechanical ventilation have emerged with the merging of ventilator and computer technologies. This has increasingly helped doctors meet individual requirements in mechanical ventilation.
Top Different Types of Mechanical Ventilation Related Articles
COVID-19 Coronavirus Disease: Articles of Interest
Read about COVID-19 Coronavirus Disease. See interesting articles related to vitamins and supplements to boost immunity, symptoms, prevention, vaccines, historical comparisons to past pandemics, and more.Emphysema
Emphysema is a COPD (chronic obstructive pulmonary disease) that often occurs with other obstructive pulmonary problems and chronic bronchitis. Causes of emphysema include chronic cigarette smoking, exposure to secondhand smoke, air pollution, and in the underdeveloped parts of the world. Symptoms of emphysema include chronic cough, chest discomfort, breathlessness, and wheezing. Treatments include medication and lifestyle changes.How Do You Do CPR On a Newborn?
Neonatal resuscitation (CPR) provides oxygen, stimulates breathing and gets the heart to start pumping normally. Most premature babies and babies with certain congenital conditions require extensive resuscitation.Lung Cancer
Lung cancer kills more men and women than any other form of cancer. Eight out of 10 lung cancers are due to tobacco smoke. Lung cancers are classified as either small-cell or non-small-cell lung cancers.Pneumonia
Pneumonia is inflammation of the lungs caused by fungi, bacteria, or viruses. Symptoms and signs include cough, fever, shortness of breath, and chills. Antibiotics treat pneumonia, and the choice of the antibiotic depends upon the cause of the infection.Popcorn Lung (Bronchiolitis Obliterans)
Popcorn lung is a term for the lung disease bronchiolitis obliterans. Popcorn lung is caused by diacetyl and 2,3-pentanedione, chemicals used when manufacturing flavorings for food and certain products like popcorn, and coffee. E-cigarettes also may cause popcorn lung. Diacetyl and 2,3-pentanedione damage lung tissue in that is irreversible.Symptoms of popcorn lung develop gradually over time. The main symptoms are chronic cough and shortness of breath. Other symptoms may include night sweats, weight loss, and fever. Symptoms of severe exposure to diacetyl and 2,3-pentanedione include inflammation of the skin, eyes, nose, and/or throat.
Popcorn lung often resembles tobacco-related COPD (chronic obstructive pulmonary disease) so it often is difficult to diagnose. Lung biopsy and surgery may be necessary.
There is no cure for popcorn lung. Life expectancy for a person with (bronchiolitis obliterans) depends upon how early the disease was diagnosed and the level of exposure to diacetyl and 2,3-pentanedione.
Pulmonary Embolism (Blood Clot in the Lung)
A pulmonary embolism (PE) occurs when a piece of a blood clot from deep vein thrombosis (DVT) breaks off and travels to an artery in the lung where it blocks the artery and damages the lung. The most common symptoms of a pulmonary embolism are shortness of breath, chest pain, and a rapid heart rate. Causes of pulmonary embolism include prolonged immobilization, certain medications, smoking, cancer, pregnancy, and surgery. Pulmonary embolism can cause death if not treated promptly.What Drugs May Fight COVID-19? Drug Trials, Treatments, Vaccines
What drugs could help fight coronavirus COVID-19? Clinical studies are ongoing for antiviral drugs like hydroxychloroquine, chloroquine remdesivir, lopinavir and favipiravir, as well as COVID-19 vaccines. Learn why anti-flu respiratory drugs and home remedies may prove useful to treat or prevent serious coronavirus infections.What Is a Laryngeal Mask Airway (LMA) Used For?
A laryngeal mask airway (LMA) is a device inserted into the area behind the mouth and nose, connecting them to the food pipe (the pharynx) to allow ventilation, oxygenation, and administration of anesthetic gases, without the need for inserting a tube in the windpipe (endotracheal intubation). It was initially used mainly in an operating room setting, but is also used in the emergency setting. Complications include aspiration of stomach contents, local irritation, upper airway injuries, mild sympathetic response, obstruction, laryngospasm, pulmonary edema, and bronchoconstriction.What Is Bag Valve Mask Ventilation (BVM) Used For?
Bag-valve-mask (BVM) or the Ambu bag is a self-inflating bag used to provide ventilation to the person not breathing normally. BVM ventilation is a critical skill for emergency providers. BVM ventilation is a technique that restores breathing in patients who are not spontaneously breathing. BVM ventilation is indicated in the respiratory (lung) failure, failed intubation (insertion of an artificial ventilation tube into the trachea), patients undergoing anesthesia for elective surgery, and apnea (slowed or stopped breathing).When Should a Tracheostomy Tube Be Changed?
A tracheostomy is an opening that surgeons make through the front of the neck and into the windpipe (trachea). The tracheostomy tube is placed into the opening to keep it open for breathing when the usual route for breathing is somehow blocked or reduced. When health problems require long-term use of a machine (ventilator) to help breathe, a tracheostomy is often needed. In rare cases, an emergency tracheostomy is performed when the airway is suddenly blocked, such as after a severe injury to the face or neck.Why Would a Newborn Need a Ventilator?
Some babies may have trouble breathing. Respiratory distress or failure may be the result of underdeveloped lungs or a congenital condition. The mechanical ventilator provides oxygen until the baby can breathe unassisted.Coronavirus COVID-19 (SARS-CoV-2) Pandemic Outbreak: What You Need to Know
A new strain of coronavirus (COVID-19, SARS-CoV-2) was reported from Wuhan, China in December, 2019. This outbreak of respiratory flu-like symptoms has quickly spread resulting in a worldwide pandemic. Learn about symptoms, treatment, prevention and vaccine efforts.Novel Coronavirus (COVID-19) Prevention Quiz
Why is coronavirus considered dangerous? What are the symptoms you should look for? Take this COVID-19 prevention quiz to learn how to protect yourself.