With close to 1.3 million COVID-19 cases worldwide and hospitals getting overloaded, why are ventilators so essential?
Recently, various news outlets have reported ventilator shortages across the United States. New York, the hardest hit state so far in this pandemic, announced in early April that they would receive a much-needed donation of 1,000 ventilators from Chinese donors.
You may know that ventilators are needed for critical COVID-19 patients, but what are they exactly and how do they work?
What are ventilators?
The first streamlined and widely used ventilator was developed in 1929 by Drinker and Shaw to treat patients during the polio epidemic. It was called the iron lung, which worked by the mechanism of negative pressure outside of the body vs. today’s ventilators which work by positive pressure delivered directly into the airways.
Since that time, researchers and doctors have made giant leaps in understanding disease processes, lung physiology, and technical aspects of ventilation. Strategies for ventilating patients even 15 years ago are obsolete now.
Ventilators are complex machines that can provide complete ventilatory support for people that go into respiratory failure. Before a patient is hooked up to a ventilator, a hollow tube with a small balloon at the end is inserted into the trachea and secured just above where the right and left airways separate. In some cases, a tube is placed through an incision in the neck.
The machine provides positive pressure breaths and support for patients that are unable to adequately breathe on their own.
How do ventilators work?
Ventilators have complex microprocessors that take continuous measurements and display them on screens so healthcare professionals like doctors, respiratory therapists, and nurses can monitor and evaluate the condition of the patient.
Ventilators can help control the amount of oxygen someone is getting with two adjustable variables:
FiO2: A knob on the ventilator allows practitioners to adjust the oxygen concentration anywhere from 21% - 100% in response to the blood oxygen level of the patient.
PEEP: When you exhale, your lungs still maintain a certain level of pressure to hold the small air sacs called alveoli open and ensure the blood is oxygenated. When a patient has a significant respiratory illness, that pressure level may need to be increased to oxygenate the blood adequately.
Vents are able to provide many levels of breathing support based on the patient’s condition. There are modes that can provide partial support in order to allow the patient to exercise their lungs and take their own breaths.
Other modes control specific variables like the amount of maximum pressure delivered during a mechanical breath, in order to limit an excess delivery of pressure to the alveoli.
Ventilators are able to perform very sophisticated calculations, allowing practitioners to adjust settings tailored to the condition of the patient’s lungs. Mechanical ventilation is not a one-size-fits-all mechanism.
Are people awake on ventilators?
Fortunately, an array of meds exist to make patients comfortable on ventilators. Sedatives, pain medication, and paralyzing agents are all used in some capacity. It is the goal of the physician and healthcare team to wean the medications and ventilator as soon as possible to prevent complications.
Are there risks to ventilators?
Like any medical treatment, there are risks associated with mechanically ventilating human lungs. What are some of the risks?
- Alveolar damage: When delivering high levels of pressure to a patient’s lungs, trauma can damage the alveoli. Although every precaution is taken to prevent excess pressure in the airways, damage can still occur, especially in association with significant disease.
- Pneumothorax: There is a space in between the chest wall and the lungs called the pleural space. When air leaks into that space, it is called a pneumothorax. A pneumothorax can range from mild to life threatening and typically requires a chest tube.
- Oxygen Toxicity: What many people don’t know is that the higher concentrations of oxygen aren’t necessarily considered better. In fact, excessive oxygen can cause damage in the body and lungs, therefore, the oxygen is kept at the lowest possible level to achieve proper oxygenation to the body.
- Pneumonia: Patients on ventilators are at high risk for what is called ventilator-associated pneumonia (VAP). This risk increases for every day the patient stays on the ventilator.
Why are ventilators crucial for COVID-19
As the COVID-19 crisis grows and critical cases of this virus climb, the need for ventilators increases. Advanced stages of the disease cause severe pneumonia and respiratory failure, requiring mechanical ventilation for a chance of recovery.
Without the ability to provide enough ventilators for COVID-19 patients, physicians face the daunting and tragic task of choosing which patients will get them based on age and condition.
With hospitals reporting limited supplies of ventilators, fortunately several companies including Dyson and Ford have risen to the challenge and are scrambling to manufacture even simple ventilators to provide critical patients with a fighting chance.
Time will tell over the coming weeks and months if manufacturers and government entities can rise to meet the needs of medical centers across the country.
Written by: Amanda Peterson