How effective is mechanical ventilation in treating COVID-19 patients?

COVID-19 is one of the worst public health emergencies of all human history, bringing the world to a stop. With over 12 million confirmed cases including more than 550,000 deaths, the world has closed down. Medical professionals and scientists all over the globe are striving to find a solution to this world crisis. The only solution that seems to be working to date is confinement, preventing the virus’ spread by avoiding human to human contact. 

COVID-19, being a SARS (Severe Acute Respiratory Syndrome) includes diseases such as pneumonia and other lung infections. A large number of deaths are linked to patients who were under artificial ventilation. Some doctors are ventilating patients much earlier than necessary leading to their potential death.  To understand the danger of the misuse of artificial ventilation there is a need to first understand the working process of mechanical ventilation, then assess its effectiveness.  We will also discuss other oxygen therapy that can prove to be suitable to treat this disease. 

Mechanical ventilation is different from how we naturally breathe. During natural inhalation, the diaphragm muscle contracts and the chest expands. This creates a vacuum that pulls air into the lungs. During a natural exhalation, the diaphragm muscle relaxes and air leaves the lungs.  A ventilator works by pushing air into the lungs. The air is pushed in until it reaches a pre-set volume or pre-set pressure. Once the lungs are full, the vent stops pushing the air into the lungs. The air then passively leaves the lungs. This is similar to letting air out of a full balloon.

Mechanical ventilation is an invasive method that has a lot of risk as it needs to supply your body in oxygen, the amount of which will depend on your physiognomy – height, weight and age.  Biologically, your body gives you a certain percentage of oxygen depending on your daily activity and the aforementioned factors. The mechanical ventilation replaces your physiological vital function which reveals to be a risky and deadly procedure in some cases. This could be the cause of all the deaths attributed to COVID-19, probably due to the failure of understanding this virus properly. 

How does it work?

The settings are selected when the patient is placed on a ventilator.  These settings differ depending on each patient’s needs.  They are chosen by a pulmonologist but managed and monitored by a respiratory therapist. 

There are different ventilator modes that control the programming to deliver a breath: controlled, supported and combination.  The latter depends on two measures (volume and pressure).  The controlled mode is used when the patient is unable to breath on their own.  The supported mode is when the ventilator will provide a small amount of pressure to increase the size of their natural breath.  The combination mode is a combination of the controlled and supported modes.  The ventilator will deliver the breath in two different ways: in a pre-set volume of air in every breath and until a pre-set pressure is reached.  

The ventilator settings depend on several criteria:

  • Oxygen concentration: The amount of oxygen delivered to the patient. When the patient is not receiving added oxygen, the oxygen level will be the same as room air (21%).

  • Tidal volume (Vt): The amount of air the vent delivers with each breath.

  • Respiratory rate: The number of breaths the ventilator is delivering to the patient per minute.

  • Pressure: The pre-set pressures the ventilator uses to create a volume of air.

  • Inspiratory time/Flow: Controls how long the patient inhales. The goal is to simulate a normal breathing pattern.

  • Dead Space: Additional tubing in the vent circuit that traps exhaled carbon dioxide (CO2) when the patient exhales. CO2 affects the pH balance in the bloodstream. The respiratory therapist will add or subtract tubing from the ventilator circuit to adjust CO2 levels and keep them within normal limits.

  • PEEP: (Positive end-expiratory pressure) adds a small amount of back pressure as the patient exhales that helps keep the lungs open.

  • Sensitivity or Trigger: Controls how hard or how easy the patient will need to inhale to signal the vent that they would like additional breaths above the set respiratory rate.

Some doctors believe that ventilators are not the appropriate instrument to use to fight the virus.  NY doctor Cameron Kyle-Sidell, on the YouTube channel EMCrit, mentions that this virus causes oxygen failure rather than respiratory failure.  This was demonstrated by the fact that when taking patients off the ventilator, there is a drastic oxygen drop and the patients die within minutes.  This shows that the ventilators do not help to cure the patients but only keep them alive.  Small studies conducted in the US, the UK and China have shown that 80% of patients that were critical and under ventilation died in the US and China and 66% in the UK.  The doctors are using high flow ventilation to keep the patients alive.  Ventilators are supposed to be used by doctors as a last resort when the patient’s lungs do not have the capacity to provide enough oxygen to the body.  The real problem of the COVID-19 is that it affects the absorption of oxygen in the body as it directly attacks the red blood cells, and not the physiological function of the lungs.  Therefore, high flow ventilation is only leading to potential lung damage or even lung failure, depending on the patient’s capacity to recover.  The following example clearly demonstrates this fact.   

New York City lawyer and legal blogger David Lat spent six days on a ventilator last month, in critical condition at NYU Langone Medical Center after he was diagnosed with COVID-19.

“This terrified me,” Lat wrote in an opinion piece in the Washington Post. “A few days earlier, after my admission to the hospital, my physician father had warned me: ‘You better not get put on a ventilator. People don’t come back from that.'”

Lat survived, and he thanks the ventilator but he also is struggling to recover his ability to breathe.

“I experience breathlessness from even mild exertion,” Lat wrote. “I used to run marathons; now I can’t walk across a room or up a flight of stairs without getting winded. I can’t go around the block for fresh air unless my husband pushes me in a wheelchair.”  

This was expected to happen as it is a machine that is breathing for them.  The patients often experience a weakening of their diaphragm and all the other muscles involved with drawing breath.  When all these muscles become weaker, it becomes more difficult for you to breathe on your own when liberated from the ventilator.

COVID-19 patients are breathing well, meaning that they do not have any lung deficiency or failure, but are still not oxygenating.  The solution would be using another oxygen therapy, hyperbaric oxygen therapy.  Ventilators create pressure in our lungs while hyperbaric oxygen therapy creates pressure in the environment.  A hyperbaric chamber can be compared to an airplane.  When flying in an airplane, there is not enough oxygen density to breathe at 30,000 ft.  We pressurise the cabin to ensure that the density of oxygen is high enough to be able to breathe.  Our ability to absorb oxygen in our body is directly connected to the pressure gradient.  The initial issue is that the virus attacks the red blood cells which result in a lack of oxygenation of our body.  The benefit of hyperbaric oxygen therapy is that the patients will breathe in pure oxygen in air pressure levels 1.5 to 3 times higher than average.  Hyperbaric oxygen therapy helps to strengthen the body’s immune system.  The ultimate goal would be to fill the blood with enough oxygen to repair tissues and restore normal body function.  The potential solution for COVID-19 patients would be to pressurise their environment for them to absorb a higher amount of oxygen.  This oxygen therapy, as a way of delivering oxygen to our cells and tissues bypassing our standard delivery system,would help to avoid damaging the lungs of patients who do not already suffer from lung diseases.

To conclude, a ray of hope for COVID-19 patients could be hyperbaric oxygen therapy as an alternative to mechanical ventilation, which is more invasive for the human body.  Although lifesaving for some, mechanical ventilation can be associated with life threatening complications, including air leaks and pneumonia.  COVID-19 can be seen as an immune system disease rather than a respiratory disease as it attacks the red blood cells, which provokes the respiratory complication that patients encounter.  Therefore, the effectiveness of ventilators for this global pandemic is limited – it only serves its purpose for a restricted number of patients.

Leave a Reply