What are Ventilators?
We have heard about it since the beginning of this pandemic. Hospitals need it more and more, but what are these lung ventilators that everyone talks about?
As we all know, ventilators are devices that are currently in short supply in hospitals around the world, and patients suffering from respiratory failure due to coronavirus may not be able to get the help they need to breathe.
The number of COVID-19 patients requiring respiratory assistance is on the rise many nations are preparing to ration machines, asking manufacturers to speed up their production and even creating improvised fans with diving masks. Some hospitals are also finding out how to share a single ventilator among multiple patients.
So what is a fan and how bad does it take to need it?
A healthy person can inhale oxygen and expel carbon dioxide at a normal rate to keep the body running. But a person with sick or damaged lungs cannot breathe regular air fast enough or strong enough to support their body’s oxygen needs. A ventilator does this work by creating pressure to open the lungs, delivering oxygen to the lungs through a tube, and removing the carbon dioxide that the lungs create.
When we breathe, the diaphragm and other chest muscles contract, this expands the chest and creates pressure to attract oxygen-rich air into the lungs. We exhale carbon dioxide when these muscles relax and the chest returns to its normal size. If the body cannot create this pressure on its own, a ventilator can be used to create it, moving air into the lungs.
The mechanical fans used in the intensive care settings are large and complex devices that run on current and are connected to a central oxygen source. Most of the machine is a monitor with dials, displays, and setting options that can be adapted to each patient’s respiratory needs. Inside the housing, there is a bellows which – like those balloons that we have seen used by paramedics on TV – pushes the oxygenated air through a series of tubes and into the lungs.
Before it reaches the patient, the air flows through a humidifier, which warms and moistens it. From there, the oxygenated air is pushed through a tube that transports it to the lungs and removes the resulting carbon dioxide.
Mechanically ventilated patients are generally intubated, meaning that they have a tube inserted through the mouth and into the respiratory tract. Once an endotracheal tube is in place, the end swells to seal the airways, which prevents any gas or fluid from escaping backward as air is pushed into the lungs.
Intubated patients are also slightly sedated for part or all of their time to mechanical ventilation. In addition to the discomfort of having a tube stuck in your throat, you may have the feeling that you are suffocating.
There are less invasive types of respiratory assistance, such as oxygen delivered through a mask, but for a COVID-19 patient, supplemental oxygen may not be sufficient.
COVID-19 affects the respiratory system, so people with pre-existing critical lung conditions start at a disadvantage. Smokers, the elderly, and patients with other respiratory problems have less efficient lungs and can be hit harder by respiratory problems resulting from the virus.
Why is there a shortage of fans?
Even before this global pandemic, there were patients attached to fans. But many of these people only require machines for a few hours (during surgery, for example) or for a few days, so they are transferred to another patient. COVID-19 patients with respiratory failure often require mechanical ventilation for a week or more, so machines are not released at the same rate.
The reason there is a bottleneck is that there are too many sick patients and when they get sick they stick to it for a long time.
In addition, a fan is not a device that just needs to be set once. It requires constant monitoring and frequent changes of parameters to balance the pressure, volume, oxygen percentage, and respiratory rate for each individual patient, which means that having many people attached to the fans affects the resources of hospitals, nurses, and doctors.
A further obstacle with COVID-19 is that medical personnel must be dressed in personal protective equipment (gowns, masks, gloves, glasses) every time they interact with a patient. This means that they cannot simply enter and turn a dial to adjust the machine. There is also the risk of exposure to the virus during intubation.