What is a negative pressure room for isolating Covid-19 patients?
All the air in the room will be renewed every 5 minutes.
As the number of SARS-CoV-2 virus infections in South Korea has reached nearly 3,000, health officials in the country said they have prepared 1,077 negative-pressure isolation rooms for patients with symptoms of depression. heaviest respiration.
Jeong Eun Kyeong, head of the Korea Centers for Disease Control and Prevention (KCDC), said that these negative pressure rooms are only prioritized for critically ill patients who require intensive care.
Other Covid-19-positive patients with milder symptoms will be isolated in a regular hospital room or at home. So what are negative pressure isolation rooms? What role do they play in preventing the spread of disease?
Let's find out in the article below.
How the SARS-CoV-2 virus spreads in the environment
We know that the virus that causes Covid-19 can be spread through droplets that an infected person releases into the air. Research shows that when a sick person sneezes, they can release 40,000 droplets into the air. These droplets can travel up to 6 m at a speed of 50 m/s.
When a person coughs or talks for 5 minutes, they can spread 3,000 droplets. Cough droplets can travel over a range of 2 m at a speed of 10 m/s. And even when a sick person breathes, they can spread droplets over a distance of 1 m at a speed of 1m/s.
The path of these droplets is even more complicated when the air flow in a hospital is free to move. Air moves from an area of high pressure to an area of low pressure. They can carry virus-containing droplets from a patient in a room out into the hallway, infecting other doctors and patients in the room.
Viruses can even spread from one ward to another. Therefore, controlling this cross-contamination pathway should be prevented. To do this, hospitals have built special isolation rooms called negative pressure rooms.
What is negative pressure room?
As the name implies, a negative pressure room is a room with lower ambient pressure where air can only enter from one side and cannot escape through that side. Imagine standing in front of this room, the wind will always blow from the outside to the inside.
If there is a patient with Covid-19 in isolation in there, their virus-containing droplets will not be able to wade up this air current to escape outside the door. At this time, the phenomenon of cross-infection through the air stream between patients will be extinguished.
Negative pressure rooms like these are often built in the infectious disease isolation ward of a hospital. It is commonly used to isolate patients with tuberculosis, measles, chickenpox, influenza, SARS, Ebola and now Covid-19.
In order to get lower pressure from one side of the room, it would have to be as enclosed as possible, with a monolithic ceiling, tight doors - leaving only a gap under the wing about a half inch high, equivalent equivalent to 1.27cm.
Windows (if any) must also be tight and have a sealing lock. Electrical sockets, lines, and pipes in and out of the room must also ensure that they do not create gaps.
After that, the pressure in the room will be reduced by an exhaust pump system. Air will be drawn out of the negative pressure room through a pipe, usually located near the head of the patient's bed.
This airflow will of course carry droplets containing Covid-19 pathogens. To ensure this pathogen is retained, the hospital will use a high-efficiency particulate air (HEPA) system.
HEPA filtration systems are designed with filters made of fiberglass and the gaps between them are only 0.3 micrometers apart. But the special feature of HEPA compared to other filtration systems is that it is capable of capturing even particles smaller than the gap size by taking advantage of the diffusion and electrostatic attraction mechanism.
In comparison, pathogen droplets are also often tens of micrometers or more in size. As a result, the HEPA filter can treat the air in the suction pipe from the negative pressure room to ensure almost absolute cleanliness (>99.99%).
The SARS-Covid-19 virus will be retained on these filters, until they die on their own or are killed when the HEPA filter is disinfected and replaced by hospital technicians.
The negative pressure room compensating air is a natural stream of clean air, drawn from the intakes. The volume of air that is circulated in a negative pressure room per hour is typically 12 times the volume of the room. Therefore, it is understandable that the entire air in the room will be renewed every 5 minutes.
Arrangement of air intakes and air compensation in a negative pressure room is also very scientific. Accordingly, the air inlets are usually located at the head of the patient's bed, closest to their breathing. This ensures that even when doctors come to the hospital bed to examine, the patient's breath is difficult to reach the doctor's respiratory tract.
In contrast, the ventilation doors in the negative pressure room will be placed high, behind the hospital bed to create a circulating clean air flow. Inside the negative pressure isolation room, there are usually full amenities, including toilets.
The toilet itself, but the negative pressure room is also another negative pressure room, where air can only enter but cannot go out. It will ensure pathogens will not spread back from the toilet to the isolation room where the sick person is lying.
In the US, negative pressure isolation rooms are often recommended to have both telephone and TV sockets for patient entertainment needs. In addition, they can also put a bicycle exercise machine in it so that the patient can exercise.
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