By the end of April 2021, more than 3 million patients died worldwide due to the infection caused by the SARS-CoV-2 coronavirus. In parallel, tens of millions of other patients developed moderate or severe forms of the disease but managed to recover from COVID-19. In common, a significant portion, regardless of the outcome, needed to be admitted to Intensive Care Units (ICUs). Some procedures were probably performed during treatment to aid recoveries, such as intubation or ECMO (extracorporeal membrane oxygenation).
Before we proceed, it is worth explaining what it means to be admitted to an ICU due to coronavirus (or other complications). In these hospital spaces, the most severe patients are treated and those who require more monitoring. Therefore, these environments are like a complete monitoring room with 24-hour surveillance. After all, the individual’s condition can worsen at any moment, and emergency measures will need to be taken.
To understand how some practices adopted by health professionals work to aid the recovery of patients hospitalized due to COVID-19, Entrepreneurship Today talked to experts on the subject.
Why does the intubation of COVID-19 patients occur?
“COVID-19 is a highly inflammatory disease, so it inflames the lung, theoretically the pulmonary alveoli [through which gas exchange occurs], leading to a degree of hypoxemia [a drop in the level of oxygen in the blood]. Then, the patient can’t breathe room air. At this moment, the person starts to depend on mechanical ventilation, which can be invasive or not and should continue for as long as the pathology lasts.
Before intubation, you perform some non-invasive measures, such as putting an oxygen catheter in the patient, through which it is possible to increase the flow of oxygen. In these circumstances, the equipment is still connected to the patient through masks – such as the helmet – or even by the simple catheter. However, depending on the evolution of COVID-19’s condition, this external source may no longer be sufficient.
The problem is that these alveoli are diseased and collapsed, sticking to each other, so you need to offer a high flow of oxygen [more increased than is possible in non-invasive measures]. This will ensure that it [the oxygen] enters the bloodstream, enters the red blood cells, and this patient again receives an adequate supply of oxygen. At this point, you have to pass a tube through the patient’s windpipe, where you have direct contact of the oxygen with these alveoli; that is, you have to intubate.
To place this tube properly into the trachea, orotracheal intubation must occur, where the person needs to be unconscious or sedated. This procedure is only possible without drugs if the patient is in cardiac arrest. Now, these COVID-19 patients have very high respiratory distress. Intubation is an invasive, aggressive procedure, so you need hypnotic drugs to take consciousness away from the patient, analgesic drugs for the patient not to have pain, and neuromuscular protector for the patient to be relaxed.
In other words, the patient has to sleep, can’t have pain, and can’t move. Even while the patient is intubated, it is necessary to maintain the use of these drugs. This means that during intubation, in which the COVID-19 patient relies on mechanical ventilation, he is unconscious. As this period can last for days, the risk of running out of drugs from the “intubation kit” is severe, as it can directly affect the health of the inpatients. The same risk is posed by oxygen shortages, as occurred currently affecting India.
How long is intubation allowed?
Since intubation is very invasive, there is a time limit for how long the patient can undergo this treatment, which can vary from 10 to 18 days, depending on the clinical conditions. This is because the trachea is composed of cartilaginous tissue, and the very rigid tube causes the tissue to lose its resistance, leaving it softer.
Tracheostomy [TCT] is an elective procedure that is done depending on the number of days the patient is already intubated. In these cases, you take the tube out of his mouth, open an incision at the neck level, and pass a smaller tube that goes ventilating. When you intubate someone, the tube passes through the vocal cord, and the patient can’t speak. When you put the tracheostomy in, the patient can stay awake and even have some degree of cognition.
It’s worth remembering, however, that the coronavirus doesn’t only affect the lungs, and the inflammation can reach other organs, such as the heart. Depending on the extent and severity, numerous other techniques may be necessary inside the ICU to keep the patient alive and aid in his recovery.
ECMO: an artificial lung+heart combo
As cases of COVID-19 escalated, a different name began circulating for the treatment of these patients: ECMO (extracorporeal membrane oxygenation). In these cases, the device seeks to serve as an artificial lung or heart.
As novel as it may seem, it is essential to emphasize that ECMO is not a new technology and was widely used during the H1N1 epidemic. Furthermore, although not widespread in some countries, the first ones were implanted in the 1970s in the United States.
When to use Extracorporeal Membrane Oxygenation?
ECMO can be used for diseases that severely affect the lungs or the heart. If it is the lungs involved, as is most often the case in COVID-19, ECMO is useful when ventilators can no longer oxygenate the blood or excrete carbon dioxide from it in a way that keeps the patient’s life safe. It can also be used to ‘rest’ the lungs from mechanical ventilation.
In cases where there is lung failure [as in COVID-19 patients], ECMO is widely used as an ‘artificial lung’ [a modality of venovenous ECMO]. To do this, blood is drained through a thick cannula that enters through the groin and goes to the vena cava; it exits it out of the body suctioned by a centrifugal pump that ejects the blood under pressure to the oxygenator membrane. This membrane artificially performs lung function; that is, it oxygenates the blood and extracts carbon dioxide from it. After that, the blood returns through a cannula inserted in the jugular vein [in the neck] and returns to the oxygenated heart.
Unlike intubation, the intensivist explains that there is no maximum time to use the machine; however, there is the risk, after a week, of the severely affected lungs fibrosing and becoming unfeasible for recovery. On the other hand, there are case reports, including BP itself, of patients intubated for more than 20 days and were still on ECMO for two weeks and survived.
Why is it unusual to adopt ECMO in many countries?
In general, many hospitals have never had cases of ECMO implanted. The device is being more widespread now with the increased demand for COVID-19, but many restrictions still exist. Among the reasons for this are logistical issues, such as the scarcity of the device to meet the demand, or technical issues, since there are few professionals trained to implant or, more difficultly, to handle the device.