COVID-19 is presenting intensive care with unprecedented new challenges. The pandemic has made working in an intensive care unit even more difficult, creating further challenges for patients, doctors, and nurses. Most patients presenting with COVID-19 to an ICU have respiratory failure and need to be invasively ventilated, i.e. intubated, to restore their body's oxygen supply.
Dr Reinhard Kitzberger, an internal medicine specialist and ICU doctor, tells us about his daily work as a Physician at the COVID-19 intensive care unit at Favoriten Hospital in Vienna and provides first-hand description of the situation there. Before coming to Vienna, he worked in Hamburg in one of the largest teaching hospitals in Europe, with 150 intensive care beds. From the pandemics start he had almost 2,300 patients with severe cases of COVID-19 in his care – 300 in intensive care, and 2,000 on the general medical wards.
Lung failure caused by other diseases is characterised by the fact that the patients have extremely poor lung compliance. This means their lungs can no longer expand properly, so their lung volume and pressure are impaired. Patients with COVID-19 tend to show normal lung compliance, yet they still develop acute oxygen desaturation, i.e. the malfunction of their body's oxygen saturation mechanism.
Despite objectively measurable oxygen desaturation, these patients do not subjectively feel short of breath – on the contrary, they feel great, and occasionally even euphoric. This contradictory clinical presentation resulted in increased mortality rates, particularly at the beginning of the pandemic, because their low oxygen saturation (hypoxia) was not adequately recognised. Doctors are now calling it 'happy hypoxia' or 'silent hypoxia'.
How does 'silent hypoxia' occur?
“Since a very common symptom of COVID-19 is the loss of smell and taste, the SARS-CoV-2 virus also seems to affect the central nervous system. It is therefore assumed that, on account of how it interacts with their brain stem, the patient does not feel a lack of oxygen."
A major factor, especially among older patients at the beginning of the pandemic, was insufficient food and fluid intake, since COVID-19 also involves a loss of appetite. These patients were often already dehydrated. This affects their entire body and causes general exhaustion. With younger patients, who often also have pre-existing conditions, the focus is currently on respiratory distress, which rapidly becomes so acute that they are beyond being admitted to the normal general ward and require immediate ICU treatment.
Currently, people aged between 40 and 65 years are more severely impacted by COVID-19, as most of the older generations have already received one vaccination. They are physically fitter, so often do not seek hospital attention until they have exhausted all their reserves. However, in the case of COVID-19 in particular, people should be getting admitted as inpatients earlier on, so they can be stabilised on the general medical ward, thus avoiding needing ICU treatment.
The easiest way is to measure their respiratory rate or their pulse oximetry, which measures their blood oxygen saturation. These are key parameters that show whether their lungs are affected or impaired before they subjectively start feeling short of breath. There is still no research available on the recommended levels, but most ICU doctors say from prior experience: "The younger the patients are, the higher their oxygen saturation should be."
One of the main factors is your age. Under 65s have an 85 % chance of survival. However, from the age of 65 on, the risk of dying of COVID-19 doubles, which is why vaccination and pandemic strategies are particularly geared towards that risk group. Women generally have better chances of surviving COVID-19 than men do.
There is also a clear correlation between patients' survival rate and how full the intensive care units are. The more patients treated, the higher the COVID-19 patient mortality rate.
There are 2,450 public hospital intensive care beds in Austria.
In 2019, before the pandemic, the average length of ICU treatment was 3.8 days.
Patients with COVID-19 usually have to be on invasive ventilation for 20 days.
Patients requiring isolation are cared for in COVID-19 ICUs. If the virus is no longer detectable, they can be transferred to non-COVID-19 wards and continue getting intensive care there.
https://www.anaesthesie.news/allgemein/anaesthesie-und-intensivmedizin-heute-und-in-zukunft/ [in German only]
https://t3-web.meduniwien.ac.at/forschung/forschung-zu-covid-19/ [in German only]