Sarcopenia (muscle weakness) is one of the geriatric syndromes that increases in frequency
with age and is characterized by a decrease in muscle mass, strength and performance.
Sarcopenia that occurs with aging is called primary sarcopenia, but sarcopenia can also occur
due to secondary causes such as malnutrition, chronic diseases and immobility. One of the
most important risk factors is advanced age. The prevalence of sarcopenia, which has been
reported between 5% and 13% in a decade, can reach up to 50% over the age of 80. Sarcopenia
is an important health problem that can cause loss of mobility, risk of functional
dependence, risk of falling, increase in hospital stay, and consequently increase in
morbidity and mortality, especially in elderly patients.

In order to be able to say sarcopenia, the investigators need to show that there is a
decrease in muscle mass and, in addition, muscle strength and/or performance. Bio-electrical
impedance analysis, anthropometric measurements or radiological measurements can be used
among the most commonly used methods when evaluating muscle mass. However, there is no single
gold standard measurement. Cross-sectional muscle area measurements, lean mass measurements
and calf circumference measurements are the most commonly used muscle mass determination
methods.

Ultrasonographic measurement of the rectus femoris muscle is a muscle mass measurement
technique that has been used frequently recently. The most important measurement method used
as a standard for muscle strength measurement is hand grip strength. The hand grip strength
values reported for weakness acquired in the intensive care unit are at lower limits. <11 kg
in male patients and <7 kg in female patients are considered significant limits for ICU-AW
(intensive care unit-aquire weakness). However, there are some difficulties in evaluating
muscle strength in intensive care patients. Most importantly, most of the patients are
bedridden, immobile, receiving ventilation support, unable to cooperate, and who will not be
conscious because they are under anesthesia. Apart from this, there are some measurement
methods by sending magnetic or electrophysiological stimuli to the peripheral nerves in
intensive care patients for muscle strength measurement, but they are mostly applied for
clinical studies for now, due to the fact that they are invasive measurement methods and
there are not enough equipped centers to apply them. In conclusion, sufficient number of
studies examining this issue are required to reach a consensus on how to diagnose sarcopenia
in intensive care patients.

In today's conditions, patients with a diagnosis of COVID-19 pneumonia are followed in the
majority of intensive care units. In the study, patients with a diagnosis of COVID-19
followed in the intensive care unit will be evaluated. It is aimed to monitor, detect and
investigate the factors affecting the muscle weakness of the disease, which the
investigatorshave just met during the pandemic the investigators are in, and which causes
different systemic involvement. There is no previous study on this subject in the literature.