Skeletal Muscle Regeneration in Survivors of Critical Illness: How to Prevent Satellite Cell Failure?
Conditions: Intensive Care Unit-acquired Weakness
Sponsor: Charles University, Czech Republic

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Clinical Study Protocol 
Project No: NU21J-06-00078 
Skeletal muscle regeneration in survivors of critical illness: How to 
 
prevent satellite cell failure? 
(SATELLITE) 
Short title: Satellite cell physiology in critical illness 
Sponsors 
Fakultní nemocnice Královské Vinohrady 
[FNKV University Hospital] 
IČ/VAT No: 00064173 
Univerzita Karlova, 3. lékařská fakuta 
[Charles University, Third Faculty of Medicine] 
IČ/VAT No: 00216208 
Principal 
Dr Adéla Krajčová, PhD 
Investigator 
Charles University, 3rd Faculty of Medicine and FNKV University 
 
Hospital, Prague, Czech Republic, 
Dept. of Anaesthesia and Intensive Care 
Address: Srobarova 50, 10034 Prague, Czech Republic 
Phone: +420267162451 Emergency 24/7 contact number: 
+420774732499 
Email: adela.krajcova@lf3.cuni.cz 
 Investigator(s) 
See separate listing 
Protocol Date 
20th December 2022 
Version: 
1.0 
NCT 
(pending) 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
SIGNATURE PAGE 
Principle investigation declaration: 
I hereby declare that this clinical trial will be conducted in accordance with the principles of 
Good Clinical Practice and Czech law. This study is exploratory in nature and no 
investigational products (shall it be drugs or medical devices) are tested in this trial. I also 
declare, that this study has been investigator initiated and supported exclusively from Czech 
Health Research Council, project No NU21J-06-00078. 
 
 
 
 
 
 
 
 
 
 
 
Dr Adela Krajcova 
Signature: 
Date: 20.12.2022 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Table of Contents 
Signature page........................................................................................................................................2 
List of abbreviations ..............................................................................................................................4 
STUDY PERSONNEL..............................................................................................................................5 
Principal investigator.........................................................................................................................5 
Investigators (alphabetical order) ....................................................................................................5 
Study monitor.....................................................................................................................................6 
NARRATIVE ABSTRACT........................................................................................................................7 
BACKGROUND .......................................................................................................................................8 
STUDY HYPOTHESES AND AIMS.......................................................................................................10 
METHODS..............................................................................................................................................11 
General methodological approaches.............................................................................................11 
Design ...............................................................................................................................................12 
Study subjects..................................................................................................................................12 
Informed consent procedure ..........................................................................................................13 
Study procedures.............................................................................................................................13 
Power analysis and statistical plan................................................................................................16 
Direct access to source data/documents......................................................................................16 
Quality control and quality assurance...........................................................................................16 
Ethical Considerations ....................................................................................................................16 
Data handling and recordkeeping ..................................................................................................17 
Publication Policy ............................................................................................................................17 
IMPACT..................................................................................................................................................17 
REFERENCES.......................................................................................................................................18 
INFORMED CONSENT FORMS……………………………………………………………………………. 21 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
LIST OF ABBREVIATIONS 
AE 
Adverse Event 
ICU 
Intensive care unit 
ICUAW Intensive Care Acquired Weakness 
ECOG Eastern Cooperative Oncology Group performance status 
eCRF Electronic Care Report Form 
FiO2 
Fraction of oxygen in inspired air 
F-up 
Follow up 
LFT 
Liver function tests MV 
Mechanical ventilation 
PEEP Positive end-expiratory pressure 
PIP 
Peak inspiratory pressure 
pCO2 Partial pressure of carbon dioxide in arterial blood 
pO2 
Partial pressure of oxygen in arterial blood 
SAE 
Serious Adverse Event 
SOFA Sequential Organ Failure Assessment 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
STUDY PERSONNEL 
Principal investigator 
Dr Adéla Krajčová, PhD 
Charles University, 3rd Faculty of Medicine and FNKV University Hospital, Prague, Czech 
Republic, 
Dept. of Anaesthesia and Intensive Care 
Address: Srobarova 50, 10034 Prague, Czech Republic 
Phone: +420267162451 Emergency 24/7 contact number: +420774732499 
Email: adela.krajcova@lf3.cuni.cz 
Investigators (alphabetical order) 
Dr František Duška, PhD, AFICM, EDIC 
Associate Professor of Intensive Care 
Dept. of Anaesthesia and Intensive Care, Charles University, 3rd Faculty of Medicine and 
FNKV University Hospital, Prague, Czech Republic, Address: Srobarova 50, 10034 Prague, 
Czech Republic 
Phone: +420267162451 Emergency 24/7 contact number: +420608405541 
Email: frantisek.duska@lf3.cuni.cz 
Dr Jan Gojda, PhD - Centre for Research on Diabetes, Metabolism and Nutrition, Dept of 
Internal Medicine, Charles University, 3rd Faculty of Medicine and FNKV University Hospital, 
Prague 
Dr Pavel Skrha, PhD - Centre for Research on Diabetes, Metabolism and Nutrition, Dept of 
Internal Medicine, Charles University, 3rd Faculty of Medicine and FNKV University Hospital, 
Prague 
Dr Petr Waldauf - Dept. of Anaesthesia and Intensive Care Medicine, Charles University, 3rd 
Faculty of Medicine and FNKV University Hospital, Prague 
Dr Michal Fric - Dept. of Anaesthesia and Intensive Care Medicine, Charles University, 3rd 
Faculty of Medicine and FNKV University Hospital, Prague 
Dr Tomas Tencer - Dept. of Anaesthesia and Intensive Care Medicine, Charles University, 3rd 
Faculty of Medicine and FNKV University Hospital, Prague 
Dr Bob Bakalar - Dept. of Anaesthesia and Intensive Care Medicine and Burn Center, Charles 
University, 3rd Faculty of Medicine and FNKV University Hospital, Prague 
Dr. Robert Zajicek - Burn Center, Charles University, 3rd Faculty of Medicine and FNKV 
University Hospital, Prague 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Study monitor 
Mrs Sarka Gregorova - Dept. of Anaesthesia and Intensive Care Medicine, Charles University, 
3rd Faculty of Medicine and FNKV University Hospital, Prague 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
NARRATIVE ABSTRACT 
Modern intensive care enables patients to survive insults that in the past would not 
have been survivable. Nonetheless, increased number of survivors suffer from failed 
functional outcomes associated with prolonged muscle weakness and fatiguability. Whilst 
alterations of skeletal muscle biology that occur during critical illness slowly disappear over 
the period of months, muscle weakness remains. Recent pilot studies have shown that 
muscle weakness is associated with loss and alteration of satellite skeletal muscle cells, 
which are supposed to proliferate and repair damaged muscle tissue. The pathogenesis of 
this phenomenon has not been fully understood. In this project, we will study function and 
structure of satellite cells and their organelles (particularly mitochondria) using both classical 
bioenergetics and advanced microscopic techniques. Satellite cells will be isolated from 
biopsies taken from critically ill patients with developed muscle weakness in the acute and 
protracted phase of a disease and after 6 months. In time points, an ultrasound examination 
of muscle mass will be performed, and metabolism will be assessed using insulin clamps and 
calorimetry. In a series of in vitro experiments, we will test also effect of nutritional and 
anabolic factors and drugs, commonly used in ICU, on satellite cells. In a control arm, cells 
will be isolated from skeletal muscle of volunteers undergoing elective hip replacement 
surgery. Results of this study could significantly contribute to understanding of mechanisms 
leading to ICU acquired muscle weakness and to identify therapeutic strategy in future. 
Key words: intensive care unit-acquired weakness; critically ill; skeletal muscle regeneration; 
satellite cells 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
BACKGROUND 
 
Skeletal muscle weakness is a frequent complication of critical illness associated with 
an increased morbidity and mortality [1]. Altered muscle strength and functional ability 
occur mostly in patients with sepsis or extensive inflammatory response who require 
prolonged duration of mechanical ventilation and hospital stay[2]. In patients surviving 
intensive care, muscle weakness remains a long-term complication leading to significantly 
decreased quality of life[3,4]. The mechanisms underlying this phenomenon have been 
extensively studied in both animal models and critically ill patients. Proteolytic muscle 
degradation, electrical alterations, and excitation-contraction decoupling are well known 
factors contributing to development of muscle weakness in the acute phase[5]. Even more 
importantly, recent studies have shown that failed long-term functional outcome in critically 
ill is associated with decreased satellite cell content[5]. Satellite cells are localized beneath 
the basal lamina surrounding each multinucleated myofiber[6]. In adult muscle, satellite cells 
are normally quiescent, but they can be recruited rapidly after a muscle damage, providing 
the muscle with an ability to regenerate[7]. During injury, satellite cells are activated from 
the quiescent state (G0 phase) and enter the cell cycle (G1 phase)[8]. Most activated satellite 
cells then proliferate and are referred to as “myoblasts”. Myoblasts subsequently 
differentiate and express myogenic factor which allows them to fuse between themselves 
into multinuclear cylindrical myotubes and with the existing fibres to regenerate the 
damaged muscle tissue[6,8]. Some satellite cells return to the G0 state to replenish the pool 
of quiescent skeletal muscle cells[6,8]. These processes are regulated by key transcriptional 
factors such as Pax7 and myogenic regulatory factors[9,10]. Myotubes are highly 
metabolically active, rely on oxidative phosphorylation in a rich population of mitochondria 
which are structured in organized networks[11]. In contrast, myoblasts are more dependent 
on glycolysis and contain less mitochondria. Shortly after muscle injury, myogenic 
differentiation occurs[11] and mitochondrial mass, protein content and number of 
mitochondrial DNA copy increase[12,13]. Moreover, recent studies have shown that shape 
of mitochondria is also remodelled during myogenic differentiation[14,15]. Mitochondrial 
morphology is controlled by balanced processes of fusion and fission machinery[15,16]. 
Balanced fusion and fission events shape mitochondria to meet metabolic cues and to 
ensure removal of damaged organelles[16]. Mitochondrial morphology is therefore 
dramatically changed in response to various metabolic inputs[16] and it is tightly 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
regulated[15,16]. The morphology of mitochondria is altered in disease: mitochondria can 
shape into elongated tubules during mild stress and starvation. In contrast, acute severe 
stress frequently causes a dramatic mitochondrial fragmentation and decreased oxidative 
phosphorylation[16]. 
Recent studies performed on animal models have shown that some of the proteins 
responsible for the processes of fusion and fission are crucial for the proper muscle growth 
and function of mitochondria in muscle cells[15]. Therefore, alterations in mitochondrial 
dynamics often play a crucial role in skeletal muscle dysfunction and have been recently 
extensively studied in several myopathies[17]. Although it has been established that skeletal 
muscle regeneration parallels altered mitochondrial dynamics and biogenesis, the cells that 
mediate the remodelling of mitochondrial networks have not been yet thoroughly 
investigated[18]. Moreover, there is still lack of clear information about mitochondrial 
dysfunction in skeletal muscle weakness after critical illness. 
Our group already adopted a method of satellite cell isolation and culture from 
human vastus lateralis biopsies and tested nutritional influences[19]. We have found in a 
pilot experiment that bioenergetic profiles of myotubes from patients with protracted ICU 
stay differ from healthy control, mostly by mitochondrial mass deficiency and reliance of 
remaining mitochondria on lipid-derived substrates[20]. In addition, we found out that 4 
days of propofol exposure induces respiratory chain alterations (mostly fatty acid oxidation 
defect)[21], which we later managed to further characterize [22]. Long term significance of 
these findings to satellite cell ability to repair damaged muscle remains unknown. 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
STUDY HYPOTHESES AND AIMS 
Hypothesis: 
Critical illness induces damage to satellite cells in skeletal muscle that later impairs 
skeletal muscle structural and functional recovery and contributes to persistent weakness 
and failed functional outcome. 
Aims of the project: 
1. We will compare structural and functional (incl. bioenergetic) characteristics of 
satellite cells in acute, protracted and post-ICU phase in critically ill patients vs. 
control subjects. 
2. We will test the hypothesis that structural and/or functional alteration of satellite 
cells corelate with gross muscle mass and power in survivors of critical illness. 
3. We will elucidate factors that influence bioenergetics and mitochondrial morphology 
of satellite cells (such as extracellular inflammatory milieu, drugs common in ICU as 
well as nutritional and anabolic factors). 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
METHODS 
General methodological approaches 
1. Clinical outcomes will be assessed by objective validated tests such as SF-36 
questionnaire for the quality of life assessment, Medical Research Council Score of 
muscle power and 6 minutes walking test to measure aerobic performance. 
2. Metabolic characteristics will be assessed at whole body level by hyperinsulinaemic 
euglycaemic clamps and at tissue level by vastus lateralis 
biopsies. 
3. We will assess global mitochondrial indices of satellite cells by oxygen consumption 
measurement (production of ATP, uncoupling of inner mitochondrial membrane, 
maximal respiratory capacity of respiratory chain, glycolytic capacity and fatty acid 
oxidation). Simultaneously, we will measure production of reactive oxygen species 
and mitochondrial membrane potential. The changes will be assessed in various time 
intervals in the acute, protracted and post-ICU phase of critical illness. 
4. We will analyze mitochondrial density, structure and organization of mitochondrial 
network in satellite cells, length of mitochondrial branches and connections in the 
acute, protracted and post-ICU phase of critical illness. 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Design 
Investigator initiated, prospective, controlled, cohort study with physiological end-points 
Study subjects 
Inclusion Criteria: All of the following must be present: 
 Critically ill patients receiving mechanical ventilation, to be enrolled within 72 hours 
of admission, who are likely to need 7 days or more of ICU stay 
 Sudden onset of disease, which can be determined in time (such as trauma, stroke, 
sudden cardiac arrest etc.) 
 Informed consent signed by patient or patient’s representative 
Exclusion criteria: None of these shall be present 
 Unlikely to survive 6 months 
 Premorbid downslope functional trajectory or poor performance status (ECOG Gr. 3 
or worse) or baseline functional status unknown 
 Bleeding disorder (INR≥1.5 or PLT< that would preclude muscle biopsies) 
 Known mitochondrial disease 
 Endocrine crisis as a reason for admission 
 Pregnant women 
Control subjects: Elective hip surgery patients with very good to excellent performance 
status, only limited to joint pain (ECOG 0) 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Informed consent procedure 
All patients with capacity will be asked to provide a prospective written informed 
consent (See Appendix 3). For patients without capacity, a deferred consent procedure will 
take a place. In this case, an independent clinician will review and sign that the patient is 
lacking capacity and he/she fulfils all criteria to be enrolled to the study. The patient’s next 
of kin will be informed about the study as soon as practical with the aid of information 
leaflet (Appendix 3). The patient will be asked to provide and sign informed consent as soon 
as he/she regains the capacity to do so. In case of consent refusal, patient’s data will not be 
used in per-protocol analysis. 
Study procedures 
Eligible patients will be assessed at baseline, after 7 days and 6 months by clinical tests, 
metabolic tests and muscle biopsies as shown in table 1. 
Test 
Baseline 
Day 7 or ICU 
6 months follow 
Note: 
Control 
 
discharge 
up 
subjects 
Enrolment 
x 
x 
criteria, informed 
consent 
Insulin clamps 
x 
x 
x 
Muscle biopsy 
x 
x 
x 
X 
Functional 
x 
x 
performance test 
Muscle mass 
by x 
x 
x 
x 
ultrasound 
Table 1: Study procedures 
Biopsies. Experimental group (= critically ill): Skeletal muscle samples (70 – 100 mg of muscle 
tissue) will be obtained from vastus lateralis muscle by needle biopsy technique (Bergström 
needle). Control group (= orthopaedic patients): Biopsies (˃ 100 mg of muscle tissue) will be 
taken from vastus lateralis muscle by open technique during surgery in control (hip 
replacement surgery)patients. 
Isolation and cultivation of cells. Skeletal muscle cells will be isolated and cultured as 
previously described [19] (see Figure 1). 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Figure 1. Primary human skeletal 
muscle cells. Myoblasts (A) and 
differentiated myotubes (B) under 
binocular inverse microscope and 
appearance of myoblasts (C) and 
myotubes (D) stained for desmin (AB 
907 rabbit anti–desmin polyclonal 
antibody [Millipore, Billerica, MA, 
USA]) under confocal laser scanning 
microscopy. Source: published data 
of main proponent [19]. 
Bioenergetic profile. Mitochondrial metabolism will be assessed in living cells using 
Extracellular Flux Analyzer (Agilent Technologies Inc.) or high resolution respirometry 
(Oroboros O2k, Austria)[26], which simultaneously measures oxygen consumption rate 
(OCR) and extracellular acidification rate (ECAR) with oxygen-sensing fluorophores and pH 
sensors in a real time. The technology uses a piston to reversibly enclose a small volume 
above the microlayer of cells seeded in a multi-well plate. During the experiment, oxygen 
consumption rate (~respiration) and proton excretion (~glycolysis) cause rapid and easily 
measurable changes in dissolved oxygen concentration and free protons in the 
microchamber. The changes are monitored at the baseline of experiment and after addition 
of up to 4 test agents. The technology enables us to determine basal respiration, ATP 
production, proton leak, maximal respiratory capacity (see Figure 2) and glycolysis or 
respiration linked to individual complexes of respiratory chain. Fatty acid oxidation will be 
measured by Extracellular Flux Analysis and independently by another method of 
measurement of radioactively labelled [1-14C] palmitate oxidation using liquid scintillation 
[21]. 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Figure 2. Principle of Extracellular Flux Analysis: 
oxygen consumption rate (OCR) measured at 
baseline and after addition of 1) oligomycin = 
ATP synthase inhibitor to distinguish ATP 
production and proton leak, 
2) 
carbonyl 
cyanide-4- 
(trifluoromethoxy)phenylhydrazone (FCCP) to 
maximally stimulate respiratory chain and 3) 
antimycin A and rotenone (AA/rot) to inhibit 
respiratory chain. Experiments were performed 
on myoblasts isolated from skeletal muscle (m. 
vastus lateralis] from orthopedic patients (n = 
8). 
Source: main author’s published data [19]. 
Mitochondrial structure and membrane potential measurement. In parallel with OCR and 
ECAR analysis, mitochondrial structure will be determined. These parameters will be 
visualized and quantified in living cells via fluorescent microscopic tools in high resolution 
using Confocal Laser Scanning Microscopy with a 63x oil immersion objective (Leica TCS SP5 
system, Leica Microsystems). Measurement will be based on accumulation of fluorescent 
dye inside mitochondria (MitoTrackerTM Green staining) which enables to determine 
number and length of mitochondrial branches. Simultaneously, a positively charged dye 
tetramethylrhodamine ethyl ester will be used to image active mitochondria with 
excitation/emission maximum 549/575 nm[24]. Intensity of fluorescence will be normalized 
to levels measured after MitoTrackerTM Green staining (see Figure 3). 
Figure 3. Satellite skeletal muscle cells after staining with MitoTrackerTM Green (MTG; left), 
tetramethylrhodamine ethyl ester (TMRE; in the middle) and after staining of both agents (right). 
Positively charged dye TMRE (mitochondrial membrane potential dependent) is accumulated only 
in active mitochondria due to its 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
relative negative charge. Determination of mitochondrial membrane potential is performed after 
normalization to MTG fluorescence (mitochondrial membrane potential independent), which 
covalently binds to mitochondrial proteins by reacting with cysteine residues. 
Acquired date will be analyzed using ImageJ™ (MacBiophotonics). 
Power analysis and statistical plan 
There is no formal primary outcome and hence no formal power analysis can be performed. The so 
far largest trials in the field have both 11 subjects with complete follow up [5,27] and in our trial we 
will have at least twice this number. Comparison of morphological and functional indices between 
the elective hip surgery patients (control cohort) and critically ill patients upon ICU admission will be 
determined using a Welch’s unpaired T-test. Changes of these parameters in time (ie. from ICU 
admission to 6 months following ICU discharge) will be determined using a linear mixed-effects 
model with random intercept. 
Direct access to source data/documents 
All study procedures will be properly recorded in accordance with the rules on medical 
records. The patient documentation shall include eligibility criteria, record of informed 
consent procedure and all relevant information obtained during subsequent visits. The 
documentation must be kept to allow for an additional assessment of possible early and late 
side effects of the method. 
Quality control and quality assurance 
To ensure compliance with Good Clinical Practices and all applicable regulatory 
requirement. 
Ethical Considerations 
The final study protocol, including the final version of the Informed Consent Form, must be 
approved or given a favourable opinion in writing by in the Ethics Committee (EC) as 
appropriate. The Investigator is also responsible for informing the EC of any amendment to 
the protocol in accordance with local requirements. The investigator is also responsible for 
providing the EC with reports of any serious side effect of study procedures. 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
The study will be performed in accordance with the protocol, ethical principles that that 
have their origin in the Declaration of Helsinki WMA, and are consistent with Good Clinical 
Practice: Consolidated Guidelines and any applicable local regulation. 
The Investigator(s) will ensure that subject (or the legal representative) is given full and 
adequate oral written information about the nature, purpose, possible risk and benefit of 
the study. Subject must also be notified that they are free to discontinue from the study any 
time. The subject (or the legal representative) should be given the opportunity to ask 
questions and allowed time to consider the information provided. 
Voluntary written informed consent will be obtained before any study-related procedures 
are performed and the Investigator(s) must maintain the original, signed Informed Consent 
Form. 
Data handling and recordkeeping 
The team of investigators are allowed to inspect subject charts, study source documents, 
drug accountability records and other records relative to study conduct. The Investigator 
must maintain all documentation to the study for a period of 5years after the end of last 
study subject. 
Publication Policy 
We follow the authorship criteria established by the international Committee of medical 
Journal editors. Minimum criteria for authorship credit based on: Substantial contributions 
to conception and design, acquisition of data or analysis and interpretation of data. Drafting 
the article or revising it critically for important intellectual content and final approval of 
version to be published. To be considered, all potential authors must fulfil all the minimum 
criteria for authorship credit. 
IMPACT 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Failed functional outcomes in survivors of critical illness not only lead to individual 
suffering, but also represent a significant burden for the healthcare system and society. 
Results of our project will lead to identifying factors contributing to this debilitating 
condition at the level of satellite cells and thereby enable to adopt treatment strategies in 
ICU and generate hypotheses for trials with patient-centered clinical trials. 
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10. 
Yin H, Price F, Rudnicki M. Satellite cells and the muscle stem cell niche. Physiol Rev. 
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21. 
Krajčová A, Løvsletten NG, Waldauf P, Frič V, Elkalaf M, Urban T, et al. Effects of 
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Urban T, Waldauf P, Krajčová A, Jiroutková K, Halačová M, Džupa V, et al. Kinetic 
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Ziak J, Krajcova A, Jiroutkova K, Nemcova V, Dzupa V, Duska F. Assessing the function 
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SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
INFORMED CONSENT FORM 
for ICU patients or their relatives 
Dear Sir or Madam, 
our faculty hospital is currently involved in the research studying patients admitted to the intensive 
care unit (ICU), who developed a complication called “ICU-acquired muscle weakness”. Given the 
fact, that you (or your relative) fulfilled all the inclusion criteria for recruitment in this project, we would 
like to provide more information about the study. 
What is the purpose of research? 
Modern intensive care can often save patients‘ live who would not been able to survive several 
decades ago. Unfortunately, more than 50 % of these patients, who survive critical illness, develop 
muscle weakness and fatigue. This problem can take more than months or even years and leads in 
significantly decreased quality of life. The mechanism of the ICU-acquired muscle weakness remains 
to be elucidated, but it is well known that muscle loss, changes in muscle metabolism and patients’ 
immobility may play a role. Recent studies are also suggestive of disorders of muscle stem cells (also 
called “satellite cells”) located inside the muscle that, under normal circumstances, have an ability to 
repair injured muscle tissue. Those patients, who survived critical illness, but developed muscle 
weakness, are suggested to have an abnormalities and dysfunction in these satellite cells. In our 
project, we focus on functional and structural changes of these cells and study also their sensitivity to 
the various nutritional and anabolic factors (e.g. insulin). 
How will the research be conducted? 
Income and outcome examinations (until 48 hours after ICU admission and subsequently after 7 days 
after recruitment). First, about 20 mL of blood will be taken from previously inserted venous catheter. 
A diagnostic ultrasound of your quadriceps femoris muscle will be performed. Then, a muscle tissue 
will be taken from your lateral part of quadriceps femoris muscle by a small needle biopsy technique. 
Upon a local anaesthesia (if needed), the muscle specimen will be removed (about 0.2 to 0.3 grams 
of tissue). Subsequently, we will quantify how sensitive you are to insulin (by glucose and insulin 
infusion administration whilst maintaining a normal glucose blood level). The levels of glucose are is 
measured in 5 min intervals from blood drop from inserted catheter. All above mentioned blood 
samples are taken from previously inserted catheter in the patients. In some cases, there is a need to 
insert one more peripheral venous catheter in your forearm. 
Note: At those patients, who needed life-threatening acute surgery, the biopsy could be performed in 
operation room based on the consent from independent medical doctor. As soon as the patient 
becomes consciousness, and then in 7 days intervals or at ICU discharge, muscle strength will be 
assessed by physiotherapeutic. After 6 months, the study participant will be contacted on phone and 
asked for about 10-15 min interview to assess quality of life. 
Are there any risks involved? 
Muscle biopsy is a common technique where the risks (of bleeding or infection) are minimal (˂ 1 %). 
However, patients with an increased risk of bleeding are excluded from the study. During the 
application of local anaesthesia, there is a risk of allergic reaction. At some patients, the small 
leakage of fluid from the subcutaneous tissue can occur at the location of the wound. From a long- 
term perspective, a small scar (several milimeters) can remain at the site of biopsy. 
Additional information: 
Your genetic information (DNA) will not be analysed or archived in any way during the study. 
When you consent this informed consent form, research will be conducted in Petri dish – thus, you will 
not be administered with any special medication/no special procedures in your treatment will be 
performed. 
 
 
 
 

 
SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
Your possible participation in the study is completely voluntary and if you refuse it, it will have 
no effect on your further treatment. You can also cancel your participation in the study at any 
time and without giving reasons. 
The attending physician will give you any additional information and answer any further questions. 
I hereby declare that I have read this informed consent form and all my questions have been 
answered. I further declare that I believe that Mrs./Mr. ………………………………….. would 
agree to participate in the study. 
Date: 
……………….. 
Name: 
………………….. 
Relationship: 
………………. 
Signature: 
…………………... 
The 
discussion 
about 
participation 
in 
the 
study 
was 
guided 
by 
this 
person: 
…………..…………………… 
Continued informed consent of the patient: 
I hereby declare that I have read this informed consent form and all my questions have been 
answered. Based on this: 
☐ I GIVE my consent to participate in the study. 
☐ I DO NOT GIVE my consent to participate in the study. 
....................................... 
…...................................................... 
signature of the patient 
signature of the attending physician 
....................................... 
.….................................................... 
signature of the witness, if the patient gave his consent orally 
date 
Reason why he couldn't sign: 
X muscle weakness 
X other: ................... 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
INFORMED CONSENT FORM 
for orthopaedic patients 
Dear Sir or Madam, 
you have been asked to participate in the research studying patients admitted to the intensive care 
unit (ICU), who developed a complication called “ICU-acquired muscle weakness”. These patients 
often have muscle fatigue and are supposed to have metabolic changes in their muscle. During their 
stay in ICU, they are biopted with a small needle to obtain muscle tissue specimen from quadriceps 
femoris muscle. The metabolism of their muscle is then studied in comparison with those patients, 
who have no muscle abnormalities or diseases. Given that you are planning to undergo elective hip 
replacement surgery, there is the opportunity to obtain the muscle sample from you by a simple, safe 
and easy procedure. Therefore, we would like to ask for your consent to this muscle sample removal. 
What is the purpose of research? 
Modern intensive care can often save patients‘ live who would not been able to survive several 
decades ago. Unfortunately, more than 50 % of these patients, who survive critical illness, develop 
muscle weakness and fatigue. This problem can take more than months or even years and leads in 
significantly decreased quality of life. The mechanism of the ICU-acquired muscle weakness remains 
to be elucidated, but it is well known that muscle loss, changes in muscle metabolism and patients’ 
immobility may play a role. Recent studies are also suggestive of disorders of muscle stem cells (also 
called “satellite cells”) located inside the muscle that, under normal circumstances, have an ability to 
repair injured muscle tissue. Those patients, who survived critical illness, but developed muscle 
weakness, are suggested to have an abnormalities and dysfunction in these satellite cells. In our 
project, we focus on functional and structural changes of these cells and study also their sensitivity to 
SATELLITE Study Protocol, ver. 1.0, 27th November 2022 
the various nutritional and anabolic factors (e.g. insulin). 
How will the research be conducted? 
Satellite cells can be obtained from a tissue sample which is taken by muscle biopsy. A particle (5x5 
mm size) is taken from the lateral part of the quadriceps muscle under general anaesthesia. Muscle 
biopsy is performed during surgery. The surgeon reveals the hip joint during surgery so that the 
muscle is exposed and it is therefore easy to remove a small particle from it with a special needle. 
The technique of the surgery does not change at all. The process of muscle biopsy will take up to 1 
min. After the biopsy, there will be no differences in the next steps and routine procedures. 
Subsequently, the tissue sample will be transferred to the university lab, where the satellite cells will 
be isolated and cultured in the growth medium supplemented with nutrients. The research will take 
place in Petri dish, perform structural and functional measurements and then the cells will be 
destroyed. At the same time, we will take your blood sample of about 20 mL (to analyse e.g. insulin 
levels, growth factors). We will also quantify how sensitive you are to insulin (by glucose and insulin 
infusion administration whilst maintaining a normal glucose blood level). In addition, diagnostic 
ultrasound of your quadriceps femoris muscle will be performed. 
Are there any risks involved? 
Muscle biopsy is a common technique where the risks are minimal. Theoretically – as with any 
surgical wound – there is a risk of bleeding and infection. However, patients with an increased risk of 
bleeding are excluded from the study. 
Additional information: 
Your genetic information (DNA) will not be analysed or archived in any way during the study. 
 
 
 
 

SATELLITE Study Protocol, ver. 1.0, 20th December 2022 
When you consent this informed consent form, research will be conducted in Petri dish – thus, you will 
not be administered with any special medication/no special procedures in your treatment will be 
performed. 
Your possible participation in the study is completely voluntary and if you refuse it, it will have 
no effect on your further treatment. You can also cancel your participation in the study at any 
time and without giving reasons. 
The attending physician will give you any additional information and answer any further questions. 
I hereby declare that I have read this informed consent form and all my questions have been 
answered. Based on this, I GIVE my consent to participate in the study. 
....................................... 
…...................................................... 
signature of the patient 
signature of the attending physician 
....................................... 
.….................................................... 
signature of the witness, if the patient gave his consent orally 
date 
Reason why he couldn't sign: 
X muscle weakness 
X other: ...................