title: Neuromuscular electrical stimulation acutely mobilizes endothelial progenitor cells in critically ill patients with sepsis.
abstract: BACKGROUND
  Endothelial progenitor cells (EPCs) have been suggested to constitute a restoration index of the disturbed endothelium in ICU patients. Neuromuscular electric stimulation (NMES) is increasingly employed in ICU to prevent comorbidities such as ICU-acquired weakness, which is related to endothelial dysfunction. The role of NMES to mobilize EPCs has not been investigated yet. The purpose of this study was to explore the NMES-induced effects on mobilization of EPCs in septic ICU patients.
  
  
  METHODS
  Thirty-two septic mechanically ventilated patients (mean ± SD, age 58 ± 14 years) were randomized to one of the two 30-min NMES protocols of different characteristics: a high-frequency (75 Hz, 6 s on-21 s off) or a medium-frequency (45 Hz, 5 s on-12 s off) protocol both applied at maximally tolerated intensity. Blood was sampled before and immediately after the NMES sessions. Different EPCs subpopulations were quantified by cytometry markers CD34(+)/CD133(+)/CD45(-), CD34(+)/CD133(+)/CD45(-)/VEGFR2 (+) and CD34(+)/CD45(-)/VEGFR2 (+).
  
  
  RESULTS
  Overall, CD34(+)/CD133(+)/CD45(-) EPCs increased from 13.5 ± 10.2 to 20.8 ± 16.9 and CD34(+)/CD133(+)/CD45(-)/VEGFR2 (+) EPCs from 3.8 ± 5.2 to 6.4 ± 8.5 cells/10(6) enucleated cells (mean ± SD, p < 0.05). CD34(+)/CD45(-)/VEGFR2 (+) EPCs also increased from 16.5 ± 14.5 to 23.8 ± 19.2 cells/10(6) enucleated cells (mean ± SD, p < 0.05). EPCs mobilization was not affected by NMES protocol and sepsis severity (p > 0.05), while it was related to corticosteroids administration (p < 0.05).
  
  
  CONCLUSIONS
  NMES acutely mobilized endothelial progenitor cells, measures of the endothelial restoration potential, in septic ICU patients.
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Stefanou
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece.
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Karatzanos
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Mitsiou
authors.affiliation: Immunology and Histocompatibility Department, Evangelismos General Hospital, 45-47 Ypsilantou Str, 106 75, Athens, Greece.
authors.forename: Katerina
authors.initials: K
authors.lastname: Psarra
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece.
authors.forename: Epameinondas
authors.initials: E
authors.lastname: Angelopoulos
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece.|Critical Care Unit, Guys and St Thomas Hospital, Westminster Bridge Road, London, SE1 7EH, UK.
authors.forename: Stavros
authors.initials: S
authors.lastname: Dimopoulos
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Gerovasili
authors.affiliation: 2nd Neurosurgical Department, Attiko University General Hospital, School of Medicine, National and Kapodistrian University of Athens, 1 Rimini Str, 124 62, Athens, Greece.
authors.forename: Efstathios
authors.initials: E
authors.lastname: Boviatsis
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece.
authors.forename: Christina
authors.initials: C
authors.lastname: Routsi
authors.affiliation: 1st Critical Care Department, Evangelismos General Hospital, School of Medicine, National and Kapodistrian University of Athens, 45-47 Ypsilantou Str., 106 75, Athens, Greece. a.icusn@gmail.com.
authors.forename: Serafeim
authors.initials: S
authors.lastname: Nanas
keywords: Acute effect; Critical illness; EPC; Early rehabilitation; Electrical muscle stimulation; NMES