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Angelopoulos E, Karatzanos E, Dimopoulos S, Mitsiou G, Stefanou C, Patsaki I, Kotanidou A, Routsi C, Petrikkos G, Nanas S. Acute microcirculatory effects of medium frequency versus high frequency neuromuscular electrical stimulation in critically ill patients - a pilot study. Ann Intensive Care 2013; 3:39. [PMID: 24355422 PMCID: PMC3878255 DOI: 10.1186/2110-5820-3-39] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 12/09/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Intensive care unit-acquired weakness (ICUAW) is a common complication, associated with significant morbidity. Neuromuscular electrical stimulation (NMES) has shown promise for prevention. NMES acutely affects skeletal muscle microcirculation; such effects could mediate the favorable outcomes. However, optimal current characteristics have not been defined. This study aimed to compare the effects on muscle microcirculation of a single NMES session using medium and high frequency currents. METHODS ICU patients with systemic inflammatory response syndrome (SIRS) or sepsis of three to five days duration and patients with ICUAW were studied. A single 30-minute NMES session was applied to the lower limbs bilaterally using current of increasing intensity. Patients were randomly assigned to either the HF (75 Hz, pulse 400 μs, cycle 5 seconds on - 21 seconds off) or the MF (45 Hz, pulse 400 μs, cycle 5 seconds on - 12 seconds off) protocol. Peripheral microcirculation was monitored at the thenar eminence using near-infrared spectroscopy (NIRS) to obtain tissue O2 saturation (StO2); a vascular occlusion test was applied before and after the session. Local microcirculation of the vastus lateralis was also monitored using NIRS. RESULTS Thirty-one patients were randomized. In the HF protocol (17 patients), peripheral microcirculatory parameters were: thenar O2 consumption rate (%/minute) from 8.6 ± 2.2 to 9.9 ± 5.1 (P = 0.08), endothelial reactivity (%/second) from 2.7 ± 1.4 to 3.2 ± 1.9 (P = 0.04), vascular reserve (seconds) from 160 ± 55 to 145 ± 49 (P = 0.03). In the MF protocol: thenar O2 consumption rate (%/minute) from 8.8 ± 3.8 to 9.9 ± 3.6 (P = 0.07), endothelial reactivity (%/second) from 2.5 ± 1.4 to 3.1 ± 1.7 (P = 0.03), vascular reserve (seconds) from 163 ± 37 to 144 ± 33 (P = 0.001). Both protocols showed a similar effect. In the vastus lateralis, average muscle O2 consumption rate was 61 ± 9%/minute during the HF protocol versus 69 ± 23%/minute during the MF protocol (P = 0.5). The minimum amplitude in StO2 was 5 ± 4 units with the HF protocol versus 7 ± 4 units with the MF protocol (P = 0.3). Post-exercise, StO2 increased by 6 ± 7 units with the HF protocol versus 5 ± 4 units with the MF protocol (P = 0.6). These changes correlated well with contraction strength. CONCLUSIONS A single NMES session affected local and systemic skeletal muscle microcirculation. Medium and high frequency currents were equally effective.
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Affiliation(s)
- Epameinondas Angelopoulos
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - Eleftherios Karatzanos
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - Stavros Dimopoulos
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - Georgios Mitsiou
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - Christos Stefanou
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - Irini Patsaki
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - Anastasia Kotanidou
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - Christina Routsi
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
| | - George Petrikkos
- Fourth Department of Internal Medicine, National and Kapodistrian University of Athens School of Medicine, Attikon University General Hospital, Rimini 1, Athens 124 62, Greece
| | - Serafeim Nanas
- First Critical Care Department, National and Kapodistrian University of Athens School of Medicine, Evangelismos General Hospital, Ypsilantou 45-47, Athens 106 75, Greece
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