Acute Effects of Sitting Out of Bed and Exercise on Lung Aeration and Oxygenation in Critically Ill Subjects.

BACKGROUND: Early mobilization during critical illness is safe and has beneficial effects on functional outcomes. However, its impact on pulmonary function has not been thoroughly explored. We hypothesized that a sitting position out of bed coupled with exercise could result in an improvement in oxygenation and lung aeration. METHODS: The study was conducted on a cohort of adult subjects within a week of their admission to an ICU. Subjects were transferred to a chair and undertook a 15-min session of exercise, either active or passive. Subjects in the control group were only transferred to a chair. Electrical impedance tomography, a reliable bedside technique monitoring regional lung aeration and the distribution of ventilation, was continuously performed, and blood gases were assessed at baseline and 20 min post-exercise. RESULTS: The cohort included 40 subjects, 17 of whom were mechanically ventilated and 23 spontaneously breathing. The control group for each modality consisted of 5 mechanically ventilated or 5 spontaneously breathing subjects. Mild hypoxemia was present in 45% of the spontaneously breathing cohort, whereas the mechanically ventilated subjects demonstrated moderate (50%) or severe (12%) hypoxemia. Compared with the control group, early mobilization induced a significant increase in lung aeration. In mechanically ventilated subjects, lung aeration increased, especially in the anterior lung regions (mean impedance [95% CI]: T1 (baseline in bed) = 1,265 [691-1,839]; T2 (chair sitting) = 2,003 [1,042-2,963]; T3 (exercise) = 1,619 [810 2,427]; T4 (post exercise in chair) = 2,320 [1,186-3,455]). In spontaneously breathing subjects, lung aeration increased mainly in the posterior lung regions (mean impedance [95% CI]: T1 = 380 [124-637]; T2 = 655 [226-1,084]; T3 = 621 [335-906]; T4 = 600 [340-860]). [Formula: see text] increased, especially in subjects with lower [Formula: see text] at baseline (< 200) (133 ± 31 to 158 ± 48, P = .041). CONCLUSIONS: For critically ill subjects, a sitting position and exercise increased lung aeration and were associated with an improvement in [Formula: see text] in the more severely hypoxemic subjects.

Impact of Very Early Physical Therapy During Septic Shock on Skeletal Muscle: A Randomized Controlled Trial.

OBJECTIVES: As the catabolic state induced by septic shock together with the physical inactivity of patients lead to the rapid loss of muscle mass and impaired function, the purpose of this study was to test whether an early physical therapy during the onset of septic shock regulates catabolic signals and preserves skeletal muscle mass. DESIGN: Randomized controlled trial. SETTING: Tertiary mixed ICU. PATIENTS: Adult patients admitted for septic shock within the first 72 hours. INTERVENTIONS: Patients were assigned randomly into two groups. The control group benefited from manual mobilization once a day. The intervention group had twice daily sessions of both manual mobilization and 30-minute passive/active cycling therapy. MEASUREMENTS AND MAIN RESULTS: Skeletal muscle biopsies and electrophysiology testing were performed at day 1 and day 7. Muscle biopsies were analyzed for histology and molecular components of signaling pathways regulating protein synthesis and degradation as well as inflammation markers. Hemodynamic values and patient perception were collected during each session. Twenty-one patients were included. Three died before the second muscle biopsy. Ten patients in the control and eight in the intervention group were analyzed. Markers of the catabolic ubiquitin-proteasome pathway, muscle atrophy F-box and muscle ring finger-1 messenger RNA, were reduced at day 7 only in the intervention group, but without difference between groups (muscle atrophy F-box: -7.3% ± 138.4% in control vs -56.4% ± 37.4% in intervention group; p = 0.23 and muscle ring finger-1: -30.8% ± 66.9% in control vs -62.7% ± 45.5% in intervention group; p = 0.15). Muscle fiber cross-sectional area (µm) was preserved by exercise (-25.8% ± 21.6% in control vs 12.4% ± 22.5% in intervention group; p = 0.005). Molecular regulations suggest that the excessive activation of autophagy due to septic shock was lower in the intervention group, without being suppressed. Markers of anabolism and inflammation were not modified by the intervention, which was well tolerated by the patients. CONCLUSIONS: Early physical therapy during the first week of septic shock is safe and preserves muscle fiber cross-sectional area.

Energy expenditure in the critically ill performing early physical therapy.

PURPOSE: Resting energy expenditure (REE) determination is of high relevance to avoid both overfeeding and underfeeding. We conducted an observational study to determine the impact of early exercise on energy requirements to adjust caloric intake accordingly in critically ill patients. METHODS: This was a prospective observational study conducted in an intensive care unit in 49 hemodynamically stable critically ill patients and 15 healthy volunteers. Indirect calorimetry (IC) was performed for 15 min at baseline during resting conditions, and then continuously recorded during 30 min of cycling at 0, 3, or 6 watts (W), followed by a 15-min resting period. REE determined by IC was compared with predictive formulas and correlated with several biomarkers. The energy cost of early exercise was compared between critically ill patients and healthy volunteers. RESULTS: In patients, REE determined by IC was higher than predicted by Harris-Benedict (29 ± 31 %, p < 0.001) and Fleisch equations (23 ± 31 %, p < 0.001) but lower than predicted by the Faisy-Fagon equation for ventilated patients (16 ± 19 %, p < 0.05). Differences between Harris-Benedict predictions and IC determination were positively correlated with C-reactive protein (CRP) in patients with sepsis (r = 0.51, p = 0.003). During a similar exercise, VO2 increase in patients was higher when compared with healthy volunteers at 3 W, close to significant at 6 W, and not present in the passive group. CONCLUSIONS: The critically ill have increased REE according to inflammation defined by CRP. Increased energy requirement for physical activity was only present for active exercise and seems to differ from that in the healthy population. For the exercise duration and intensity tested, nutritional adjustment is not indicated.