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

Abstract

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) 5 1,265 [691-1,839]; T2 (chair sitting) 5 2,003 [1,042-2,963]; T3 (exercise) 5 1,619 [810 2,427]; T4 (post exercise in chair) 5 2,320 [1,455]). In spontaneously breathing subjects, lung aeration increased mainly in the posterior lung regions (mean impedance [95% CI]: T1 5 380 [124-637]; T2 5 655 [226-1,084]; T3 5 621 [335-906]; T4 5 600 ).

The Effect of Physical Therapy on Regional Lung Function in Critically Ill Patients

“…As the resilience of mechanically ventilated patients is usually lower, early mobilization for these patients consists of lighter and shorter exercises and is therefore not necessarily comparable to the training we chose for our study. Hickmann et al (2021) showed that an upright position and early mobilization improved ventilation distribution and gas exchange especially in severely hypoxemic subjects, some of whom were also mechanically ventilated. Thus, it remains unclear whether the effects we observed in our study might have been different in patients with severely impaired gas exchange.…”

“… Schujmann et al (2020) showed that patients who participated in an ICU mobility program, whose protocol included mobilization to standing position, had a better functional outcome at discharge than the control group. Hickmann et al (2021) showed that sitting in combination with active exercise resulted in better lung aeration. The question arises whether mobilization into standing brings a significant additional gain during physiotherapy than just sitting.…”

Mobilização precoce a prática do fisioterapeuta intensivista: intervenções e barreiras

“…16,20 Nossos resultados revelam que a sedestação (91,2%) foi a intervenção para MP mais citada pelos participantes. Segundo Hickmann et al 21 , quando acompanhada de exercícios ativos, otimiza a aeração pulmonar e minimiza a hipoxemia.…”

Improving mobility in the intensive care unit with a protocolized, early mobilization program: observations of a single center before-and-after the implementation of a multidisciplinary program

“…Importantly, sitting out of bed itself is the major achievement offered by such a program. This posture is associated with improved oxygenation and respiratory mechanics [22,23]. Further, this posture requires substantial truncal tone and early mobilization cohort (mean, 1.2; SD, 1.5); and upon discharge in control group (mean, 1.8; SD, 1.8) and early mobilization group (mean, 4.9; SD, 2.9).…”