Body Positioning and Pulmonary Aeration During Mechanical Ventilation

Study Overview
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Brief Summary
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The present randomized crossover clinical trial aims to evaluate the influence of different body postures on pulmonary aeration among mechanically ventilated critically ill patients. Patients admitted to the intensive care unit receiving invasive mechanical ventilation >24 hours, and without contraindications to mobilization, will be randomly assigned to one of two sequences of interventions at a single day: arm 1: bedside sitting posture followed by orthostatic board at 45º and 60º; arm 2: orthostatic board at 45º, 60º and 80º followed by bedside sitting posture. Each postural protocol (bedside sitting posture protocol or orthostatic board posture protocol) will last 30 minutes. A washout window period between 1,5h and 2,5h will be applied between the two postural interventions. The primary outcome is the lung aeration assessed using the Lung Ultrasound Score (LUS) performed by trained evaluators at the end of postural protocol. Secondary outcomes include ventilatory mechanics (static compliance, airway resistance and respiratory work), PaO2/FiO2 ratio, Level of consciousness according to the Richmond Agitation-Sedation Scale (RASS), and adverse events (hypertension, hypotension, tachicardia, bradycardia, tachypnea, bradypnea, decreased level of consciousness, patient distress, fall to knees, invasive device traction or loss, filter hemodialysis clotting or disruption).

Official Title
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Influence of Body Positioning on Pulmonary Aeration Among Mechanically Ventilated Critical Ill Patients

Conditions
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Critical Illness

Intervention / Treatment
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* Device: Orthostatic board posture
* Other: Bedside sitting posture


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older; Invasive Mechanical Ventilation > 24 hours; no weaning expectation on screening day for study eligibility; Signature of Informed Consent. Exclusion Criteria: Patients using vasoative drugs (noradrenaline > 0.2mcg/kg/min or sodium nitroprosside > 1mcg/kg/min); Increase > 50% in noradrenaline dose in the last 2 hours; since exceeds 0,1 mcg / kg / min in that period; Inclusion of norepinephrine in the last 2 hours, with the dose > 0.1mcg/kg/min; Heart rate less than 40 beats per min or more than 130 beats per min Active myocardial ischaemia; Systolic blood pressure more than 200 mmHg, Mean arterial blood pressure less than 65 mm Hg or more than 110 mm Hg; Arrhythmia Intra-aortic balloon RASS <-4 ou > +1; Intracranial hypertension; Patient agitation External ventricular drain; Neurologic and/or orthopedic conditions that prevented orthostatism spinal cord injury) or Spinal cord injury and/or risk od instabilitity Acute stroke; orthopedic fractures in the lower limf Inability to walk with- out assistance before acute ICU illness (use of a cane or walkers its not exclusions; MRC > 3 MMII; Major pressure ulcers in the calcaneal region; FiO2 > 60% Positive end-epiratory pressure > 10cmH2O; Pulse oximetry less than 88% Respiratory rate less than 5 breaths per min or more than 40 breaths per min Neuromuscular blocking; Reserved Prognosis; Peritoneostomy; Temperature> 38.5 °C; Active gastrointestinal blood loss Intra-abdominal Hypertension; Thrombocytopenia (platelet count <50 000); Diarrhea; Hyperglycemia, with HGT < 70mg/g Intermittent haemodialysis Large abdominal surgery Continuous Epidural infusion

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: at a single day: arm 1: bedside sitting posture followed by orthostatic board at 45º and 60º; arm 2: orthostatic board at 45º, 60º, and 80º followed by bedside sitting posture.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Bedside Sitting followed by Orthostatic Board<br>Bedside sitting posture protocol followed by orthostatic board posture protocol. | Device: Orthostatic board posture<br>* Patients will be verticalized at at 45º, 60º and 80º using an orthostatic board. The total posture protocol will last 30 minutes<br>Other: Bedside sitting posture<br>* Patients will be placed at the bedside, with support for the back and upper limbs. They will be kept at 90º of hip and knee flexion and feet supported. The total posture protocol will last 30 minutes.<br>|
| Other: Orthostatic Board followed by Bedside Sitting<br>Orthostatic board posture protocol followed by bedside sitting posture protocol. | Device: Orthostatic board posture<br>* Patients will be verticalized at at 45º, 60º and 80º using an orthostatic board. The total posture protocol will last 30 minutes<br>Other: Bedside sitting posture<br>* Patients will be placed at the bedside, with support for the back and upper limbs. They will be kept at 90º of hip and knee flexion and feet supported. The total posture protocol will last 30 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung Aeration Scores Post Intervention (Verticalization) | Evaluation of lung aeration using the Lung Ultrassound Score. The division landmark it is the anterior and posterior axillary lines, with each region being divided into upper and lower. Thus, six representative zones of each lung are assessed. Normal aeration is represented by the presence of pleural sliding and horizontal A lines, or by at least three vertical B lines, a 0 score is assigned. When a moderate loss of aeration takes place, characterized by multiple B lines, either regularly or irregularly spaced, originating from the pleural line, a score of 1 is assigned. When coalescent B lines are present in several intercostal spaces occupying the whole intercostal space, a score of 2 is assigned to the region. If there is a total loss of lung aeration, as observed in lung consolidation, a score of 3 is assigned. The total LUS score is achieved by summing the 12 regions examined, with its scores ranging from 0 to 36, and the higher the score, the worse lung aeration. | Single day assessment post intervention of the sitting posture (protocol lasts 30 minutes) and post intervention of the standing board (protocol lasts 30 minutes) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tidal Volume | Variations in tidal volume according to body position. Tidal volume expresses the value (in ml) that enters and leaves the lungs at each respiratory cycle. Variations extracted directly from the mechanical ventilation monitor. Outcome has no range, neither higher or lower values are considered to be a better or worse outcome | Single day assessment at the end of sitting posture protocol (the protocol lasts 30 minutes) and at the end of orthostatic board protocol (the protocol lasts 30 minutes). | 
| Minute Volume | Variations in minute volume according to body position. Minute volume expresses the value (in L/min) that enters and leaves the lungs during one minute. Variations extracted directly from the mechanical ventilation monitor. Outcome has no range, neither higher or lower values are considered to be a better or worse outcome | Single day assessment at the end of sitting posture protocol (the protocol lasts 30 minutes) and at the end of orthostatic board protocol (the protocol lasts 30 minutes) | 
| Number of Professionals for Verticalization | The absolute number of professionals required to perform each the chest verticalization protocols was counted. Outcome has no range, neither higher or lower values are considered to be a better or worse outcome | Single day assessment at the end of sitting posture protocol (the protocol lasts 30 minutes) and at the end of orthostatic board protocol (the protocol lasts 30 minutes) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Critical Care, Sitting Position, Tilt Table, Ultrasonography