Effects of standing at different angles on transpulmonary pressure

Objective: To study the effect of different standing angles on cross-lung pressure.Background: Long-term bed rest in ICU patients leads to upward movement of diaphragm and increased intrathoracic pressure in mechanically ventilated patients, resulting in lower cross-lung pressure. If the end-expiratory cross-lung pressure is negative, lung tissue compression and atelectasis will occur.Standing can lower the diaphragm, improve the pressure across the lungs, and improve ventilation.Selection methods: patients with invasive mechanical ventilation in the ICU, on the premise of stable hemodynamics, with the aid of electric bed training in standing in different angles, start from 20 degrees, 5 degrees up every five minutes, the largest up to 80 degrees, each Angle across the pulmonary pressure, die cavity ratio, tidal volume and breathe out carbon dioxide at the end of the record, and record whether low blood pressure, an accident in the process of take off the tube and other adverse reactions.

Inclusion Criteria:

• The age is ≥ 18 years old;
• the hemodynamics is stable;
• 50 < heart rate < 120 beats / min ;
• 90 < systolic blood pressure < 200mmHg ;
• 55 < mean arterial pressure < 120mmHg;
• do not increase the dose of pressor drugs for at least 2 hours;
• intracranial pressure is stable and there are no seizures within 24 hours;
• the respiratory state is stable;
• the patient's finger pulse oxygen saturation ≥ 88%;
• 10 < respiratory frequency < 35 beats / min.

Exclusion Criteria:

• Pregnancy;
• acute cardio-cerebrovascular events;
• spinal or limb fractures;
• active bleeding.