Respiratory failure occurs when the lung fails to perform one or both of its roles in gas exchange; oxygenation and/or ventilation. Presentations of respiratory failure can be mild requiring supplemental oxygen via nasal cannula to more severe requiring invasive mechanical ventilation as see in acute respiratory distress syndrome (ARDS).It is important to provide supportive care through noninvasive respiratory support devices but also to minimize risk associated with those supportive devices such as ventilator induced lung injury (VILI) and/or patient self-inflicted lung injury (P-SILI). Central to risk minimization is decreasing mechanical stress and strain and optimizing transpulmonary pressure or the distending pressure across the lung, minimizing overdistention and collapse. Patient positioning impacts ventilation/perfusion and transpulmonary pressure. Electrical impedance tomography (EIT) is an emerging technology that offers a noninvasive, real-time, radiation free method to assess distribution of ventilation at the bedside. The investigators plan to obtain observational data regarding distribution of ventilation during routine standard of care in the ICU, with special emphasis on postural changes and effects of neuromuscular blockade, to provide insight into ventilation/perfusion matching, lung mechanics in respiratory failure, other pulmonary pathological processes.

Inclusion Criteria:

• 18 years or older
• admitted to UC San Diego La Jolla or Hillcrest Campus Intensive Care Units
• Patient requiring supplemental oxygen (including but no limited to nasal cannula, high flow devices, noninvasive positive pressure ventilation or mechanical ventilation

Exclusion Criteria:

• <18 years
• Chest wall, anatomical, physical abnormalities, skin integrity issues precluding placement of electrode belt in direct contact with skin
• Patient is too unstable to position the belt/electrodes or tolerate head of bed changes
• Confirmed or suspected intracranial bleed, stroke, edema
• Active implants (i.e. implantable electronic devices such as pacemakers, cardioverter defibrillators, neurostimulators) or if device compatibility is in doubt
• Pregnant or lactating patients as safety and efficacy for use of EIT in such cases has not been verified

Human subjects admitted to the UC San Diego La Jolla Campus and Hillcrest Campus Intensive Care Units who are admitted with a pathologic condition requiring supplemental oxygen (including but not limited to nasal cannula, high flow devices), noninvasive positive pressure ventilation, mechanical ventilation.

Reasonable requests for IPD will be considered by the investigators