Could lying Head-Down save lives? small trial tests simple fix for low blood pressure in ICU

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age \>18 years * Admitted to the intensive care unit (ICU); * Invasive mechanical ventilation; * Pharmacological sedation; * Mean arterial pressure (MAP)\<65 mmHg or need of fluids infusion or any vasopressor in order to keep MAP \> 65 mmHg * Ongoing invasive and/or non-invasive arterial blood pressure monitoring * Central venous line with central venous pressure (CVP) monitoring * Naso-gastric tube in situ * Indwelling bladder catheter * Consent according to local ethical committee rules Exclusion Criteria: * Body mass index \> 45 * Documented or suspected increased intracranial pressure, based on medical history or actual clinical condition (es. intracranial tumor, cerebral hemorrhage, encephalitis,...); * Intra-abdominal hypertension \>25 mmHg * Documented or suspected increased intraocular pressure (any degree of glaucoma) * Full stomach pyloric incontinence; * Gastric stasis, defined as aspiration from the NG (nasogastric) tube of fecal, bloody, or green fluid greater than 100 mL upon insertion of the tube or within the preceding hour; * Ongoing enteral nutrition * No central line inserted or femoral central line only * Not sutured known diaphragm lesions * Known hiatus hernia * Aortic bifurcation and/or lower extremity arterial stenosis ≥70% combined with stage 3 intermittent claudication (pain at rest) * Patients who are not able to be investigated with a leg raising test (eg lower extremities fractures, backbone fractures or backbone pain or deformity, and those patients with large cannulas in the femoral vessels) * Demand of specific postures (eg Trauma, fractures, backbone pain or deformity, patients with large cannulas in the femoral vessels, pronation including first pronation planned within 6 h…) * Any device which, according to the clinician, makes it unfeasible or unsafe to put patients in the Trendelenburg position (eg Drainage in thoracic cavity) * Mechanical Circulatory Support; * (CHD) (Gleen, Fontaine); * Advanced right ventricular dysfunction or advanced cardiac failure, in which volume overload worsens cardiac function (plateau stage in the Frank-Starling curve); * Actual upper gastrointestinal bleeding * Passive leg raising test non-responder