Hypervolemia

CAPITAL OFFLOAD-SHOCK will aim to answer if early use of renal replacement therapy, like dialysis, in patients with reduced body fluids causing the heart to be unable to pump enough blood through the body reduces in-hospital death when compared to the current standard of care. The current standard of care is to wait until renal replacement therapy is clinically necessary.

The goal of this observational study is to learn about renal and hepatic blood flow abnormalities detected by bedside ultrasound in adult patients admitted to the intensive care unit (ICU) following major trauma. The main questions it aims to answer are: * How reliably can trained operators measure renal Doppler and venous congestion scores (RDRI and VExUS) across different hospitals? * How common are abnormal kidney and liver blood flow patterns in major trauma patients during the first 72 hours of ICU admission? * Are these abnormal patterns associated with acute kidney injury or the need for mechanical ventilation? Participants admitted to ICUs or high-dependency units (HDUs) with major trauma (Injury Severity Score \>15) will undergo non-invasive bedside ultrasound assessments at admission and at 24, 48, and 72 hours. No additional treatments or interventions will be given as part of this study. Kidney function will also be checked at 6 months after hospital discharge.

This purpose of this study is to determine the effectiveness of a mobile phone application in helping to control body swelling in patients with kidney problems. The application will help in the day to day adjustments in diuretic medication dosing. Participants in this study will have an application loaded on to their mobile phone by the study team and be taught how to use it over a 2 hour visit. Participants will need to check their blood pressure and weight daily and enter this information into the mobile phone application every day. Participants will need to follow daily instructions in their medication dosing provided by the application. There will be periodic blood testing. This will happen at 2 weeks, 90 days, and up to 4 other times if necessary. At the end of the study there is a 2 hour study visit during which participants will answer a survey. The total length of the study is 90 days.