Pv-aCO₂ Gap-Guided Resuscitation in Adult Polytrauma Patients: A Prospective Randomized Controlled Trial

All polytrauma patients admitted to the ICU from the operating theater, emergency department, or hospital wards who fulfill the inclusion criteria will be enrolled in the study after obtaining written informed consent from the patients or their legal representatives. Participants will be randomized in a 1:1 ratio using a computer-generated method into two groups: an intervention group managed with a Pv-aCO₂ gap-targeted approach and a control group managed according to standard resuscitation end-points. As part of routine hemodynamic monitoring in critical care, a central venous catheter (two- or three-lumen catheter-Arrow) and an arterial catheter (Arterial Leader Cath-Vygon or Teleflex) will be inserted in all participants before or immediately after ICU admission. After insertion, the position of the central venous catheter tip at the junction of the superior vena cava and right atrium will be confirmed by chest X-ray. Arterial and venous blood samples for blood gas analysis (ABGA and VBGA) will be obtained in the ICU using a point-of-care gas analyzer (ABL800 FLEX®, Radiometer) within 1 hour of ICU admission and subsequently at 6, 12, 24, 48, and 72 hours. The time interval between arterial and venous blood sampling will be kept under 5 minutes to minimize bias, and the measurements obtained at different time points will be compared with standard resuscitation end-points.