End-tidal carbon dioxide monitoring to predict hypovolaemic shock and the subsequent need for blood transfusions in adult pre-hospital trauma patients: a systematic review

A universal definition for major blood transfusion is still lacking. Further research is needed to identify accurate markers of haemorrhage, including EtCO₂ as a potential predictor. A high index of suspicion for haemorrhage and need for blood transfusion is recommended for adult trauma patients with EtCO₂ levels below 35 mmHg (4.7 kPa).