Background: Point of care testing (POCT) in trauma resuscitation, particularly viscoelastic haemostatic assays and prehospital lactate, can accelerate recognition of coagulopathy and shock and may enable earlier, targeted interventions. We aimed to analyze original articles on emergency department (ED) and prehospital POCT guided trauma resuscitation regarding time to intervention, resource utilization, and patient outcomes. Methods: A PRISMA aligned systematic review of full text original studies evaluating POCT guided trauma resuscitation in ED and prehospital settings. Included studies reported at least one of: time to intervention, transfusion use, or clinical outcomes. Risk of bias was assessed using design appropriate tools. Results: Ten original studies (2 randomized trials; 8 observational cohorts) were included. In an ED pragmatic randomized trial, TEG guided massive transfusion protocol (MTP) management improved survival and reduced early plasma exposure compared with conventional assays. In the multicenter iTACTIC trial, adding VHA to empiric major hemorrhage protocols did not change the primary composite outcome or 28 day mortality overall, but VHA facilitated earlier targeted interventions. Observational ED and prehospital studies generally showed feasibility and potential improvements in transfusion targeting and decision making, triage, but outcome effects were inconsistent and limited by heterogeneity and confounding. Prehospital lactate predicted resuscitative care and supported decision tools for transfusion escalation. Conclusion: ED and prehospital POCT can shorten time to targeted hemostatic interventions and support more selective resource use. However, clinical outcome benefit is inconsistent in settings and protocols. Future trials should focus on protocol fidelity, standardized outcomes (time to hemostatic treatment, avoidable transfusion, and patient centered endpoints), and integrated aprehospital to ED pathways.