Physicians providing medical oversight of EMS clinicians and those providing direct patient care in the prehospital environment must possess a significant level of expertise in the use of noninvasive and invasive procedures for the prehospital stabilization of trauma patients. Procedures discussed in this chapter include needle thoracostomy, tube thoracostomy, pericardiocentesis, and spinal motion restriction. The nature of the care and the procedures that are appropriate for different levels of clinicians is based on the education, training, and legal scope of practice of the clinicians in the EMS system. An EMS physician or medical director must be skilled in these procedures and maintain active educational programs and continuous quality improvement activities to ensure these procedures are being performed correctly and under the correct circumstances.