Clinical meaning
The ATLS framework integrates the primary survey with simultaneous resuscitation and a comprehensive secondary survey for definitive injury identification. The primary survey focuses on 6 immediate life-threatening conditions requiring recognition and treatment within minutes: airway obstruction, tension pneumothorax, open pneumothorax, massive hemothorax (>1500 mL initial output or >200 mL/hr for 2-4 hours requiring thoracotomy), flail chest with pulmonary contusion, and cardiac tamponade. The secondary survey is a systematic head-to-toe examination performed after primary survey completion and hemodynamic stabilization. It includes: scalp/cranium examination (lacerations, depressions, CSF leak), face (midface stability, Le Fort fractures, dental occlusion), cervical spine (tenderness, step-off deformity), chest (auscultation, palpation for subcutaneous emphysema and crepitus), abdomen (distension, peritoneal signs, evisceration), pelvis (stability — assessed once only), perineum (urethral meatus blood, rectal tone, vaginal examination in females), extremities (deformity, vascular status, compartment syndrome), and complete neurological examination (GCS, cranial nerves, motor/sensory, reflexes). Log roll examination of the posterior thoracolumbar spine is essential — spinal column injuries are missed when posterior examination is omitted. Tertiary survey is performed within 24 hours and includes repeat physical examination and review of all imaging — it captures injuries missed during the acute resuscitation phase (missed injury rate in trauma is 1-39%).