Two large bore IVs should be initiated. If they cannot be inserted and the patient is in profound hypovolemic shock, then one should move onto a different form of access and consider an intraosseous line, central venous access, or a venous cutdown. Options for venous access and considerations for choice will be elaborated on in Chap. 17. Crystalloid infusion should be initiated, but the primary goal is to find and stop the bleeding or correct the underlying cause of shock. In blunt trauma with head injury, hypotension worsens outcomes and should be avoided. In penetrating trauma with ongoing hemorrhage, aggressive resuscitation prior to surgical control of bleeding may exacerbate hemorrhage and coagulopathy and worsen outcomes. Newer strategies, termed damage control resuscitation, will be considered in Chaps. 14 and 15.

If the patient is in shock and hemorrhage is suspected, then the institution massive transfusion protocol should be activated. These protocols have streamlined resuscitation and help avoid coagulopathy through early introduction of packed red blood cells, plasma, and platelets. This will be discussed further in Chap. 14. Tranexamic acid is also now an accepted adjunct. It is an antifibrinolytic which is cheap, safe, and potentially effective. Review your institution’s massive transfusion protocol.

Always remember that hypotension is a late sign of shock and in the case of hemorrhage typically does not occur until the loss of one third of the blood volume or more. Early signs are anxiety, confusion, tachycardia, and narrowed pulse pressure. Repeat the vital signs to follow trends and monitor resuscitation.

The goal is to find and correct the cause of shock. In the case of hemorrhage, stop the bleeding. ATLS^® teaches “blood on the floor and four more.” In addition to external hemorrhage, principal sites of occult blood loss are the chest, pelvis, abdomen, and long bones. A CXR, pelvic X-ray, EFAST exam, and palpation of the extremities will review the potential sources of blood loss. EFAST exam will also demonstrate tamponade and can identify pneumothoraces.

A patient in shock due to hemorrhage or tamponade requires immediate definitive management. In the case of pleural hemorrhage or tamponade, thoracotomy should be performed. In cases of positive abdominal FAST exam, the treatment is immediate laparotomy. With long bone fractures, splinting and resuscitation should be definitive [29].

Pelvic fractures represent a special challenge. This may be associated with abdominal hemorrhage in which case initial management should be in the OR. The three patterns of pelvic trauma are lateral compression with pubic rami fractures, open book fractures, and vertical sheer injury. Lateral compression fractures are associated with pubic rami and acetabular fractures but usually do not present with massive hemorrhage. These patients often can have urethral or extraperitoneal bladder injury. Open book fractures frequently have major bleeding. Compression with a binder or sheet to temporize is useful. Vertical shear fractures usually present in hemorrhagic shock. Pelvic binders are less practical and often have to be combined with axial traction. Early orthopedic consultation is very helpful. In cases where shock is present, a decision is required on whether the next step is surgery with packing and pelvic stabilization followed by angio-embolization, immediate embolization, or CT first to plan therapy followed by either surgery and or angio-embolization. This can be difficult as angiography while particularly useful for retroperitoneal or solid organ arterial hemorrhage does not stop venous bleeding and can miss low flow bleeding. In profound shock, patients should go directly to the operating room. Patients who respond to initial resuscitation may be reasonable candidates to be taken by the team to CT. Patients with partial or transient response can be divided into FAST positive or negative groups. FAST positive should have laparotomy first; FAST negative can be managed initially with angio-embolization [30–32]. These challenging scenarios will be further highlighted in Chaps. 15 and 16.

Neurogenic shock patient should receive initial 1–2 L boluses of crystalloid but then frequently require pressor therapy and ICU monitoring. Patients with coexistent cardiac pathology due to an MI or severe contusion will need to be supported in an ICU with other physiological adjuncts such as inotropes.

Remember that shock is not due to head injury. In addition a wide mediastinum with suspected blunt aortic injury is also almost never the source of hemorrhagic shock. Once the aortic adventitia gives way, death typically occurs within minutes. Look elsewhere for a cause of bleeding. Do not get fixated on a single body cavity or single cause. Patients who are relatively stable in the trauma assessment area are candidates for truncal CT for definitive diagnosis and in particular require this to exclude occult injury. Abdominal examination is not sensitive in patients following major mechanism of injury or with multiple extremity or spine injuries. FAST is not sensitive for solid or hollow viscous injury. It simply identifies free fluid, which may indicate bleeding.