Etiology of shock
Pulse
BP
Skin
Jugular venous pressure
Hemorrhagic
Rapid, thready
Low with reduced pulse pressure
Cool
Low
Tension pneumothorax
Rapid, thready
Low with reduced pulse pressure
Cool
Elevated
Tamponade
Rapid, thready
Low with reduced pulse pressure
Cool
Elevated
Spinal
Normal, slow, full
Low with wide pulse pressure
Warm
Low
Cardiogenic
Rapid, thready
Low with reduced pulse pressure
Cool
Elevated
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.
Neurologic Injury
The goal during the primary survey is simply to recognize life-threatening neurologic injury, particularly severe traumatic brain injury. Everything else can wait until time permits for a more thorough evaluation. Pupils and GCS should be inspected and estimated as part of the D in the ABCDE of initial assessment. Severe traumatic brain injury is characterized by GCS less than or equal to 8. Asymmetric pupils may indicate mass effect with impending transtentorial herniation. The presence of either mandates prompt neurosurgical consultation. The most effective initial management is to ensure that viable brain is preserved by maintaining oxygenation and perfusion. In these patients, vigorous resuscitation to avoid or correct hypotension is a priority. Resuscitation for patients with hemorrhagic shock should employ the institutions massive transfusion protocol. Mannitol 0.5–2 g/kg may be an effective temporizing maneuver in order to transiently minimize brain swelling and herniation. The same is true of temporary hyperventilation. In most cases normal PaC02 levels are desirable to avoid cerebral vasoconstriction, but in the case of impending herniation, this can be lifesaving.
CT of the head should be performed as soon as possible. Treatment of hemorrhage in order to maintain cerebral perfusion still takes precedence. Patients presenting with hemorrhagic shock still need to have the bleeding stopped first in most cases. Patients who respond to resuscitation and who in the judgment of the trauma team leader will maintain perfusion while undergoing CT may have an expedited CT performed first [33].
Traumatic brain injury (TBI) may be characterized as severe (GCS </= 8), moderate (GCS 9–12), and mild (GCS 13–15) including concussion. Patients with moderate traumatic brain injury should undergo CT. Patients with mild TBI should be assessed in accordance with the Canadian CT head rule to determine whether CT vs. simple observation and follow-up is required. See Chap. 24 for an evidence-based discussion of imaging in stable patients. CT is required for patients with evidence of open, depressed, or basal skull fracture, persistent GCS < 15 beyond 2 h, age > 65 with loss of consciousness, amnesia or disorientation and/or vomiting two or more times. Consideration should be given to imaging those with dangerous mechanisms or amnesia for events >30 min [34, 35].
Musculoskeletal Trauma Including Spine
The priority is to identify long bone fractures in the primary survey. Another important goal is to do no further harm. Patients are initially exposed and log rolled, and extremities are inspected and rapidly palpated. During the secondary survey, all extremities and joints should be examined, including sensory, motor, and neurovascular examination.
Management of fractures is by immobilization and splinting. The entire spine, cervical, thoracic, and lumbar should be immobilized until spinal column injury has been ruled out. In most cases of major blunt mechanisms or penetrating injury with trajectory near the spine, X-rays are required. CT is not required for all injured patients but has proven invaluable for major blunt trauma patients, particularly those that also require truncal CT. If CT of the chest and abdomen/pelvis are not being performed, then plain radiographs should be obtained. For patients who did not have major mechanism, the Canadian C Spine rule [36] provides guidelines on when to request C-spine X-rays and when clinical exam is sufficient. If clinical exam is being relied upon, patients should be alert and cooperative, have no midline pain, and be able to actively rotate, extend, and flex the neck comfortably [37].
Patients who present with spinal cord or peripheral nerve injury should have initial findings carefully documented, and the injured part should be protected through immobilization. The primary management of these injuries in early trauma care is preservation of oxygenation, ventilation, and perfusion while taking care to do no further harm [38].
Management of extremity fracture is by splinting and immobilization. As already noted, direct compression of bleeding and/or application of a pelvic binder should already have been performed. Open fractures should receive antibiotic and tetanus prophylaxis as well as prompt orthopedic consultation. Dislocated joints should be recognized and reduced emergently, ideally in the trauma resuscitation area. If operative reduction is required, this should be performed emergently [39, 40].
Musculoskeletal injuries in major trauma patients are frequently not recognized during initial trauma assessment. A thorough secondary assessment when appropriate as well as routine performance and documentation of a tertiary survey within 24–36 h will identify these injuries. Reassessment, particularly when level of consciousness improves if initially compromised, will enhance detection rates and prevent morbidity due to delayed recognition.
Conclusions
An organized consistent approach by trauma practitioners and trauma teams will allow effective and safe management of the severely injured. Early identification and appreciation of shock is critical. Remember that in cases of hemorrhage, the priority is to stop the bleeding. As noted, rapid performance of an ABCDE assessment accompanied by a CXR, pelvic XR, and EFAST exam simplifies decision making in blunt trauma. Operative control or angio-embolization and musculoskeletal stabilization should occur immediately when required in trauma centers. In referring centers, well-organized trauma systems will focus on early identification, communication, and arrangement of transport.
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