Abdominal trauma





A 26-year-old man shoveling snow from the roof of a five-story apartment building slips and falls to the ground. On arrival to the emergency department 20 minutes later, he is awake and alert and can accurately state his name. He is not oriented to place, and he cannot recount what happened. He is complaining of pain. On physical examination, he is shivering, has a grossly deformed right proximal femur, and has a tender abdomen to palpation. His vital signs are heart rate 135 beats per minute, blood pressure 88/69 mm Hg, respirations 22 breaths per minute, and oxygen saturation by pulse oximetry (SpO 2 ) 99% on facemask oxygen.


The primary survey reveals a patent, well-protected airway; adequate oxygenation with supplemental oxygen; impaired ventilation secondary to pain and splinting; clear breath sounds bilaterally; sinus tachycardia; hypotension responsive to rapid fluid boluses of 100–200 mL; intact cranial nerves; normal pupillary examination; intact sensation; and movement in all four extremities. He has two 16-gauge intravenous (IV) catheters in his upper extremities.


After tracheal intubation, the patient is brought to the radiology department. He continues to have ongoing fluid-responsive hypotension, and packed red blood cell transfusions are initiated. Computed tomography (CT) scan of the brain is unremarkable, although diffuse axonal injury cannot be excluded. CT scan of the pelvis reveals an unstable, “open-book” pelvic fracture. The abdominal CT scan demonstrates an avulsed, grade 5 right kidney injury with significant retroperitoneal bleeding. The patient proceeds directly to the operating room for a damage control laparotomy. The planned procedures are exploratory and decompressive laparotomy; right nephrectomy; and pelvic, right femoral, and right ulnar external fixations. Trauma, urology, and orthopedic surgical teams will operate concurrently. Significant intraoperative blood loss is anticipated.





What injuries and abnormalities can be anticipated from the history?


In general, our ability to anticipate significant injuries is poor. The best marker of severe injuries after trauma is a recorded systolic blood pressure <90 mm Hg. Other associations are far less valuable predictors, especially pertaining to the mechanism of injury. Frequently, hearsay reports arrive before or concurrent with the patient describing a fall of several floors, an occupant ejected from a motor vehicle, or a through-and-through gunshot wound. Subsequent evaluation of the patient reveals no injuries. Just as often, patients are brought in with vague histories, such as falling from a standing position, bicycling-pedestrian accident, or extremity stabbing, and they are found to have significant, life-threatening injuries.


Because of these frequent discrepancies, all patients in whom significant trauma is considered possible must be managed using a protocol-driven system specified by the American College of Surgeons advanced trauma life support (ATLS). The objectives of ATLS are quick and accurate diagnosis and initiation of treatment for all life-threatening injuries. All patients are managed similarly initially focusing on the primary and secondary surveys of ATLS. The price paid to expedite diagnosis and treatment of trauma patients as well as to avoid missing occult severe injury is that some patients receive otherwise “unnecessary” testing; evaluation; and possibly even nontherapeutic interventions, such as tracheal intubation, tube thoracostomy, or exploratory laparotomy.


Specifically for this patient, it is relevant to appreciate that a fall of four stories is associated with approximately 50% mortality. Given that he has arrived at the hospital alive and talking, it is likely that his fall was broken somehow during descent. First aid initiated by bystanders and emergency medical services (EMS), especially tourniquets and pressure applied to bleeding areas, must be maintained during transfer to the hospital trauma team. Injuries from the following categories can be anticipated ( Table 77-1 ).



TABLE 77-1

Suspected Injuries after Trauma
















































































































Type Injury Comments
Neurologic Traumatic brain injury
Spinal injury
Glasgow Coma Score
Cervical immobilization
Careful logrolling
Penetrating wounds Hemorrhage Apply pressure to bleeding areas
Place extremity tourniquet proximal to bleeding site
Orthopedic Long bone fractures Splint fractures to avoid fat embolism syndrome and disruption of clots
Expect 1–3 units of blood loss per closed fracture
Pelvic fracture Immobilization
Expect several liters of blood loss
Thoracic Rib fractures Excruciatingly painful
Leads to splinting, hypoventilation, and hypoxia
Hemothorax
Pneumothorax
Pulmonary contusion
Hemothorax/pneumothorax Chest tube insertion should not be delayed waiting for chest x-ray
Diaphragmatic rupture Herniation of abdominal contents into thoracic cavity
Cardiac Impaired ventricular function Most common presentation
Arrhythmias Monitor electrocardiogram for at least 24 hours
Cardiac rupture In extreme cases
Valvular dysfunction
Coronary occlusion
Aortic Avulsed at ligamentum arteriosum Rapid deceleration
Rupture Death before arrival to hospital
Dissection May be occult
Manifests later with hypotension, stroke, aortic valve insufficiency, or myocardial infarction
Abdominal Bowel Vascular injury and ischemia
Liver and spleen Most common after blunt trauma
Kidneys and pancreas Less common
Systemic Shock Lactic acidosis
Hypothermia Exposure at scene and emergency department
Room temperature intravenous fluids
Coagulopathy Shock, hypothermia, and acidosis
Consumption of coagulation factors
Coagulation factors diluted by crystalloid solution resuscitation


Neurologic injury


Traumatic brain injury


The Glasgow Coma Scale (GCS) is the traditional means of quickly assessing neurologic function when traumatic brain injury is suspected. The GCS is a coarse screening tool that encompasses eye-opening, verbal, and motor responses ( Table 77-2 ). GCS scores range from 3–15. A score of 3 represents a completely nonresponsive patient with a predicted mortality rate of 65%–90%. A GCS score of 13 predicts mortality rates of <10%. Although the GCS score on admission correlates with survival outcomes, more importantly, the specific details of neurologic function should be accurately noted. Often, loss of consciousness is reported from the field, yet when patients arrive at the hospital, they are awake with normal GCS scores. This finding does not exclude neurologic injury; the “lucid interval” of a potentially fatal epidural hematoma follows precisely this pattern. The presence of seizures has a high correlation with positive findings on CT scans of the brain (80%). Headache, amnesia, and vomiting are each associated with structural brain injury in 40%–45% of cases. Brief loss of consciousness predicts positive CT scan findings in only 29% of cases.



TABLE 77-2

Glasgow Coma Scale












Eye opening 1—none
2—to pain
3—to loud voice
4—spontaneously
Verbal 1—none
2—moaning
3—incomprehensible words
4—confused or disoriented
5—alert and oriented
Movement 1—none
2—decerebrate extension
3—decorticate flexion
4—withdraws
5—localizes
6—obeys commands


Spinal injury


In a patient who has sustained blunt injury, the default approach is to presume that the spinal column is unstable until proved otherwise. Consequently, neck immobilization must be maintained, and logrolling must be carefully performed when examining or transferring the patient. In a patient who is hemodynamically unstable, clearance of the cervical spine is not a priority, even if the airway must be managed. For the cervical spine to be clinically cleared, the patient must be able to do the following:




  • Focus fully on the examination (no distractions)



  • Localize and discriminate mildly noxious stimuli



  • Move and feel all extremities



For this patient, full spinal immobilization would be maintained until detailed imaging and clinical clearance could be possible. Imaging would be obtained nonurgently. Provided that no radiographic abnormalities were noted, a clinical evaluation for clearance could be performed at a later time.


Penetrating wounds


During the patient’s fall and on landing, it is possible that a sharp object (e.g., debris, tree branch) could have impaled the patient. Pressure should be applied and maintained to all bleeding areas. Tourniquets must be appropriately applied (i.e., proximal to any extremity bleeding) and maintained.


Orthopedic injuries


Long bone fractures


Obvious deformities should be noted and the involved limb maintained splinted so as to minimize fat embolism syndrome and disruption of formed blood clots. For each closed fracture, 1–3 units of blood loss should be anticipated.


Pelvic fractures


If a pelvic fracture is suspected, the pelvis must be immobilized as soon as possible with a tied sheet or binder. A rich venous plexus resides on the anterior surface of the pelvis. Pelvic fractures disrupt these veins, and neither embolization nor suturing can be performed. A tremendous amount of bleeding can occur, eventually filling the retroperitoneum and providing venous tamponade. Until that occurs, a blood loss of several liters should be anticipated.


Thoracic injuries


Rib fractures


Even small rib fractures can be excruciatingly painful leading to respiratory splinting, hypoventilation, and hypoxia. Larger, multiple (flail chest), and comminuted rib fractures are associated with hemothorax or pneumothorax and are markers for significant pulmonary contusion.


Hemothorax or pneumothorax


If hemothorax or pneumothorax is suspected from the physical examination (i.e., absent breath sounds, tracheal shift, distended jugular veins, hypotension, or hypoxia), chest tube insertion should not be delayed for a chest radiograph.


Pulmonary contusion


Pulmonary contusion may not manifest initially. However, hypoxia, decreased lung compliance, and infiltrates develop within hours. Care is supportive.


Diaphragmatic rupture


Diaphragmatic rupture can occur when high pressure develops acutely in the abdomen. Depending on the object hit and the patient’s position at impact, abdominal contents may eviscerate into the thoracic cavity.


Blunt cardiac injury


Most cases of blunt cardiac injury manifest as impaired ventricular function. Death, when it occurs, is usually due to malignant arrhythmias. Consequently, when blunt cardiac injury is suspected, the patient must have continuous electrocardiogram monitoring. If no arrhythmias are noted in 24 hours, monitoring may be discontinued. In extreme cases, blunt cardiac injury can lead to cardiac rupture, valvular dysfunction, or coronary occlusion.


Aortic injury


During rapid deceleration, the aorta can be avulsed at the ligamentum arteriosum, where the arch is tethered. Aortic rupture is catastrophic and usually results in death before arrival at the hospital. However, aortic tears and dissections can be occult initially and manifest later with hypotension, stroke, aortic valve insufficiency, or myocardial infarction.


Abdominal injuries


Abdominal wall laxity and the absence of anterior bony protection results in abdominal contents being particularly vulnerable to blunt trauma. Forces applied anteriorly can compress abdominal contents against bony structures of the spine or pelvis. Additionally, tremendously high or even brief increases in intraabdominal pressure during impact can rupture both solid and hollow viscera. Shear forces during deceleration are another mechanism of injury, which can manifest immediately as solid organ rupture or hours later as vascular insufficiency leading to bowel necrosis.


Bowel injury


Bowel injury is generally less common following blunt trauma compared with penetrating trauma. When bowel injury occurs after blunt force trauma, it is often associated with vascular injury and ischemia. A late mechanism of bowel and renal injury is abdominal compartment syndrome.


Solid organ injuries


The liver and spleen are the most commonly injured intraperitoneal abdominal organs from blunt trauma. If the patient is hemodynamically stable, nonoperative management may be appropriate in select cases of hepatic and splenic trauma. The kidney is occasionally injured following blunt trauma, and the pancreas is injured less frequently. Both the kidneys and the pancreas reside in the retroperitoneal space.


Systemic abnormalities


Shock


A reliable marker for a shock state does not exist. In this patient, hemorrhagic shock is presumed because he has hypotension, tachycardia, altered mental status, and distended abdomen. Lactic acidosis develops as a consequence of hypoperfusion. The degree of metabolic acidosis present on admission correlates with mortality.


Hypothermia


Although the patient was in the field for only 20 minutes, he is shivering. The largest contributor to hypothermia is depressed metabolism that accompanies shock. Additional factors contributing to this patient’s hypothermia include exposure to cold temperatures in the field and in the emergency department when fully disrobed and treatment with room temperature IV fluids.


Coagulopathy


The development of coagulopathy is inexorably linked to the patient’s shock, acidosis, and hypothermia. Patients surviving massive blunt trauma arrive at the hospital with a measurable coagulopathy. This coagulopathy is exacerbated further by consumption and dilution by EMS-administered crystalloid solutions of coagulation factors.





Explain the primary and secondary surveys according to advanced trauma life support.


Trauma care follows a standardized approach starting in the field and continues through evacuation, triage, primary survey, resuscitation, secondary survey, and definitive care.


Primary survey


The primary survey is the initial evaluation on arrival at the hospital. Objectives of the primary survey are to assess and address quickly life-threatening conditions. The sequence is easily remembered by the mnemonic A, B, C, D, E .


Airway maintenance with cervical spine protection


The initial focus is on airway patency. The ability to phonate and converse is usually sufficient proof of an adequate airway. Many of the criteria for immediate tracheal intubation of trauma patients are similar to criteria typically used for other patients (i.e., hypoxemia, hypoventilation, lack of airway reflexes). The presence of oropharyngeal bleeding or stridor is always cause for concern. Other times, the threshold for tracheal intubation of the trauma patient is lowered. For example, if victims are intoxicated, combative, and actively bleeding, they may need tracheal intubation expeditiously despite the presence of adequate cough, gag and swallow reflexes. By default and until proved otherwise, trauma patients are presumed to have a full stomach and cervical spine instability.


Cervical spine protection begins with immobilization in the field using minimally padded extrication collars made of stiff, thin plastic. Cervical spine clearance is usually deferred until after the primary and secondary surveys have been completed. If the airway needs to be secured, the risk of exacerbating a cervical spine injury is negligible provided that adequate precautions are maintained. These precautions include manual in-line stabilization, minimizing neck extension, and management of the airway by an experienced laryngoscopist.


Extrication cervical spine collars and backboards can quickly lead to decubitus ulcer formation, sometimes in <1 hour. As soon as possible, backboards should be removed, and the extrication collar should be changed to one that is padded and designed for longer term use.


Breathing and ventilation


In a spontaneously breathing patient, auscultation of both lung fields is performed to establish the presence of bilateral breath sounds. In a hypotensive tracheally intubated patient, unilateral right-sided breath sounds (later discovered to be from a right main-stem intubation) occasionally lead to the avoidable placement of an emergent left thoracostomy tube for suspected pneumothorax.


Trauma patients generally arrive at the emergency department on supplemental oxygen. If the only monitor of ventilatory adequacy is oxygen saturation, significant hypoventilation could be missed because oxygen saturation can be maintained with a fraction of inspired oxygen (FiO 2 ) of 100% oxygen despite very low tidal volumes.


Circulation with hemorrhage control


Blood pressure is the initial vital sign used to establish adequacy of circulation. However, in severe hypovolemia, especially in young, healthy victims, compensatory mechanisms can maintain blood pressure until precipitous circulatory collapse occurs. Active hemorrhage is controlled with applied pressure or tourniquets. If it has not been done so already, large-bore peripheral IV access is established. Fluids administered from this point forward should be warmed.


Disability (neurologic evaluation)


This stage of the primary survey encompasses a quick assessment of both central and neuraxial integrity. The GCS score ( Table 77-2 ) is correlated with survival in traumatic brain injury and is commonly used as a shorthand method of communicating mental status. Patients with a GCS score <8 are unlikely to be able to protect their airway and may require tracheal intubation.


Beyond the GCS score, it is crucial to assess and document specific findings of an immediate baseline neurologic examination, including cranial nerve function, pupillary size, movement of extremities, lateralizing signs, sensation (if the patient is able to cooperate), and higher functions. Any deterioration from baseline requires immediate investigation.


Exposure and environmental control


The patient should be fully undressed (exposure) while maintaining cervical spine immobilization and kept warm with blankets (environmental control); this facilitates the head-to-toe examination, which is part of the secondary survey.


Secondary survey


When the primary survey objectives are met and stable (or supported) and adequate vital signs are achieved, the secondary survey can begin. The secondary survey comprises a head-to-toe physical examination and a review of the patient’s history, if available. The findings during the secondary survey guide a further focused physical examination as well as obtaining appropriate ancillary diagnostic tests (e.g., laboratory, radiographic, ultrasound). If the patient’s condition deteriorates, the primary survey is repeated.

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Jul 14, 2019 | Posted by in ANESTHESIA | Comments Off on Abdominal trauma

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