TRAUMA Dr Abdollahi
Trauma and associated life-threatening injuries account • for 10% to 15% of all patients hospitalized. Rapid • transport of a trauma victim to a trauma center rather than to the nearest hospital has resulted in improved outcome for the victim.
A level I trauma center is characterized by the • immediate availability of medical and nursing personnel • (emergency medicine physician, trauma surgeon, neurosurgeon, orthopedic surgeon, plastic surgeon, anesthesiologist,critical care specialist, radiologist, and nurses), as well as the facilities needed to treat trauma patients (emergency room, operating rooms, radiology suite, intensive care unit [ICU], central laboratory, and blood bank).
INITIAL EVALUATION • On arrival at the hospital, the patient's airway, breathing, circulation, and neurologic status (Glasgow Coma Scale, computed tomography [CT], magnetic resonance imaging) must be rapidly evaluated with the advanced trauma life support (ATLS) protocol. The first priority is establishment • of an airway and administration of oxygen.
Occasionally, the trauma victim's trachea has been intubated by the paramedic before arrival at the hospital. • Confirmation of tube placement as reflected by a sustained end-tidal CO2 waveform needs to be established and documented immediately on arrival at the hospital.
Early tracheal intubation in selected patients has been • a major factor in decreasing mortality from trauma. • Nasotracheal intubation should not be attempted if there • is the possibility of a basal skull fracture. If airway obstruction exists and tracheal intubation cannot be accomplished, emergency cricothyrotomy or tracheostomy is indicated.
All trauma victims are assumed to be at risk for pulmonary aspiration of gastric contents .
Cervical Spine Injury • In patients with a possible cervical spine injury (present • in 1.5% to 3% of all major trauma victims), orotracheal intubation should be attempted only with the patient's head stabilized in a neutral position (a rigid collar decreases flexion and extension to about 30% of normal and rotation and lateral movement to about 50% of norma!).
CT is the best way to diagnose cervical spine injury, although two thirds of all trauma victims have multiple injuries that may interfere with the ability or safety of performing routine CT.
Thoracic Trauma • Thoracic trauma may involve the lungs or cardiovascular system, or both. An upright inspiratory chest radiograph is preferred for visualization of a pneumothorax (high index of suspicion if rib fractures are present), although the more likely radiograph will be an anteroposterior supine film.
Pneumothorax or hemothorax is treated with a tube thoracostomy (tube placed in the fourth or fifth interspace in the midaxillary line and directed posteriorly and attached to suction). Intrathoracic vascular injury is suggested by a widening mediastinum, whereas lung contusion is predictable when a flail chest is present.
Abdominal Trauma • Abdominal injuries after blunt trauma are most often splenic rupture or laceration of the liver, with both resulting in profound hemorrhage. Intra-abdominal hemorrhage is diagnosed by diagnostic peritoneal lavage (DPL), abdominal ultrasound, or CT. Continued hematuria after placement of a bladder catheter indicates a possible bladder injury and the need for a cystogram or intravenous pyelogram.
Orthopedic Trauma • If suspicion of a pelvic fracture is entertained, the patient should be placed in a pelvic binder and transferred to interventional radiology for an emergency angiogram and possible intravascular embolization instead of rushing the patient to the operating room.
Evaluation of the extremities includes palpation of distal pulses and visual inspection for symmetry of the extremities to detect evidence of bleeding, especially in the thighs after femur fractures. Early immobilization of fractures is indicated.
Management of Anesthesia • General anesthesia is necessary for most trauma patients who require surgical intervention. A "trauma operating room" should be designated and appropriately equipped . There is no ideal anesthetic drug or technique for a trauma patient.
If the patient's trachea has not already been intubated, rapid-sequence induction of anesthesia is indicated. In the presence of hypovolemia, etomidate (0.1 to 0.3 mg/kg IV) or ketamine (1.0 to 3.0 mg/kg IV) is often selected for induction of anesthesia because these drugs are usually able to maintain stable hemodynamics. In patients with suspected or known cervical spine injury, avoidance of excessive head movement during direct laryngoscopy is necessary.
Frequently, the dose of anesthetic tolerated by the • patient is too small to prevent movement, thus necessitating skeletal muscle paralysis with a neuromuscular blocking drug. In this regard, some patients may experience recall of intraoperative events.
Hemodynamic stabilityresults from control of surgical bleeding and restoration of the patient's blood volume. Arterial blood gases, pH, and hematocrit are measured at frequent intervals during anesthesia and surgery. On a less frequent basis, it may be useful to analyze blood for electrolytes, glucose, and coagulation factors.
Fluid Resuscitation • Hypotension plus cellular hypoxia as a result of massive hemorrage is the resone for production of lactic acid . Goal-directed fluid resuscitation should be initiated immediately after the establishment of venous access because it serves to improve poorly perfused organs, including the liver and skeletal muscles.
Initially, administration of a crystalloid solution such as lactated Ringer's or Plasma-Lyte solution restores intravascular fluid volume to help maintain venous return and cardiac output.
SELECTION OF INTRAVENOUS FLUIDS • There is no advantage in using colloid for initial • resuscitation. When hemorrhage is extreme, it will be • necessary to eventually administer blood products. • Dilutional thrombocytopenia may accompany the massive blood transfusion necessary to reestablish intravascular fluid volume, whereas disseminated intravascular coagulation may accompany persistent hypotension.
Rarely, transfusion-related acute lung injury (ALI) can also occur in trauma victims receiving blood transfusions. A fluid warmer device should be used for all intravenous fluids to minimize the likelihood of hypothermia. The ambient operating room temperature should be kept warm. A massive transfusion protocol should be established. • Invasive monitoring, including an intra-arterial and • central venous pressure catheter, is recommended
Transport from the Operating Room • Severely injured patients often require continued postoperative support of major organ function in an rcu, especially mechanical ventilation of the lungs. Patients usually remain intubated, sedated, and paralyzed during transport to the Icu. Appropriate and necessary drugs and equipment should accompany the patient to the Icu. A transport ventilator is preferred if the patient's oxygenation or ventilation (or both) needs to be continuously supported.
Head Injuries Linear Depressed Stellate Basilar Skull Fractures
TRAUMATIC BRAIN (HEAD) INJURY • Traumatic brain injury (TBl) reflects an insult to the brain • from an external mechanical force (high-energy acceleration or deceleration) that might cause a temporary or permanent impairment of physical and cognitive functions along with changes in mental status. TBl resulting from head injury is the leading cause of death in individuals younger than 45 years and accounts for approximately 40% of all deaths from acute injuries in the United States.
Recognition • The hallmark of closed head injury is loss of consciousness. • CT should be performed early because it is the most important diagnostic test (evidence of increased intracranial pressure [ICP], types of hematoma, and hemorrhage), and the level of consciousness should be classified according to the Glasgow Coma Scale .
Patient age, imaging studies, pupillary response, mean arterial pressure, and initial Glasgow Coma Scale score have been used to predict the overall outcome in TBI patients.
Head Trauma Assessment • Glasgow Scale • Eye Opening • Motor Response • Verbal Response
Head Trauma Assessment • Glasgow Scale--Eye Opening • 4 = Spontaneous • 3 = To voice • 2 = To pain • 1 = Absent
Head Trauma Assessment • Glasgow Scale--Verbal • 5 = Oriented • 4 = Confused • 3 = Inappropriate words • 2 = Moaning, Incomprehensible • 1 = No response
Head Trauma Assessment • Glasgow Scale--Motor • 6 = Obeys commands • 5 = Localizes pain • 4 = Withdraws from pain • 3 = Decorticate (Flexion) • 2 = Decerebrate (Extension) • 1 = Flaccid
Hypotension, hyperthermia, hypoxia, and elevated ICP • are strong predictors of a poor outcome. Patients with a • Glasgow Coma Scale score of less than 8 by definition • have severe TBI, and the mortality rate is about 33% to • 55%. In contrast, the mortality rate is lower (around 2.5%) in patients with mild to moderate TBI (Glasgow Coma Scale score of 8 or greater).
CriticaL Care • Critical care of a head-injured patient is based on recognition and treatment of hazardous increases in ICP.Interventions designed to provide cerebral protection and resuscitation have been successful in patients who experience TBI. Invasive monitoring, including intraarterial and central venous catheter, is recommended. Fluid resuscitation to maintain adequate hemodynamics is important.
Low-volume resuscitation with hypertonic solution saline, dextran, or a hemoglobin-based oxygen carrier may be favored over conventional crystalloid therapy. Jugular venous oxygen saturation (Sjo2), potentially representing cerebral tissue oxygenation, may be used to guide therapy. • Administration of barbiturates is recommended when • ICP remains increased despite traditional therapy.
MANAGEMENTOF INTRACRANIAL PRESSURE • A catheter placed through a burr hole in a cerebral ventricle or a transducer placed on the surface of the brain is used to monitor ICP. Normally, ICP is around 15 mm Hg. Cerebral perfusion pressure is the difference between mean arterial pressure and ICP. Patients with a Glasgow Coma Scale score less than 8 should probably have their ICP monitored in a neurosurgery ICU.
An abrupt increase in ICP during continuous monitoring is known as a plateau wave . Painful stimulation in an otherwise unresponsive patient can initiate a plateau wave. Hence, the liberal use of analgesics to avoid pain is indicated even in unresponsive patients. Efforts to minimize the secondary injury from hypoxia or decreased cerebral perfusion will ultimately be the main goal for the care ofTBI patients.
Head Trauma Assessment Cerebral Perfusion Pressure = Mean Arterial Pressure - Intracranial Pressure CPP = MAP - ICP
TREATMENT • Early tracheal intubation plus mechanical ventilation of • the patient's lungs to avoid arterial hypoxemia has been • shown to improve outcome in the presence of TBI. • Hyperventilation may be deleterious because of cerebral vasoconstriction.
Methods to decrease ICP • Posture; • Administration of osmotic diuretics, • Hypertonic saline, • Barbiturates; • Institution of cerebrospinal fluid drainage; • Craniectomy, lobectomy, and craniotomy.
A frequent recommendation is to treat sustained increases in ICP greater than 20 mm Hg. Treatment may be indicated when ICP is less than 20 mm Hg if the appearance of an occasional plateau wave suggests low intracranial compliance.
POSTUR • Elevation of the head to about 30 degrees is useful in the care of head-injured patients to encourage venous outflow from the brain and thus lower ICP. It should also be appreciated that extreme flexion or rotation of the head can obstruct the jugular veins and restrict venous outflow from the brain. Placement of a central catheter via the subclavian or the internal jugular vein should be guided by the ultrasonic technique.
If central venous pressure monitoring is needed, the patient's neck should be prepared and draped before the patient is placed in the Trendelenburg position. The procedure should be terminated if ICP increases during placement.
Hyperventilation • In the past, deliberate hyperventilation of an adult patient's lungs to a Paco2 between 25 and 30 mmHg to decrease ICP has been recommended. It was presumed that the beneficial effects of hyperventilation of the lungs on ICP reflect decreased cerebral blood flow and resulting decreases in intracranial blood volume.
However, deliberate hyperventilation as a treatment to lower ICP has been questioned because of data showing an increase in mediators, lactate, and glutamate, even with a short period of hyperventilation. • .
Hyperventilation of a head-injured patient's lungs as a technique to reduce ICP is recommended only • in the presence of a mass lesion and impending herniation before definitive surgical intervention
Osmotic Diuretics • Administration of hyperosmotic drugs, such as mannitol • (0.25 to 1 g/kg IV over a period of 15 to 30 minutes), • decreases ICP by producing a transient increase in the • osmolarity of plasma, which acts to draw water from • tissues, including the brain.
However, if the blood-brain barrier is disrupted, mannitol may pass into the brain and cause cerebral edema by drawing water into the brain. The duration of the hyperosmotic effect of mannitol is about 6 hours. The brain eventually adapts to sustained increases in plasma osmolarity such that chronic use of • hyperosmotic drugs is likely to become less effective.
The diuresis induced by mannitol may result in acute • hypovolemia and adverse electrolyte changes (hypokalemia, hyponatremia), thus emphasizing the need to replace intravascular fluid volume with infusions of crystalloid and colloid solutions. A rule of thumb is to replace urine output with an equivalent volume of crystalloids, most often lactated Ringer's solution.