Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
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 stability results 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 Depressed Linear Stellate Basilar Skull Fractures 5/6/2017 25 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 5/6/2017 39 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 1. 2. 3. 4. 5. 6. 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. Glucose and water solutions are not recommended because they are rapidly distributed in total-body water, including the brain. If the blood glucose concentration decreases more rapidly than the brain glucose concentration, the brain water becomes relatively hyperosmolar, and water enters the central nervous system and exaggerates the existing cerebral edema. Hypertonic Saline Hypertonic saline decreases ICP, improves cerebral perfusion pressure, and enhances hemodynamic function in TBI patients. In addition to its osmotic effect on edematous brain tissue, hypertonic saline also has vasoregulatory, neurochemical, and immunologic effects. Nevertheless, there is no significant outcome difference in patients who receive either 7.5% hypertonic solution or 20% mannitol. Corticosteroids Corticosteroids such as dexamethasone or methylprednisolone have been used to decrease ICP for more than 30 years. The mechanism for the beneficial effect of corticosteroids is not known, but it may involve stabilization of capillary membranes or a decrease in the production of cerebrospinal fluid, or both. Nevertheless, there is no reduction in mortality in patients treated with methylprednisolone in the first 2 weeks after TBl, thus suggesting that steroids should no longer be routinely administered to these patients. Decompression Craniectomy Emergency decompression craniectomy is a surgical procedure performed to resolve the elevated ICP and prevent herniation after head insults, especially severe TBI. Barbiturates Administration of barbiturates may be recommended when ICP remains increased despite deliberate controlled hyperventilation of the lungs and druginduced diuresis. . This recommendation is based on the predictable ability of these drugs to decrease ICP, presumably by decreasing cerebral blood volume secondary to cerebral vasoconstriction and decreased cerebral blood flow. The goal of barbiturate therapy is to maintain ICP at less than 20 mm Hg without the occurrence of plateau waves Discontinuation of the barbiturate infusion can be considered when ICP has remained in a normal range for 48 hours. Failure of barbiturates to decrease ICP is a grave prognostic sign. A hazard of barbiturate therapy to lower ICP is hypotension, which can jeopardize the maintenance of adequate cerebral perfusion pressure. Such hypotension is particularly likely in the presence of decreased intravascular fluid volume. Dopamine or dobutamine may be necessary in the event of barbiturate-induced hypotension secondary to myocardial depression. Transthoracic echocardiography can be useful for evaluating cardiac function in head injured patients. Blunt Cardiac Injury CHEST INJURIES Chest injuries are a significant cause of mortality in injured patients and account for 20% of traumarelated deaths in the United States. Both blunt and penetrating chest injuries are treated with similar principles of management. The initial evaluation of patients with chest injuries should emphasize the presence of an adequate airway and ventilation. Thoracic Trauma Penetrating Chest Injuries • Majority are stab wounds or gunshot wounds (GSW) • Lower mortality rates-less likely to include multiorgan injury • 85% of penetrating chest wounds can be treated with tube thoracostomy and supportive measures Penetrating Chest Injuries • 25,000 deaths per year in the U.S. due to GSWs to the chest Penetrating Chest Trauma • Wounds that enter or exit inferior to the nipple or the posterior tip of scapula may perforate the dome of the diaphragm. • Any penetrating wound such as this should be considered to have an abdominal component until proven otherwise. Work-up of Penetrating Chest Trauma • Physical examination – Look, Listen, Feel – Contusions, diminished or absent breath sounds, SQ emphysema can readily be found • CXR- best, least expensive and fastest initial evaluation • Ultrasound-may soon replace CXR as initial radiographic study in chest trauma • Angiography- to look for great vessel injuries • CT Scan: for better evaluation of chest wall and parenchyma • Transesophogeal Echocardiography Penetrating Chest Injuries • Operative intervention required for: – Massive or persistent bleeding – Massive air leak – Tracheobronchial injuries – Esophageal perforation – Cardiac or great vessel injuries – Post-traumatic empyema Penetrating Chest Trauma Wounds that enter or exit inferior to the nipple or the posterior tip of scapula may perforate the dome or the diaphragm. Any penetrating wound such as this should be considered to have an abdominal component until proven otherwise. Penetrating Chest Trauma:Indications for Mechanical Ventilation Intrapulmonary Foreign Bodies • When left in lung: – 20% developed into chronic bronchitis – 6% : lung abscess – 10%: bronchopleural fistula – 5%: Empyema Pulmonary Parenchymal Laceration Massive air leaks and hemorrhage require immediate operation High Velocity Missile Injuries • Wounds due to high velocity missiles that travel > 25,000 ft/s are being seen with everincreasing frequency • Military and civilian Operative Intervention for Hemothorax • As noted previously • Hemothorax: massive = initial drainage more than 1,000 cc or • Continuous bleeding of 200 cc/hr for 2 hrs Blunt Cardiac Injury EKG (for any blunt chest injury, persistent tachycardia, ST-T changes or ectopy) Cardiac enzymes (CPK, CK-MB and Troponin I) Echocardiography (TEE) Categories of chest wall injuries • Scapular fractures – 3% of blunt trauma cases – 54% have pulmonary contusions – 11% have associated ipsilateral subclavian, axillary or brachial artery injury • Over 1/3 are missed on initial evaluation Categories of chest wall injuries • Flail chest – Fx of at least 4 consecutive ribs in 2 or more places – Incompetent segment of chest wall large enough to impair respirations – Paradoxic motion hinders creation of the expected ipsilateral negative inspiratory force Categories of chest wall injuries Flail chest Combination of pulmonary contusion and flail chest has a mortality of 42% Pulmonary contusion with flail chest: 75% require ventilation Flail chest ALONE: 48% require ventilation tx Aggressive respiratory txs and IS with pain control Pulmonary Contusion Increase in pulmonary vascular resistance and A-aO2 difference Diagnosis: Dyspnea Tachypnea Hemoptysis Cyanosis Hypotension Pulmonary Contusion Treatment Oxygen to maintain PaO2 above 60 mmHg Vigorous chest physiotherapy Use colloids instead of crystalloids when rapid volume replacement is needed Place PA catheter when large or rapid volume replacement is needed Use of steroids and antibiotics are controversial Intra-thoracic Trauma: Great Vessel and Mediastinal Trauma Aorta Pulmonary vessels Tracheobronchial lacerations Esophageal lacerations Intra-thoracic Trauma: Great Vessel and Mediastinal Trauma— Work-up Plain CXR to identify thoracic aorta injuries Look for air in the mediastinum Persistent airleak should cue into: Bronchopulmonary or tracheobronchial injury Mediastinitis, tube feedings in chest tube or saliva in chest tube should cue into: Esophageal injury Intra-thoracic Trauma: Great Vessel and Mediastinal Trauma— Work-up Bronchoscopy Esophagoscopy CT Serial CXR Initial CXR of Concern Indications for Angiography Lateral deviation of the NGT in esophagus Widened mediastinum (>8cm) Loss of visualization of the aortic knob Hematoma of the Left cervical pleura (pleural cap) Depressed left main stem bronchus Rt lateral deviation of the trachea Indications for Angiography • Widened mediastinum (>8cm) Indications for Angiography • Forward displacement of the trachea on the lateral CXR • Fx of the 1st or 2nd rib • Massive chest trauma w/ multiple rib fx • Fx or dislocation of the thoracic spine • Major deceleration injury The chest radiograph is analyzed for the presence of pneumothorax, hemothorax, pulmonary contusion, deviation of the tracheobronchial tree, widening of the mediastinum, and abnormal mediastinal shadows. These findings determine the need for additional diagnostic or therapeutic interventions. Tension Pneumothorax Tension pneumothorax is a relatively common cause of respiratory distress in a patient with chest trauma. Placement of a chest tube without waiting for a chest radiograph is warranted in patients with penetrating chest trauma who are in significant respiratory distress or have systemic hypotension. Patients with chest trauma may also have significant hemorrhage that requires prompt administration of crystalloid solutions and blood. Urgent Thoracotomy The need for urgent thoracotomy because of chest trauma is rare. In fact, because lobectomy and pneumonectomy are associated with high mortality in trauma patients, treatment techniques have been developed that emphasize rapid and minimal lung resection. Guidelines for the need for emergency thoracotomy include an initial blood loss of 1500 mL on placement of the chest tube and continued bleeding of 200 to 300 mL/hr. Additional indications for thoracotomy consist of injuries to the heart or great vessels and tracheal, bronchial, or esophageal injuries. Diaphragmatic repair is usually performed via an abdominal approach. MANAGEMENT OF ANESTHESIA Before induction of general anesthesia for trauma patients undergoing emergency thoracotomy, it is critical to exclude the presence of a pneumothorax that could become a tension pneumothorax with the institution of mechanical ventilation of the patient's lungs. Management of these patients often includes an intra arterial and central venous pressure catheter, as well as peripheral large-bore intravenous catheters placed above the diaphragm. Because of the presence of lung injury, these patients' lungs need to be ventilated with low tidal volume ventilation (6 mL/kg ideal body weight) and a small amount of positive end-expiratory pressure. Placement of a double-lumen endotracheal tube to perform one-lung ventilation may be warranted for lung resection or repair of the esophagus or large intra thoracic vessels. These patients are usually transferred to the Icu with the trachea intubated and the lungs mechanically ventilated. ABDOMINAL INJURY Abdominal injury accounts for a small, but significant number of trauma-related deaths, especially when the abdominal injury is not recognized. One of the major reasons for a fatal outcome is that the peritoneal cavity and retroperitoneal space are potential reservoirs for large and occult blood loss. During initial evaluation of the trauma victim, peritoneal signs of abdominal trauma are often subtle and difficult to diagnose because of the intense pain associated with extra-abdominal injuries or because of the presence of TBl and altered mental status. Thus, during the initial evaluation of a severely traumatized patient, the first step is to diagnose the presence of abdominal trauma. Classification Traumatic abdominal injuries are classified as penetrating or blunt injuries. Penetrating injuries associated with overt signs of peritoneal irritation or acute blood loss (or both) are clear indications for surgery. If there is no violation of the peritoneum, local exploration is usually sufficient. Blunt trauma is generally caused by collisions or falls. The severity of the injury is determined by the accelerationdeceleration process sustained by the victim. The organs most commonly injured are the liver, spleen, and kidneys. Diagnosis Ultrasound performed in the emergency department is an important diagnostic tool for detecting the presence of an abdominal injury, including the presence of blood in the abdomen. Diagnostic peritoneal lavage (DPL) is a sensitive method for detecting the presence of serious intra-abdominal bleeding. The classic indication for DPL is suspicion of intraabdominal bleeding associated with arterial hypotension. In stable patients, an abdominal CT scan with radiocontrast is often performed instead of DPL. A CT scan allows the clinician to detect the location and magnitude of intra-abdominal injuries in hemodynamically stable patients. CT may also be important for investigating genitourinary injuries when intravenous radiocontrast is used. Management of Anesthesia Severe abdominal injuries require general anesthesia and often placement of an intra-arterial and central venous pressure catheter. In many institutions, a large-bore catheter is placed in a femoral vein on arrival at the emergency department.. It is important to recognize that the femoral venous catheter should not be used for rapid blood transfusions when abdominal venous injuries are suspected. It is good practice to place an additional large-bore catheter above the diaphragm for rapid intravenous administration of volume to these patients PELVIC FRACTURES Pelvic fractures are the third most frequent injury in victims of motor vehicle accidents and are often associated with other abdominal injuries. The overall mortality from pelvic fractures is between 15% and 50%, depending on the extent of the injuries. The combination of pelvic fracture and severe TBI has high mortality.. The initial treatment of pelvic fractures associated with bleeding is nonoperative, and they are managed by angiographic embolization. In addition to this treatment, patients may require external fixation of the fractures to allow mobilization. Alternatively, stabilization of the pelvis can be achieved with the use of military antishock trousers (MAST). The anesthesiologist has a critical role to play during the initial resuscitation of patients with severe pelvic fractures. These patients frequently require the administration of large volumes of blood, thus necessitating activation of the massive transfusion protocol. As with other abdominal injuries, it is also imperative to place largebore intravenous catheters above the diaphragm. BLUNT SPLENIC AND LIVER INJURIES There has been a change in the management of blunt splenic and liver injuries toward a more conservative approach. Patients without signs of hemodynamic instability or intra-abdominal bleeding can be monitored closely in the ICU after the initial evaluation and placement of large-bore intravenous catheters. Usually, it is mandatory to obtain sequential hematocrit measurements during the first 24 hours and to frequently examine these patients for detection of any signs of new intra-abdominal bleeding. Furthermore, these patients are at risk for abdominal compartment syndrome because of the increased vascular permeability associated with severe trauma. Thermal (Burn ) injury Continuous improvement in the care of burned patients for the last 30 years has resulted in an increase in survival after the initial insult. It is not uncommon to see patients with burns affecting 70% to 80% of the total body surface area to survive this injury. Critical factors that affect mortality in these patients include age older than 60 years, third-degree burns over more than 40% of the total body surface area, and smoke inhalation. Mortality increases in proportion to the number of risk factors present. In addition, the mortality rate of burned patients is also affected by the presence of significant coexisting diseases and delays in treatment. Initial Evaluation The initial clinical evaluation of an acutely burned patient includes a careful analysis of the burned body surface area, the depth of the burns, the mechanisms of injury (electrical, smoke inhalation), and the presence of associated traumatic injuries . Furthermore, information should be obtained as soon as possible about the presence of significant comorbid conditions that may affect the survival of a severely burned patient. 5/6/2017 113 Initial Fluid Resuscitation The initial treatment of burned patients includes an assessment of the fluid resuscitation requirements for the first 24 hours. The most commonly used guideline for calculation of fluid replacement needs is the Parkland formula (4 mL/kg/% burn); the replacement fluid is given as lactated Ringer's solution. Half the volume should be given during the first 8 hours and the other half during the following 16 hours. After the first 24 hours, protein repletion is frequently needed and is typically provided by 5% albumin (0.3 to 0.5 mL/kg/total body surface area of burned tissue). In addition to colloid replacement, a burned patient should receive maintenance fluid, which can be estimated as basal maintenance (1500 mL/m2 +evaporative water loss [(25 + % burn) x m2 x 24]). 5/6/2017 116 Clinical evidence of adequate fluid resuscitation includes normalization of systemic blood pressure, urine output (> 1 mL/kg/hr), and values for blood lactate, base deficit,plasma sodium concentration, and central venous pressure Urine output is not a reliable guide to the adequacy of resuscitation after the first 24 to 48 hours following a burn injury because of the presence of osmotic diuresis associated with glucose intolerance and high caloric feeding. Furthermore, a non-anion gap arterial base deficit may reflect the excessive intravenous administration of 0.9% sodium chloride solution. In elderly patients or those with significant preexisting cardiac disease, hemodynamic parameters should be monitored carefully, possibly with placement of a pulmonary artery catheter, to prevent the development of acute congestive heart failure as a result of vigorous fluid resuscitation. Rapid fluid resuscitation can be associated with the development of severe tissue edema compromising limb perfusion or an abdominal compartment syndrome. Management of Anesthesia Burned patients will require general anesthesia, initially for escharotomy of the limbs, thorax, and/or abdomen and later for excision of the burned skin and grafting. If the injuries do not preclude conventional airway management, standard anesthesia induction and tracheal intubation procedures are appropriate. However, succinylcholine should not be administered when the burn injury is older than 24 hours because drug-induced hyperkalemia may result in cardiac arrest. The trachea of a severely burned patient should remain intubated after the initial escharotomies because the aggressive fluid management that occurs during the following 24 to 48 hours to compensate for the burn shock often causes airway edema and compromise. The patient's lungs should be ventilated with low-tidal volume ventilation (6 mL/kg ideal body weight) if smoke inhalation injury or acute lung injury from another origin is present. Placement of an intraarterial and central venous catheter should be done under sterile conditions. . Particular attention should be paid to the impaired temperature regulation associated with severe burns. Excision of burned skin is accompanied by substantial blood loss, which can be estimated at 0.5 mL/cm2 of burned area At the conclusion of surgery, transport of severely burned patients to the ICU should be planned carefully because accidental extubation during the transport of these patients may result in an inability to ventilate the patient's lungs by mask because of face and neck burns. Lean body weight or mass Ideal Body Weight (men) = 50 + 2.3 ( Height(in) - 60 ) ( Devine formula) Ideal Body Weight (women) = 45.5 + 2.3 ( Height(in) 60 ) (Robinson formula) 5/6/2017 125 Lean body weight or mass Ideal Body Weight (men) = 50 + 2.3 ( Height(in) - 60 ) ( Devine formula) Ideal Body Weight (women) = 45.5 + 2.3 ( Height(in) 60 ) (Robinson formula) 5/6/2017 126