Robert P. Foglia
Between age 1 month and 18 years, one half of all deaths in children are the result of a traumatic injury. Trauma accounts for more deaths in children in this age range than all forms of cancer, heart disease, and infections combined. The objectives of this chapter will be to review the differences between adults and children in regard to mechanism of injury and physiologic response; discuss pathophysiology and the initial management of the trauma victim; and outline common injuries involving various organ systems.1-16
The often invoked axiom that children, and especially infants and young children, are not small adults applies also to understanding and treating traumatic injuries. The differences involve anatomical and physical characteristics, physiological and psychological responses, and even the very mechanisms by which trauma occurs. Adult practitioners often need to be reminded that, for instance, children have greater surface ratio of area to mass than do adolescents or adults. This results in greater dissipation of heat and water, which may compound the effects of other traumatic injuries. The child’s skeleton exhibits greater elasticity than the adult’s and is therefore more likely to allow compression and visceral injury without fractures. A vast majority of childhood injuries are passive and result from blunt trauma and thus tend to involve multiple organs. Yet, children tend to experience better outcomes compared to the adult with the same mechanism of injury because of factors such as the occurrence of fewer bone fractures and the lack of comorbid disorders. Yet, it is important to remember that, while a recovery of function and quality of life after blunt injury is common, physical function tends to remain lower than age-matched norms at 6 months postinjury, and often the childhood trauma victim and his or her family bears the consequence of that injury for a lifetime.
A common language that describes injuries and their consequences is very useful in the frenzied circumstances that are the norm in the trauma management process. The Glasgow Coma Scale (GCS, see Chapter 104) and Injury Severity Scale (ISS) have been mainstays in the assessment and subsequent review of outcomes in pediatric trauma patients. The New Injury Severity Score (NISS) has been shown to have an improved predictive value in adult trauma victims compared to the ISS, but this superiority has not been corroborated in children. Likewise, trauma scores specifically designed for children have not been found to be superior to trauma scores in general.
The evaluation and management of the injured child is best performed using a standard protocol. The Advanced Trauma Life Support (ATLS) protocol is widely used and establishes three sequential events: the primary survey, the secondary survey, and a definitive care phase.
The primary survey is performed in the first several minutes. Seminal to this phase is the rapid assessment of vital functions followed by the appropriate resuscitation measures.
The presumption that every patient may have suffered a cervical spine injury has become integral to initial trauma management. Cervical stabilization is thus one of the first steps of the stabilization and is continued until cervical injury can be adequately excluded. Immobilization of the cervical spine is usually carried out by prehospital personnel and can be achieved with appropriately sized Philadelphia or Aspen collars or by using sandbags on either side of the head and applying tape over the sandbag and the forehead of the patient. A foam cervical collar will not adequately stabilize the neck. A care-giver can stabilize the cervical spine by holding both mastoids and mandibles in a manner that prevents flexion-extension and lateral movements. If the child is awake and cooperative, the absence of pain or other findings upon careful full range mobilization of the neck is usually sufficient to exclude injury. However, physical examination alone cannot exclude a spinal injury in: (1) patients who are uncooperative or unresponsive; (2) the young child unable to give a meaningful or reliable response to questions; or (3) the patient with a significant distracting painful injury elsewhere. Pain with neck movement, tenderness to palpation of the cervical vertebrae, a detectable cervical spine deformity, or a neurologic abnormality referable to the neck are all good reasons to continue immobilization and protection of the cervical spine and to obtain specialized imaging studies and neurosurgical consultation if available.
ASSESSMENT OF VITAL FUNCTIONS
In children inadequate oxygenation and ventilation are the more common causes of arrest after trauma. For this reason, primary attention must be directed toward assessing airway patency and the efficiency of breathing effort. In every case, the mouth should be opened and the pharynx examined for foreign material or loose teeth. Secretions should be cleared and, if the child is unconscious, a jaw thrust maneuver or insertion of an oral airway may be used to prevent upper airway obstruction. Supplemental oxygen should be instituted. The presence of persistent respiratory distress or insufficient respiratory effort is usually an indication for tracheal intubation, which should be performed by the most experienced individual. If it is difficult to establish a patent airway, a needle cricothyroidotomy can provide rapid stabilization. A tracheostomy attempted outside of the operating room, particularly in a small child, can be a very difficult procedure, and is not the treatment of choice in this situation. Bag and mask ventilation can often provide adequate ventilation even in the most difficult circumstances and is preferable to unskilled tracheal intubation, particularly if laryngeal or tracheal injuries are suspected.6
If the patient has a suspected injury and no stridor but apparent upper airway obstruction, after several unsuccessful attempts of endotracheal intubation, a cricothyroidotomy is the next step. In the circumstance where there is a suspected laryngeal crush injury and stridor, consideration should be given to proceeding directly to a cricothyroidotomy without attempted endotracheal intubation because of the risk of creating a false passage in placing the airway via an endotracheal route.
After airway patency is assured, attention should move to other aspects of the breathing function (see Chapter 102). Palpation and auscultation are used to determine whether the trachea is in the midline. If it is, breath sounds can be heard well bilaterally. A tracheal shift or a decrease of breath sounds on one side of the chest may indicate a pneumothorax or hemothorax (the tracheal will deviate to the side opposite to the shift). If the patient is stable, a chest radiograph should be obtained to establish the origin of the findings.
If there is a tension pneumothorax, urgent treatment is indicated. This can be carried out by simply placing a needle into the pleural space through the second intercostal space at the midclavicular line. This allows relief of the tension and provides an opportunity to place a chest tube for continued evacuation of air. Chest tube placement or tube thoracostomy is the appropriate treatment for a traumatic accumulation of gas or liquid in the pleural space. In a small infant, a 12 to 14 French chest tube is appropriate. In an older child, an 18 to 24 French chest tube is preferable. A larger bore chest tube is more appropriate if a hemothorax is suspected.
A child with several contiguous rib fractures may have a flail chest, a condition characterized by a paradoxic inward movement of a portion of the chest during inspiration. This reduces both the functional residual capacity and the tidal volume, almost always requiring positive pressure ventilation. A sucking chest wound involves a penetrating injury that allows air to enter the chest during inspiration. The resulting pneumothorax can be prevented from becoming larger by placing a flap valve dressing over the injury until a chest tube can be inserted and the chest wall can be subsequently repaired.
An often overlooked reason for respiratory dysfunction after trauma is equipment failure. Worsening respiratory function can not infrequently be traced to kinking, disconnection or obstruction of an endotracheal tube, or insufficient suction on a chest tube. The importance of surveying the life support equipment frequently and thoroughly cannot be overemphasized, especially when a child experiences an unexplained worsening.
The next step in the primary survey is assessing the adequacy of tissue perfusion (see Chapter 103). A number of physical signs can reflect inadequate perfusion including tachycardia, pallor, cool extremities, confusion, combativeness, or a decreased blood pressure. After hemorrhage, blood pressure is usually maintained until the child loses 20% of his or her blood volume; thus, hypotension is a late manifestation of a significant injury. Checking the capillary refilling time provides a quick assessment of perfusion, provided that the patient is not cold.
Completion of the primary survey requires an assessment of neurologic function. It is particularly important to establish at this point whether the child has any lateralizing neurological signs that suggest an intracranial space-occupying lesion or spinal cord injury.
Adequate venous access is essential for the treatment of traumatic injuries. It has become the norm that any child with a significant traumatic injury should have two intravenous lines. If there is an injury involving the abdomen then at least one of the intravenous lines should be in an upper extremity or neck. Attempts should first be made to place intravenous lines percutaneously, although this may be challenging in the young child, particularly if hypovolemic. In such conditions, successful placement of a small bore intravenous line may gain precious time for the initial resuscitation. A larger gauge catheter can be inserted then under less pressing circumstances. If peripheral intravenous access cannot be achieved within several minutes, alternative methods of access should be attempted (see Chapter 107), including intraosseous access and, if skilled personnel are available, insertion of a central venous catheter either percutaneously or by surgical venotomy.
After vascular access is established, fluid resuscitation can be initiated accompanied by frequent reassessment of hemodynamic function (heart rate, blood pressure, state of alertness, capillary refill). A urinary catheter should be placed in a major trauma patient.
The secondary survey includes a history and a complete head to toe examination of the child with a focus on specific organ systems. The mnemonic AMPLE stands for obtaining a history in regard to Allergies, Medications, Past illnesses, Last meal, Events, and Environment involved with the injury. In the secondary survey the evaluation, testing, and interventions should be individualized for each patient. Every part of the body should be palpated, the chest and abdomen should be auscultated and the patient “log rolled” to examine the back and to perform a rectal examination.
Head and Neck
The assessment and management of acute neurological injuries are discussed in Chapters 104 and 111. Inspection and palpation of the head focuses on the detection of eye and ear injuries, and craniofacial fractures. Crepitus usually indicates a communication between the sinuses and the subcutaneous tissue through a facial bone fracture. Tenderness over the maxilla, and mandible, and malocclusion also indicate facial bone fractures. Rhinorrhea or otorrhea suggest a spinal fluid leak through a base of the skull fracture.
Examination of the neck and cervical spine includes palpation to identify tenderness, mobilization to assess range of motion, a motor and sensory examination, evaluation of reflexes, and appropriate imaging studies. Difficulty in carrying out this examination is most commonly the result of an altered level of consciousness and/or lack of ability to cooperate because of the patient’s age, or the distracting effects of other injuries. Signs of airway obstruction, hoarseness, stridor, crepitus, or significant soft tissue swelling are alerts for a possible airway injury.
In patients who have undergone stabilization of the neck with a collar, examination of the cervical spine requires the removal of the collar. This may not be appropriate in patients who are unconscious or uncooperative. After inspecting for injury, the cervical spine is palpated. If there is pain on palpation or if there is a deformity or swelling, the cervical collar is re-applied and an imaging study should be performed. If no abnormality on examination is noted and no pain elicited, the patient is asked to rotate the head and neck to each side, move it laterally, and then flex and extend it. If movement is limited or pain occurs, the collar is re-applied and imaging studies are indicated. If again no pain or abnormality is noted, the patient’s cervical spine has been “cleared” and no diagnostic imaging is needed. The decision process is more difficult, if for any reason, usually loss of consciousness or lack of cooperation, the cervical spine cannot be “cleared” in this manner. Computerized tomography (CT) examination provides a practical method to assess for neck injuries in children. A combined head and neck CT scan will, in the right circumstances, decrease the number of studies that a child will eventually undergo. It is important to recognize, however, that a normal neck CT scan does not eliminate the need to perform a functional examination of the neck once it is possible to obtain patient cooperation.
More than 80% of thoracic injuries in children are caused by blunt trauma. The incidence decreases to slightly less than 60% in adolescents. In the patient with blunt chest injuries, the most common cause of death is a head injury; in patients with penetrating chest injury, the death is most often caused by the chest injury itself.
The majority of thoracic injuries can be handled well with supplemental oxygen, tube thoracostomy, and analgesia. Approximately 5% to 10% of all blunt chest injuries may require a thoracotomy. Immediate life-threatening conditions include complete airway obstruction, tension pneumothorax, massive hemothorax, cardiac tamponade, and penetrating cardiac injury. Also potentially life-threatening conditions include pulmonary contusion, myocardial contusion, aortic disruption, diaphragmatic rupture, tracheobronchial disruption, and esophageal perforation. Indications for emergency thoracotomy include a penetrating wound to the heart or aorta, continued significant intrathoracic bleeding from other source (≥ 3–4 mL/kg/hour), an imaging study indicating an injury to the aorta or other large vessel, a pneumothorax with an open chest wall injury, a large continuing air leak indicative of a bronchial injury, cardiac tamponade, impalpable pulses with closed chest compression, diaphragmatic rupture, and esophageal perforation.
The secondary survey of the abdomen includes inspection, palpation, percussion, auscultation, and the use of imaging studies as needed. Abdominal blunt trauma carries an increased risk of injuring multiple organs. The presence of a “seat belt” sign, a linear abdominal wall ecchymosis, is indicative of a rapid deceleration mechanism of injury. This deceleration can often cause significant intra-abdominal injuries. The combination of a seat belt injury and significant tenderness on palpation should cause a high degree of suspicion for injuries of the abdominal viscera.
The abdominal plain film may show evidence of inferior rib fractures, vertebral anomalies, a pelvic fracture, and an abnormal bowel gas pattern. A nasogastric tube should be placed to decompress the stomach if distended. If there is any evidence of a mid-face fracture, the tube should be placed via an orogastric route to avoid the possibility of the tube being misplaced into the cranial cavity. Urethral injury is common in males and should be suspected if there is blood in the urethral meatus or a high riding prostate on rectal examination. If there is a significant suspicion to a urethral injury, a retrograde urethrogram should be performed before inserting a Foley catheter.
The presence of a pelvic fracture should raise suspicions of a concomitant retroperitoneal or urethral injury. Contemporary evaluation of the abdomen often includes an abdominal and pelvic computerized tomography scan. With the new generation of helical scanners, a full abdominal examination can be carried out in minutes. Radiological assessment should only be performed, however, once the patient is sufficiently stable. Peritoneal lavage is now used in very limited circumstances, because the presence of free blood in the abdominal cavity is no longer considered an automatic indication for surgery.
The spleen and the liver are two of the abdominal organs most commonly injured. The conservative management of childhood splenic and liver injuries is common practice today. A retrospective study of 440 patients from 17 pediatric trauma centers who had isolated splenic injuries showed that only 4% required surgery.12 Large multi-institutional studies have shown that children with isolated splenic or hepatic injuries (Grades I–III) injuries typically do not require admission to the intensive care unit (ICU), infrequently require blood transfusion, and, in their majority, can be managed nonoperatively. Indications for surgery include a persistently low hemoglobin unresponsive to blood transfusion, or hemodynamic instability unresponsive to fluid resuscitation.
Injuries to the pancreas are often the result of a blunt injury, such as those caused by the handlebar of a bicycle, a rapid deceleration injury in a motor vehicle accident, a fall, or intentional child abuse. Because of the location of the pancreas, there are often coexisting injuries to the stomach, duodenum, kidneys, or spine. The diagnosis is made on the basis of laboratory studies (elevation in amylase and lipase) and imaging studies (a CT scan demonstrating pancreatic edema, hematoma, or disruption). A penetrating injury of the abdomen with a pancreatic injury requires laparotomy. A blunt injury with stable vital signs and no peritonitis can usually be managed nonoperatively. The decision to operate is usually prompted by the persistence of fever, pain, ileus, and hyperamylasemia. Treatment otherwise consists of bowel rest, intravenous nutrition, and administration of octreotide to decrease pancreatic exocrine secretions. A pancreatic pseudocyst is a known complication of pancreatic trauma, often associated with an elevation in lipase and amylase. The pseudocyst is initially managed nonoperatively. Many of these will decrease spontaneously in size and resolve. If the pseudocyst if still present for over six weeks, consideration should be given to internal drainage, a cystgastrostomy, or drainage into the bowel depending upon the location of the pseudocyst (see Chapter 417).
Intestinal injuries can occur throughout the large or small bowel. The ligament of Treitz and the ileocecal valve are the two most vulnerable points because shear forces tend to tear the bowel at its tethering points to the abdominal wall. The duodenum, on the other hand, is often injured when compressed between the abdominal wall and the spine. A duodenal hematoma can be diagnosed by an upper GI contrast study or an abdominal CT scan. Management is nonoperative, and in approximately 85% of cases the hematoma will resolve spontaneously.
The presence of microscopic hematuria may not require admission if the CT scan of the abdomen shows no abnormalities. An algorithm for management is shown in eFigure 116.1 . If there is microscopic hematuria and a normal CT scan outpatient follow-up is reasonable. An abnormal CT scan or macroscopic hematuria provides indication for hospital admission. If the CT scan shows a major blood extravasation, or nonvisualization of renal flow, arteriography is indicated. If the vasculature is normal, bed rest and observation is reasonable. However, if there is disrupted vasculature, operative intervention is required. Bladder rupture also requires operative intervention.
This subject is covered more extensively in Section 4. However, in the evaluation of the trauma patient, the suspicion of child abuse should be kept in mind. This is particularly true if any or several of the following are noted: (1) a discrepancy between the history and the degree of injury; (2) a prolonged interval from injury to treatment; (3) a history of repeated similar injuries; (4) an inappropriate parental response; or (5) a changing history given by the caretaker.
In this phase of care, decisions are made regarding transfer from the Emergency Department to the next site of care. This begins with a reassessment of the patient, review of the need for medications (antibiotics, analgesics, immunizations), further imaging studies, monitoring, and consultation. A comprehensive outline of the status of the patient and the injuries identified is given to the accepting unit in the hospital.
Burn injuries are the third most common cause of death due to trauma in children in the United States, accounting for 2500 deaths and over 10,000 cases of severe, permanent disability annually. Many of these injuries are preventable. The majority of pediatric-burn hospital admissions are in children under age 2 years. Burns are often caused by hot liquids in younger children, particularly those under three years of age, and by fire in older children and adults. The initial resuscitation has a fundamental role, particularly in the case of large surface-area burns. The outcome for the burned patient is related to the magnitude of the injury, and is influenced substantially by the quality of the care provided. Patients with significant burn injuries are best cared for in a burn center. Survival rates in pediatric burn victims with 40% to 60% body surface area (BSA) burns have been reported to be as high as 100% and with 60% to 100% BSA burn survival of 86%.17-27
Burns can be categorized as the result of thermal, electrical, chemical, or radiation mechanism. The majority of burns in children have a thermal mechanism. Developmental differences in body surface area to body mass ratio and thickness of the skin account for most differences in the response to a burn injury between infants, children and adults. The child has a larger body surface area (BSA) to body mass ratio in comparison to an adult. A 1 year old weighing 10 kg has one seventh the body mass of an adult and one third the adult’s body surface area. Accordingly, the child has a larger evaporative fluid loss and greater difficulty maintaining temperature regulation. The child’s skin is less thick than the adult’s, and thus can burn more deeply after the same duration of contact with a comparable heat source.
The severity of tissue damage after a burn is related to several factors: (1) temperature of the heat source responsible for the burn; (2) duration of exposure; (3) area of the body burned; and (4) age of the patient. Grease, casseroles, and other hot liquids that tend to stick to the skin, have a longer exposure time, and have the potential to cause a deeper burn than a hot liquid of the same temperature that remains in contact with the skin for a shorter length of time. Burns to the palms of the hand and soles of the feet tend to be less deep than similar burns to other parts of the body because of the relative thickness of the epidermis in those areas. Likewise, while a shoulder burn may require a skin graft because of the depth of burn, a facial burn after a similar exposure may heal spontaneously, because the rich blood supply of the face limits the injury by dissipating heat more rapidly from that area.
DETERMINING BURN SURFACE AND DEPTH
The accurate determination of the burned surface area is an integral part of burn-wound management. In adults, the rule of nines is a simple and accurate way of estimating this surface. Each upper extremity, and each of the anterior or posterior surfaces of the chest, abdomen, and lower extremities represent 9% of the total body surface. Unfortunately, the same rule is not applicable to children. The head and neck of a child less than age 1 year accounts for 21% of the body surface area. The modified Lund-Browder body surface area chart (Fig. 116-1) can be used to estimate the percent of the body surface area involved in a burn. Except in “stocking-glove” type burns that extend from the tip of an extremity to the trunk, it is often necessary to approximate the magnitude of involvement of a body part. Especially in the case of irregular burns, it is also useful to know that the palm of a child represents approximately 1% of the body surface area.
FIGURE 116-1. Lund-Browder body surface area chart.
Burn depth is categorized as either partial or full thickness. Partial-thickness burns involve the epidermis and portions of the dermis. This corresponds to first-degree burns in the older nomenclature, which are exemplified by sunburn, and second-degree burns, which are characterized by a red or mottled appearance, blisters, edema, and a weeping, moist surface. Because of involvement of the dermal nerve endings, they are both painful to the touch and sensitive to cold air. Partial-thickness burns are subclassified as superficial or deep partial-thickness burns. Superficial partial-thickness burns tend to heal spontaneously over 7 to 14 days postinjury. Deep partial-thickness burns may heal spontaneously, but over a longer period of time, and may require tangential excision and skin grafting. Full-thickness or third-degree burns involve all skin layers. Their color can be variable. The tissue appears dry and inelastic, and the area is insensitive. Full-thickness burns will not heal spontaneously. As a rule, they require excision and skin grafting. Small full-thickness burns may heal by wound contracture. In some burns, the central portion is full thickness and the peripheral portion is partial thickness.
The first step of immediate burn care is to make sure that there is no ongoing injury. If there is any clothing or object that may still be a significant source of heat, it should be immediately removed from the patient. Jewelry should also be removed from the area and the burn should be wrapped with a clean, dry cloth. Cold liquids should not be applied to burns larger than 1% or 2% of the body surface area because the cold can result in diminished local perfusion, which may worsen the injury. The patient should be made as comfortable as possible, and rapid transport should be arranged to a hospital.
ADMISSION AND FLUID RESUSCITATION
Criteria for hospital admission include: (1) a partial-thickness burn of greater than 5% body surface area; (2) a full-thickness burn of greater than 1% body surface area; (3) an inhalation injury; (4) a chemical burn; (5) an electrical burn; (6) circumferential burn of an extremity or trunk; and (7) burns involving the hands, face, feet, or perineum. Intravenous access should be obtained in any patient with greater than a 10% body surface area burn, and fluid resuscitation should be initiated. The guideline is to achieve a urine output of 1 mL/kg/hour in young children and 30 to 50 mL/hour in adolescents. A Foley catheter should be inserted to monitor urinary output. If there is a perineal burn, bladder catheterization should be performed before edema formation makes this difficult.
AIRWAY AND LUNG INJURIES
Any patient with a potential for a smoke-inhalation injury requires a rapid physical examination with special attention to the integrity of the airway and to gas exchange. Carbonaceous material in the oropharynx, nasopharynx, or sputum should be noted. Pharyngeal burns, stridor, significant bronchorrhea, dyspnea, or decreased arterial oxygen saturation are indications of airway or lung injuries. Supplemental oxygen should be given. Any concern about airway patency should be addressed by cannulating the trachea before edema makes endotracheal intubation difficult. Arterial blood gas and carboxyhemoglobin levels (see Chapter 120) should be determined.
Three important complications are associated with smoke-inhalation injuries: carbon monoxide poisoning (Chapter 120), thermal injury to the upper respiratory tract, and chemical injury by combustion products to the lower respiratory tract. Carbon monoxide intoxication should be suspected in any patient who has been exposed to combustion products, especially if the exposure occurred in a closed environment and if the patient has an altered state of consciousness or signs of poor oxygen delivery, such as a metabolic acidosis.
Thermal burns can affect the pharynx, the nasopharynx, and the upper airway, causing edema and mucosal sloughing. Direct thermal injuries are rare below the glottis, although steam may carry sufficient heat to cause burns in the trachea and bronchi. Inhalational injuries in the subglottic airways are almost invariably due to chemical damage to the lower respiratory tract, including the bronchi, terminal bronchioles, and alveoli. Their severity varies from bronchial irritation causing cough, increased mucus production, and bronchospasm to more serious alveolar-capillary disruption resulting in respiratory failure. In patients with burns greater than 25% to 30% of their body surface area, pulmonary edema is a common complication, independent of smoke inhalation. Its mechanism involves fluid overload, hypoalbuminemia, and systemic inflammation initiated by the burn. Infection of the respiratory tract is common and carries a high morbidity and a significant mortality risk. Respiratory failure resulting from any of the aforementioned mechanisms occurs in more than half of the children who die as a result of their burns.
Fluid resuscitation within the first 24 hours can be done with crystalloid alone, crystalloid and colloid, or hypertonic saline. Each regimen has its rationale and proponents. The majority of burn centers favor a crystalloid resuscitation based on an initial intravenous infusion of 4 mL of Ringer lactate solution per kilogram of body weight per percent of body surface area burned. In addition, the patient should receive maintenance fluid. Half of the calculated resuscitation fluid is given in the first 8 hours of the resuscitation and the remaining half in hours 9 through 24. In the course of the treatment, the volume of Ringer lactate infusion is adjusted to maintain urine output at 1 mL/kg/hour. The initial fluid calculation is a guide to fluid management. The adequacy of fluid resuscitation is manifest by an appropriate urine output. In this manner, the patient’s homeostatic mechanisms are used to guide the therapy and to avoid over-and underhydration. Tissue edema of the burn wound, although unavoidable, can cause complications of its own. A partial-thickness burn of the back may progress to a full-thickness burn because of dependent edema. This is particularly true if the patient is resuscitated with excessive amounts of fluid.
In patients with myoglobinuria or hemoglobinuria, a larger urine output is desirable and consideration should be given to the administration of sodium bicarbonate to raise urine pH. The use of a diuretic during the resuscitative phase is rarely indicated.
A number of metabolic disturbances can occur with fluid resuscitation. Metabolic acidosis is most often due to inadequate perfusion and is best treated by increasing fluid volume. Hyperkalemia can be seen in patients with electrical burns and is a consequence of red blood cell breakdown. Moderate hyponatremia can occur after fluid resuscitation with Ringer lactate. This often can be corrected by limiting the amount of crystalloid infused. If the patient is symptomatic, the judicious use of hypertonic saline may be indicated.
Circumferential burns deserve specific attention because they have a potential to cause additional vascular or respiratory derangements. In the case of an extremity injury, burned skin and subcutaneous tissue constrict the extremity, limiting venous outflow. Continued arterial inflow causes edema in the distal portion of the extremity, eventually occluding the arterial vessels. Arterial inflow is then compromised. Cyanosis, paresthesia, weakness, or a decreased or absent pulse can be observed and are indications for escharotomy involving both sides of the fingers, toes, foot, hand, arm, or leg. For circumferential burns to the chest, a limited tidal volume or chest rise and blood–gas exchange abnormalities should prompt similar action. The chest escharotomy consists of bilateral vertical incisions in the midaxillary line and a transverse costal incision. The escharotomy can be done at the bedside because these burns are full thickness in nature and the skin is insensitive.
BURN CENTER TRANSFER
Burn victims should be transferred to a burn center if the type or degree of injury can not be managed well at the receiving hospital. Criteria for transfer are outlined in Table 116-1.
Initial treatment consists of debridement of the wound injury and application of a topical silver-containing antimicrobial such as silver sulfadiazine (Silvadene). Daily wound care involves either whirlpooling and wound debridement of the burn eschar or applying a silver salt product and leaving it on the burns for several days. After this, the burn is assessed for signs of spontaneous reepithelialization and formation of capillary buds, followed by the reapplication of the antimicrobial, assessment of mobility, and wrapping. Sedation facilitates aggressive wound debridement and alleviates the anxiety and discomfort associated with this type of repetitive care.
Table 116-1. Burn Center Transfer Criteria
Burn Center Transfer
Partial thickness > 10%
Any full thickness burn
Involvement of face, hands, feet, genitalia, perineum or major joint
Burned children in hospitals without qualified personnel or equipment for pediatric care
Burn injuries in children with preexisting medical conditions which could complicate management, recovery or affect mortality
The use of split-thickness skin grafting is often indicated in full-thickness and deep partial-thickness burns. An early decision to carry out tangential excision of the burn and split thickness skin grafting has the advantage of a lower risk of infection, shorter hospitalization, and improved outcome. After several days of burn-wound assessment, a determination of whether the burn will heal spontaneously can usually be made.
Burn patients have perhaps the largest caloric needs of any single group of pediatric patients. In a child who has suffered a large body surface area burn, the caloric needs may be 50% greater than the calculated basal needs for body weight or surface area. Many patients will not ingest a sufficient amount of calories orally. In addition, because of the need for daily burn-wound debridement and procedural sedation, the patient may not ingest nutrients for a number of hours before or after the debridement procedure. The use of enteral feeding via a nasogastric tube is an excellent method for supplying the appropriate caloric needs and carries a much lower risk of morbidity when compared to intravenous nutrition. Enteral feedings can be started as soon as 24 hours after the burn. If enteral feedings can not be used, central parenteral nutrition is indicated. Central intravenous access can be challenging if the areas typically used for access are burned. Rotating intravenous access for total parenteral nutrition can markedly decrease the risk of bacteremia.
Infections are the major cause of death and a major cause of morbidity in burn patients. The infections can be divided into three types: (1) primary wound or graft infection; (2) bacteremia and catheter-related sepsis; and (3) infections at other sites (lung, urinary tract). In children risk of infection is increased in inhalation injuries, burns greater than 30% body surface area and full thickness burns.
The type of bacterial flora that colonizes burn injuries changes with time. In the first week, gram-positive organisms predominate. By week 2, gram-negative organisms increase in frequency and number. By week 3, infections due to fungal organisms and antibiotic-resistant organisms are often found. There has been no proven benefit of using prophylactic intravenous antibiotic therapy in burn patients.
In contrast, the use of topical antimicrobials is well documented to be efficacious in burn-wound management. Almost all of the topical antimicrobial agents have silver as the antimicrobial agent. There has been an evolution over the past 40 years in the use of various topical agents for burn care. Silver nitrate was associated with a marked decrease in burn-wound infection and improved survival with its use. However, difficulty with dressing changes, staining, and metabolic complications were noted. For the past three decades, silver sulfadiazine is the topical agent used most frequently throughout the United States because it affords good gram-positive and gram-negative coverage and it is relatively easy to apply. A disadvantage to its use is the development of leukopenia in a small number of patients. It is often unclear whether this is the result of using the silver sulfadiazine or infection. Sulfamylon is an alternative agent that has the advantage of better penetration of the burn eschar. It is of particular benefit in ear burns, where the cartilage may be involved. Its disadvantages are that it acts as a carbonic anhydrase inhibitor and that it may be painful for the patient. More recently, a series of silver impregnated products for example Aquacel Ag (Convatec Princeton, NJ) and Acticoat (Smith and Nephew) have become available and have been associated with excellent results in burn-wound care. This family of topical agents often has greater ease of use than silver sulfadiazine. They come in sheets, are easier to apply, and can be left in place for a number of days. This decreases both the amount of care-giver time needed for wound care and the number of times the patient must be sedated and exposed to discomfort with dressing changes.
A major principle in burn care is to obtain coverage of the burn wound. This can be achieved by spontaneous re-epithelialization or by graft coverage. Most superficial partial-thickness burns heal spontaneously and do not require skin grafting for a satisfactory cosmetic result. Tangential excision of the burn eschar and split-thickness skin grafts are indicated in children with full-thickness burns and deep partial-thickness burns. Tangential excision removes the dead burn tissue to the point that capillary bleeding is identified. The recipient bed is then usually covered with a meshed graft (1.5:1, 3:1, or 6:1) of approximately 14/1000-inch thickness. The meshing allows for expansion of the skin graft, an important consideration in the patient with an extensive burn. In addition, it prevents the accumulation of fluid between the native tissue base and at the graft, which would hinder graft adherence. The cosmetic result declines as more widely meshed grafts are used.
A major research interest for decades in the field of burn injury has been in the area of biological dressings. Ideally, the patient’s own skin would and should be used. However, in large-surface-area burns, there is often not enough skin. The use of cultured epidermal autografts began in 1985. This technique consists of taking a portion of skin from a patient and growing that tissue in culture. Large sheets of autograft can be harvested and applied to a recipient bed on the patient. However, the tissue is very fragile and the cost of producing the cultured autografts is high. Another technique is to place a combination of a thinner (6 to 7/1000-inch) split-thickness skin graft and a donor dermal base (AlloDerm) on the recipient site. This allows for earlier reharvesting of a graft from the same donor site of the burn patient and affords good coverage for a deep burn.
In patients where there is a clear need for wound coverage but not enough tissue available for skin grafting, cadaveric homograft or porcine xenograft can be used as a temporary biological dressing. These types of grafts would typically be recognized as foreign tissue by an immunocompetent recipient and rejected in 4 to 5 days. In patients with significant burns, there often is a degree of immune dysfunction and these grafts may last for up to 10 to 14 days. Biological dressings decrease the risk of infection based on the same principle as do grafts. They also decrease fluid loss and discomfort with dressing changes, while allowing spontaneous epithelialization of the native skin. They can be used in patients where: (1) there is not enough native skin to cover a burn and coverage is needed until sufficient skin is available for grafting, (2) there is a burn-wound infection and a split-thickness skin graft is likely to become infected, and (3) there is a reasonable likelihood that the wound will epithelialize spontaneously and thus will not require a skin graft, but prompt coverage is desirable.
As with other forms of traumatic injury in children, there are ample opportunities for avoidance of burn injuries through educational processes. Burn injuries in children less than three years of age are often due to hot liquids, and not fires. This age group compromises the majority of pediatric burn injuries. Therefore, prevention in this population could potentially significantly decrease the number of burns seen in children.
In children less than six months of age, burns due to hot liquids often occur because of a parent carrying both a child and a cup containing hot liquids such as coffee or tea. The child is burned by the spilling of the contents of the cup on the child. As the child becomes a toddler, their curiosity can lead to burn injuries because of the home not being “burn safe.” Parents are often well educated in terms in “child proofing” various rooms in the house, so that the child doesn’t tumble down a flight of stairs or pull a lamp off of a table. The two rooms that carry the highest risk or burns in children are the kitchen and bathroom. Any electrical cord hanging off a counter affords the opportunity for the child to pull on the cord and thus pull the coffee pot, electric fryer, or electric slow cooker, and its contents, onto themselves. Likewise, allowing a bathtub to be filled with warm or hot water with an unsupervised child carries significant risk of burn injury. During the summer months, the child is at risk for injuries in the area of outdoor cooking appliances such as barbecue grills and campfires. The latter is particularly problematic when the family is camping out. Although the campfire may have been extinguished, if the child awakes during the night and begins to walk around the camping area, he or she may either walk on or fall upon coals that are still quite hot. Fortunately, the incidence of electrical burns has markedly decreased over the past thirty years with the use of much better insulation for electrical wiring of home products.
In children over five years of age, burn wounds are more commonly due to fire. Again, there are excellent educational opportunities. Fire-related injuries are often due to children playing with matches or other combustible products. These types of injuries are very predictable, with burn injuries from fireworks being a common example.
ANIMAL AND HUMAN BITES
There are 3 to 6 million bites in the United States every year. Approximately 80% to 90% are inflicted by dogs and 5% to 15% by cats.26 The remainder involve humans or a variety of species including rodents, bats, and other wild animals. Bites merit consideration either because they involve substantive tissue injuries or because of the potential for the transmission of zoonosis to the victim. A discussion on the latter can be found in Chapters 257, 289, and 321.
Approximately 5 million dog bites occur in the United States annually. Of these, approximately 800,000 require medical attention. More than 50% of all bite injuries occur in children. The incidence is highest in 5- to 9-year-old boys and decreases with age thereafter. Severe injuries occur almost exclusively in children less than 10 years of age.27 Over 75% of the dogs causing the injury either belong to the child’s family or a neighbor.
All pediatric dog bite victims should be treated as trauma patients. The force of a dog’s bite may not only result in soft tissue laceration or puncture, but also cause bone fractures. The upper extremity is the most commonly injured area, particularly in older children; the head and neck are more frequently involved in children younger than 4 years. Facial and neck wounds can be associated with mandibular fractures and cervical spine injuries.
After a bite, the wounds should be thoroughly cleaned, debrided of devitalized tissue, and copiously irrigated. Options regarding wound management include primary, delayed, and secondary closure. The decision is based on the amount of wound contamination, the degree of tissue loss, and the length of time since the injury. Particularly in wounds involving the face, the infectious risks of early closure need to be weighted against the potential for a poor cosmetic result if the wound is allowed to close without suture repair. Infection occurs in one third of pediatric hand wounds, despite appropriate initial therapy, prompting the recommendation of antibiotic prophylaxis in most cases. Amoxicillin/clavulanate provides good coverage for many of the organisms isolated.
Education has been shown to decrease the number of dog bite injuries. Common recommendations rooted in common sense include avoiding contact with strange dogs; not leaving young children alone at home with a dog; and teaching children, if they are old enough, of the need to respect a dog’s territory, particularly while the dog is feeding or protecting her pups.
Although cat bites are less common than dog bites, they appear to carry a higher risk of infection. Pasteurella multocida is the most common organism; it is isolated from 20% to 80% of all infected cat bites and from the mouth of 90% of the cats tested.28 Cat scratch fever is caused by Bartonella henselae, which can be transmitted by a cat bite or scratch from the cat’s claw and is discussed in detail elsewhere (see Chapter 257).
The injured area is typically much smaller than in a dog bite. Treatment principles, however, are the same in regard to initial management, assessment, and infection prevention and treatment. Since the vast majority of cat bites are not deep or associated with tissue loss, wounds are typically left open. A significant index of suspicion is appropriate for the patient who develops subsequent fever or lymphadenopathy. This may be indicative of an abscess or cat scratch disease.
Human bites are considered to be the third most common bite wound following dog and cat bites. The true incidence is unknown; many cases are not reported because they involve only minor injury or because the patient or family does not wish to admit the mechanism of injury. The bite can be either accidental or purposeful, and can range from minor to serious. Some wounds do not involve an occlusive bite and result from an accidental or purposeful impact against another person’s teeth. Over one half of bite wounds occur in the upper extremity and 10% to 20% involve the head and neck area. Human oral flora includes potentially infectious species of both aerobe and anaerobe organisms and the overall risk of infection is at least as high as with dog bites.
BITE WOUND EVALUATION AND CARE
Evaluation of bite injuries includes a history of the event, a pertinent medical history, assessment of the vulnerability of the patient to infection (very particularly for tetanus and rabies, see Chapters 289 and 321), and a detailed examination of the wound. The patient may not seek medical attention for several days after the injury. In these cases, there often is an increased likelihood of infection. The initial evaluation should note and document the following: wound size and depth; type of wound (eg, abrasion, puncture, avulsion, laceration) and whether there is any tissue loss; where appropriate, motor and sensory function of the affected area; and signs of infection, such as pain, swelling, erythema, drainage, red streaking, or fever.
Bite wounds resulting in a superficial abrasion or contusion need no further treatment after cleaning and evaluation. With more extensive wounds, if exploration appears appropriate or if there is any concern regarding neurovascular abnormalities, a surgical consultation should be obtained. Potential complications include abscess formation, joint penetration, fracture, tendon disruption, tenosynovitis, osteomyelitis, and a paronychia. A decision to close the wound is best made by an experienced clinician and should consider factors such as the degree of contamination, length of time since the injury, signs of infection, the location of the wound, the degree of tissue loss, and whether the patient is immunocompromised. For example, a facial wound with tissue loss may be best treated with wound closure or approximation and an antibiotic therapy, while a hand wound that is 24 hours old and with signs of infection may be better treated by leaving the wound open, elevating the extremity, and administering parenteral antibiotics.