Anesthesia for pediatric trauma

Historical development

In North America, improvements to trauma care began in the 1960s and 1970s (( ; ; ; ). Pediatric trauma systems did not develop in isolation but in concert with adult care. Trauma care was advanced in both the Korean and Vietnam wars with the military experiences of treating injured soldiers. A report by highlighted the enormity of the injury problem and stressed its significance as a neglected public health problem. Furthermore, a series of “preventable death studies” was published that provided fodder for community and political support of coordinated care for injured patients ( ). Funding for emergency medical services first became available in 1966 with the National Highway Safety Act, and further support followed with the Emergency Medical Services System Act in 1973 ( ). In 1968 Cook County Hospital in Chicago (for adult care) and Kings County Hospital in Brooklyn (for pediatrics) were recognized as the first specialized centers for civilian trauma care in the United States. In 1969 the University of Maryland and the Maryland State Police developed a coordinated transport system for injured patients to preferentially take them to a hospital, with specific interest in caring for injured patients ( ; ). Illinois is credited as the first state to develop a comprehensive statewide trauma system that included categorization of trauma hospitals and the establishment of a communication system and a trauma registry ( ). In 1984 the Department of Health and Human Services, in conjunction with the National Highway Traffic Safety Administration, began the Emergency Medical Services for Children Program in the United States. This funding has been a critical resource for developing programs and research to improve emergency service systems for children.

The American College of Surgeons Committee on Trauma (ACSCOT) has also strived to improve trauma care in North America. This has been accomplished through the publication of standards for trauma systems, the creation of educational courses for healthcare professionals, and the establishment of verification programs to ensure published standards are met. In 1976 the first version of the Optimal Resources for Care of Seriously Injured was released. The most recent version of this publication is currently in use and has been retitled Resources for the Optimal Care of the Injured Patient ( ). It remains a dynamic and important document. This publication established criteria for defining levels of trauma centers (I through III) and trauma systems (I and II), and it defined resource requirements for prehospital care through discharge, in addition to specific pediatric needs. Level I centers offer the widest range of services for the most severely injured patient, whereas level III centers allow for stabilization and triage. With respect to trauma system development, eight criteria were defined and have become accepted benchmarks for trauma care.

Level I trauma centers provide comprehensive care, act as a regional resource, and provide leadership in education research and system planning. The facility must have on-site and immediately available trauma surgeons, anesthesiologists, physician specialists, nurses, and resuscitation equipment. In addition, the institution must have the following volume requirement: either 1200 hospital admissions per year or 240 major trauma admissions per year or an average of 35 major trauma patients per 1 surgeon. Level II trauma centers provide comprehensive care as a supplement to a level I center or as a lead center in a less populated region. Like level I centers, level II centers must have on-site and immediately available trauma surgeons, anesthesiologists, physician specialists, nurses, and resuscitation equipment. There are no volume requirements, and there is no expectation for the center to provide leadership in education research and system planning. Level III trauma centers provide prompt assessment, resuscitation, emergency surgery, and stabilization for transfer to an appropriate level I or II center ( ). Recently, designation of a level IV trauma center has occurred in some states where the resources do not exist for a level III trauma center. Level IV trauma centers are able to provide initial evaluation, stabilization, preliminary diagnoses, and transportation to a center with a higher level of care. These centers may also provide surgery and critical care services (as defined in the scope of services of trauma care). A trained trauma nurse and physicians are available on the patient’s arrival to the emergency department ( Box 40.1 ).

In 1986, the ACSCOT established its consultation and verification program to ensure that these standards were being met. Over the past three decades the ACSCOT has nurtured the development of trauma systems in the United States. As of 2016, 41 states had trauma systems ( ) and, at present in North America there are 94 verified level I centers for adult care and 46 level I centers for pediatrics.

Another valuable contribution by the ACSCOT is the Advanced Trauma Life Support (ATLS) course. First released in 1979, the course is now taught all over the world ( ). The first pediatric chapter was introduced in 1983. Although initially designed for surgeons, a wide variety of healthcare professionals involved in trauma care participate today. The ATLS course provides a common language, framework, and approach to injured patients that facilitate communication between healthcare professionals in order to optimize and prioritize care. Regular recertification is mandated to keep physicians current with advances in trauma management. Similar to other ACSCOT programs, the ATLS course is constantly evolving. The current version is the 10th edition.

Glasgow coma scale

In 1974, Teasdale and Jennett first introduced the GCS. A lower score reflects a lower level of consciousness and therefore a potentially more serious head injury ( ). Scores can range from 3 to a maximum of 15 (normal). The GCS measures three specific components of consciousness (eye movement, verbal, and motor responses), with higher scores (up to 5) given to the best response. A patient with a GCS between 13 and 14 is considered to have a mild head injury, 9 to 12 indicates a moderate injury, and a score of 8 or lower indicates a severe insult. Adaptations of the GCS for the pediatric population have occurred, and a Pediatric GCS is now widely used ( Table 40.1 ).

GCS scores determined in the field are less predictive of outcome than those generated at a hospital ( ). When each individual component of the GCS is evaluated, the motor component is the strongest predictor of outcome.

Other triage scores include Revised Trauma Score; Alert, Verbal, Painful, or Unresponsive Scale; Pediatric Trauma Score (PTS); and Age-Specific PTS. None of these are in wide use clinically.

Severity of illness

The second type of scoring system quantifies the severity of illness (SOI), or the risk of mortality. These are typically determined retrospectively and serve as markers for quality assurance, benchmarking, and research, particularly for health services and outcome studies. Triage scores can also form a component of an SOI tool. These models rely on a variety of variables, including the diagnosis (using the International Classification of Diseases [ICD-9/10-CM]); the demographic of the injured patient; and anatomic, physiologic, and laboratory variables. Thus the SOI scoring systems have many variables, are more cumbersome, and are often computer generated. The two most widely used are the Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS).

Abbreviated injury scale

The AIS emerged from the automotive industry in 1969. It was initially designed as an epidemiologic tool to describe motor vehicle crashes but has been adapted to all types of trauma (“ ; ). Revised and updated several times over the years, the first version published was the AIS-90 (for the year 1990) in 1998 ( ). This score evaluates nine body regions: Head, Face, Neck, Chest, Abdomen, Spine, Upper Extremity, Lower Extremity, and Other (External/Thermal/Drowning). The AIS is used to calculate an ISS by taking the sum of the squares of the three highest injury regions. A scale from 1 to 6 is used to define injuries (1, minor; 2, moderate; 3, serious; 4, severe; 5, critical; and 6, maximal). The underlying premise is an association of injury with threat to life. A body region with a score of 6 is considered a nonsurvivable injury. The scores are determined retrospectively and based primarily on ICD-9-CM codes. A significant amount of expertise is required to assign these ratings, and interrater and intrarater variability are common. To help limit this phenomenon, software has been developed to convert the ICD-9-CM codes directly to an AIS score. Unfortunately, ICD-9-CM coding itself is inherently variable ( ).

Injury severity score

The ISS is one of the most widely used scoring systems in the trauma literature. It correlates well with several important trauma outcomes, such as mortality and duration of hospitalization. Developed in 1974, the ISS is a method of characterizing the trauma patient with multiple injuries ( ; ). The ISS is based on the AIS, which describes the severity of injury to different body regions (see the previous section). For example:

This formula shows AIS scores of the three most injured of the following body regions: A, the head, neck, and face; B, the thorax and abdomen; and C, the extremities (including the external pelvis). The ISS takes scores from 0 to 75 (i.e., AIS scores of 5 for each category). However, if any of the three scores is a 6, the score is automatically set at 75, because a score of 6 indicates that an injury is not survivable.

Two modifications have been reported to the ISS: the modified ISS (MISS) incorporating the GCS, and the new ISS, which focuses on injuries over body regions. However, evaluations of both the MISS and new ISS have not shown advantages over the standard ISS; therefore in many centers and registries, the AIS-90 remains the standard SOI scoring system.

Survival probability: Trauma score and injury severity score

The Trauma Score and Injury Severity Score (TRISS) is not a score but rather a method of predicting mortality. It was first proposed in 1987 and combines the physiologic variables of the Revised Trauma Score (RTS) with the anatomic SOI scores generated by the ISS ( ). The final result is that a probability of survival (Ps) is generated.

where e is the base of the natural log 2.72183 and b is derived from the following formula:

The age factor is 0 for those younger than 55 years of age and 1 for those who are 55 years of age or older. The variables b0, b1, b2, and b3 are blunt and penetrating trauma coefficients for adult and pediatric populations ( ).

TRISS is the most widely used predictor of survival in the trauma literature. As with other statistical processes, limitations exist. These are specifically noted in patients older than 55 years of age (extremes of age) and with trauma patients whose ISS is greater than 25. In fact, some authors suggest that because of the TRISS deficiencies, this method of calculating survival probabilities should be abandoned completely, particularly in urban centers ( ; ).

Clinical application of trauma scores

In practical terms, the GCS and region-specific criteria are used to triage pediatric trauma patients. Individually, all patients will receive an AIS, ISS, and survival probability score. However, because the goal is to improve the care of the injured patients, the TQIP and P-TQIP reports are the most important ones that each participating trauma center receives. These reports are generated by the American College of Surgeons (ACS). They focus on improving quality care by providing validated, risk-adjusted benchmarking for pediatric trauma centers. The risk-adjusted data, combined with training and collaboration with other TQIP participants, allow TQIP participants to track outcomes and improve patient care.

Role of the anesthesiologist in pediatric traumas

Anesthesiologists play various roles in trauma response. These roles span from assisting as primary responders in airway management and vascular access to coordinating operating room resources to ensure that patients are treated in a timely and effective fashion. A pediatric anesthesiologist is an invaluable resource when treating injured children. A 1993 report from the Institute of Medicine identified specific pediatric emergency medical service deficiencies in rural states ( ), including pediatric airway management, vascular access, and special resuscitation needs of injured children. Airway control is a primary tenet of trauma care, and proper endotracheal intubation (ETI) is recognized as a definitive method to achieve airway control. However, ETI in injured children is required less often than in adults; hence, maintaining skills can be difficult for healthcare providers ( ). Several studies have examined significant aspects of airway management in pediatric trauma, including how success and complication rates of ETI vary by location (e.g., field, transferring hospital, or trauma center) and personnel, whether bag-and-mask ventilation is effective with respect to oxygenation and ventilation before ETI, and whether multiple attempts at intubation adversely affect patient care or outcomes ( ; ; ). These studies have demonstrated that field intubation success rates are poor. Successful pediatric intubations relate to the skill of the person performing the intubation, and anesthesiologists’ airway management skills are considered superior to those of all other healthcare professionals. Failed attempts at ETI appear to produce a spiral effect that results in multiple failed attempts and delayed transfer to definitive care. Complications resulting from ETI seem far more common when the intubation is attempted in the field, and the risk of complication is exacerbated with each attempt. Increased complication rates do affect patient recovery, as shown by longer durations of hospitalization ( ; ; ).

Airway

The first step in trauma resuscitation is to assess the airway and then secure it when necessary to ensure respirations (see Chapter 19 , “Airway Management”). Indications for ETI include inability to oxygenate or ventilate and the need to protect the airway against aspiration. Appropriate management of the airway may be challenging or difficult without proper preparation and familiarity with the unique characteristics of the pediatric airway. In a young child or infant, the tongue is relatively large and the larynx and glottic opening are more anterior. A child’s airway has a smaller diameter and a shorter length. Airway edema occurring in an already small airway results in significant changes in the internal diameter of the airway and in increased resistance to airflow. The short length of the trachea makes right mainstem intubations more likely and increases the likelihood of extubation from small positional changes of the endotracheal tube (ETT). Because the pediatric midface is small compared with the tongue, airway obstruction is common. Blood, vomit, teeth, and foreign bodies are common causes of airway obstruction. In addition, children are often placed in cervical collars that may be too large for them. This can make it hard to see a child’s face and can present a challenge to identifying an airway obstruction. The first step to making the obstructed airway patent (while keeping the cervical collar on) is a jaw thrust with suction. Oral or nasal airways may be required if a jaw thrust is unsuccessful. If the airway is still not patent after these maneuvers, there should be consideration of a possible airway foreign body.

The initial management of the pediatric airway involves bag-valve-mask ventilation with a jaw-thrust maneuver. Intubation is indicated in patients with respiratory or cardiac compromise or an altered level of consciousness. All pediatric trauma patients should be considered to have a full stomach and possible cervical spine injury ( Video 40.2 ). Because of this, the airway should be secured after a rapid-sequence induction (RSI) (which may include cricoid pressure) with manual inline stabilization and an oral ETI. Nasotracheal intubation may be suboptimal and difficult because of the small size and acute angle of the nasopharynx and the more anterior and cephalad position of the glottic opening. This route is contraindicated in the presence of known or suspected head trauma.

The size and type of the ETT should be considered if ETI is required. It has been often stated that the narrowest portion of the neonatal airway is at the level of the cricoid ring, compared with the adult, where the laryngeal opening is the narrowest. Evidence of laryngeal shapes in children was based on an examination of 15 plaster casts made from cadaveric larynxes preserved from children ages 4 months to 14 years who died in 1897 ( ). A study by examined 135 anesthetized children aged 6 months to 13 years of age, using video bronchoscopy to measure laryngeal dimensions ( ). The authors concluded that “the glottis, rather than the cricoid, was the narrowest portion of the pediatric airway.” Thus the shape of the pediatric airway was actually cylindrical, similar to the adult shape. This study prompted further discussion of cuffed versus uncuffed ETTs in children. The advantages of an uncuffed ETT include a larger internal diameter, lower resistance to airflow, and avoidance of trauma to the subglottic region. The advantages of cuffed ETTs include lower fresh gas flow, reduced air pollution, less inhalational agent used, reduced risk of aspiration, no need for multiple intubations, and improved ventilation and end-tidal CO ₂ monitoring ( ). In a review of the current literature, Taylor and colleagues concluded that there was strong evidence to support the use of cuffed ETTs in children ( ). Table 40.2 refers to recommended ETT sizes for children for both cuffed and uncuffed tubes. The Khines formula may underestimate the correct ETT size. Duracher describes a revised formula to predict the correct size of cuffed ETT sizes (3.5 + age/4) ( ). Interestingly, a review by Holzki and colleagues concluded that in vivo studies may be affected by motion artifact and argued that the cricoid cartilage remains the likely narrowest portion of the pediatric airway; however, although controversy remains, the evidence does still support the use of cuffed endotracheal tubes in pediatric patients ( ).

The RSI for pediatric trauma patients can be accomplished with an induction agent that is immediately followed by a muscle relaxant. Standard induction agents for trauma patients include etomidate (0.2 to 0.3 mg/kg) and ketamine (2 to 4 mg/kg) or the combination of fentanyl (2 to 3 mcg/kg) and midazolam (0.05 to 0.1 mg/kg) with lidocaine (1 mg/kg). Propofol should be reserved for patients who are hemodynamically stable. Ketamine is relatively contraindicated in patients with increased intracranial pressure (ICP), though in a meta-analysis, ketamine did not increase ICP compared with opioids with maintenance of hemodynamic status ( ). Etomidate provides hemodynamic stability in trauma patients who are hypovolemic, but it may decrease survival in patients with sepsis secondary to adrenal suppression, although the data are inconclusive ( ; ; ; ). Muscle relaxation can be achieved with rocuronium (0.8 to 1.2 mg/kg) or succinylcholine (1 to 1.5 mg/kg). Succinylcholine is contraindicated in crush injuries, long bone fractures, and patients who are susceptible to malignant hyperthermia. In patients who are hemodynamically stable, the combination of propofol (4 mg/kg) and remifentanil (3 mcg/kg) can be used for RSI and has an onset and offset similar to propofol and succinylcholine (1 mg/kg) ( ).

ETIs have been deemphasized in the prehospital setting, because they are often unsuccessful. reported a success rate of only 57% ( ), although more recent data suggest that prehospital success rates are higher. In fact, in two national database studies, pediatric intubations were successful in 58% to 73% of patients ( ; ). All intubated trauma patients who come to the emergency department should have the placement of their endotracheal tubes confirmed with either end-tidal CO ₂ and/or direct laryngoscopy.

If initial intubation attempts are unsuccessful after an RSI, the patient should be ventilated with bag-and-mask ventilation. If a patient cannot be ventilated or if it is very difficult, a laryngeal mask airway (LMA) can be placed to facilitate ventilation and subsequent intubation. However, it must be recognized that the LMA does not protect the airway from aspiration and must be replaced by an ETT as soon as skilled personnel become available. The stomach should be decompressed with a nasogastric or orogastric tube after intubation, and a chest x-ray should be obtained to verify the ETT position ( Fig. 40.2 ).

Depending on the nature of the underlying injury, securing the airway in a patient who has sustained multiple injuries or even isolated facial injuries can be extremely complicated, as illustrated in Fig. 40.3 A. The management of such cases calls upon the resourcefulness and skills of the anesthesiologist and requires careful consideration of damage to surrounding structures such as major blood vessels and the airway structures themselves ( Fig. 40.3 B). The ability to maintain a patent airway via face mask and the potential for an expanding hematoma that may subsequently compromise an airway that may be patent at the current time must be anticipated. Additional considerations include the risks of increased ICP with concomitant head trauma, exacerbating an existing cervical spine injury, and aspiration during airway manipulation. The presence of rhinorrhea, otorrhea, or ecchymosis around the eyes should raise suspicion about a possible basilar skull fracture, and any instrumentation of the nasal passages, including passage of a nasal ETT or a NG tube, should be avoided. Similarly, crepitus may herald the presence of a tracheal disruption, and intubation under direct vision using a fiberoptic scope should be considered to avoid false passage of the ETT (see Video 40.2 ).

Predictors for difficult intubation in the prehospital environment include obesity, a large tongue, short neck, small mandible, cervical immobility, blood in airway, vomitus in airway, airway edema, and facial or neck trauma ( ). In cases in which significant airway difficulty is anticipated, it may be prudent to transport the child to the operating room with an anesthesiologist and otolaryngologist once the child has been stabilized hemodynamically and additional injuries have been ruled out. The airway may then be secured with preparations to perform an emergent tracheostomy in case of failed laryngoscopy. An inhalational induction may be tolerated by the patient who has been volume resuscitated, although the risk of aspiration must be weighed against the risk of a compromised airway. Performing a fiberoptic intubation with or without sedation may also be a consideration but, once again, this must be assessed in the context of cooperation and weighed against the subsequent risk of injuring the cervical spine. An inhalation induction or sedation permits direct laryngoscopy or flexible fiberoptic intubation while the patient is breathing spontaneously. In patients who have suffered loss of consciousness or head injury, there should be a high index of suspicion for cervical spine injury, even with the absence of radiologic evidence. When performing laryngoscopy, inline axial stabilization must be performed ( Fig. 40.4 ). Inline axial stabilization is performed by an assistant during laryngoscopy. The assistant should place both hands on either side of the patient’s head. The assistant’s function is to maintain the patient in a neutral position during laryngoscopy, avoiding flexion, extension, traction, or rotation of the cervical spine. Conventional wisdom has long dictated that if the patient appears to be at high risk of compromised ventilation and intubation, the use of muscle relaxants is best avoided until the airway is secured. However, an analysis of difficult airway experiences in the PeDI registry by Garcia-Marcinkiewicz and colleagues suggests that controlled ventilation was associated with less frequent nonsevere complications than spontaneous ventilation ( ). Additionally, with the commercial availability of sugammadex, use of rocuronium may be an acceptable alternative in certain patients in order to optimize intubating conditions ( ). If intravenous agents are required to induce anesthesia, it is preferable to use short-acting agents such as propofol and remifentanil that effectively blunt ICP responses to direct laryngoscopy yet permit return of spontaneous respiration in case of failed intubation.

Breathing

Ensuring adequate ventilation is the next task after securing the airway. Breathing is best assessed by auscultation and observation of chest motion. During the primary assessment, the patient should be assessed for the presence or absence of breathing, respiratory rate, and work of breathing. The chest should be observed for symmetry of chest motion and breath sounds. The chest wall should also be observed for evidence of direct chest trauma resulting in abrasions, penetration, or chest wall instability. The back needs to be assessed as well for posterior chest wall trauma. Although there are no concrete recommendations to guide intubation, pediatric patients with increased work of breathing or life-threatening injuries (head injuries with GCS <8) may require ETI. Immediately after ETT placement, the position should be confirmed with end-tidal CO ₂ . Patients in cardiac arrest or very small patients may require direct laryngoscopy or fiberoptic examination for confirmation. A portable chest x-ray and arterial blood gas should be obtained before leaving the trauma bay to determine the position of the ETT and its adequate delivery of oxygenation and ventilation. Continuous end-tidal CO ₂ monitoring and pulse oximetry are useful adjuncts. Many injuries that impair respiration include simple, tension, and open pneumothorax; massive hemothorax; flail chest; and pulmonary contusion. The most common thoracic injury in trauma is a pulmonary contusion in the pediatric patient, as opposed to rib fractures in an adult patient. A sudden change in the respiratory status after successful intubation should prompt an immediate evaluation for a reversible cause. An enlarged pneumothorax or development of a tension pneumothorax can occur after converting from spontaneous ventilation to positive pressure ventilation. The pneumonic DOPE can aid in the differential diagnosis for a decline in respiratory status: D isplaced ETT (e.g., extubation or right mainstem intubation), O bstruction in the ETT (e.g., blood or secretions), P ulmonary pathology (pneumothorax, aspiration, bronchospasm, anaphylaxis), and E quipment failure.

Circulation and access

Children who sustain multiple injuries often arrive in hypovolemic or hemorrhagic shock, which must be promptly recognized and treated. Unlike adults, children maintain an almost normal blood pressure until 25% to 35% of their circulating blood volume is lost ( Fig. 40.5 ). This is likely because of their high sympathetic tone, which causes peripheral vasoconstriction in an effort to maintain blood pressure in the face of diminished blood volume. Therefore tachycardia is an earlier sign of impending shock than hypotension. Additionally, signs of poor peripheral perfusion such as delayed capillary refill (more than 2 seconds), weak pulses, mottling or cyanosis of the skin, and impaired consciousness are earlier indicators of shock than low blood pressure. The presence of hypotension as a result of hypovolemia should be considered an ominous sign that usually heralds impending cardiovascular collapse. Table 40.3 describes the stages of pediatric shock and clinical signs seen at these stages.

It is imperative to rapidly assess the pediatric trauma patient for signs of shock upon arrival in the trauma center and at regular intervals thereafter. The initial fluid bolus administered in the trauma setting is warmed isotonic crystalloid (lactated Ringer’s solution, PlasmaLyte, or normal saline) in a bolus of 20 mL/kg intravenously (IV) (see Fig. 40.1 ). The pulse, capillary refill, and blood pressure are reassessed. A second bolus of 20 mL/kg is administered if there is no significant response or only a transient improvement in these parameters. If a third crystalloid bolus fails to maintain appropriate vital signs and circulation, then blood (10–20 mL/kg) should be administered next if additional fluid resuscitation is required. The need for blood transfusion initially is uncommon and usually signals surgical bleeding that may require an operation.

If shock persists and fails to respond to fluid therapy, other causes should be sought. Such causes may include long bone or pelvic fractures. Pericardial effusion and tamponade are less common occurrences in blunt trauma compared with penetrating injuries. The classic clinical signs of cardiac tamponade are shock, muffled heart sounds, pulsus paradoxus, electrical alternans, and distended neck veins. Treatment requires immediate pericardiocentesis.

Pneumothorax is a common complication of blunt chest injury in children, with nearly one-fourth of pneumothoraces under tension ( ). Unilateral or bilateral tension pneumothoraces may produce hypotension and hypoxemia. The classic signs of tension pneumothorax are ipsilateral tympany, shift of the trachea to the contralateral side, and distended neck veins.

Significant occult blood loss may be overlooked on the initial examination of the small child and infant. Because the absolute blood volume of a child is small, the significance of external blood loss may be underestimated. In addition, blood accumulation in the infant’s large, expandable head and open fontanelles can produce shock. Careful assessment of the abdomen is also central in the evaluation of the injured patient in shock.

Adequate large-bore IV access must be established as early as possible in the course of the resuscitation. Although peripheral routes offer the most rapidly accessible sites, such access may be difficult or impossible to obtain in the child with depleted intravascular volume or shock and resultant peripheral vasoconstriction. Delays in establishing vascular access may be life threatening; therefore intraosseous (IO) access should be rapidly initiated to expedite the administration of volume expanders and necessary pharmacologic agents. Once the child has been resuscitated, additional vascular access should be obtained. In such cases, a central venous catheter may be placed in the femoral or neck vessels if personnel with the necessary skills are available.

The use of IO infusions in the algorithm of trauma and cardiopulmonary resuscitation has evolved over the years and now takes a more prominent role for providing vascular access to children. IO access is placed in the medial surface of the proximal tibia 1 to 3 cm below the tibial tuberosity or the distal femoral metaphysis. IO has been used as a lifesaving measure to establish short-term vascular access in critically ill or injured children ( Fig. 40.6 ).

Access needles for IOs include manual devices such as butterfly needles, spinal needles, a bone marrow biopsy needle such as Susfast (Cook Critical Care; Bloomington, Indiana), and the basic Jamshidi needle (Baxter Healthcare Corporation; Deerfield, Illinois). More recently, automated devices have been marketed ( Fig. 40.7 ). The EZ-IO (Vidacare; San Antonio, Texas) functions like a battery-powered drill, with a beveled drill and a preset depth. It is designed to be used in the tibia. The Bone Injection Gun (BIG; Waismed; Kansas City, Missouri) is a spring-locked device also designed to be used in the tibia. It comes in a range of sizes for use in infants, small children, and adults. A device specifically designed for entry into the bone marrow of the sternum is the FAST1 (First Access for Shock and Trauma, PYN6 Medical Corporation; Vancouver, British Columbia). It is approved for patients ages 12 and older. Table 40.4 summarizes these devices. Details regarding instructions on the use of these devices can be viewed on the manufacturers’ websites.

A review of the use of IO access in pediatric trauma patients up to 10 years of age reported successful placement of access in 28 out of 32 attempts in the prehospital setting and in the trauma care center ( ). In this study, IO access was placed successfully by paramedics, nurses, and physicians, with only one incident of minor extravasation of fluid and no long-term complications in the survivors. The most common complication of IO access is subperiosteal infiltration, which in most cases resolves spontaneously without further problems. The most feared complication—osteomyelitis—occurs in 0.6% of cases ( ). Other rare complications include fractures, compartment syndrome, and emboli ( ). Although few complications have been reported with this technique, it must be recognized that the high mortality in patients who require IO access prevents the assessment of long-term complications. Ultrasound-guided vascular access has become more common in both adults and children ( ). In skilled hands, this technique can be used for rapid access in emergencies. See Chapter 20 “Point-of-Care Ultrasound” for more details.

Disability (neurologic assessment)

A brief, rapid neurologic evaluation is performed as part of the primary survey. It should include an assessment of the patient’s level of consciousness and pupillary function such as with the GCS. Periodic reassessment of the level of consciousness is necessary to detect neurologic deterioration caused by progression of traumatic brain injury (TBI), hypoxemia, or hypovolemia. Changes in mental status require prompt reevaluation of the ABCs. If they are adequately managed, then deterioration in mental status should be considered to be a result of TBI, prompting further brain imaging and consultation with a neurosurgeon.

Pediatric patients with traumatic injury are suspected to have a spinal injury until proven otherwise. This normally requires a size-appropriate collar to be placed to stabilize the cervical spine, along with a rigid board to stabilize the thoracic and lumbar vertebrae. In general, removal of the precautions requires clinical and radiographic assessment. In addition, if a neurologic injury exists in one location, the chances of a neurologic injury at another location increase significantly. Falls usually result in lumbar or lower vertebral crush or burst injuries, whereas a motor vehicle injury can create an injury at any location, but is usually a rotational or sliding injury because of a sudden acceleration–deceleration event.

In patients under 3 years, independent predictors of cervical spine injury include GCS less than 14, GCS eye of 1, motor vehicle crash, or age 2 years or older. If fewer than two of these occur, The negative predictive value was 99.93% in ruling out cervical spine injury, therefore the collar can be removed without any further imaging in this setting. Spinal cord injury without radiographic appearance (SCIWORA) creates the risk of missing a cervical spine injury with computed tomography (CT) scan imaging, and 90% occur in children less than 8 years of age ( ). In younger patients with suspected cervical injury where a clinical examination cannot be performed or is equivocal, magnetic resonance imaging (MRI) should be performed. Severe spinal cord injury could result in hypotension unresponsive to vasopressors. Additional IV access to administer vasoactive agents and steroids should be considered. Furthermore, monitoring and augmenting the blood pressure can help prevent further injury.

Exposure

Exposure involves removing the trauma patient’s garments, usually with shears, to allow detailed physical examination and detect injuries. Rolling the patient while maintaining cervical spine precautions is necessary to identify injuries to the dorsal surface of the body that would otherwise be occult. Padding should be placed on the backboard at this time to prevent decubitus ulcer formation. This assessment should be rapid, and the patient should be covered in warmed blankets or with a warming device to prevent hypothermia. In addition, IV fluids should be warmed, and the room temperature should be raised. This is especially important in small children, who are more prone to hypothermia because of their larger surface area–to-volume ratio.

As part of the “lethal triad,” along with hypotension and acidosis, hypothermia can lead to increased mortality in trauma. After adjusting for seasonal variation, the odds of a hypothermic pediatric trauma patient dying compared with a normothermic trauma patient were 9.2 times higher ( ). In a multicenter, international, randomized controlled pediatric trial, hypothermia (32.5° C) initiated within 8 hours of injury versus normothermia after severe TBI resulted in no improvement in neurologic outcome and an increase in mortality ( ). Similar results have been noted in adult studies as well ( ).

Secondary survey