Pre-hospital care of pediatric patients with trauma.

Prehospital pediatric care is an important component in the treatment of the injured child, as the prehospital responders are the first medical providers performing life saving and directed medical care. Traumatic injuries are the leading cause of morbidity and mortality in the pediatric patient population. Nevertheless, for most prehospital provider it is a rare event to treat pediatric trauma patients and there is a still existing gap between the quality of care for pediatric patients compared to adults. To improve pediatric prehospital trauma care more provider need to be trained in identifying the specific differences between adult and pediatric patients.

INTRODUCTION

Prehospital care is an important link in the chain of survival in trauma patients and medical emergencies. There are many emergency medical service (EMS) systems that established a survival benefit for patients by early interventions performed by prehospital providers. But almost all of these studies were performed on the adult population. There is a paucity of data about pediatric prehospital care outcomes. This is primarily a result of the higher percentage of adult emergencies and thus the higher number of adult patients for whom the EMS providers are involved in the early care. Another problem may lay in the fact that pediatric emergency training is only a small part of the training curriculum for prehospital providers, and so prehospital pediatric care may not be performed at the same high level as adult prehospital care. This article focuses on the epidemiology of prehospital pediatric injuries, the special considerations that apply to pediatric patients, and the training and limitations of the EMS provider. Caring for the injured child requires a different skill set from those required for adult providers, including attention to the unique characteristics and needs of children. We will address primarily pediatric trauma, as it is the major cause of pediatric morbidity and mortality, but much of the information, especially the described differences from adults and the training of EMS providers, is also applicable to other pediatric diseases encountered in the prehospital setting like acute exacerbation of asthma, and sepsis.

EPIDEMIOLOGY

Trauma is the most common cause of mortality and morbidity for children in the US. Since most traumatic injuries occur at a certain distance from dedicated trauma or pediatric trauma center, most pediatric as well as adult patients immediately after their trauma rely on prehospital providers and regional EMS systems. These EMS systems therefore play a pre-eminent role in stabilization and transportation to centers with definitive care facility for trauma patients.

In a secondary analysis of the Emergency Department (ED) component of the 1997-2000 National Hospital Ambulatory Medical Care Survey Shah, et al.[1] found there were 110.9 million ED visits by children aged <19 years between 1997 and 2000. Pediatric patients constituted 27% of all ED visits from 1997-2000, and 7.9 million (7%) of these patients arrived via EMS. Pediatric patients represented 13% of all EMS transports. In their study, 62% of pediatric patients arriving at the ED by EMS were transported as a result of injury or poisoning. Compared with children arriving by other means, children arriving by EMS more frequently required care within 15 minutes after arrival (17% vs 40%), suggesting a higher acuity. Furthermore, EMS-transported patients had an elevated acute illness level demonstrated by a greater admission rate to non-ICU (3.9% vs 14%) and ICU (0.12% vs 1.8%). These findings reflect a significant number of pediatric trauma patients and the higher acuity and urgency of pediatric patients transported by EMS provider.

Information from the National Center for Health Statistics at the Center for Disease Control (CDC) list the top 10 causes of death by age group, and highlights traumatic injury as a major source of mortality in pediatric population. After the age of one year, unintentional injury or trauma becomes the leading cause of death [Table 1].

Table 1

Top 10 causes of death for pediatric patients by age group[2]

While falls are the highest number of incidents causing pediatric trauma morbidity, it is closely followed my motor vehicle accidents, which account for the highest number of fatalities in pediatric patients.[2] Data from the American College of Surgeons demonstrates that in 2011, over a thousand children (age 0 to 19 years) die from traffic related accidents [Table 2]. Firearm injuries are the 5th leading cause of injury and show the highest case fatality rate of all injury mechanisms, accounting for 805 fatalities in 2011. While firearm injuries are rare in smaller children, there is a dramatic increase in teenage children.[3]

Table 2

Incidence and case fatality rate[3]

As demonstrated by the chart, most trauma is unintentional and likely to affect multiple organ systems (Fall, MVC) [Table 3].

Table 3

Selected Mechanism of injury[3]

PEDIATRIC EMS SYSTEMS AND PERFORMANCE

Emergency Medical Services have regional variety in structure and providers. Modern EMS as it is practiced in the US today started in the 1950s and 1960s as advances in military triage and transport developed during World War II and the Korean War were later translated to the civilian population. The EMS Systems Act of 1973 created a grant program leading to the nationwide development of regional EMS systems and was the stimulus for rapid growth in prehospital care. Adult trauma care was the primary focus and specialized pediatric emergency care was a rarity at that time. In the early 1980's, research by Seidel, et al. and Ramenofsky, et al. demonstrated up to half of pediatric deaths from trauma might be preventable, and that children's outcomes, compared to adults with similar severity of injury tended to be worse.[4-6]

For example, a study of 88 general acute care hospitals in Los Angeles County found nearly twice as many deaths among children with serious traumatic injuries compared to adults with similar injuries.[5] These studies also revealed that prehospital personnel generally had little training in pediatric care. And, the availability of age appropriate equipment to manage children was lacking.[7]

In response to these noted deficiencies, the federal government developed the Emergency Medical Services - Children (EMS-C) program, a grant program for states that focused on correcting pediatric deficiencies within EMS systems, that is still in place today. In the 1990's pediatric emergency medicine became a recognized specialty by the American Board of Medical specialties, due to collaboration between the American Board of Emergency Medicine and the American Board of Pediatrics. And in 1993, the Institute of Medicine published a report entitled Emergency Medical Services for Children that set targets for research, training, and standardization of prehospital and emergency care for children. Since then, there have been great advances in closing the gap between pediatric and adult care, but the discrepancy still exists and research offer myriad reasons why the difference persists.

A retrospective study published in 2011 by Bankole, et al. compared the prehospital care of 99 adult and 103 pediatric head injury patients with GCS <15 on scene. The metrics of comparison were intravenous access, endotracheal intubation and fluid resuscitation. Their results showed: A total of 91 patients, 52 adults (52.5%) and 39 children (38.2%), needed endotracheal intubation at the scene. Significantly more pediatric patients had problems with intubation, 27 children (69.2%) vs. 11 adults (21.2%), P < 0.001. Intravenous access was successfully established in 85.9% of adults compared to 65.7% in children at the scene (P <0.001). On arrival at the trauma center, more children required intravenous access, 80.4% compared with 63.6% for adults (P < 0.011). More children (25.5%) required initial or additional fluid bolus at the trauma center compared with adults (9.1%, P < 0.003). The authors concluded that, based on these metrics, prehospital pediatric care is suboptimal compared to adults in controlling the essentials of trauma, airway, breathing and circulation. In their discussion the authors suggest that EMS providers receive insufficient training and practice with these challenging skills and that this may account for the discrepancy.[8]

In some European countries pediatric EMS includes EMS units and ambulances with special pediatric equipment. In addition these units are often staffed with personnel who received specific training in pediatric care and in some cases they are transporting a pediatric physician to the scene of an pediatric emergency or during inter-hospital transports.

PEDIATRIC AIRWAY

Like in adult patients, airway control is a priority in pediatric resuscitation and often required in pediatric trauma care. Unlike adults in whom cardiac problems are the leading cause of cardiac arrest, the cause of childhood cardiac arrest is commonly due to hypoxia secondary to respiratory arrest.[9] For this reason early and aggressive airway management is recommended. Due to the lack of training opportunities, most prehospital providers have only limited experience in managing the pediatric airway.

The pediatric airway is anatomically different from an adult's. The large size of the infant's tongue relative to the oropharynx increases the likelihood of airway obstruction and difficulties during laryngoscopy; the larynx is anterior and more cephalic in the neck, the epiglottis is shorter, omega shaped and angled over the laryngeal inlet, so control with the laryngoscope blade is more difficult; the vocal cords are angled, so a “blindly” passed endotracheal tube may easily lodge in the anterior commissure rather than slide into the trachea; and the infant larynx is funnel shaped, the narrowest portion occurring at the cricoid cartilage. Further, children have a shorter neck and a larger head, so ideally positioning a child for laryngoscopy (the sniffing position) is challenging, especially when child is in full spine precautions with a rigid cervical stabilization collar. The large occiput tends to force the neck into flexion while lying flat and the airway tends to buckle and obstruct. For this reason, a towel or blanket may be put between the shoulders to bring the child into a more anatomically neutral position.

PEDIATRIC ANATOMY RELATED TO TRAUMA

The head of an infant constitutes a higher percentage of total body mass compared to the adult and the neck muscles do not support this relatively larger head as effectively. Children have more flexible interspinous ligaments and joint capsules, their vertebral bodies are wedged anteriorly and tend to slide forward with flexion, and their facet joints are flat. This predisposes them to injuries of both the bones and soft tissues of the cervical spine. Also, the skull of the infant is soft and the closure of fontanelles and sutures is not completed until age 3.

The child's body makes it susceptible to different injury patterns than adults. Simply by virtue of their size, there is more force per square inch of body surface than adults. In children, the abdomen begins at the level of the nipple and both the supple rib cage and underdeveloped abdominal muscles afford little protection to internal organs. This makes children vulnerable to injury, and as a result multi-organ injury is more frequent. Since a child's bones are more flexible than adult's, it is possible for a child to have serious internal injuries without fracture.

PEDIATRIC METABOLISM

The pediatric metabolism shows certain differences to adults and this needs to be accounted for when caring for pediatric trauma patients, Healthy children have already increased metabolism and therefore higher O2 consumption compared to adults. Because of the larger body surface area to size ratio, hypothermia is a common occurrence in injured children. It is very important to avoid hypothermia as early as possible. Hypothermia induces shivering and catecholamine release, causing and even higher oxygen consumption that can result in lactic acidosis. The hypothermia and resulting acidosis does affect the coagulation system and can cause or exacerbate coagulopathy resulting in further bleeding and can lead into a vicious cycle of hypothermia, coagulopathy, increased bleeding. Rapid (cold) fluid administration can lead to further hypothermia. It is therefore crucial to pay close attention to maintaining euthermia in the prehospital setting.

PEDIATRIC CARDIOVASCULAR SYSTEM

In children, hypotension is defined as systolic blood pressure below the fifth percentile for age or by clinical signs of shock. These ranges can be difficult to remember, especially if used infrequently. However, several standard principals apply: (1) no child's respiratory rate should be >60 breaths/min for a sustained period; (2) normal heart rate is roughly 2-3 times normal respiratory rate for age; and (3) a simple guide for pediatric blood pressure (BP) is that the lower limit of systolic BP should be <60 mm Hg for neonates; <70 mm Hg for 1 month–1year olds; <70 mm Hg + (2 × age) for 1-10 year olds; and <90 mm Hg for any child older than 10 years [Table 4].[9]

Table 4

Normal vital signs according to age[8]

It must be emphasized that, in children, blood pressure is often maintained until late in shock because of their vigorous sympathetic and vasoconstrictive response. So appropriate fluid resuscitation must start early. Because of their small blood volume, children can lose a small amount of blood but a large percentage of their volume. A rough estimate of blood volume can be made based on the child's weight. Blood volume is approximately 100 to 120 mL/kg for a preterm infant, 90 mL/kg for a full-term infant, 80 mL/kg for a child 3 to 12 months old, and 70 mL/ kg for a child older than 1 year (#5). The lower limit of systolic blood pressure (5th percentile) for age may be estimated by the formula: 70 mm Hg + (2× age in years). Median (50th percentile) systolic blood pressure for children older than 1 yr may be estimated by the formula: 90 + (2× age in years).[10] The initial fluid bolus should be 20 mL/kg of isotonic crystalloid and the Pediatric Advanced Life Support guidelines recommend up to 60 mL/kg for initial resuscitation. Clinical circumstances, such as the mechanism of injury or burn and vital signs will dictate this. Because of the pediatric patients risk for hypothermia, all intravenous fluid should be warmed. While isotonic crystalloid solution offers a temporary measure to maintain blood pressure, the administration or large amounts crystalloids can cause further problems in trauma patients by worsening bleeding, hypothermia and coagulopathy. For this reason the crystalloids in the prehospital trauma care should be used carefully. There is a paucity of data about the optimal amount of fluid resuscitation and optimal blood pressure in pediatric trauma patients. Studies with adult trauma victims and especially with the younger military trauma patients have shown benefits of utilizing permissive hypotension and restricted crystalloid fluid resuscitation.[1112] While these results cannot be entirely translated into the pediatric trauma care, pediatric patients can tolerate lower blood pressure than adult patients. With a lack of evidence of the benefit of permissive hypotension in pediatric patients, the current standard of care is primarily maintaining tissue perfusion with crystalloid boluses until definitive control of hemorrhage is available.[13] Interestingly, a retrospective study by Vella, et al. examined 154 pediatric trauma patients that presented to a level 1 trauma center over one year and found that 70% of patients did not receive a fluid because it was deemed not necessary by the attending ER physician or trauma surgeon. Twenty percent received one bolus of 20 ml/kg, 7% received two boluses and 3% received three or more. The injury severity score (ISS) was correlated to the amount of fluid a child received. As the ISS is a number generated post-hoc, the ISS cannot help guide fluid resuscitation during the event, and the authors could not identify any other variables to help guide resuscitation, however the study is limited by its retrospective design. Also, 48% of the patients did not have a second IV, as recommended by current ATLS guidelines. No reasons for the single IV are assessed, but the authors do call into question the practice of a mandatory second IV because so few patients received much volume resuscitation at all.[14]

In 2005, Boluyt, et al. conducted a meta-analysis to develop a clinical practice guideline for all hypovolemic pediatric patients, including septic, trauma, burn, and other sources of hypovolemia like diarrhea. They identified 12 studies addressing pediatric patients and because of the paucity of evidence, they also included studies from the adult population and this accounts for the Grade A recommendation for the first conclusion. Their recommendations were: 1. In neonates and children with hypovolemia the first-choice fluid for initial resuscitation is isotonic saline (Grade A): 2. When large amounts of fluids are required (e.g. sepsis), it is possible to use a synthetic colloid because of its longer duration in the circulation (Grade C): 3. The initial fluid volume should be 10-20 ml/kg and repeated doses should be based on individual clinical response (Grade C).[15] Their effort should be applauded as there is little research available to guide fluid resuscitation in children.

PREHOSPITAL PEDIATRIC PROCEDURES

Pediatric patients require the same kind of invasive procedures as adult patients, but due to the different size and anatomy, many of these procedures are more difficult to perform, and the lack of specific pediatric training makes these procedure even more challenging. Indications for peripheral IV access are identical to the adult patient, but children require smaller intravenous catheters and the procedure itself is more difficult because of uncooperative pediatric patients the small size of veins, especially in smaller children. In severely hypovolemic patients it may be impossible to gain peripheral venous access and intraosseous (IO) access provides a suitable alternative. In critical situations, if IV access is not successful in three attempts or 90 seconds, IO access should be considered. The majority of prehospital providers are not sufficiently trained to perform central venous access, which leaves only the intraosseous access as the only alternative to peripheral IV access. This route has been a well-validated and is a rapid route of access used by multi-disciplinary providers in both adult and pediatric trauma patients in different settings.[1617]

Airway management in pediatric patients is, in some aspects, more challenging compared to adult airway procedures. The biggest challenge is again the smaller size of the patient, requiring smaller equipment and different and more precise techniques. In addition there are specific difference between the pediatric and adult airway, which were described earlier. These anatomical differences result in some differences that already start with the patient preparation for advanced airway management. In the adult patient the sniffing position, by elevating the head and preforming neck extension, has been established as the best position to visualize the vocal cords. For the infant patient with large occiput, padding is often put underneath the infant's shoulders to place the neck into normal anatomic position as shown above. The older the pediatric patient, the airway procedures become similar to adult airway procedures. This may be the main reason that airway procedures become less likely to be successful by prehospital provider in the younger pediatric patient.

Due to the anatomical differences many clinicians recommend the use of a straight blade over a curved blade in small children, especially for children under one year of age as the straight blade allows for better control of the floppy and large epiglottis. Unfortunately many prehospital providers are more comfortable using a curved blade, since the curved blade is more commonly used in adult patients and are therefore not familiar with the specific advantages and disadvantages of straight blades. Glidescopes are used in difficult airway and some centers as a first choice to intubate in adults, however the use in pediatrics is limited despite their availability.

If oral intubation is not possible, the preferred surgical airway is needle cricothyrodotomy. Surgical cricothyroidotomy is rarely indicated in infants or small children and carries a likelihood of damaging the cricoid cartilage causing secondary subglottic stenosis.

Classic teaching mandated a cuffless ETT because the funnel shaped larynx provided a natural cuff. However, new prospective and cadaveric studies have challenged this teaching and use of cuffed tubes in children is becoming more common.[18] One can estimate the necessary size of the endotracheal tube by the child's fifth digit or by the formula (age + 16)/4. The ETT should be passed under direct vision just through the cords, or to a depth of three times the ETT size (i.e. a 4.0 tube should be advanced about 12 cm) and inflated with just enough air to provide an adequate seal for ventilation without leak. The cuffed ETT should be one-half size smaller than the uncuffed.

TRAINING AND EDUCATION

As shown in most of the studies presented in this article, pediatric emergencies often represent only 10% or less the calls to which EMS providers respond, which explains the often unfamiliarity of medical providers with pediatric patients. A study from Germany showed a pediatric emergency rate of 3.5% and concluded from these patients are often not treated adequately and recommended intensified education about this patient group.[19]

Furthermore even this small percentage of EMS runs does not represent a homogenous group, but range from newborn to teenage children. There is a recognized gap between adult and pediatric quality of care that has persisted despite efforts to improve pediatric prehospital care. Baker, et al. analyzed EMS run sheets over a 3-year time period and compared the performance of PALS trained versus non-PALS trained providers. There was a significant difference in the ability to obtain vascular access (100% vs 70%, P < 0.01) and intraosseous access (100% vs 55%; P < 0.01), but no significant difference in mortality (37% PALS vs 32% non-PALS). The authors concluded that PALS training improves procedural skills among EMS personnel and should be strongly considered as part of EMS training.[20]

Studies have demonstrated that following completion of Pediatric Advances Life Support (PALS) prehospital providers show an initial increase in clinical knowledge, assessed by a written test. But there is decay back to baseline pre-course levels in as soon as 6 months. This decay persisted at 12 months despite re-training with mock resuscitation training refreshers.[21]

CONCLUSION

Prehospital EMS systems have undergone fundamental changes over the decades and have shown improvement in patient care and survival rates of patients. Most of these changes and improvements addressed medical conditions of the adult patients and the magnitude of these advances cannot be seen in pediatric prehospital care. There are still significant differences in the care of pediatric versus adult emergency patients in the prehospital setting. The majority of the publications and research are performed with and for adult patients. Traumatic injuries are a leading cause of morbidity and mortality in the pediatric patient. Nevertheless, for most prehospital provider it is a rare event to treat pediatric trauma patients and there is a still existing gap between the quality of care of pediatric patients compared to adults. Essential skills like airway management and IV placement by prehospital providers have a higher complication or failure rate in pediatric patients versus adult patients. Pediatric prehospital care is an important component in the treatment of the injured child as it is for adult medical emergencies. The prehospital responders are the first medical providers performing life saving and directed medical care that affects the patient's morbidity and mortality.

To improve pediatric prehospital trauma care more prehospital providers need to be trained to address specific pediatric care and the differences between adult and pediatric patients.