Healthy children have compensatory mechanisms to maintain blood pressure, even when cardiac output is decreasing. Children have the ability to increase their heart rate and vasoconstrict peripherally to shunt blood centrally, while very young children have limited ability to increase their cardiac contractility. Hypotension is a late finding of shock in previously healthy children, and interventions should ideally occur before the onset of hypotension. The earliest sign of cardiovascular compromise in most patients is tachycardia. Unfortunately, tachycardia is nonspecific and may be due to fever, pain, or anxiety. Repeated assessment of the heart rate can be helpful. In a crying child, a true resting heart rate can be obtained by leaving the pulse oximeter on until the child is calm. Unexplained tachycardia in a calm or sleeping child should be investigated for the cause of the tachycardia. The quality of the pulse is also helpful. A thready peripheral pulse associated with tachycardia should be considered a sign of shock. Bradycardia in ill children is especially ominous and may signal impending cardiopulmonary failure.

Growing children have musculoskeletal injury patterns different from those of adults. Ligaments are stronger relative to the immature bone, so children are more likely to fracture bones than sprain ligaments. The weakest part of a growing child’s bone is the physis, or growth plate. If tenderness is present on examination, physeal injuries should be considered in children with normal radiographs. Treatment of fractures in children should consider future growth potential. For example, certain physeal injuries can lead to long-term growth disturbances, whereas greater degrees of angulation are acceptable in many fractures due to the increased potential for bone remodeling.

Due to their immature immune system, young infants are at increased risk of serious bacterial infections. Febrile infants younger than 1 month are a particularly high-risk group and have a 10% or higher rate of serious bacterial infection. For this reason, the evaluation of infants with fever differs from the evaluation of older children and adults; the evaluation varies by age and vaccination status (see Chapter 161 ).

Infants younger than 2 months are especially challenging to assess because they have a limited behavioral repertoire. They may not make eye contact nor have a social smile. Normal behavior includes sleeping, crying, quiet alert time, feeding, and stooling. A change in any of these activities may indicate serious disease. Increased sleeping or crying or decreased interest in feeding may herald a serious illness, such as sepsis or an underlying cardiac or metabolic disorder.

Infants typically develop a social smile and track close objects by 2 to 3 months of age. After 6 months, infants may develop significant stranger anxiety, making the physical examination challenging. Whenever possible, examining the infant in the parent’s lap, with the infant initially facing away from the examiner, can mitigate anxiety and facilitate physical examination. Bubbles or interactive toys can distract infants and may help keep them calm.

Toddlers have variable reactions to a physical examination. A toddler may provide a limited history due to their narrow expressive language skills (e.g., only pointing to the location of pain). Some are fearful and will not cooperate, whereas others are curious and cooperate more easily with the examination. In a stable patient, begin the encounter standing or sitting at a distance from the child while taking the history. Speaking in a soothing voice and distracting the child with toys or other interesting objects can facilitate the examination. Emergency clinicians should interact with the parents, because this will be perceived by the child as a sign of endorsement and indicate that the parents are involved with the emergency care. Conversely, toddlers will often negatively react to parental anxiety.

Preschool-age children have increasing language skills. Like toddlers, their receptive language skills exceed their expressive language skills, and they often understand more than is realized. Preschoolers should be included in the conversation when possible. Emergency clinicians should be cautious about talking to the parents about procedures or diagnoses in front of the preschool child, even if the child seems not to be paying attention or not to understand. Like toddlers, preschool children vary greatly in their cooperation with the physical examination. Providing limited options, such as sitting with the parent or on the gurney, or choosing which ear should be examined first, may give the child a sense of control and improve cooperation. Distraction with stories, videos, or games on a smartphone or other devices can also facilitate the physical examination. The young child will build up anxiety awaiting a procedure. For this reason, clinicians should provide children with simple concrete explanations of procedures only immediately before and during the procedure. Preschool children may perceive illness or painful procedures as punishment for their actions, making simple explanations of what and why it is occurring even more important.

Some questions during the history should be directed at the school-age child, because many can provide much of the history themselves. At this age, children are often cooperative with the examination, but may regress when they are frightened or in pain. Additionally, children at this age become increasingly modest, and conscious attempts should be made to provide privacy.

School-age children may develop anxiety and attempt to negotiate or stall when a painful or unpleasant examination or procedure is planned, particularly if there is a long delay between the explanation and procedure. Firm but reassuring explanations of what will happen are important. Appropriate concrete explanations include the sequence of events and what physical sensations the patient will experience. It is also crucial to involve parents in the process to provide not only a candid explanation of the procedure itself, but also anticipated reactions from their child. When available, child life specialists are particularly helpful with this age population, using play and education to prepare children for anxiety-provoking procedures.

Adolescents will be able to provide much, if not all, of the history. However, despite desired independence from their parents, adolescents may regress in times of stress. It is therefore important to elicit the concerns of the adolescent and parent, and to ensure that both understand the diagnosis and plan. The adolescent should be given a chance to speak to the emergency clinician without the parent in the room. Any sensitive questions, such as those about drug use, alcohol consumption, tobacco and vaping, and sexual activity should be asked privately. State laws vary on confidentiality and ages of consent, so it is important for emergency clinicians to know those specifics which may be applicable to their patients.

Adolescents can generally be examined in a manner similar to that for adults. They may or may not prefer to have a parent present during the physical examination, and providers should clarify the patient’s preference. Adolescents are often extremely modest, and attempts should be made to preserve privacy with the examination in a private room, when possible, with exposure of only the body part being examined.