other signs of infection, a subarachnoid hemorrhage may be the cause Common avoidable errors in the evaluation and management of children with coma are listed in Table 17.6 TABLE 17.6 COMMON ERRORS IN THE EVALUATION AND MANAGEMENT OF CHILDREN WITH COMA Assuming no head trauma has taken place if no such history is given Neglecting to secure the airway before imaging studies are performed Hyperventilating intubated patients to a Pco2 well below 35 mm Hg Not sedating patients once they are paralyzed and intubated Believing that a toxic ingestion has not occurred because the “tox screen” is negative Suggested Readings and Key References Ashwal S In: Swaiman KF, ed Disorders of Consciousness in Children Pediatric Neurology: Principles & Practice 6th ed Elsevier; 2018:e1741– e1773 Moler FW, Silverstein FS, Holubkov R, et al Therapeutic hypothermia after inhospital cardiac arrest in children N Engl J Med 2017;376(4):318–329 Richards JR, Smith NE, Moulin AK Unintentional cannabis ingestion in children: a systematic review J Pediatr 2017;190:142–152 CHAPTER 18 ■ CONSTIPATION SARANYA SRINIVASAN, JAIME L VELASCO MASSON INTRODUCTION Constipation is one of the most common complaints in the pediatric emergency department, accounting for 3% of primary care visits There are many causes of constipation ( Table 18.1 ), some rare and some very common ( Table 18.2 ) Most constipation in children is functional, meaning that no underlying medical disease can be identified Occasionally, the presentation of constipation is atypical, with chief complaints that superficially seem unrelated to the gastrointestinal tract ( Table 18.3 ) Although relatively rare, some causes of constipation are potentially life-threatening and need to be recognized promptly by the emergency physician ( Table 18.4 ) In addition, constipation may produce symptoms that mimic other serious illnesses such as appendicitis DEFINITION Although constipation most commonly is defined as decreased stool frequency, the definition is not simple The stooling pattern of children changes based on age, diet, and other factors and there exist a variety of “normal” stooling patterns Average stooling frequency in healthy infants is approximately four stools per day during the first week of life, decreasing to 1.7 stools per day by years of age, and approaching the adult frequency of 1.2 stools per day by years of age Nevertheless, normal infants can range from seven stools per day to one stool per week It is normal for older children to defecate every to days It is easier to define constipation as a problem with defecation This may encompass infrequent stooling, passage of large and/or hard stools associated with pain, incomplete evacuation of rectal contents, involuntary soiling (encopresis), or the inability to pass stool PHYSIOLOGY The passage of food from mouth to anus is a complex process that relies on input from intrinsic nerves, extrinsic nerves, and hormones The colon is specifically designed to transport fecal material and balance water and electrolytes contained in the feces When colonic function is normal, the fecal bolus arrives in the rectum formed but soft enough to easily pass through the anus Normal defecation requires the coordination of the autonomic and somatic nervous systems and normal anatomy of the anorectal region The internal anal sphincter is a smooth muscle, innervated by the autonomic nervous system and contracted at baseline It relaxes involuntarily in response to the arrival of a fecal bolus in the rectum, allowing stool to descend into the portion of the anus innervated by somatic nerves At this point, the external anal sphincter, striated muscle under voluntary control, tightens until the appropriate time for fecal passage Before defecation, squatting or sitting straightens the angle between the rectum and anal canal, allowing easier passage Voluntary relaxation of the external anal sphincter and increasing intra-abdominal pressure via Valsalva allow passage of the feces EVALUATION AND DECISION The evaluation of the child presumed to have constipation should begin with a thorough history and physical examination Special attention should be paid to the age of the patient, duration of symptoms, timing of first meconium passage after birth, changes in frequency and consistency of stool, stool incontinence, pain with defecation, rectal bleeding, presence of abdominal distention, and/or palpable feces A rectal examination to assess anal position, sphincter tone, widening of the rectal vault, and presence of hard stool is also helpful Signs and symptoms concerning for more serious underlying pathology include onset of constipation in the first month of life, delayed meconium passage >48 hours, ribbon-like stools, blood in the stool without an anal fissure, failure to thrive, bilious emesis, fever, severe abdominal distention, an abnormally positioned/appearing anus, or an abnormal neurologic examination A complaint of constipation is not adequate to make the diagnosis A decrease in stool frequency or the appearance of straining is often interpreted as constipation The physician should be aware of the grunting baby syndrome, or infant dyschezia, in which an infant grunts, turns red, strains, and may cry while passing a soft stool This is the result of poor coordination between the Valsalva maneuver and relaxation of the voluntary sphincter muscles Examination reveals the absence of palpable stool in the rectum or abdomen Complaints of constipation not supported by history or physical examination are called pseudoconstipation ( Fig 18.1 ) Acute Constipation Constipation is not a disease; it is a symptom of a problem Constipation is acute when it has occurred for less than month in duration The patient’s age and the duration of the constipation are important in determining the cause and significance of the problem The infant younger than months of age with acute constipation is particularly concerning Potential causes include dehydration, malnutrition, infant botulism, and anorectal malformations Constipation is often the first presenting sign in infant botulism A recent viral illness accompanied by dehydration from vomiting, diarrhea, fever, and increased respiratory rate can precipitate acute constipation in an infant Paralytic ileus or decreased intake after gastroenteritis may slow transit through the colon, leading to hard stools Dietary protein allergy (i.e., cow’s milk protein allergy) may also present with constipation Anal fissures and/or diaper rash after a bout of diarrhea may precipitate painful defecation, resulting in stool retention ... JAIME L VELASCO MASSON INTRODUCTION Constipation is one of the most common complaints in the pediatric emergency department, accounting for 3% of primary care visits There are many causes of constipation... causes of constipation are potentially life-threatening and need to be recognized promptly by the emergency physician ( Table 18.4 ) In addition, constipation may produce symptoms that mimic other