In all types of dehydration and their methods of treatment, the patient must be monitored closely Physical examination and vital signs should be reassessed continually, urine output monitored closely, ongoing losses quantified and replaced, and therapy individualized Patients should be considered for admission if they are severely dehydrated, unable to adequately keep up with the ongoing losses, if they are persistently hypoglycemic, appropriate care cannot be provided as an outpatient, or if the etiology of the dehydration is unclear and further workup is required Suggested Readings and Key References Allen CH, Etzwiller LS, Miller MK, et al Subcutaneous hydration in children using recombinant human hyaluronidase: safety and ease of use Ann Emerg Med 2008;52(4 suppl):S75–S76 American Academy of Pediatrics subcommittee on fluids and electrolyte therapy Clinical practice guideline: maintenance intravenous fluids in children Pediatrics 2018;142(6):e20183083 Epifanio M, Portela JL, Piva JP, et al Bromopride, metoclopramide, or ondansetron for the treatment of vomiting in the pediatric emergency department: a randomized controlled trial J Pediatr (Rio J) 2018;94:62–68 Falszewska A, Szajewska H, Dziechciarz P Diagnostic accuracy of three clinical dehydration scales: a systematic review Arch Dis Child 2018;103(4):383–388 Freedman SB, Adler M, Seshadri R, et al Oral ondansetron for gastroenteritis in a pediatric emergency department N Engl J Med 2006;354(16):1698–1705 Freedman SB, Willan AR, Boutis K, et al Effect of dilute apple juice and preferred fluids vs electrolyte maintenance solution on treatment failure among children with mild gastroenteritis: a randomized clinical trial JAMA 2016;315(18):1966–1974 Gray JM, Maewal JD, Lunos SA, et al Ondansetron prescription for home use in a pediatric emergency department Pediatr Emerg Care 2017 Nov 14 Hartling L, Bellemare S, Wiebe N, et al Oral versus intravenous rehydration for treating dehydration due to gastroenteritis in children Cochrane Database Syst Rev 2006;3:CD004390 Hew-Butler TD, Eskin C, Bickham J, et al Dehydration is how you define it: comparison of 318 blood and urine athlete spot checks BMJ Open Sport Exerc Med 2018;4:e000297 King CK, Glass R, Bresee JS, et al Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy MMWR 2003;52(RR-16):1–16 Lazzerini M, Wanzira H Oral zinc for treating diarrhoea in children Cochrane Database Syst Rev 2016;12:CD005436 Spandorfer PR, Alessandrini EA, Joffe M, et al Oral vs intravenous rehydration of moderately dehydrated children: a randomized controlled trial Pediatrics 2005;115:295–301 Spandorfer PR, Mace SE, Okada PJ, et al A randomized clinical trial of recombinant human hyaluronidase facilitated subcutaneous versus intravenous rehydration in mild to moderately dehydrated children in the emergency department Clin Therapeut 2012;34(11):2232–2245 Steiner MJ, Nager AL, Wang VJ Urine specific gravity and other urinary indices: inaccurate tests for dehydration Pediatr Emerg Care 2007;23(5):298–303 CHAPTER 23 ■ DIARRHEA FARIA PEREIRA, DEBORAH C HSU INTRODUCTION Diarrhea, defined as a decrease in the consistency of the stool (loose/watery) and/or greater than three stools in a 24-hour period, is a common presenting complaint to the emergency department (ED) Infants and children have variability in frequency and type of stools; therefore, any deviation from the usual stooling pattern should arouse at least a mild concern, regardless of the actual number of stools or their water content An acute diarrheal illness typically lasts less than days In the United States, diarrhea accounts for approximately 1.7 million annual outpatient visits Although most bouts of illness are self-limited, approximately 70,000 patients are hospitalized each year Since the introduction of the rotavirus vaccine in 2006, the number of children hospitalized due to diarrheal disease has decreased significantly DIFFERENTIAL DIAGNOSIS Diarrhea may be the initial manifestation of a wide spectrum of disorders as outlined in Table 23.1 The most common etiology for diarrhea in pediatric patients presenting to the ED is viral gastroenteritis, with norovirus and rotavirus being the most common agents Other causes include bacterial and parasitic infections, parenteral diarrhea (nongastrointestinal infection such as otitis media), and antibiotic induced The emergency physician must be vigilant in recognizing the few children who have diseases that are likely to be life threatening from among the majority of children who have self-limiting infections Particularly urgent are intussusception, hemolytic uremic syndrome (HUS), pseudomembranous colitis, and appendicitis ( Table 23.2 ) In addition, children may develop severe dehydration with diarrhea secondary to any etiology Intussusception is a potentially life-threatening condition that can present with bloody diarrhea, although this is not the typical presenting complaint Intussusception peaks in frequency between and 10 months of age and tapers off rapidly after years of age unless there is a predisposing pathologic condition This topic is covered in more detail in Chapter 53 Pain: Abdomen HUS should also be considered in a child presenting with bloody diarrhea HUS is an uncommon but potentially life-threatening disease that typically presents with the classic triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury Children are affected most often in the first years of life They often present with abdominal pain, vomiting, and diarrhea that become bloody Five to 10 days after onset of diarrhea, children with HUS develop pallor, petechiae, and decreased urine output The most common cause of HUS is Shiga-like toxin-producing Escherichia coli (E coli 0157:H7) Pseudomembranous colitis is another serious disorder that may cause bloody diarrhea Clinically, the child with pseudomembranous colitis appears ill with prostration, abdominal distention, and blood in the stool This disease results from an overgrowth of toxin-producing Clostridium difficile, usually as a result of destruction of the normal intestinal microflora It may occur at any age but is uncommon in early childhood Although the incidence of pseudomembranous colitis is highest after treatment with clindamycin, studies have shown that exposure to any antibiotic increases susceptibility to C difficile infection In fact, because of its common use, amoxicillin is responsible for most cases of pseudomembranous colitis in childhood, even though overall incidence of C difficile infection after therapy with this agent is low Occasional cases occur in children with no recent usage of antibiotics ... Oral vs intravenous rehydration of moderately dehydrated children: a randomized controlled trial Pediatrics 2005;115:295–301 Spandorfer PR, Mace SE, Okada PJ, et al A randomized clinical trial... facilitated subcutaneous versus intravenous rehydration in mild to moderately dehydrated children in the emergency department Clin Therapeut 2012;34(11):2232–2245 Steiner MJ, Nager AL, Wang VJ Urine specific... (loose/watery) and/or greater than three stools in a 24-hour period, is a common presenting complaint to the emergency department (ED) Infants and children have variability in frequency and type of stools;