Pediatric emergency medicine trisk 135

and schistocytes. The urinalysis shows hematuria (dipstick detection of free
hemoglobin) and proteinuria. In patients with suspected pseudomembranous
colitis, stool toxin analysis provides the mainstay of diagnosis. Polymerase chain
reaction (PCR) has been shown to have higher sensitivities for toxin A and B than
enzyme immunoassay (EIA). Testing for fecal leukocytes is neither sensitive nor
specific for inflammatory diarrhea; fecal lactoferrin is a more sensitive marker
but not specific for detection of particular pathogens. When selected bacterial or
parasitic pathogens are strongly suspected, appropriate microbiologic studies
should be collected. If a multiplex polymerase chain reaction assay, is collected,
the results should be interpreted in the context the clinical picture as these panels
detect DNA and not viable organism.


FIGURE 23.1 Diagnostic approach to the immunocompetent child with diarrhea.


FIGURE 23.2 Dehydration scales. A: WHO dehydration scale. (From Jauregui J, Nelson D,
Choo E, et al. External validation and comparison of three pediatric clinical dehydration scales.
PloS
One
2014;9(5):e95739.
Copyright
©
2014
Jauregui
et
al.
.) B: Gorelick scale. (From Pringle K, Shah SP,
Umulisa I, et al. Comparing the accuracy of the three popular clinical dehydration scales in
children with diarrhea. Int J Emerg Med 2011;4:58. Copyright © 2011 Pringle et al; licensee
Springer. .) C: CDS dehydration scale. (From

Jauregui J, Nelson D, Choo E, et al. External validation and comparison of three pediatric
clinical dehydration scales. PloS One 2014;9(5):e95739. Copyright © 2014 Jauregui et al.
.)

TREATMENT
The treatments for the different causes of diarrhea are covered in the medical and
surgical sections of this book; however, the therapy for viral gastroenteritis or
parenteral diarrhea merits a summary. All children with circulatory compromise


and many children with moderate to severe dehydration need intravenous
rehydration with isotonic (normal saline or lactated Ringer’s) fluids, given rapidly
in increments of 20 mL/kg boluses. Infants and children who are symptomatically
hypoglycemic should receive IV glucose. However, most pediatric patients with
acute gastroenteritis can be managed with oral solutions. Most children will
tolerate small feedings given frequently. Fluids may also be delivered via a
nasogastric tube if needed.
Optimal oral rehydration therapy emphasizes the use of appropriate glucose
and electrolyte solutions, as well as the early reintroduction of feeding. Ideal oral
rehydration solutions, based on formulas carefully tested by the WHO, have a
carbohydrate:sodium ratio that approaches 1:1. Although some recommend,
particularly for young infants, initial oral rehydration with a solution that contains
75 to 90 mEq/L of sodium (i.e., WHO 2003 oral rehydration salts solution) and
subsequent maintenance with a more hypotonic formulation (i.e., Pedialyte), most
clinicians use a single preparation during the course of routine, brief illnesses.
Older children with mild gastroenteritis tolerate juices and other commercial
products, even though the carbohydrate:sodium ratio deviates from the WHO
standard. Feeding with age-appropriate diet, including breast-feeding for infants,
is recommended as soon as rehydration is complete. Doing so appears to reduce
stool output and duration of the diarrheal disease. Foods with complex

carbohydrates, lean meats, fruits, and vegetables are better tolerated than those
that contain fat and simple sugars. The commonly recommended restriction to
clear liquid and BRAT (bananas, rice, applesauce, toast) diets provide suboptimal
nutrition and are no longer recommended.
Probiotics (Lactobacillus rhamnosus GG strain most commonly used) has
previously been recommended to reduce duration and frequency of diarrheal
stools in children with presumed infectious diarrhea. However, a recent
multicenter, prospective, randomized, double-blind trial of children 3 months to 4
years of age with infectious diarrhea failed to show a difference in outcomes of
patients receiving probiotics (5-day course of L. rhamnosus ) versus placebo. No
differences in frequency and duration of moderate to severe diarrhea, rate of
household transmission, and duration of absenteeism from work or daycare were
seen between the two study groups. Antibiotics are not routinely recommended
for patients with diarrhea, even for those with bloody diarrhea, because acute
diarrheal illnesses are usually self-limited. Antibiotics should only be used when
diagnostic tests reveal a treatable bacterial or parasitic etiology. In general,
antidiarrheal agents are ineffective, have potentially serious side effects, and
therefore have no role in the treatment of infectious gastroenteritis. Antimotility