15. Two siblings: 4 year-old male and 8 week-old male with vomiting
Assessing severity of illness by telephone
"Has he been around anyone else who has been ill?" Asking about sick contacts is important because viral gastroenteritis is easily transmitted from person to person. "Has he had significant abdominal pain?" Severe or localized abdominal pain would suggest a more serious condition than viral gastroenteritis. "What is the character of the emesis (stomach contents, bilious, bloody)?" Bloody or bilious emesis would suggest a more serious condition than viral gastroenteritis. "What is the character of the stool (bloody, watery, mucus-containing)?" Bloody stool would suggest a more serious condition than viral gastroenteritis. "Has he had fever?" If yes, is consistent with an infectious cause. "Is he eating and drinking? How much?" A child with a serious illness typically is not interested in eating or drinking. Knowing the quantity of fluid taken in over a certain time period is helpful in assessing hydration status. Children with significant fluid loss should be thirsty. Lack of desire to take fluids can actually be a primary symptom of severe dehydration.
Basic steps of fluid management
Basic steps of fluid management For any pediatric patient who is dehydrated, it is important to: 1. Replace the fluid deficit 2. Provide maintenance fluids 3. Replace any ongoing fluid losses Deficit replacement: Fluid boluses administered during the immediate assessment period expand intravascular volume and should improve vital signs and peripheral perfusion. The amount of fluid required to replace the patient's deficit is dictated by an assessment of the degree of dehydration. and is typically replaced over 24-48 hours. Maintenance fluids are generally provided in a volume as follows: For the first 10 kg, 4mL/kg/hour For the second 10 kg, 2mL/kg/hour For any additional kg, 1mL/kg/hour Ongoing losses include vomiting, diarrhea, nasogastric tube output, and increased insensible losses due to fever or tachypnea.
Electrolyte abnormalities in pyloric stenosis
A hypochloremic, hypokalemic metabolic alkalosis is one of the hallmarks of pyloric stenosis.
Solid foods in setting of vomiting and diarrhea
Children who have vomiting and diarrhea and are not dehydrated should continue to be fed age-appropriate diets. Children who are dehydrated should be fed as soon as they have been rehydrated. Breastfeeding and formula feeding can continue through the period of rehydration. (This is especially important in lesser developed countries where malnutrition is an important contributing factor to morbidity and mortality associated with diarrhea and dehydration.)
Diagnostic workup of possible pyloric stenosis
Diagnostic workup of possible pyloric stenosis It is important to first consider potential causes of emesis in infancy that would require emergency management, such as volvulus or increased intracranial pressure. For example, in the setting of bilious emesis, a diagnostic study for volvulus would be an important initial study. If an infant has neurologic symptoms or behavioral changes suggestive of increased ICP, a head CT scan would be critical. In the absence of signs or symptoms of diagnoses requiring emergency management, it is appropriate to pursue diagnostic studies for pyloric stenosis. Pyloric ultrasound In experienced hands, a pyloric ultrasound is the study of choice to confirm pyloric hypertrophy. Upper GI contrast study If ultrasound is unavailable, an upper GI contrast study will demonstrate a very narrow pyloric channel (the "string sign"), indentation of the hypertrophied pylorus on the antrum of the stomach, and delayed gastric emptying. If there is significant concern for malrotation or volvulus, the upper GI study should include imaging of contrast passing through the small intestine as well. (The absence of bilious emesis suggests no obstruction beyond the pylorus.) Electrolytes Pyloric stenosis is typically associated with electrolyte abnormalities because of loss of stomach fluid and inadequate fluid intake. These abnormalities include hypochloremia, hypokalemia, and alkalosis. (There may also be some metabolic acidosis related to lactic acidosis from dehydration, but the primary abnormality is typically metabolic alkalosis.) Correction of metabolic status is necessary before corrective surgery can be performed.
Differential diagnosis for recurrent emesis in the infant
GERD Regurgitation/spitting up may be difficult to distinguish from true vomiting. Infants who reflux with overfeeding may sometimes have forceful vomiting. Severe esophagitis may result in blood-streaked emesis. Pain from reflux or esophagitis may lead to feeding aversion when gastroesophageal reflux is severe. An infant who is dehydrated due to severe GE reflux should also have significant failure to thrive. Milk protein allergy Milk protein allergy may present with vomiting immediately after eating but more typically will present with a rash or loose stools; it does not typically cause dehydration. Viral gastroenteritis Early in the course of the infection there may be isolated vomiting, but large watery stools are the hallmark of infectious gastroenteritis. Dehydration due to fluid losses often accompanies gastroenteritis. Bilious emesis is not typically seen with gastroenteritis or a GI tract obstruction above the ligament of Treitz, but small amounts of bile may be seen with repetitive vomiting. "Enteritis" is not truly present if diarrhea is not present. Malrotation +/- volvulus Malrotation may be present without volvulus (twisting of the intestine on itself) and by itself it does not necessarily cause symptoms. However, malrotation may result in volvulus, with acute onset vomiting and other signs of bowel obstruction. Bilious emesis is common with intestinal volvulus. Blood may be seen in the stool but not typically in the vomitus. Bowel ischemia from volvulus can cause significant abdominal pain. Infants with malrotation and volvulus may present with shock, which may initially be difficult to distinguish from dehydration. Inborn error of metabolism Although uncommon, metabolic disorders should be considered, particularly in infants with recurrent emesis. Symptoms may be triggered by intercurrent illness such as gastroenteritis or infections. Infants with inborn errors may present with diminished oral intake for a variety of reasons, including lethargy and irritability. Metabolic disorders may also present with shock, which may be difficult to distinguish from severe dehydration. Pyloric stenosis An escalating pattern of forceful (projectile), non-bilious vomiting is a hallmark of pyloric stenosis. Bilious emesis is not typical because the obstruction is above the ligament of Treitz. Infants with pyloric stenosis can have rapid dehydration due to inadequate fluid absorption, but they typically have a vigorous appetite until late in the clinical course. Infants with pyloric stenosis often present with mild-moderate dehydration due to persistent vomiting. The presence of hypochloremic, hypokalemic metabolic alkalosis with dehydration is another hallmark of pyloric stenosis. Bloody emesis is sometimes seen in pyloric stenosis and other causes of forceful emesis due to the development of Mallory-Weiss tears in the esophagus. Infants with pyloric stenosis may demonstrate a visible peristaltic wave (particularly just after eating). A palpable "olive" (the hypertrophic pyloric muscle) in the epigastric region very strongly suggests the diagnosis but is often difficult to appreciate. Intussusception Infants with intussusception typically have bilious emesis and crampy or severe intermittent abdominal pain. The classic "currant jelly" stool of intussusception occurs late and may be mis-identified in the history as diarrhea. The abdominal exam in children with intussusception often shows the presence of a "sausage-like" mass due to the telescoped bowel. CNS disease CNS diseases causing increased intracranial pressure -such as hydrocephalus, intracranial neoplasm, and trauma (accidental or non-accidental)-must be considered in vomiting children, especially in the absence of fever and diarrhea. UTI UTI is an important extraintestinal cause of vomiting in children. In infants, symptoms of UTI are non-specific and may include fever, poor feeding and vomiting, leading to dehydration if not identified and treated. Infants with a UTI are unlikely to have watery diarrhea but loose stools may be seen in the setting of significant infection.
GERD:
GERD: Infants who reflux with overfeeding may sometimes have forceful vomiting. Severe esophagitis may result in blood-streaked emesis. Pain from reflux or esophagitis may lead to feeding aversion when gastroesophageal reflux is severe.
A 15-month-old boy presents to the ED in January with a 3-day history of diarrhea. His current weight is 11 kg. He was born at 39 weeks, without any perinatal complications. There is no significant history of travel, sick contacts, or recent changes in diet. The mother notes that he has had only 2 diaper changes over the last day. Physical exam is remarkable for an irritable but consolable infant with tachycardia and normal blood pressure. He is crying without tears and his mucous membranes are dry. His abdominal exam is benign. There is no tenting, and capillary refill is 2 seconds. He is diagnosed with gastroenteritis and started on rehydration therapy. Which of the following statements is true?
In addition to correcting this patient's hydration status, a work-up for the infectious causes of this patient's diarrhea might include a stool Wright's stain for fecal WBCs (which would suggest a bacterial cause if this is infectious diarrhea), a Rotazyme test (given the high incidence of rotavirus in the winter months), and a stool sample for culture and sensitivity. Additional studies might include stool guaiac (for occult blood) and a check for stool C. diff toxin.
Assessing hydration status by telephone
In assessing hydration status by telephone, the most reliable findings to inquire about are: the child's level of activity his ability and/or desire to take fluids by mouth urine output (frequency/amount) Asking a parent to try to assess physical examination features for dehydration (such as moistness of mucus membranes or skin turgor) should not be part of your telephone "exam."
Oral rehydration therapy
Oral rehydration therapy (ORT) using commercially prepared oral rehydration solutions (ORS) that contain glucose and electrolytes is used in cases of mild-moderate dehydration. ORT is as effective, safer, and much less costly than intravenous therapy. ORT can be used effectively even when children are still having some vomiting. ORT should be given as 50-100mL/kg total volume over 2-4 hours in small aliquots like sips or with a spoon. The oral rehydration solutions available commercially in the U.S. (such as Naturalyte, Pediatric Electrolyte, Pedialyte, Infalyte, Rehydralyte) typically have sodium concentrations of 45-50 mmol/L. They may be used for rehydration of healthy children with mild or moderate dehydration. In the setting of gastroenteritis, "sports beverages," apple juice, colas, and ginger ale should not be used for rehydration, as their relatively low sodium concentration can lead to hyponatremia.
Pyloric stenosis:
Pyloric stenosis: history of frequent vomiting, poor weight gain, and the finding of an abdominal mass are consistent with pyloric stenosis. Children with pyloric stenosis often present at 3 weeks of age.
Severe dehydration treatment:
Severe dehydration treatment: Lactated Ringer's solution or normal saline in 20 mL/kg boluses until urine output is established and mental status improves, then 100 mL/kg oral rehydration solutions over next 4 hours. This follows current CDC guidelines for treating a severely dehydrated child. Intravenous hydration with 5% dextrose ½ normal saline at twice maintenance fluid rates may be substituted for the oral rehydration solution if the child is not tolerating PO intake. To replace ongoing losses, the CDC recommends 60-120mL of oral rehydration solution per diarrheal/emetic episode (through a nasogastric tube, if necessary).
Fluid therapy for severe dehydration
The primary recommended mode of therapy for severe dehydration is to provide volume restoration via IV bolus therapy with an isotonic saline solution. Repeated 10-20 mL /kg boluses of normal saline are given (up to three times, reassessing after each bolus) until the patient has improved to only mild dehydration or normal fluid status. Normal saline is the preferred fluid choice in pyloric stenosis because of its high chloride content - and because it does not contain lactate, a base which could worsen the alkalosis. Rehydration can then be completed either orally (if vomiting has resolved) or with ongoing IV fluids.
Calculating rehydration volume in mild-moderate dehydration
The recommended fluid replacement volume for mild-moderate dehydration is 50-100 mL/kg, to be replaced over 2-4 hours. Example: Patient's weight = approx. 18 kg 50 mL/kg = 900 mL 100 mL/kg = 1800 mL Total replacement volume should be 900-1800 mL (30-60 oz.), to be given over 2-4 hours.
Viral gastroenteritis treatment:
Viral gastroenteritis treatment: Because he is still tolerating some PO feeds, has no obvious signs of dehydration, and has normal vital signs, there is no need for aggressive IV fluid administration or diagnostic work up. Strict return precautions should be given and it should be advised that Johnny maintains fluids as much as possible.
