15 Flashcards
Diff for vomiting and diarrhea 3
Viral gastroenteritis
Bacterial gastroenteritis
Surgical need (SBO, appendicitis)
Determining degree of dehydration
The most accurate method of determining a patient’s degree of dehydration is to subtract the patient’s current weight from his or her weight immediately prior to the illness.
Acute weight loss in this setting can be assumed to be primarily loss of water weight. Therefore:
Weight loss (in grams) = water loss (in milliliters) or
Weight loss (in kg) = water loss (in liters) This result is usually converted to a "percent dehydration":
Percent dehydration is the percent of total euvolemic body weight lost as water.
Of course, a recently recorded accurate baseline weight is often unavailable. Therefore, additional physical exam findings are also used to estimate the degree of dehydration.
Oral rehydration therapy
Calculate rehydration volume in mild to moderate dehydration
Solid foods in setting of vomiting and diarrhea
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.
View a chart of commercial ORT solutions.
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 bevarages,” apple juice, colas, and ginger ale should not be used for rehydration, as their relatively low sodium concentration and high glucose content make them inappropriate.
recommended volume for mild-moderate dehydration is 50-100 mL/kg.
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.)
Viral gastroenteritis
Transmission and prevention
Viruses are present in the stool and vomit of people who are infected. Infected people may contaminate surfaces, objects, food, and drinks with viruses, especially if they do not wash their hands thoroughly after using the bathroom
Good hand washing
primary therapy for severe dehydration
IV bolts therapy using 20 mL/kg aliquots of normal saline or lactated Ringer’s.
Differential dx for recurrent emesis is in the infant 8
Gastroesophageal reflux
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.
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, causing obstruction) and by itself it does not necessarily cause symptoms. However, malrotation may result in volvulus and result in vomiting and other signs of bowel obstruction.
Bilious emesis is common.
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 not uniformly perceptible.
Intussusception
Infants with intussusception typically have bilious emesis and crampy or severe abdominal pain.
The classic “currant jelly” stools of intussusception 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—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.
Milk 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.
Urinary tract infection
UTI is an important cause of non-GI vomiting in children. In infants, symptoms of UTI are non-specific and may include fever, poor feeding and vomiting, and it may lead 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.
Pyloric stenosis suspected- workup
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. But 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.
Correction of metabolic status is necessary before corrective surgery can be performed.
Fluid management in pyloric stenosis
Definitive tx
Administer repeated IV normal saline boluses (20 mL/kg) until there is significant clinical improvement, then continue IV fluids (dextrose, sodium chloride and potassium) until after surgery
IV fluids designed to provide energy needs (dextrose) and to continue correction of his metabolic abnormalities (sodium chloride and potassium chloride) as well as his dehydration
Pyloromyotomy
Procedure
Pyloric stenosis is corrected surgically with a pyloromyotomy (Ramstedt pyloromyotomy), a procedure in which the pyloric muscle is split (divided) without cutting through the mucosa. A pyloromyotomy can be performed via a small upper abdominal incision or laparoscopically. Both procedures are relatively short and simple and have very low complication rates.
Pre-operative Care
As illustrated in this case, it is very important to correct electrolyte abnormalities and dehydration prior to surgery.
Post-operative Care
Oral feeding can generally be resumed within 12-24 hours after surgery.
Vomiting in the first few days after surgery is common but not severe.
Most babies can return home within just a couple of days of the surgery.
Moderate dehydration and severe dehydration
Moderate slightly sunken eyes and anterior fontanelle, cool extremities, nml or decreased tears
Oral rehydration
Severe deeply sunken eyes and fontanelle, cyanotic and mottled extremities, absent tears
IV of NS or LR
