Case 15

Question 1

What are the key history findings for acute gastroenteritis?

Answer 1

Diarrhea for two days, vomiting, tactile fever, children sick at child care.

Question 2

What are the key findings from physical exam for acute gastroenteritis?

Answer 2

Weight loss, afebrile, mild dehydration, normal bp and abdominal exam.

Question 3

What are the key history findings for pyloric stenosis?

Answer 3

Forceful vomiting, no fever, no diarrhea, increasing sleepiness.

Question 4

What are the key physical exam diagnosis for pyloric stenosis?

Answer 4

Arousable, but excessively sleepy, weak cry, weight loss, tachycardia, sunken eyes and fontanel, dry mucous membranes, poor perfusion, no abdominal tenderness or masses, visible peristaltic waves.

Question 5

What is on the differential diagnosis for pyloric stenosis?

Answer 5

Gastroenteritis, UTI, GERD, Intussusception, Lower GI obstruction, metabolic disorder, CNS disease

Question 6

What are the key findings from testing for pyloric stenosis?

Answer 6

BMP: hypochloremic, hypokalemic metabolic alkalosis.
US: Pyloric stenosis

Question 7

Rehydration therapy for children:

Answer 7

When fluid therapy is planned for patients (i.e. when their fluid and electrolyte intake will be controlled by means other than their normal oral intake), it is necessary to consider both their water and their electrolyte needs.

• Primary solutes (electrolytes) to consider are sodium, potassium, and chloride (chloride is usually coupled to the sodium and potassium to maintain electrical neutrality)
• For both water and electrolytes, consider:
• -Daily maintenance needs
• -Any fluid and/or electrolyte deficits
• -Any unusual ongoing losses (eg diarrhea, fever)

Question 8

Maintenance fluid definition:

Answer 8

Replacement of fluid and electrolytes lost through normal basal metabolic processes (eg, heat dissipation, growth, energy metabolism) and urine output.

• Heat is dissipated by insensible evaporation of water from the skin or by elimination of warm vapor from the upper respiratory tract during exhalation.
• Soluble waste products of metabolism are excreted in urine

Question 9

How were fluid and electrolyte replacement for a child with dehydration calculated previously?

Answer 9

It involved calculating both the maintenance needs and the estimated fluid and electrolyte deficit, and administering these over a 24-48 hour time period (termed “deficit therapy”)

Question 10

How to treat children with mild-moderate (5-9 percent) dehydration?

Answer 10

Oral or enteral rehydration, using an appropriate oral rehydration solution (ORS) is recommended, using the following guidelines:

• 50-100 mL/kg of oral rehydration solution (ORS) over 2-4 hours; begin with very small volumes - teaspoons - given very frequently
• Give 10 mL/kg ORS for each additional diarrheal stool and 2 mL/kg ORS for each additional emesis.

Question 11

How to treat children with moderate-severe (10-15 percent dehydration)?

Answer 11

Initial rehydration should be via IV bolus therapy, using an isotonic, non-dextrose containing solution (normal saline or lactated Ringer’s solution are common choices), as follows:

• 20 mL/kg IV fluid bolus
• Repeat bolus after re-evaluation until patient is clinically improved:
• -Awake, alert, well perfused
• -Interested in and tolerating oral fluids
• -Urine output present
• Often 60-100 mL/kg total (in 10-20 mL/kg increments) of bolus fluids are required, with repeated evaluation
• Depending on the clinical situation, rehydration can be completed with oral rehydration therapy, or with IV fluids at a rapid rate (eg, 1.5 maintenance fluids with D5 1/2 normal saline)

Question 12

Maintenance fluid and electrolyte calculations:

Answer 12

Used to derive the appropriate amount of fluid administration in patients who cannot be allowed free access to oral fluids.

• These calculations assume that patient is in a normal situation (i.e. normal urine output, no abnormal fluid losses, etc.)
• Individuals with losses outside the norm (eg, due to renal failure, diabetes insipidus, increased evaporative fluid loss due to persistent high fever) require modifications of the formulas.

Question 13

What are the two calculation methods for maintenance fluids?

Answer 13

Maintenance fluids can be calculated using either the (1) weight method or the (2) body surface area (BSA) method.

• BSA method is technically somewhat more accurate, but an accurate BSA is often not available
• Both methods provide an adequately accurate estimate of daily fluid and solute requirements.

Question 14

What is the weight method of calculating maintenance fluids?

Answer 14

Water - 100 ml/kg/day (first 10 kg body weight) plus 50 ml/kg/day (next 10 kg body weight) plus 20 ml/kg/day (any additional body weight)
Sodium - 3-4 mEq per 100 mL fluid
Potassium - 2-3 mEq per 100 mL fluid

Question 15

What is the body surface area (BSA) method?

Answer 15

Water - 1500-2000 mL/m2/day, Sodium - 45 mEq/m2/day, Potassium - 35-40 mEq/m2/day

Question 16

What is the composition of D5W IV?

Answer 16

Glucose, 50 g/L solute concentration, 278 mOsm/L Total.

Question 17

What is the composition of D10W IV?

Answer 17

Glucose, 100 g/L solute concentration, 556 mOsm/L Total.

Question 18

What is the composition of 0.2 percent saline (1/4 NS)?

Answer 18

NaCl 2.0 g/L solute concentration. 34 mEq/L Na, 34 mEq/L Cl, 68 mOsm/L Total.

Question 19

What is the composition of 0.4 percent saline (1/2 NS)?

Answer 19

NaCl 4.5 g/L solute concentration. 77 mEq/L Na, 77 mEq/L Cl, 154 mOsm/L Total.

Question 20

What is the composition of 0.9 percent saline (NS)?

Answer 20

NaCl 9.0 g/L solute concentration. 154 mEq/L Na, 154 mEq/L Cl, 308 mOsm/L Total.

Question 21

What is the composition of D5 0.2 percent saline?

Answer 21

Glucose 50 g/L and NaCl 2.0 g/L solute concentration. 34 mEq/L Na, 34 mEq/L Cl. 346 mOsm/L Total.

Question 22

What is the composition of D5 0.45 percent saline?

Answer 22

Glucose 50 g/L and NaCl 4.5 g/L solute concentration. 77 mEq/L Na, 77 mEq/L Cl. 432 mOsm/L Total.

Question 23

What is the composition of D5 NS?

Answer 23

Glucose 50 g/L and NaCl 9.0 g/L solute concentration. 154 mEq/L Na, 154 mEq/L Cl. 586 mOsm/L Total.

Question 24

What is the composition of Lactated Ringer’s (LR)?

Answer 24

NaCl (6.0), KCl (0.3), CaCl2 (0.2), Na lactate (3.1). 130 Na, 109 Cl. K (4.0), Ca (3.0), lactate (28). 272 mOsm/L Total.

Question 25

What is the composition of Ringer's?

Answer 25

NaCl (8.6), KCl (0.3), CaCl2 (0.3). 147 Na, 156 Cl. K (4.0), Ca (3.0). 309 mOsm/L Total.

Question 26

What is the composition of hypertonic saline?

Answer 26

3 percent NaCl. NaCl 30. 513 Na 513 Cl. 1026 mOsm/L Total.

Question 27

What is the composition of Sodium bicarbonate 5 percent?

Answer 27

NaHCO3 50. Na 595. HCO3 (595), 1190 mOsm/L Total.

Question 28

What is the composition of sodium bicarbonate 8.4 percent?

Answer 28

NaHCO3 84. Na 1000. HCO3 (1000), 2000 mOsm/L Total.

Question 29

What is the composition of 5 percent albumin?

Answer 29

Albumin 50. Na 100-160. Less than 120 Cl.

Question 30

What is the composition of 25 percent albumin?

Answer 30

Albumin 250. Na 130-160.

Question 31

How can you assess a child's hydration status by telephone?

Answer 31

- Child's level of activity - Presence of fever - Ability/desire to take fluids/food by mouth - Sick contacts (viral gastroenteritis is easily transmitted from person to person) - Signs of abdominal pain - Contents of emesis or stool (bloody or bilious emesis or stool would suggest a more serious condition) - Urine output - Stool output

Question 32

Pregnancy and birth history:

Answer 32

An abnormal prenatal ultrasound (polyhydramnios) could suggest a congenital anomaly that may be associated with vomiting.

Question 33

Diet history:

Answer 33

May identify causes of vomiting such as overfeeding or identify inappropriate feeding regimens (dilute formula resulting in excessive free water intake)

Question 34

Immunizations:

Answer 34

Helpful to know if infant has been immunized against rotavirus (first due at 2 months of age)

Question 35

What is the most accurate method of determining degree of dehydration?

Answer 35

Subtract patient's current weight from the weight immediately prior to the illness (since any acute weight loss in this setting can be assumed to be primarily loss of water weight). - Weight loss in kilograms is equivalent to water loss in liters - Result can be converted to a "percent dehydration" (percent of total euvolemic body weight lost as water)

Question 36

What are additional exam findings indicative of dehydration?

Answer 36

- Tachycardia - Hypotension - Sunken fontanel in an infant - Sunken eyes - Tacky or dry mucous membranes - Loss of skin turgor - Poor peripheral perfusion (delayed capillary refill)

Question 37

What is on the differential diagnosis for Pyloric stenosis?

Answer 37

Viral gastroenteritis, UTI, malrotation w/ or w/o volvulus, GE reflux, Inborn error of metabolism, CNS disease, Intussusception.

Question 38

What are less likely diagnosis on differential for pyloric stenosis?

Answer 38

Milk allergy, Cystic fibrosis, Overfeeding, Inflammatory bowel disease, food poisoning.

Question 39

Viral gastroenteritis:

Answer 39

Large watery stools are the hallmark of infectious gastroenteritis ("enteritis" not truly present if no diarrhea). Vomiting may be present early in the infection. Dehydration from fluid losses is common. Outbreaks can occur in child care centers.

Question 40

Pyloric stenosis:

Answer 40

An escalating pattern of forceful (projectile), non-bilious vomiting and hypochloremic, hypokalemic metabolic alkalosis with dehydration are hallmarks of pyloric stenosis. Bilious emesis is not typical (obstruction is above the ligament of Treitz). Infants with pyloric stenosis can have rapid rehydration, but typically have vigorous appetite until late in clinical course. Can be associated with streaks of blood in emesis.

Question 41

Urinary tract infection (UTI):

Answer 41

Important non-gastrointestinal cause of vomiting in children. Symptoms of UTI in infants are nonspecific and may include fever, poor feeding, and vomiting - potentially leading to dehydration if not identified and treated.

Question 42

Malrotation with/without volvulus:

Answer 42

Malrotation without volvulus (twisting of the intestine on itself, causing obstruction) may be asymptomatic. Malrotation with volvulus causes bilious emesis (below the ligament of Treitz). Bowel ischemia can cause significant abdominal pain. Infants with malrotation and volvulus may present with shock, which may initially be difficult to distinguish from dehydration.

Question 43

Gastroesophageal (GE) reflux:

Answer 43

Regurgitation/spitting up may be difficult to distinguish from vomiting. 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.

Question 44

Inborn error of metabolism:

Answer 44

Uncommon, but need to consider in any infant with recurrent vomiting, since symptoms of the underlying disorder may be triggered by intercurrent illness. Infants with inborn errors of metabolism may present in shock, which may be difficult to distinguish from severe dehydration.

Question 45

Central nervous system (CNS) disease:

Answer 45

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.

Question 46

Intussusception:

Answer 46

Typically associated with bilious emesis and crampy or severe abdominal pain. The classic "current jelly" stools of intussusception may be misidentified in the history as diarrhea. A "sausage-like" mass due to the telescoped bowel may be palpated on abdominal exam.

Question 47

Milk allergy:

Answer 47

May present with vomiting immediately after eating but more typically will present with a rash or loose stools; does not typically cause dehydration.

Question 48

Cystic fibrosis:

Answer 48

May present with failure to thrive and loose, malabsorptive stools but does not typically present with vomiting unless infant has bowel obstruction at birth (meconium ileus).

Question 49

Overfeeding:

Answer 49

Can cause vomiting, but unlikely to cause poor weight gain, weight loss or dehydration.

Question 50

Inflammatory bowel disease:

Answer 50

Usually associated with changes in stool pattern and growth; extremely unlikely in a young infant.

Question 51

Food poisoning:

Answer 51

Presents with vomiting, but is usually short-lived and occurs after ingestion of foods that are more likely to harbor bacteria (i.e, not typically after formula feeding with usual formula)

Question 52

BMP (serum electrolytes, blood urea nitrogen (BUN), creatinine, calcium, glucose):

Answer 52

Because of loss of stomach fluid and inadequate fluid intake, pyloric stenosis commonly leads to a hypochloremic, hypokalemic metabolic alkalosis: - Deceased chloride - Decreased potassium - High bicarbonate - Elevated BUN

Question 53

Pyloric ultrasound:

Answer 53

Study of choice to confirm pyloric hypertrophy.

Question 54

Upper GI contrast study:

Answer 54

- Also may be used to diagnose pyloric stenosis. Will show the "string sign" (narrowed pyloric channel), indentation of the hypertrophied pylorus on the antrum of the stomach, and delayed gastric emptying. - If there is concern for malrotation or volvulus, include imaging of contrast passing through the small intestine.

Question 55

Urinalysis and urine culture:

Answer 55

Should obtain in an infant presenting with vomiting and fever.

Question 56

Head computed tomography (CT):

Answer 56

May be needed to look for signs of increased intracranial pressure if pyloric stenosis is ruled out.

Question 57

Oral rehydration therapy (ORT) for Viral gastroenteritis management:

Answer 57

Commonly prepared solutions containing glucose and electrolytes that may be used in mild-moderate dehydration for patients who can tolerate small amounts of fluids. - Just as effective as IV fluids, less expensive and safer - ORT can even be effective when vomiting is still present - There are several oral rehydration solutions available commercially in the US including naturalize, pediatric electrolyte, pedialyte, infalyte, rehydralyte. - All typically have Na concentrations of 45-50 mmol/L - Sports beverages, apple juice, colas, and ginger ale have a relatively low sodium concentration and high glucose content, which make them less appropriate for ORT.

Question 58

Solids foods for management of viral gastroenteritis:

Answer 58

- 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

Question 59

Breast and formula feeding for management of viral gastroenteritis:

Answer 59

- Breastfeeding and formula feeding can continue through the period of rehydration. - Esp. important in lesser developed countries where malnutrition is an important contributing factor to morbidity and mortality associated with diarrhea and dehydration.

Question 60

What anticipatory guidance should clinicians tell parents of children with viral gastroenteritis?

Answer 60

- Continue to offer ORT through the day - Need medical attention if: - -Patient again becomes listless - -ORT is not tolerated - -Diarrhea persists

Question 61

How do you prevent transmission of viral gastroenteritis?

Answer 61

- Most effective way to prevent further spread of viral gastroenteritis is good hand-washing - Medication is not useful in preventing transmission

Question 62

What is the best management of Pyloric Stenosis?

Answer 62

1. Admit to hospital 2. Rehydration and correction of electrolyte imbalances 3. Surgical consult 4. Refeeding

Question 63

How do you manage rehydration and correction of electrolyte imbalances in a child with pyloric stenosis?

Answer 63

- Correction of fluid status and any electrolyte abnormalities is necessary before surgery can be performed - Provide volume restoration via IV boluses of isotonic saline solution. Repeated boluses of NS or lactated ringers solution, in 10-20 ml/kg aliquots, are given (reassessing after each bolus) until patient has improved to only mild dehydration or normal fluid status. - Rehydration can then be completed either orally or with ongoing parenteral fluids.

Question 64

What does a surgical consult do for pyloric stenosis?

Answer 64

- Pyloric stenosis is corrected surgically with a pyloromyotomy (Ramstedt pyloromyotomy), a procedure in which the pyloric muscle is cut - Can be performed via a small upper abdominal incision or laparoscopically - Both procedures are relatively short and simple and have very low complication rates

Question 65

How does referring occur with pyloric stenosis?

Answer 65

- Usually 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.