GI and IV

Question 1

Types of Dehydration

Answer 1

Hyponatremic/Hypotonic = Na less than 130
From excess loss of Na, or most commonly replacement fluid w/ excess of free water (hypotonic solutions)

Isonatremic/Isotonic = Na 130-150
Proportional loss of Na and water
Most common and what we’ll focus on today

Hypernatremic/Hypertonic = Na >150
Implies free water loss or increased insensible losses (DI)
Slow rehydration (over two days) to avoid fluid shifts that could cause cerebral edema or intracranial bleeding – drop sodium no faster than 15meq/day 
** Maybe be deceiving clinically --> extravascular fluid is maintained for longer while intracellularly the patient may be dehydrated

Question 2

signs of dehydration

Answer 2

turgor, skin feel dry --> clammy
mucosa dry--> parched
eyes deep set--> sunken
fontanelle--> soft--> sunken
CNS irritable --> lethargic/ obtunded
pulse rate mild increase --> increased
pulse quality weak--> feeble
cap refill 2 sec --> over 3 sec
urine output decreased --> anuric

Question 3

ORAL REHYDRATION

Answer 3

Oral rehydration therapy (ORT) is recommended as the preferred treatment of fluid and electrolyte losses caused by diarrhea in children with mild to moderate dehydration, 50-100cc/kg over four hours.
WHO packets: mix one packet with 1L water.
World-wide use has decreased mortality by 50% since 1980s

Question 4

When to choose intravenous rehydration therapy over Oral rehydration therapy?

Answer 4

• Inability of the child to take ORT (altered mental status, ileus, anatomic anomaly)
• Inability of the caregiver to provide ORT
• Failure of ORT to provide adequate rehydration (eg, persistent vomiting)
• Severe electrolyte problems in clinical setting where ORT cannot be closely monitored or electrolytes frequently assessed

Question 5

crystalloid fluids

Answer 5

• Based on crystalloid solutions, thus containing water and electrolytes, but have the added component of a colloidal substance that does not freely diffuse across a semipermeable membrane

Question 6

THE APPROACH TO FLUID REPLACEMENT IN DEHYDRATION

Answer 6

• 1. Restore intravascular volume for hemodynamic stability: the boluses!**
• 2. Calculate 24 hr water requirements
     Part 1: Maintenance – given at constant rate over 24 hrs
     Part 2: Deficit – divided so that ½ is given over first 8 hrs, then ½ over the next 16 hrs.

Calculate 24 hr electrolyte requirements
Part 1: Maintenance Na+ and K+
Part 2: Deficit Na+ and K+ (especially important in hypo/hypernatremic dehydration)

4. Select appropriate fluids
5. Replace ongoing losses

Question 7

1. RESTORE INTRAVASCULAR VOLUME in hemodynamically unstable patients

Answer 7

usually for severe dehydration

bolus therapy

• Rapid infusion of relatively isotonic fluid
• 20 ml/kg (consider 10 ml/kg for cardiac pts)
• Normal saline or Lactated ringers

Question 8

2. Calculate 24 hr water requirements- maintenance

Answer 8

Maintenance

Daily water needs based on energy expenditure

1 kcal expended/day = 1 ml water required

You can calculate it by

- Caloric expenditure method (more needed for illness)	 
- Holliday-Segar (based solely on weight), kids only, over 4 wks
- BSA

Question 9

Holliday-segar method (maintenance)

Answer 9

4+2+1

4 ml/kg/hr for the first 10 kg
2 ml/kg/hr for the next 10 kg

remainder 1 ml/kg/hr

Question 10

2. Calculate 24 hr water requirements part 2- deficit

Answer 10

Deficit
“How much is he down?”

Fluid deficit (ml) 
= 	%dehydration of pre-illness wt.(kg) X 1000 ml/kg

Example: infant with weak pulses, tenting of skin, irritability, etc, would be estimated at 10% dehydration, so:
10% of 12 kg child = 1.2 kg 
then 1.2 kg X 1000 ml/kg = 1200 ml fluid deficit

Question 11

maintenance of Na+ and K+

Answer 11

Na+: 3 Na+ mEq per 100ml of H2O

K+: 2 K+ mEq per 100ml of H2O

Question 12

electrolytes and compartments

Answer 12

Na+ is essentially all EXTRACELLULAR, while

K+ is essentially all INTRACELLULAR.

Question 13

selection of fluids

Answer 13

In general, for isonatremic dehydration :

<10 kg use 0.25 NS
10-20 kg use 0.5 NS

Question 14

add potassium

Answer 14

K+ to be added after the patient has voided

K+ concentrations should not exceed 40 mEq/L or rate of 0.5mEq/kg/hr in peripheral IVs

Question 15

little kid vs bigger kid maintenance

Answer 15

Little kid maintenance:
D1/4 NS with 20-40 mEq KCl or K acetate added per liter

Bigger kid maintenance:
D ½ NS with 20-40 mEq KCl or K acetate added per liter

Question 16

bolus calculation

Answer 16

20 ml/kg - now

make sure the subtract the bolus out from the deficit later!

Question 17

Duodenal atresia

Answer 17

Congenital obstruction of 2nd portion of duodenum

Failure of recanalization of bowel segment
Recanalization occurs during the 4th - 5th week of gestation

Usually occurs below the ampulla of Vater

Associations
Polyhydramnios
Down syndrome 25% of patients
CHD in 20%
Presentation: bilious emesis 
in neonate

Question 18

double bubble

Answer 18

The double bubble sign on x-ray is pathognomonic for duodenal atresia

Question 19

3 types of duodenal atresia

Answer 19

Type I – mucosal web with normal muscular wall (most common)
Type II – short fibrous cord connecting two atretic ends of duodenum
Type III – complete separation of the atretic ends

Question 20

viral gastroenteritis bs bacterial

Answer 20

watery diarrhea- viral
normally self-limiting but can cause severe dehydration

bacterial– often bloody bowel movements
fecal leukocytes

Question 21

most common causes of bloody stools

Answer 21

Campylobacter
Salmonella
Shigella
Yersinia
Enterohemorrhagic 
E. Coli

Question 22

causes of viral gastroenteritis

Answer 22

rotavirus
caliciviruses
astroviruses
adenoviruses
food borne: NOROVIRUSES

Question 23

diarrhea workup

Answer 23

** Vast majority of cases do not require work up
Electrolyte disturbances rare in children with moderate dehydration.
Consider baseline BMP if starting IVF

Fecal leukocytes and stool culture with hx of bloody diarrhea

C. difficle toxin in those 12m or older recently treated with Abx
Rarely occurs in children less than 12-24 months

Stool for ova/parasites in those with prolonged watery diarrhea (>14d) and travel in endemic area of parasites

CBC/blood cultures in those suspecting systemic infection

Question 24

Oral rehydration therapy

Answer 24

ORT with electrolyte solution is the preferred method of rehydration for mild to moderate dehydration
If patient has been vomiting, then small sips of electrolyte solution till emesis stops then slow reintroduction of liquids/bland solids (labor intensive!!): ideally 5 cc every 1-2 minutes, but commonly 5 cc (one teaspoon) every 10 minutes or 30 cc (one ounce) every 15 minutes
Can try Zofran (ondansetron) ODT (oral disintegrating tablet) if vomiting

Intravenous rehydration recommended for severe dehydration (or if not tolerating ORT)

Question 25

antimotility agents

Answer 25

Do not use antimotility agents in children!

Question 26

Reflux episodes occur most often during

Answer 26

transient relaxations of the lower esophageal sphincter (LES) unaccompanied by swallowing

Question 27

important symptoms, signs maybe associated with GE reflux

Answer 27

Recurrent regurgitation with/without vomiting

extra-esophageal, like Cough (which can be mistaken for URI)

esophagitis
recurrent pneumonia
dental erosion
Sandifer syndrome (dystonic neck posturing)

Question 28

STANDARD MEDICAL CARE of GERD

Answer 28

**First line therapy is nonpharmacologic
Advise on appropriate amounts of formula
Thickening of feedings by adding rice cereal to formula
Prone positioning at 30 degrees while awake
Elevating HOB and placing on back while asleep
Hold upright for 30 min after feeding

H2 receptor blockers
proton pump inhibitors

surgical treatment

Question 29

Constipation

Answer 29

The most common nonorganic cause is functional fecal retention or voluntary stool withholding.

It can be associated with encopresis (overflow stool) and urinary tract infections.

Question 30

INTUSUSSCEPTION

Answer 30

intermittent episodes of severe abdominal pain
Telescoping of the intestine, sometimes from a lead point
Between episodes patients are active and asymptomatic.
“currant jelly” stools

air contrast enema can be diagnostic and potentially therapeutic

Question 31

FUNCTIONAL ABDOMINAL PAIN

Answer 31

Diagnosis of exclusion
Generally presents * between 6 and 14 years of age
Normal physical exam findings without weight loss or blood in stools, normal labs
Symptoms are usually present for * more than three months.

be concerned if the pain awakens child at night

Question 32

Esophageal foreign bodies- urgent or emergent intervention:

Answer 32

• When the object is sharp, long, or consists of magnets
• When the object is a disc battery in the esophagus
  If airway compromise,

Question 33

ESOPHAGEAL FOREIGN BODY

Answer 33

Coins easily pass

Most esophageal foreign bodies are retained at the thoracic inlet, the level of the aortic arch, or the gastroesophageal junction.

Less than 1% of esophageal foreign body cause significant morbidity. These uncommon complications include esophageal erosion and perforation, esophageal stenosis, or fistula.

Ingested button batteries and sharp objects should be removed immediately!!!

Question 34

MECKEL DIVERTICULUM

Answer 34

the MOST COMMON cause of SERIOUS lower GI bleeding in children (blood transfusions often needed)
May see currant jelly stool (despite being lower GI bleed) as with intussusception or bright red blood

Question 35

Pyloric Stenosis

Answer 35

between 3-5 weeks of age, and very rarely occur after 12 weeks of age.

Typical nonbilious vomiting that is forceful immediately after feeding, while the infant remains hungry.
–> “Projectile vomiting”

A firm “olive-like” mass may be palpable in the right upper quadrant of the abdomen

–> hypochloremic metabolic alkalosis