ACUTE DIARRHEA

      get a good history (daycare, travel, drugs, foods, other symptoms) Etiology     viral infection most c...

 

 

 

get a good history (daycare, travel, drugs, foods, other symptoms)

Etiology 

 

1. viral infection
   • most common in Canada, e.g. Rotavirus
   • associated with URTIs
   • slight fever, malaise, vomiting, vague abdominal pain
   • resolves in 3-7 days 
2. bacterial infection
   • Salmonella, Campylobacter, Shigella, pathogenic E. coli, Yersinia
   • more severe abdominal pain, high fever, bloody diarrhea
3. parasitic infection : Giardia lamblia, E. histolytica 
4. toxin-induced: staphylococcal food poisoning, C. difficile toxin
5. allergic: food intolerance
6. antibiotic-induced
7. non-specific: associated with any non-GI infection, generalized sepsis  or shock
   

Complications 

 

1. dehydration
2. electrolyte disturbances: hyper or hyponatremia, hypokalemia, metabolic acidosis 
3. secondary disaccharidase deficiency (transient, due to villous damage)

 

Investigations

 

• stool for C&S and O&P, blood and WBC, C. difficile toxin, Rotazyme assay

Management

 

1. rehydration: most children managed with oral fluids e.g. Oral Rehydration Solution (Pedialyte, Gastrolyte)
2. fluid replacement: consider deficit (% of body weight),maintenance and ongoing losses

Maintenance fluid requirements

1. newborn: 120-160 ml/kg/day (may vary with weight)
2. 100 ml/kg/24 hours for first 10 kg
3. 50 ml/kg/24 hours for second 10 kg
4. 20 ml/kg/24 hours thereafter

• for example ,the maintenance fluid requirement of 24 kg child are :(100×10)+(50×10)+(20×4) = 1580 ml/24h
• IV fluid rate per hour = total per day divided by 24

 

OR use 4:2:1 rule :

 

1. For first 10 kg : 4 mL/kg/hr
2. For second 10 kg : + 2 mL/kg/hr
3. Thereafter: + 1 mL/kg/hr

• for example ,the maintenance fluid requirement of 24 kg child are :(4×10)+(2×10)+(1×4) = 64 ml/h

 

Commonly used IV fluids

1. first week of life: Dextrose 5%(D5W) + 0.2 NS
2. 2/3 D5W 1/3 NS
3. NS: as bolus to restore circulation in very dehydrated child

• continue breast feeding when possible

DRUGS

 

NOT INDICATED: kaolin, pectin, anticholinergics,antispasmotics, opiate derivatives

 

Antibiotics used in:

1. Salmonella sepsis
2. Shigella/Yersinia/enterotoxic E. coli (Septra)
3. C. difficile (oral Flagyl/Vancomycin)
4. Campylobacter (Erythromycin)

Correction of Fluid and Electrolyte Deficits

 

Dehydration	5% (mild )	10% ( severe)	Rate
Isotonic	Na 4-5 mmol/kgNa	Na 8-10 mmol/kg K  4-5   mmol/kg	1/2 deficit over 1st 8 hours, then 1/2 over 16 hours
Hypotonic Na < 130 mmol/LK	Na 5-6 mmol/kg K 3  mmol/kg	Na 10-12 mmol/kg K 5       mmol/kg	If Na = 105, correct as above If Na < 105, correct by 20 mmol/L maximum over 0.5-4 hour with hypertonic saline
Hypertonic Na > 150 mmol/L	Na 2-4 mmol/kg K   2-4 mmol/kg	Na 2-4 mmol/kg  K    2-4 mmol/kg	Correct over 48-72 hours Do not allow serum Na to drop faster than 10-15 mmol/L/day

 

Note:

 

• For all types dehydration, H₂0 for 5% dehydration = 50ml/kg; for 10% dehydration = 100 ml/kg
• To calculate exact deficit:

[Na] deficit = ([Na]target - [Na]actual) x body weight (kg) x total body H₂0 (L/kg)

• To lower serum Na by a predictable amount, remember: 4 ml/kg of free H₂0 lowers serum Na by 1 mmol/L