Diarrhoeal diseases and fluid resuscitation Flashcards
Definition of diarrhea
Definition of diarrhea
*Passage ofthree or more watery or loose motions per day. Or single motion
containing blood.
*WHO defines it as: increased volume, fluidity, or frequency ofmotions relative to
the usual pattern o f individual
Normal pattern of motions per day
- From birth to 4th month ~ Breast fed : 1-7 motions I day
~ Formula fed : 2-3 Motions I day - From 4th month to end of Ist year ~ 1-3 motions I day (Firmer)
*Above 1 year ~ 1-2 motions I day (adult like)
Classification of diarrhea
i. Acute Diarrhea:
- Starts acutely,
-Watery without visible blood,
- Last less than 14 days.
(Desentry is acute diarrhea with visible blood in stool)
ii. Persistent diarrhea :
- Started as acute diarrhea (watery or desentry)
but persist more than 14 days.
iii. Chronic diarrhea :
- Diarrhea of gradual onset,
- lasting >=1month or
recurrent due to non infectious cause
- Stool output is more than 10 gm /kg/day.
View table in page 114 in text book
Mechanisms of diarrhea
i- Osmotic diarrhea
~ 1-2 motions I day (adult like)
- Starts acutely,
-Watery without visible blood, - Last less than 14 days.
(Desentry is acute diarrhea with visible blood in stool) Started as acute diarrhea (watery or desentry) but persist
more than 14 days.
- Diarrhea ofgradual onset, lasting ::: 1month or
recurrent due to non infectious cause
- Stool output is more than 10 gm /kg/day.
Due to presence ofnon-absorbable solutes in GIT ~ osmotic load ~ shift ofwater to intestinal lumen.
Examples:
1- Lactase deficiency; either primary or 2ry to gastroenteritis (Lactose intolerance). 2- Congenital glucose-galactose malabsorption.
3- Ingestion ofnon-absorbable solutes (e.g. lactulose, sorbitol)
ii- Secretorv diarrhea Due to either:
1- Damaged absorptive villi cells with intact secretory crypt cells that migrate to
cover the raw villi ~ excessive secretions & diminished absorption Causes:
- Viral diarrhea e.g Rota virus.
- Bacterial e.g Shigella, Entero invasive E-coli
-Parasitic e.g Giardia Iamblia (induce mucosal adhesion)
2- Entero toxins release -+ stimulate adenyle cyclase in crypt cells -+ excessive intestinal secretions
Causes:- Vibrio cholerae -Entero toxtgemc E-C0 r
** View table in page 114 in text book 📖
iii- Change in intestinal motility
- Decreased motility -+~ transit time e.g thyrotoxicosis
- Increased motility -+t bacterial overgrowth e.g stagnant loop syndrome.
iv- ~intestinal surface area e.g short bowel syndrome -+ both osmotic & motility disorders.
Acute Diarrhea)
i- Acute non infective diarrhea
Causes
A— Acute non infective diarrhea
I— Dietitic
1- Over feeding
2- Under feeding: Starvation diarrhea (scanty, greenish, excessive mucus) 3- Bad feeding: - Change in milk type or concentration
- New unsuitable food.
4- Lienteric diarrhea: Hyperactive gastro-colic reflex -+ motion short after every feed
II— Drugs: e.g.
1- Oral antibiotics (e.g ampicillin)
2- Laxatives e.g. magnesium sulphate to the baby or to lactating mother.
III— Parentral diarrhea (better called 2ry gastroenteritis).
-Due to infections outside GIT e.g otitis media, respiratory infections, urinary tract infections
- Possible mechanisms: - toxic absorption
- reflex gastro intestinal irritation
- The term parentral diarrhea is no longer used due to possible associated intestinal infection.
ii- Acute Infective diarrhea (Gastro Enteritis)
ii- Acute Infective diarrhea (Gastro Enteritis)
Gastro-enteritis involve enteritis & reflex gastritis ~ vomiting & diarrhea.
Risk Factors
i. Host factors:
1. Failure of breast feeding
2. Bottle feeding.
3. Infants in ages 6-24 months due to:
- Fading maternal acquired immunity. - Little active immunity.
- Contaminated weaning.
- Picking up contaminated objects.
4. Malnutrition: delay repair ofdamaged gut mucosa
5. Impaired immunity: in severe malnutrition and following measles 6. Incomplete vaccination especially against measles.
ii. Maternal factors:
1. Failure ofexclusive breast feeding in the first 4-6 months 2. Use ofeasily contaminated feeding bottles
3. Unsanitary storing of foods
4. Unsanitary food handling
5. Unsanitary disposal offeces.
Severity
• Mild =4-6 motions /day
• Moderate = 6-1 0 motions /day • Severe > I0 motions /day
Causes of Gastroenteritis
1. VIral (60%)
Due to:
- Rota virus.
- Adenovirus
- Enteroviruses (e.g. Echo & coxachie) -Norwalk virus
Criteria:
- Age usually less than 2 years.
- Common in winter
- May be associated upper respiratory tract infections
- Pyrexia if present usually less than 38.5 °C.
-Diarrhea is:
- Mild to moderate.
- Transient = (5-7 days).
-Watery
-Odorless
- Bacterial
Criteria: - Common in summer -With high fever
- Cramping abdominal pain
-Usually severe diarrhea which may be:- *Bloody with: - Salmonella
- Shigella desentyrie type 1.
- Entero invasive E-Coli.
- Entero hemorrhagic (Shiga toxin producing) E-Coli
* Watecy with:- Shigella (diarrheal type) - Entero pathogenic E-Coli
- Entero toxigenic E-Coli
-Vibrio cholerae 01.
* Watecy offensive for 2-4 days then tum bloody–+ Campylobacter jejuni. - Protozoal
Etiology & criteria
1-Giardia Lambelia -Watery
-Offensive
- No fever nor vomiting 2. Entameaba histolytica
-Bloody ±tenesmus
-No fever nor vomiting 3- Ccyptosprodium parvum:
- Coccidian protozoan that infect mainly the immunodeficients. - Diarrhea is watery with fever & vomiting
Complications of Gastroenteritis
Complications of Gastroenteritis
1- Dehydration
-Due to vomiting, diarrhea and anorexia (see later)
- The main cause ofdeath in gastroenteritis
- Shock
Types:
- Hypovolemic shock with severe dehydration
- Septic shock.
Clinically
1- Hypotension & rapid thready pulse 2- Decreased vital organ perfusion:-
- Brain –+ lethargy
- Kidney –+ oliguria
3- Decreased peripheral perfusion:-
- Pallor
- Skin mottling
- Cold extremities
3- Acute renal failure (ARF) Due to:
1- Hypovolemia -+.1. renal blood flow (pre renal failure).
2- Untreated pre renal failure -+ tubular necrosis -+ intrinsic renal failure
Clinically:
-Oliguria or anuria
-Edema
- Acidotic breath (Rapid, deep breathing). 4- Metabolic Acidosis
Due to:
• Loss ofbicarbonate in stool
• Acute renal failure. Clinically:
- Acidotic breath
- Disturbed consciousness.
-Arterial blood gases (.J,pH, .J,paC02, .J,HC03)
5- Electrolyte disturbance:
i- Hypokalemia: (serum potassium< 3 meq /L)
• Due to loss ofpotassium in stool in severe gastroenteritis. * Aggravated by vigorous correction o f acidosis. Clinically:- Apathy (disturbed consciousness)
- Cardiac arrhythmias
-Abdominal distension (paralytic ileus) -Hypotonia (atony).
II- Hypocalcemia:
*Occur especially in:
- Rackitic patients
- During rapid correction o f metabolic acidosis -+ calcium shift to bones
and decreased ionized calcium (post acidotic tetany). Clinically:- Tetany or convulsions.
Ill- Hypo or hyper natremla.
6- Convulsions -+ possible causes:
- Hypoglycemia ; mainly in mal nourished. -Febrile convulsions
-Hyper or hyponatremia(best treated with ORS) -Toxic (e.g. with shigella)
- CNS infections
- Hypocalcemia
- Brain edema due to (over hydration espicially in hypernatremic dehydration).
7- CNS infections: meningitis & encephalitis due to shigella or neurotropic virus
8.Bleeding — View table page 118 in textbook
9- Persistant diarrhea
10- Malnutration (PCM) In recurrent or prolonged diarrhea. 11- Others:
1- Hepatitis ~ toxic or infectious.
2- Encephalopathy–+ due to:
-Prolonged acid-base disorder.
- Cortical vein thrombosis.
-Hypernatremia.
3. Rectal prolapse
Workup of Gastroenteritis
Workup of Gastroenteritis
1-For the cause :
-Stool analysis
- Stool culture
2- For the complications:
- Serum electrolytes –+ potassium, sodium and calcium. - Arterial blood gases (ABO) –+ for metabolic acidosis. - Renal functions tests
- Lumbar puncture ~ for CNS infections.
-Abdominal X-ray–+ multiple fluid levels in intestinal obstruction. -Coagulation screen–+ PT, PIT, FDPs, platelets for bleeding.
Treatment
Treatment of Gastroenteritis
J. Supportive
1· Gastroenteritis without dehydration (plan A)
Home management consisting of: Plenty offluid , plenty offood &follow up 1- Fluid therapy
>Main aim oftreatment is to avoid dehydration by plenty of fluid: -9- The best fluid is oral rehydration solution (ORS).
-9- Amount ofORS·.
***** View table in page119
-9- How to give ORS:
-One tea spoonfuVl-2 minutes for a child under2 years.
- Frequent sips from a cup for an older child
- Ifvomiting occur ,wait 10 minutes and give ORS more slowly.
+Food based fluids:- For infants >6months or weaned
-Rice water, soup, yogurt drinks, belila water
- Avoid hyperosmolar fluids as it increase diarrhea -9- Continue fluids till diarrhea stops
2- Plenty of feeds to avoid malnutrition: -¢- Continue breast feeding
-9- Ifnot breast fed ~ give the usual milk formula.
-9- For infants >6months or weaned, give: mashed potatoes, cereals, rice
pudding, mashed banana(supply potassium)
-9- Feeds given 6 times a day.
-9- Continue food after diarrhea stop and give extrameal each day for 2 weeks 3- Follow up for detecting early cases ofdehydration:
Inform mother to seek medical consultation if there’s: -9- No improvement for 3 days
-9- Presence ofa warning sign: - High fever.
- Refusal oforal fluids or feeding. - Frequent vomiting.
- Marked thirst
- Bloody motions.
- Frequent watery motions 2- Gastroenteritis with dehydration (plan B & C) => See later
2- Specific treatinent 1-Antibiotics
• Indications : largely depends on clinical judge;
- Ifbacterial cause is identified or strongly suspected.
- Associated bacterial infection (e.g otitis media or pneumonia)
(Fever perse even high is not an indication for antimicrobial therapy) • Route: - Oral usually.
- Parenteral with severe vomiting or life threatening infections. • Choice: 1. Bloody diarrhea( probably shigella): 5 days course of
- Trimethoprirnlsulphamethoxazole(l 0/50 mglkg) ru:
-Nalidixic acid 60 mglkg m:
- Others : Ampicillin , cefotriaxone , ciprofloxacin 2. Suspected cholera : 5 days course of
- Trimethoprirnlsulphamethoxazole or
- Erythromycin (or azithromycin) m:
-Tetracycline; 50 mg/kg/day (for children> 9 years).
2-Anti-parasitic
• Entameoba histolytica : Metronidazole 40 mglkg in 3 doses for 10 days oral.
• Giardia Iamblia : Metronidazole 30 mglkg for 7 days.
m: furazolidone 25 mglkg for 5 days.
3- Treatinent ofcomplications
1- Acute renal failure : usually pre renal –+ responds to volume expansion.
2- Metabolic acidosis:- Mild –+ improves with adequate hydration with ORS. -Severe–+ Na Hco3 1-2 meq/ kg- slow i.v.
3- Electrolyte disturbances:
-Hypocalcemia–+ Calcium gluconate slow i.v.
- Hyponatremia and hypokalemia–+ Can respond to ORS
- Hypoglycemia-+ Give 20% glucose 2.5 mllkg iv
4- Convulsions:- Anticonvulsants (e.g. i.v. diazepam) and treat the cause. 5- Bleeding is treated according to the cause: e.g.
- DIC–+ fresh blood or plasma transfusion
- Intussusception –+ reduction by enema & surgical consultation. 4- Additional tlterapy:
a. Probiotic non pathogenic bacteria e.g. lactobacillus ,bijidobacterium
b. Racecadotril(Acetorphan) ,an enterokinase inhibitor, reduce stool output
c. Nitazoxnide: antimicroj>ial agent active against many pathogens e.g. Rota virus,
Giardia, Entamoeba histolytica,….
d. Ondansetron : anti emetic , a single sublingual dose o f 2 mg for older child with
severe vomiting
Prevention of gastroenteritis
Prevention of gastroenteritis 1. Promote breast feeding:
- Exclusive for the first 4-6 months
- Continued for 2 years
- Continued during illness including diarrhea
2. Proper weaning practice:
- Started at 6 months
- Proper choice of weaning food
- Sanitary measures in preparing, giving and storing foods.
3. Measles vaccine:
- Cost effective in reducing diarrhea
- Prevent up to 25% o f diarrhea associated mortality in children < 5 years.
4. Hygienic measures: -¢- Water sanitation:
- Frequent hand washing
- Protect water sources from contamination
- Boil water for few seconds i f contamination is suspected
-¢- Safe disposal ofstool ofyoung children -¢- Use of safe sanitary latrines
Persistent Diarrhea
Persistent Diarrhea
Definition
-Started as acute diarrhea (watery or dysentery) but persist more than 14 days - About 5-10% ofacute diarrhea progress to persistent diarrhea
-Persistent diarrhea account for 35-50% ofdiarrhea associated fatality
Etiology
1. Persistent infection:
- Giardia Iamblia is the commonest cause ofpersistent watery diarrhea
- Others : salmonella, shigella , cryptosprodium ; in severely malnourished. 2. Post-enteritis malabsorption:
- Due to mucosal damage ~ damaged villi with 2ry digestive enzymes deficiency Risk Factors
*Repeated gastroenteritis in infants in ages 6-24 months due to: - Fading maternal acquired immunity.
-Little active immunity.
- Contaminated weaning.
- Picking up contaminated objects.
* Malnutrition: delay repair ofdamaged gut mucosa
* Prolonged I.V. fluids
* Impaired immunity: in severe malnutrition and following measles *Recentintroduction ofanimalmilkorformula.
Clinical picture: in post-enteritis malabsorption 1- Refeeding diarrhea that may appear with:
-Breast & cow milk~ suspect 2ry lactase deficiency (lactose intolerance)
- Sucrose containing formula (e.g Isomil) ~ suspect 2ry sucrase deficiency 2. Vomiting
3. Abdominal distension & cramps
4. Perianal soreness (due to watery acidic motions).
Diagnosis
1- For post enteritis malabsorption:-
- Symptoms resolve with suspected milk elimination
- Reducing substance in stool. } In carbohydrate malabsorption -Stool pH< 5
-Small intestinal biopsy~ villous atrophy in cow milk protein allergy.
2- For persistent infection:- - Stool analysis.
- Stool culture.
Treatment
1. Adequate hydration according to WHO plans.
2. Treatment ofthe cause: Indicated ifstool is bloody(treat for shigella) or stool
culture reveal specific pathogen as giardiasis 3. Nutritional therapy:-
A. If still breast fed: give more frequent breastfeeds day and night B. Iftaking other milk:
- Replace with increased breast feedings or
- Replace with fermented milk products, such as yoghurt or
-Replace half the milk with nutrient- rich semisolid food as rice, beans and
vegetable soup.
- Limit animal milk to < 50 ml/kg/day
- Feeds given in frequent small meals at least 6 times daily
C. Iflactose intolerance is suspected~ use lactose free milk for 1-2 weeks (till villi regeneration occur).
D. Supplemental vitamins & minerals once daily for 14 days
-Vitamin A— 8000 iu
-Folic acid— 100 micro gram
-Iron — 20mg
-Zinc — 20mg
-Copper— 2mg
- Magnesium— 150mg
Chronic Diarrhea
Etiology
1. Malabsorption syndrome
1- Impaired digestion *Hepatic
* Pancreatic :
2- Intestinal stasis
-Biliary atresia (bile salt insufficiency)
- Chronic hepatitis
- Acid hypersecretion (Zollinger Ellison syndrome) - Cystic fibrosis
- Chronic pancreatitis
-Protein caloric malnutrition (acini atrophy).
- Stagnant loop syndrome& short bowel syndrome. -Inflammatory bowel diseases: - Crohns’ disease
- Ulcerative colitis
- Giardia Iamblia, tuberculous enteritis - Lactose intolerance (1ry or 2ry)
- Cow milk protein allergy
- Celiac disease
3- Impaired absorption
* Chronic infection
*Food intolerance
*Acrodermatitis enteropathica (autosomal recessive disorder); Zinc deficiency leads to - Dermatitis ~ around orifices & acral
-Alopecia.
- Chronic diarrhea~ protein losing enteropathy
2- Endocrinal e.g thyrotoxicosis
3· Immunodeficiency
4- Neoplasia e.g.- Neuroblastoma~ due to vasoactive intestinal peptide (VIP)
- Zollinger Ellison Syndrome ~ due to increased gastrin. 5- Chronic non specific diarrhea (toddler diarrhea)
