Gastroenteritis

GASTROENTERITIS

Dr Tariq Al thobaiti ,MBBS

• Diarrheal diseases are the second leading cause of death worldwide in children.

• Rotavirus is the most common pathogen in areas without a vaccination program.

• in areas with widespread rotavirus vaccination, norovirus is the most common pathogen.

CLINICAL FEATURES

• Diarrhea associated with acute viral gastroenteritis typically lasts <7 days and not longer than 14 days, and it may be accompanied by vomiting or fever.

• Isolated vomiting should not be diagnosed as acute gastroenteritis.

• Although appendicitis typically manifests with abdominal pain followed by vomiting associated with constipation,

• it may also cause diarrhea, particularly once the appendix has perforated. This is presumed to occur because the inflammation irritates the colon, resulting in diarrhea

LABORATORY TESTING

• Obtain a CBC only if the child is ill appearing or has bloody diarrhea.
• (mainly to identify bacterial enterocolitis or hemolytic-uremic syndrome).
• The WBC count and C-reactive protein are not reliable for distinguishing viral from bacterial gastroenteritis.

hypoglycemia, hypokalemia, acidosis, leukocytosis

LABORATORY TESTING

• Given that the reported prevalence of hypoglycemia may be as high as 9% in pediatric gastroenteritis.

• measuring serum glucose in infants and young children is essential.

• Obtain serum electrolytes only in specific circumstances.

LABORATORY TESTING

• BUN is elevated in severe dehydration.
• it does not identify lesser degrees of dehydration very well.
• Serum bicarbonate>15 mEq/L makes dehydration unlikely.

TABLE 129-2 Clinical Guidelines for Assessing Dehydration in Children

	None to Minimal Dehydration ( $<3\%$ loss of body weight)	Some (mild to moderate) Dehydration ( $3\%$ to $9\%$ loss of body weight)	Severe Dehydration ( $>9\%$ loss of body weight)
Mental status	Well, alert	Fatigued, restless, irritable	Apathetic, lethargic, unconscious
Thirst	Normal, slight increase, or refusing fluids	Increased, eager to drink	Very thirsty or too lethargic to indicate
Heart rate	Normal	Normal to increased	Tachycardic with brady- cardia in severe cases
Blood pressure	Normal	Normal	Normal to reduced
Pulse quality	Normal	Normal to reduced	Weak, thready
Breathing	Normal	Normal to tachypneic	Deep
Eyes	Normal	Slightly sunken orbits	Deeply sunken orbits
Tears	Present	Decreased	Absent
Mucous membranes	Moist	Dry	Parched
Anterior fontanelle	Normal	Sunken	Sunken
Skin turgor	Instant recoil	Recoil in $<2$ s	Recoil in $>2$ s
Capillary refill	Normal	Prolonged 1–2 s	Prolonged $>2$ s
Extremities	Warm	Cool	Cold, mottled, cyanotic
Urine output	Normal to decreased	Decreased ( $<1$ mL/ kg/h)	Minimal ( $<0.5$ mL/ kg/h)

Organism	Typical Clinical Features	Risk Factors	Complications	Antimicrobial Therapy
Shigella	Ranges from watery stools without constitutional symptoms to fever, abdominal pain, tenesmus, mucoid stools, hematochezia; Shigella dysenteriae serotype 1 causes more severe symptoms	Contact with infected host or fomite, poor sanitation, crowded living conditions, day care	Pseudomembranous colitis, toxic megacolon, intestinal perforation, bacteremia, Reiter’s syndrome, hemolytic-uremic syndrome, encephalopathy, seizures, hemolysis	Typically self-limited Treat if: immunocompromised, severe disease, dysentery or systemic symptoms If susceptibility unknown: azithromycin, ceftriaxone, ciprofloxacin; if susceptible, ampicillin or trimethoprim-sulfamethoxazole
Salmonella	Nontyphoidal: May be asymptomatic or cause watery diarrhea, mild fever, abdominal cramps Enterica serotypes: “enteric fever” may include high fever, constitutional symptoms, headache, abdominal pain, dactylitis, hepatosplenomegaly, rose spots, altered mental status	Direct contact with animals: poultry, livestock, reptiles, pets; consuming food contaminated by human carrier: beef, poultry, eggs, dairy, water	Meningitis, brain abscess, osteomyelitis, bacteremia, dehydration, endocarditis, enteric (typhoid or paratyphoid) fever	Typically self-limited Treat if: <3 mo of age, hemoglobinopathy, immunodeficiency, chronic GI tract disease, malignancy, severe colitis, bacteremia, sepsis Options: ampicillin, amoxicillin, trimethoprim-sulfamethoxazole; if resistant, azithromycin, fluoroquinolone Invasive disease: cefotaxime, ceftriaxone
Campylobacter	Diarrhea, hematochezia, abdominal pain, fever, malaise	Contamination from poultry feces or undercooked poultry, untreated water, unpasteurized milk, pets (dogs, cats, hamsters, birds); person-to-person transmission possible	Acute: dehydration, bacteremia, focal infections, febrile seizures Convalescence: reactive arthritis, Reiter’s syndrome, erythema nodosum, acute idiopathic polyneuritis, Miller Fisher syndrome, myocarditis, pericarditis	Often self-limited; 20% have relapse or prolonged symptoms Treat if: moderate-severe symptoms, relapse, immunocompromised, day care and institutions Options: erythromycin, azithromycin, ciprofloxacin
Escherichia coli -Shiga toxin producing	Initially nonbloody diarrhea, often becoming bloody; severe abdominal pain	Food or water contaminated with human or cattle feces, undercooked beef, unpasteur-	Hemorrhagic colitis, hemolytic-uremic syndrome	None indicated; debated risk of increased incidence of hemolytic-uremic syndrome with treatment

Escherichia coli –Shiga toxin producing	Initially nonbloody diarrhea, often becoming bloody; severe abdominal pain	Food or water contaminated with human or cattle feces, undercooked beef, unpasteurized milk	Hemorrhagic colitis, hemolytic-uremic syndrome	None indicated; debated risk of increased incidence of hemolytic-uremic syndrome with treatment
E. coli –enteropathogenic	Severe watery diarrhea, usually children <2 years in resource-limited countries	Food or water contaminated with feces	Dehydration	Treat if severe Options: trimethoprim-sulfamethoxazole, azithromycin, ciprofloxacin
E. coli –enterotoxigenic	Moderate watery diarrhea, abdominal cramps; traveler’s diarrhea	Food or water contaminated with feces	Dehydration	Treat if severe Options: trimethoprim-sulfamethoxazole, azithromycin, ciprofloxacin
E. coli –enteroinvasive	Fever, bloody or nonbloody diarrhea, dysentery	Food or water contaminated with feces	Dehydration	Treat if severe Options: trimethoprim-sulfamethoxazole, azithromycin, ciprofloxacin
E. coli –enteroaggregative	Watery diarrhea, may be prolonged	Food or water contaminated with feces	Dehydration	Treat if severe Options: trimethoprim-sulfamethoxazole, azithromycin, ciprofloxacin
Yersinia	Bloody diarrhea with mucus, fever, abdominal pain; pseudoappendicitis syndrome: fever, right lower quadrant pain, leukocytosis; Yersinia pseudotuberculosis causes fever, scarlatiniform rash, abdominal pain	Contaminated food: improperly cooked pork, unpasteurized milk, untreated water; contact with animals (ungulates, rodents, rabbits, birds)	Acute: bacteremia, pharyngitis, meningitis, osteomyelitis, pyomyositis, conjunctivitis, pneumonia, empyema, endocarditis, acute peritonitis, liver/spleen abscess; convalescence: erythema nodosum, glomerulonephritis, reactive arthritis	Typically self-limited; if severe, treat with trimethoprim-sulfamethoxazole, aminoglycosides, cefotaxime, fluoroquinolones, tetracycline, doxycycline, chloramphenicol
Vibrio cholerae	Voluminous watery diarrhea, usually without cramps or fever, classically described as “rice water” stools	Travel to affected areas, consumption of contaminated water or food (particularly undercooked seafood)	May rapidly lead to hypovolemic shock, hypoglycemia, hypokalemia, metabolic acidosis, seizures	Treat if moderate or severe: azithromycin, doxycycline; ciprofloxacin or trimethoprim-sulfamethoxazole if resistant

By lina serhan