Acute diarrhea resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Definition

• Three or more bowel movements daily are considered to be abnormal, and the upper limit of stool weight is generally agreed to be 200 g daily.

• Acute diarrhea has a duration of less than four weeks. Most cases of acute diarrhea are due to infections with viruses and bacteria and are self-limited. The evaluation of patients for a noninfectious etiology should be considered as the course of diarrhea persists and becomes chronic.

Causes

Life Threatening Causes

• E. coli (O157:H7)
• Human immunodeficiency virus
• Inflammatory bowel disease

Common Causes

Inflammatory Causes

• Bacterial : Campylobacter, clostridium difficile, E. coli (O157:H7), salmonella typhi, salmonella(nontyphoidal), shigella, vibrio parahaemolyticus
• Viral : Cytomegalovirus
• Parasitic : Entamoeba histolytica

Noninflammatory Causes

• Bacterial : E.coli (toxigenic), vibrio cholerae
• Viral : Rotavirus, norovirus
• Parasitic : Giardia, cryptosporidium, cyclospora
• Performed toxin : Staphylococcus aureus, bacillus cereus, clostridium perfringens

Management

Adults with acute diarrhea (<4 wks)

History and physical examination

Assessment of volume status

No dehydration

Some dehydration

Severe dehyration

Altered diet +/- ORT

ORT + altered diet + reassess status every 4 hr

Start IVFs, Ringer lactate at 30ml/kg in the first 1/2hr and 70ml/kg for the next 2 1/2 hr, if unavailable use NS, CBC, electrolytes + Assess status every 15 mins until strong pulse felt and then every 1 hr + Start ORT when the Pt is stable and able to drink + then assess status every 4 hr

Warning signs

NO

YES

Loperamide (4-6 mg/day)

Assess the pt in 24 hrs

Resolved

Unresolved

Investigations

Gradually add solid foods to diet

CBC, electrolytes, UA, fecal WBC, fecal OBT

Anemia, thrombocytopenia, elevated BUN and creatinine

YES

E. coli O157:H7 suspicion, stool culture and ELISA for Shiga toxin and supportive care

NO

Negative fecal WBC/OBT

Positive fecal WBC/OBT

Non-inflammatory

Inflammatory

Symptomatic Rx

Recent antibiotics?

Resolved

Unresolved

NO

YES

Negative C-diff

Positive C-diff

Stool culture, followed by empiric ABx

Metronidazole/Vancomycin

Negative culture

Positive culture

Check ova and parasites

Negative

Positive

Consider imaging/scope

Rx per results

Rule out IBD, colon cancer, diverticulitis, appendicitis etc.

History and Physical Examination

• H/O : Onset, duration, stool frequency, type, volume, bloody, abdominal pain/cramps, nausea, vomiting, underlying medical conditions, radiation exposure and medications profile.
• Epidemiological clues : Travel H/O, dietary H/O, outbreaks, seasons, institutionalization and sexual H/O.
• PE : General status, level of consciousness, eyes, mucosa, ability to drink, skin turgor, pulse, blood pressure and respiratory rate.

Evaluation of Volume Status by Dhaka Method

Assessment	No dehydration	Some dehydration†	Severe dehydration‡
General condition	Normal	Irritable/less active*	Lethargic/comatose§
Eyes	Normal	Sunken	—
Mucosa	Normal	Dry	—
Thirst	Normal	Thirsty	Unable to drink§
Radial pulse	Normal	Low volume*	Absent/ uncountable§
Skin turgor	Normal	Reduced	—

† Some dehydration = At least two signs, including at least one key sign (*) are present.
‡ Severe dehydration = Signs of “some dehydration” plus at least one key sign (§) are present.

Altered Diet

• Stop lactose products, avoid alcohol and high osmolar supplements.
• Drink 8-10 large glasses of clear fluids, preferably sugar containing fluids like fruit juices and soft drinks.
• Eat frequent small meals like rice, potato, banana, pastas etc.

Oral Rehydration Therapy

For each degree of dehydration, treatment is divided into two phases:

• Rehydration phase : Water and electrolytes are administered to replace losses. The fluid deficit is replaced quickly over three to four hours, returning the patient to a euvolemic state.
• Maintenance phase : Maintenance fluid therapy to take care of ongoing losses once rehydration is achieved (along with appropriate nutrition).

• No dehydration : ORT is used to maintain hydration by replacement of stool losses.
• Some dehydration : Hydration should be restored by administering ORT at a volume of 50-100 mL/kg.
• Severe dehydration : As the patient's clinical condition stabilizes and his/her level of consciousness returns to normal, therapy can be changed to ORT. A nasogastric tube can be used in patients who have a normal mental status but may be too weak to adequately drink the necessary volume of fluid. The intravenous line should remain in place until it is certain there is successful transition to ORT. ORT therapy is started at a volume of 100 mL/kg over 4 hours. Additional ORS is given to replace ongoing loss of stool. At the end of each hour, the patient's hydration status and continuing stool and emesis losses should be calculated, with the total hourly loss added to the amount to be given over the next hour.

Warning Signs

• Temperature ≥38.5ºC (101.3ºF)
• Severe abdominal pain
• Bloody diarrhea
• Passage of ≥6 unformed stools per 24 hours
• Severe dehydration
• Acute presentation of persistent diarrhea
• Diarrhea in the elderly (≥70 years of age)
• Immunocompromised
• Hospital-acquired

Anti-motility Drugs

• Loperamide : The dose is two tablets (4 mg) initially, then 2 mg after each unformed stool, not to exceed 16 mg/day for ≤2 days.
• Bismuth subsalicylate : This has also been used for symptomatic treatment of acute diarrhea. Though not as effective as loperamide, it may be used in patients with significant fever and dysentery, where loperamide is contraindicated. The dose is 30 mL or two tablets every 30 minutes for eight doses.
• Diphenoxylate : Dont use it, as it has central opiate effects and may cause cholinergic side effects. In addition, patients should be cautioned that treatment with these agents may mask the amount of fluid lost, since fluid may pool in the intestine.

Antibiotic History

• All antibiotics, including metronidazole and vancomycin, can predispose to C. difficile and should be evaluated in the management of acute diarrhea.
• The antibiotics most frequently implicated in predisposition to C. difficile infection are fluoroquinolones, clindamycin, cephalosporins, and penicillins.
• Other possible associations are macrolides, trimethoprim, sulfonamides, aminoglycosides, tetracyclines, chloramphenicol etc.

Empirical Antibiotics

• Fluoroquinolone : Oral ciprofloxacin 500 mg BD / norfloxacin 400 mg BD / levofloxacin 500 mg OD X for 3-5 days.
• Macrolides : Oral azithromycin 500 mg OD X 3 days / erythromycin 500 mg BD X 5 days are alternative agents, particularly if fluoroquinolone resistance is suspected.

Specific Antibiotics

• Salmonella : Oral ciprofloxacin 500 mg BD or levofloxacin 500 mg OD / oral trimethoprim-sulfamethoxazole 160 mg/800 mg BD / oral amoxicillin 500 mg TID / if intravenous therapy is required, ceftriaxone 1 to 2 g OD or cefotaxime 2 g intravenously TID.
• Vibrio cholera : Oral ciprofloxacin 500mg BD X 3 days / doxycycline 300mg OD single doze / azithromycin 1g OD single doze / tetracycline 500 mg QID X 3 days.
• Shigellosis : Oral ciprofloxacin 500mg BD X 3 days / oral pivmecillinam 400mg TID or QID X 5 days / IV ceftriaxone 2-4g as OD.
• Campylobacter : Oral Azithromycin 500 mg OD X 3 days / Oral ciprofloxacin 500mg BD X 3 days.
• Giardiasis : Metronidazole 250 mg TID for 5 days / tinidazole OD 50 mg/kg orally to a maximum dose of 2 g / ornidazole 2 g OD as single doze.
• Amebiasis : Metronidazole 750 mg TID for 5 days.

Do's

• For acute diarrhea, maintaining adequate intravascular volume and correcting fluid and electrolyte disturbances take priority over identifying the causative agent from detailed history and clinical findings, including stool characteristics.
• Assess ABCD periodically depending on the patient status and check for any warning signs during the course of management.
• When using normal saline due to unavailability of ringer lactate in diarrhea patients, ORT should be initiated as soon as they are able to drink, to replace bicarbonate and potassium losses.
• Stool cultures are usually unnecessary for immune-competent patients who present with watery diarrhea, but may be necessary when there is clinical and/or epidemiological suspicion of a causative agent, particularly during the early days of outbreaks/epidemics.
• Report to the public health authorities in case of suspected outbreaks.

Dont's

• Dont treat patients with severe diarrheal dehydration using 5% dextrose with 1/4 normal saline, as using solutions with lower amounts of sodium (such as 38.5 mmol/L in 1/4 saline with 5% dextrose ) would lead to sudden and severe hyponatremia with a high risk of death.
• ORT is contraindicated in the initial management of severe dehydration and also in patients with frequent and persistent vomiting (more than four episodes per hour), and painful oral conditions such as moderate to severe thrush.
• Loperamide should be avoided in patients with significant abdominal pain, fever and bloody diarrhea that suggests inflammatory diarrhea.

References

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