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

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• 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 weeks)

Obtain a brief history: ❑ Onset ❑ Duration ❑ Pattern (Continuous or intermittent) ❑ Type (Watery, bloody or fatty) ❑ Fever ❑ Abdominal pain ❑ Nausea and vomiting ❑ Weight loss ❑ Epidemiological factors (Travel H/O, dietary H/O, outbreaks, seasons, institutionalization or sexual H/O) ❑ Previous evaluations (Medications, radiation therapy or surgery) ❑ Underlying medical condition (Cancer, diabetes, hyperthyroidism or other conditions) Examine the patient ❑ General condition ❑ Level of consciousness ❑ Ability to drink ❑ Pulse ❑ Blood pressure ❑ Respiratory rate ❑ Eyes ❑ Skin turgor ❑ Mucosa

Assessment of volume status 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.

No dehydration

Some dehydration

Severe dehyration

Start altered diet: ❑ Stop lactose products ❑ Avoid alcohol and high osmolar supplements ❑ Drink 8-10 large glasses of clear fluids (Fruit juices, soft drinks etc) ❑ Eat frequent small meals (Rice, potato, banana, pastas etc) Can start oral rehydration therapy (ORT) for replacement of stool losses

❑ Start ORT at a volume of 50-100 mL/kg ❑ Start altered diet ❑ Reassess status every 4 hr

❑ Start IV fluids: Ringer lactate at 30ml/kg in the first 1/2hr and 70ml/kg for the next 2 1/2 hr, if unavailable use normal saline ❑ CBC ❑ Electrolytes ❑ Assess status every 15 mins until strong pulse felt and then every 1 hr

Patient stable and able to drink

Check for the following warning signs: ❑ Temperature ≥38.5ºC (101.3ºF) ❑ Severe abdominal pain ❑ Bloody diarrhea ❑ Passage of ≥6 unformed stools per 24 hours ❑ Acute presentation of persistent diarrhea ❑ Diarrhea in the elderly (≥70 years of age) ❑ Immunocompromised ❑ Hospital-acquired

❑ Start ORT at a volume of 100 mL/kg over 4 hour ❑ Calculate the continuing stool and emesis losses every hour for additional maintenance ORT therapy ❑ Reassess status every 4 hr

NO

YES

Anti-motility drugs: ❑ Loperamide: Two tablets (4 mg) initially, then 2 mg after each unformed stool OR ❑ Bismuth subsalicylate, 30 mL or two tablets every 30 minutes for eight doses

Assess the pt in 24 hrs

Resolved

Unresolved

Gradually add solid foods to diet

Order investigations: ❑ CBC ❑ Serum electrolytes ❑ Urinalysis ❑ BUN ❑ Creatinine ❑ Fecal occult blood (OBT) ❑ fecal WBC

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

Any recent antibiotic useage

Resolved

Unresolved

NO

YES

Negative C-diff

Positive C-diff

Stool culture

Metronidazole/Vancomycin

Emperical antibiotic trial: ❑ Oral ciprofloxacin 500 mg BD X 3-5 days OR ❑ Oral levofloxacin 500 mg OD X 3-5 days OR ❑ Oral norfloxacin 400 mg BD X 3-5 days OR ❑ Oral azithromycin 500 mg OD X 3 days OR ❑ erythromycin 500 mg BD X 5 days

Negative culture

Positive culture

Check ova and parasites

Negative

Positive

Consider imaging/scope

Specific antibiotics as per results

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

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, oral rehydration therapy ORT should be initiated as soon as they are able to drink, to replace bicarbonate and potassium losses.
• A nasogastric tube can be used to deliver ORT in patients who have a normal mental status but may be too weak to adequately drink the necessary volume of fluid.
• Always check for warning signs before initiating anti-motility drugs.
• Use bismuth subsalicylate for symptomatic treatment of acute diarrhea with significant fever and dysentery, where loperamide is contraindicated.
• 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.

Don'ts

• Don't 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.
• Dont use diphenoxylate, 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.

References

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