Module 5: Case Studies of GI Decontamination

This module will reinforce key concepts through interactive discussion of patient case scenarios involving gastrointestinal decontamination. Learners will explain the rationale and approach for GI decontamination methods selected in each case.

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5.1 Case 1

A 28-year-old female presents to the ED 1 hour after intentional ingestion of 40 acetaminophen 500 mg tablets (total dose 20 grams). She is awake and alert.

Discussion prompts:

• Would GI decontamination be indicated in this patient case? Why or why not?
• If so, what method of GI decontamination would you recommend and why?
• Provide specifics on medications, dosing, and administration instructions.

Explanation:

• GI decontamination would be indicated in this case since the patient ingested a potentially toxic amount of acetaminophen relatively recently.
• Activated charcoal would be the preferred method here. The patient is awake and able to protect her airway, and acetaminophen is adsorbed to activated charcoal.
• Recommended dose is 1 gram/kg, which equals about 50-100 grams for most adults. This can be administered as a 50 gram first dose, followed by 25-50 grams every 2-4 hours for several doses.
• The charcoal should be given as a suspension in water and administered orally if the patient can drink it, or via nasogastric tube. Sorbitol should not be used to avoid electrolyte abnormalities.

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5.2 Case 2

A 22-year-old male is brought to the ED by ambulance 2 hours after taking an unknown amount of sustained-release verapamil tablets in a suicide attempt. He is obtunded and hypotensive on arrival.

Discussion prompts:

• Would GI decontamination be indicated in this case? Why or why not?
• If so, what method of GI decontamination would you recommend and why?
• Provide specifics on medications, dosing, and administration instructions.

Explanation:

• GI decontamination is indicated given the patient took a potentially toxic amount of sustained-release medication, has severe symptoms already, and it is within a few hours of ingestion.
• Whole bowel irrigation is likely the best approach here since verapamil is poorly adsorbed to activated charcoal.
• The polyethylene glycol electrolyte solution can be administered via nasogastric tube at a rate of 1-2 L/hour initially.
• Input and output should be monitored closely to watch for fluid overload or electrolyte abnormalities.
• Would continue WBI until rectal effluent is clear, likely requiring 10+ liters total.

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5.3 Case 3

A 55-year-old male is brought to the ED by his spouse 6 hours after intentionally taking 60 tablets of 5 mg amlodipine (total 300 mg) along with an unknown amount of wine. His blood pressure is 88/52 mmHg but he is awake and alert.

Discussion prompts:

• Would GI decontamination be indicated in this case? Why or why not?
• If so, what method of GI decontamination would you recommend and why?
• Provide specifics on medications, dosing, and administration instructions.

Explanation:

• Despite it being more than 6 hours since ingestion, the amount ingested and the patient’s symptoms warrant consideration of GI decontamination.
• Activated charcoal would be preferred for amlodipine. The recommended dose is 1 gram/kg (50-100 grams).
• This could be given as the initial 50 gram dose followed by 25-50 grams every 2-4 hours for 1-2 days due to the sustained-release formulation.
• The patient is awake so it can be administered orally. Would give with sorbitol as a cathartic.
• Also give intravenous fluids, calcium, and vasopressors for hypotension as needed.