Decontamination Exam 1 Flashcards
1
Q
Which meds can be used via NG tube?
A
- activated charcoal
- WBI products
2
Q
What are various methods for decontamination?
A
- emesis
- gastric lavage
- activated charcoal
- whole bowel irrigation
- hemodialysis
3
Q
indication for emesis
A
no indication
4
Q
efficacy of emesis
A
- reliable vomiting
- unreliable in drug recovered (range 6-89%)
5
Q
contraindications of emesis
A
- Non-toxic ingestions - emesis should not be used as a method of punishment.
- Prior significant vomiting - ipecac induced emesis is no better than “natural” emesis, and would not be expected to recover additional material.
- Any patient who is comatose, seizing, hypotensive, or has lost his/her protective airway reflex.
- The patient who is presently awake, but may be expected to rapidly deteriorate before emesis has been completed.
- Caustic agents may cause additional injury during emesis.
- Aspiration risk: ingestions of poorly absorbed hydrocarbons.
- Sharp objects and other foreign body ingestions.
- Need for rapid administration of oral antidotes, such as NAC, especially approaching 6-8 hours after acetaminophen ingestion.
- Late in pregnancy
- Hypertensive crisis or intracranial hypertension.
6
Q
complications of emesis
A
- Intractable vomiting (rare)
- Diarrhea
- Aspiration
- Myocardial toxicity - associated with extract of ipecac
- Neuromuscular weakness
- Mallory-Weiss tear of the esophagus
- Lethargy
- Spontaneous abortion
7
Q
indications for gastric lavage
A
- not indicated but considered in:
- Potentially life-threatening poisoning and presentation within 1 hour.
- Potentially life threatening poisoning with drug with anticholinergic effects and presentation within 4 hours
- Ingestions of sustained release preparation of significantly toxic drug
8
Q
contraindication for gastric lavage
A
Corrosive ingestions or esophageal disease
9
Q
gastric lavage technique
A
- Protect airway (endotracheal intubation) if patient is stuporous or comatose.
- Lie patient on their left side.
- Insert a large bore double lumen orogastric tube.
- Aspirate stomach contents.
- Use a small cycle lavage of 50-100 mL (and then aspirate).
- Lavage is rarely indicated beyond 5 minutes, unless tablets are still actively being returned.
10
Q
complications of gastric lavage
A
- may increase gastric delivery of tablets into the small bowel, especially those that have formed into large clumps. This could lead to increased absorption.
- Aspiration of gastric contents occurs in about 3% of patients.
- Esophageal rupture is a very rare but potentially fatal complication.
- Profound bradycardia, cardiac arrest, and asystole may be precipitated by lavage in poisonings with propranolol, calcium channel blockers and other drugs affecting cardiac conduction.
11
Q
Which toxic substances are minimally decontaminated with charcoal?
A
PHAILS
- Pesticides
- Hydrocarbons, Heavy metals
- Acid/Alkali, Alcohols
- Iron
- Lithium
- Solvents
12
Q
mechanism of activated charcoal
A
- drugs are carbon-based and their side chain adhere to carbon compounds
- activated charcoal provides a large surface area of carbon that it can bind to
- cathartics given to shorten GI time so that the bound drug can leave the body
- giving with water or sorbitol results in equal efficacy
13
Q
indications for activated charcoal
A
- Drug ingested is adsorbed by charcoal and has significant potential for toxicity
- Time since ingestion is less than 1
- The drug has significant enterohepatic recirculation
- The drug delays gastric emptying and time since ingestion is less than 4 hours
- The drug is in a controlled release preparation and time since ingestion is less than 12-18 hours
- Single dose not as effective as multiple-dose
14
Q
administration of activated charcoal
A
- for kids, can be mixed with something to make it palatable but may decrease efficacy
- in adults, goal is to drink 50g within 20min (if cannot, do via NG tube)
15
Q
complications of activated charcoal
A
- Charcoal aspiration
- Bowel obstruction may occur when excessive doses are administered.
- Hypotension / tachycardia may occur due to hypovolemia if a cathartic is administered. This develops due to fluid shift into the bowel
16
Q
indications for Multiple-Dose Activated Charcoal (MDAC)
A
“Charcoal Doesn’t Polish the Queen’s Tea set”
- Carbamazepine
- Dapsone
- Phenobarbital
- Quinine
- Theophylline
17
Q
mechanism of MDAC
A
- Repeated doses of activated charcoal can increase the clearance of drugs by interrupting enterohepatic recirculation.
- Gastrointestinal dialysis: Lipid soluble drugs of relatively low molecular weight are able to move from the gut capillaries back into the lumen (if there is a diffusion gradient) and be bound to charcoal (which maintains the gradient).
- should be used until clinical condition improves; most of the time, less than 12 hours
18
Q
indications for whole bowel irrigation (WBI)
A
- Medications not absorbed by charcoal (e.g., iron and lithium)
- Sustained release preparations (e.g., bupropion and verapamil)
- Other toxins that form pharmacobezoars (e.g. salicylates)
19
Q
mechanism of WBI
A
- Whole bowel irrigation physically flushes tablets from the gastrointestinal tract.
- uses large volumes of an iso-osmolar solution (polyethylene glycol, PEG-ELS, Golytely®) that is not absorbed
20
Q
administration of WBI
A
- Oral or via NG tube
- If the patient agrees to drink the solution, they should be reassessed after 15 minutes to determine their compliance. Many patients require administration via NG tube.
- Some patients may require an antiemetic if they are vomiting. Metoclopramide or ondansetron are usual initial choices.
- endpoint: clear rectal effluent (after 4-5L of fluid consumption within 2-4H)
21
Q
What kind of characteristics must a drug / poison in order to use hemodialysis effectively in removing them from the body?
A
- Low molecular weight (< 500 Daltons)
- Highly water soluble
- Low volume of distribution (< 1 L/kg)
- Low protein binding
- The toxic effects of the poisons should be serious, related to the plasma concentration, and not treatable easily by less invasive means.
22
Q
Which drug / poison can be removed by the body using hemodialysis?
A
- Ethanol
- Methanol
- Ethylene glycol
- Lithium
- Salicylates
- Theophylline
23
Q
adverse effects of hemodialysis
A
hypotension
24
Q
Skin Decontamination
A
- The contaminated skin should be washed thoroughly with soap and water.
- If possible, water from a tap, a hose or a shower should be used to wash the body, or water may be poured from a bucket.
- Clothing should be removed carefully while bathing the skin with a stream of water.
- Some poisonings such as hydrofluoric acid require special decontamination.
25
Q
Ocular Decontamination
A
- If a poison enters eyes, they should be washed thoroughly for 15 minutes with running water.
- The patient should continuously blink during the procedure.
- If blurring of vision, pain or redness persists, an ophthalmologist should be consulted.
