1. RATIONALE AND OBJECTIVES
A Review of Gastrointestinal Decontamination for Overdose Patients at The Ottawa Hospital
Sabrina Natarajan1, Alex Kuo1, Céline Corman1, Andrew Gee2, Rakesh Patel3,4, Salmaan Kanji1,3,5
Departments of Pharmacy1, Emergency Medicine2, Critical Care Medicine3, Division of General Internal Medicine4, The Ottawa Hospital; The Ottawa Health Research Institute5, Ottawa, Ontario, Canada
BACKGROUND
ADJUDICATION
DISCUSSION
Gastrointestinal (GI) decontamination is a consideration for all poisoned patients, however, selection of appropriate patients requires risk assessment
In an acute poisoning, activated charcoal (AC) and whole bowel irrigation (WBI) are considered first-line therapies for GI decontamination
Single doses of AC have the best efficacy when given within two hours of the ingestion
WBI involves administration of a large volume of osmotically balanced polyethylene glycol electrolyte solution to decrease absorption by expelling the contents of the entire GI tract
AC and WBI are contraindicated if the patient is thought to have a bowel obstruction or there is a high risk of bowel perforation
Adverse events related to GI decontamination are rare, but sequelae can be severe
adverse events include aspiration, bowel obstruction, and bowel perforation
Appropriate Administration of AC:
Administered within two hours of toxin ingestion where there is risk of a severe toxidrome
Administered beyond two hours for toxins with a sustained-release preparation, toxins that may form concretions in the gut, toxins which may delay gastric emptying, drugs that undergo enterohepatic recycling
Inappropriate Administration of AC:
Administered to patients with absent bowel sounds or with a GCS < 12 without securing the airway
Appropriate Administration of WBI:
Administered within two hours of toxin ingestion where there is risk of a severe toxidrome and the toxin does not adsorb to activated charcoal
Administered beyond two hours for sustained-release or enteric coated toxins, or for removal of ingested packets of illicit drugs
Inappropriate Administration of WBI:
Administered to patients with absent bowel sounds or with a GCS < 12 without securing the airway
GI decontamination can be an important tool in the treatment of the poisoned patient, but it must be used with discretion--the clinician must weigh the possible sequelae of the poisoning versus the potential for adverse events due to the GI decontamination
Physicians ordered only AC for GI decontamination except for one case in which WBI was ordered.
Methods which are not recommended for GI decontamination (ipecac syrup, gastric lavage, administration of a cathartic) were not ordered or administered
Only 33 cases (17.2%) were deemed to be eligible for treatment with activated charcoal
There were only 16 cases where patients were treated with activated charcoal
Eight of these 16 cases were deemed to be eligible for this treatment
The most common reasons for ineligibility were the lack of potential for a serious toxidrome due to the toxin or the patient presenting too late to receive benefit from the AC
For the one case in which WBI was ordered, reviewers deemed the patient ineligible due to both the very late presentation and the lack of potential for positive effects from the treatment
There were three cases in which the patient vomited after administration of AC
There were no cases aspiration following vomiting
Among the four reviewers there were differences of opinion in some cases as to whether AC or WBI could have been administered, speaking to the difficulty of making these decisions
AC and WBI was considered to be withheld inappropriately if patients met above criteria for administration but it was not prescribed
All other methods of GI decontamination (ipecac, gastric lavage, administration of a cathartic) were considered inappropriate
RATIONALE AND OBJECTIVES
RESULTS
Guidelines for the use of GI decontamination in the poisoned patient have been produced by the American Academy of Clinical Toxicology (AACT) and endorsed by the Canadian Association of Poison Control Centres
At The Ottawa Hospital (TOH) anecdotal reports of inappropriate use of charcoal prompted the Department of Emergency Medicine to formulate guidelines for the use of AC in overdose patients
The purpose of this study was to review TOH current practice with respect to the utilization of GI decontamination in overdose patients admitted to the Emergency Department (ED) relative to the TOH guidelines for activated charcoal use, and the AACT guidelines for GI decontamination
Study objectives included:
Evaluate the use of AC relative to the TOH Department of Emergency Medicine Best Practice Guidelines for the Rational Use of Activated Charcoal in Overdose Patients
Evaluate use of WBI with respect to the AACT position paper on use of WBI in management of poisoned patient
Describe which other methods of GI decontamination were being used at TOH for poisoned patient
Determine incidence of preventable adverse events related to utilization of GI decontamination
Demographics
Time from Ingestion to ED Presentation
Treatment Group
N=192 (%)
Gender:
Male
79 (41.1)
Ethanol Use:
Never
Occasional
Binges
Daily
Not Documented
36 (18.8)
11 (5.7)
17 (8.9)
42 (21.9)
85 (44.3)
History of Illicit Drug Use
70 (36.5)
Documented Psychiatric History
150 (78.1)
Previous Documented Suicide Attempt
N=16 (%)
Number of Doses of Charcoal:
Single Dose
Multiple Doses
14 (87.5)
2 (12.5)
Adverse Events:
Vomiting during charcoal administration
Vomiting after charcoal administration
1 (6.25)
CONCLUSION
Physicians at TOH appear to be wary of using GI decontamination and rarely prescribe this treatment modality
While most poisoned patients do not meet the requirements for treatment there are eligible patients being missed
Those patients who do receive treatment do not always meet published guidelines for GI decontamination
Further educational efforts to raise awareness of institutional guidelines are warranted to ensure appropriate use of GI decontamination and minimize avoidable adverse events
Ingested Toxins
REFERENCES
METHODS
192 cases of poisonings for analysis
American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists. Position paper: Single-dose activated charcoal. Clin Toxicol 2005;43:61-87.
Gatien M. The Ottawa Hospital Department of Emergency Medicine best practice guidelines for rational use of activated charcoal in overdose patients.
Green JP, McCauley W. Bowel perforation after single-dose activated charcoal. Can J Emerg Med 2006;8(5):
American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists. Position paper: Whole bowel irrigation. Clin Toxicol 2004;42:
American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists. Position paper: Gastric lavage. Clin Toxicol 2004;42(7):
American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists. Position paper: Ipecac syrup. Clin Toxicol 2004;42(2):
Design:
Retrospective chart review of all poisoned patients who presented to the Civic Campus ED
Approval obtained from The Ottawa Hospital Research Ethics Board
Population:
Consecutive patients with intentional or accidental poisoning presenting between January 1 and December 31, 2006
Exclusion criteria:
Patients under 18 years of age
Patients transferred from other hospitals
Patients who presented with non-ingested poisonings
Data Collection:
Patient demographics, type, time, and quantity of overdose, treatment, GI decontamination use, eligibility, and hospital outcomes were collected
Acute or chronic overdose, Glasgow Coma Scale (GCS) on admission, type of GI decontamination used, time of GI decontamination, hospitalization, intubation prior to or after GI decontamination, nasogastric (NG) tube inserted for GI decontamination
Adverse event data included vomiting, aspiration, bowel obstruction, morbidity, mortality
33 cases eligible for activated charcoal administration
3 cases eligible for whole-bowel irrigation
156 cases not eligible for gastrointestinal decontamination
8 eligible cases in which patient was administered activated charcoal
0 cases in which patient was administered whole-bowel irrigation
8 ineligible cases in which patient was administered activated charcoal
1 episode of vomiting in an eligible patient who received activated charcoal
2 episodes of vomiting in ineligible patient who received activated charcoal