Toxicology - Whole bowel irrigation
Indications
Life-threatening toxic ingestion of sustained release or enteric coated preparations
Contraindications (absolute in bold)
Immediate resuscitation required
Good outcome expected with supportive care and antidote therapy alone
Vomiting
Ileus or intestinal obstruction
Uncooperative patient
Decreasing level of consciousness or risk of seizure (unless intubated)
Alternatives
Supportive care and antidote therapy
Informed consent
Medical emergency
Consent is not required if the patient lacks capacity or is unable to consent
Brief verbal discussion is recommended if the situation allows
Potential complications
Vomiting and diarrhoea (interfering with other interventions)
Pulmonary aspiration
Bowel obstruction with perforation
Metabolic acidosis
Distraction from resuscitation and supportive care priorities
Hypothermia (if solution not warmed)
Procedural hygiene
Standard precautions
PPE: non-sterile gloves, aprons, protective eyewear
Area
Acute bed or resuscitation bay (depending on conscious level, expected course and risk assessment)
Staff
Procedural clinician
1:1 nursing required for at least six hours
Equipment
12g nasogastric tube with position confirmed by X-ray
Commode (severe diarrhoea expected)
Positioning
Sitting up or supine with head of bed elevated to at least 45 degrees
Commode nearby
Medication
Polyethylene glycol electrolyte powder (macrogol 3350 powder with electrolytes prewarmed to 37 degrees)
Water for mixing solution (up to 12 litres over six hours)
Metoclopramide 10mg IV
Ondansetron 4mg IV
Activated charcoal (depending on toxicology discussion)
Sequence
Toxicology discussion prior to starting therapy (call poisons information on 13 11 26)
Allocate an extra nurse to carry out the procedure (for up to six hours)
Place nasogastric tube for all patients, confirming position on chest X-ray
Consider activated charcoal 50g (children 1g/kg) via the nasogastric tube (if indicated)
Administer polyethylene glycol (PEG) solution via the nasogastric at 2l/hour (25ml/kg/hour in children)
Administer IV metoclopramide and ondansetron to minimise vomiting and to enhance gastric emptying
Continue irrigation until effluent is clear (this may take up to six hours)
Cease whole bowel irrigation if abdominal distension or loss of bowel sounds are noted
If vomiting occurs, reduce infusion rate by 50% for 30 minutes, then return to the original rate
Continue infusion until rectal effluent is clear or there is resolution of the toxic effect
Post-procedure care
Toxicology discussion (call poisons information on 13 11 26)
Maintain head up positioning and observe for vomiting
Supportive care and monitoring
Check electrolytes after treatment (electrolyte disturbance may occur)
Tips
Toxicology discussion is always recommended prior to whole bowel irrigation
Always confirm nasogastric position with an X-ray prior to administration of activated charcoal
Abdominal X-ray is useful to assess decontamination of radio-opaque substances (e.g. iron and potassium salts)
Discussion
The aim of whole bowel irrigation is to physically flush ingested toxins out of the gastrointestinal tract before absorption.
Whole bowel irrigation is potentially useful for:
Iron overdose >60mg/kg
Slow-release potassium chloride ingestion >2.5mmol/kg
Slow-release diltiazem and verapamil
Life-threatening slow-release verapamil or diltiazem ingestions
Symptomatic arsenic trioxide ingestion
Lead ingestion
Body packers
Patients with intact airway-protective reflexes may drink the solution, however nasogastric tube placement is recommended for all patients as the large volume and taste often limit intact. Unconscious intubated patients with may receive whole bowel irrigation via a nasogastric tube. Waste products may be passed on a commode or via a rectal tube (if intubated).
Toxicology discussion is recommended prior to this therapy, with additional discussion of whether 100g of activated charcoal should be added to each litre of irrigation solution. It is essential to carefully balance the possible benefits against the significant risk of aspiration and practical difficulties of administering whole bowel irrigation. Vomiting and profuse diarrhoea can interfere with timely retrieval and life-saving interventions.
Peer review
This guideline has been reviewed and approved by the following expert groups:
Emergency Care Institute
Please direct feedback for this procedure to ACI-ECIs@health.nsw.gov.au.
References
Murray L, Little M, Pascu O, Hoggett KA. Toxicology handbook. 3rd ed. Sydney: Elsevier Australia; 2015.
eTG complete. Melbourne: Therapeutic Guidelines; 2012 Jul (updated 2018 Jul). Toxicology: general approach. Available from: https://tgldcdp.tg.org.au/viewTopic?topicfile=toxicology-general-approach
Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.
Dunn RJ, Borland M, O’Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 2019.
Hendrickson RG, Kusin S. Gastrointestinal decontamination of the poisoned patient. In: UpToDate. Waltham (MA): UpToDate. 2019 Mar 15. Retrieved Apr 2019. Available from: https://www.uptodate.com/contents/gastrointestinal-decontamination-of-the-poisoned-patient
Thanacoody R, Caravati EM, Troutman B, et al. Position paper update: whole bowel irrigation for gastrointestinal decontamination of overdose patients. Clin Toxicol (Phila). 2015;53(1):5-12. doi:10.3109/15563650.2014.989326
Tenenbein M. Position statement: whole bowel irrigation. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists. J Toxicol Clin Toxicol. 1997;35(7):753-762. doi:10.3109/15563659709162571