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Plant Poisoning, Emergency Medicine

Basics

Description

  • Plant exposure is 1 of the most common reasons to contact the poison center
  • Majority of cases involve unintentional ingestion in children <6 yr old.

Etiology

Identification of ingested plant species should be attempted whenever possible. ‚

Plants with Anticholinergic Properties

  • Genera include Atropa, Datura, Hyoscyamus, Solandra, and Solanum.
  • Common names of anticholinergic plants include Jimson weed, deadly nightshade, henbane, and angel trumpet.
  • Competitive antagonists of acetylcholine at the muscarinic acetylcholine receptor

Plants with Cardiac Glycosides

  • Genera include Digitalis, Nerium, Thevetia, and Helleborus.
  • Common names of cardiac glycoside plants include foxglove, oleander, yellow oleander, lily of the valley, and hellebore/Christmas rose
  • Inhibit Na+/K+-ATPase:See separate chapter on Digoxin Poisoning

Plants with Nicotine-like Alkaloids

  • Genera include Nicotiana, Caulophyllum, and Conium
  • Common names of plants containing nicotine include tobacco, blue cohosh, and poison hemlock.
  • Direct-acting agonists at the nicotinic acetylcholine receptor

Plants with Cyanogenic Compounds

  • Genera include Hydrangea, Malus, Prunus, Sambucus
  • Common names of plants containing cyanogenic compounds (in some part of the plant) include apricot, cherry, peach, plum, apple, cassava, and elderberry
  • Metabolized to cyanide, which interferes with electron transport chain and leads to cellular poisoning

Plants with Calcium Oxalate Crystals

  • Genera include Alocasia, Dieffenbachia, and Philodendron as well as many others
  • Common names for calcium oxalate " “containing plants include elephants ear, dumb cane, and mother-in-law's tongue
  • Clinical manifestations occur after release of intracellular calcium oxalate crystals:Local tissue exposure to calcium oxalate crystals leads to inflammatory response.

Plants with Pyrrolizidine Alkaloids

  • Genera include Crotalaria, Heliotropium, Senecio, and Sesbania
  • Common names of plants with pyrrolizidine alkaloids include scorpions tail, ragwort, groundsel, and rattlebox
  • Metabolized to highly reactive pyrroles, which are directly hepatotoxic acutely and lead to hepatic vascular proliferation and veno-occlusive disease chronically.

Plants with Sodium Channel Activity

  • Genera include Aconitum, Delphinium, Leucothoe, Lyonia, Pernettya, Pieris, Rhododendron, Schoenocaulon, Veratrum, and Zigadenus
  • Common names of plants with aconitine, veratrum alkaloids, and zygacine, all sodium channel openers, include: Aconite (monkshood, wolfsbane, delphinium), veratrum (false hellebore), and zygacine (death camas)
  • Common names of plants with grayanotoxins, which have variable effects on sodium channels, include sweet bells, rhododendron, azalea, and lily-of-the-valley bush
  • Variable sodium channel effects depending on toxin, although most lead to prolonged sodium channel influx.

Plants with Toxalbumins

  • Genera include Abrus, Jatropha, Phoradendron, Ricinus, Robinia, Wisteria
  • Common names of plants with toxalbumins include rosary pea, mistletoe, and castor bean
  • Cause direct cellular toxicity by interfering with ribosomal function

Diagnosis

Signs and Symptoms

Anticholinergic

  • Dry, warm, and flushed skin
  • Absent bowel sounds
  • Urinary retention
  • Agitated delirium

Cardioactive Steroids

  • Digoxin-like toxicity
  • Abdominal pain, nausea, vomiting
  • Multiple cardiac effects, ranging from junctional bradycardia to v-tach/v-fib
  • ‚ ± hyperkalemia

Nicotine-like Alkaloids

  • Hypertension
  • Tachycardia ˘ † ’ bradycardia (late)
  • Diaphoresis
  • Salivation
  • Vomiting
  • Fasciculations
  • Muscle weakness

Cyanogenic Compounds

  • Potentially delayed (unlike cyanide gas)
  • Initial symptoms:Abdominal pain, nausea, vomitingLethargyDiaphoresis
  • Followed by:Altered mental statusLactic acidosisSeizuresCardiovascular collapseMultiorgan system failure

Calcium Oxalate Crystals

  • Oropharyngeal burning pain and swelling (after biting or chewing)
  • Ocular exposure results in keratoconjunctivitis
  • Dermal irritation after dermal contact

Pyrrolizidine Alkaloids

  • Acutely causes hepatitis
  • Chronic exposure may lead to hepatic veno-occlusive disease

Sodium Channel Activators

  • Abdominal pain, nausea, vomiting
  • CNS: Progress from paresthesias to depressed mental status, respiratory depression, coma, and seizures.
  • CV: Bradycardia with atrioventricular blocks, progressing to tachydysrhythmias

Toxalbumins

  • Effects depend on plant (e.g., mistletoe is rarely toxic, whereas ricin can be deadly) and route of exposure
  • Gastroenteritis, diarrhea, or abdominal pain if ingested
  • Localized pulmonary effects if inhaled
  • Diffuse organ dysfunction if injected
  • Often present with lip, tongue, and oropharyngeal irritation and swelling from oxalate crystal " “containing plants:Potential for airway compromise
  • Usually consume leaves, seeds, and berries
  • Nicotine group: 1 or 2 cigarettes potentially lethal
  • Jimson weed:Seeds highly concentrated100 seeds equal 6 mg of atropineLethal at 4 " “5 g of leaf
  • Yellow oleander:2 leaves lethal in 12.5 kg child

Essential Workup

  • Identification of ingested material
  • Workup depends on plant ingested

Diagnosis Tests & Interpretation

Lab

  • Electrolytes, BUN, creatinine, glucose, liver function tests
  • ABG/VBG for blood pH determination
  • Digoxin level for cardiac glycoside plants
  • Lactic acid for cyanogenic plants

Imaging

Differential Diagnosis

  • Altered mental status:Drug use/alcoholSeizuresTraumaCerebrovascular accidentHypoglycemia
  • Digoxin toxicity
  • Gastroenteritis
  • Agents causing metabolic acidosis (see Acidosis chapter)
  • Cardiotoxic drugs

Treatment

Pre-Hospital

  • Examples of common nontoxic houseplants:African violetBird of paradiseFicusGardeniaGrape ivyOrchidsPoinsettia (despite reputation)Rubber treeSpider plantWandering JewWax plantZebra plant
  • Collect seeds, leaves, spores in paper bag.
  • Contact local botanist.
  • Syrup of ipecac is not recommended

Initial Stabilization/Therapy

  • Airway, breathing, and circulation management (ABCs)
  • 0.9% normal saline IV:Aggressive volume replacement for dehydration/hypotensionInitiate pressors for hypotension unresponsive to fluids
  • Cardiac monitoring
  • Supportive care for most ingestions

Ed Treatment/Procedures

  • Supportive care
  • Rare plants necessitate focused/antidotal therapy

Anticholinergic

  • Benzodiazepines for agitation
  • Consider physostigmine for severe agitated delirium

Cardioactive Steroids

Digoxin-specific Fab indicated in: ‚

  • Significant bradycardia
  • Tachydysrhythmia
  • Hyperkalemia

Nicotine-like Alkaloids

  • Parenteral short-acting antihypertensives such as nitroprusside for hypertensive crisis
  • Treat seizures with benzodiazepines.

Cyanogenic Compounds

  • Correction of electrolyte abnormalities
  • Hydroxocobalamin or prepackaged cyanide antidote kit if severe lactic acidosis or hemodynamic compromise

Calcium Oxalate Crystals

  • For mild symptoms, popsicles may decrease burning
  • Viscous lidocaine and analgesics for more severe oral exposure
  • Copious irrigation for ocular, oropharyngeal, and dermal exposure

Pyrrolizidine Alkaloids

  • Supportive care
  • Removal from source. Pyrrolizidine alkaloids have been found in herbal medication products as well as food contaminants
  • Liver-specific management in conjunction with hepatologist

Sodium Channel Activators

  • Atropine for bradycardia and atrioventricular blocks
  • Normal saline bolus for hypotension, or vasopressor therapy if normal saline fails

Toxalbumins

Supportive care based on clinical symptoms: Replace GI losses with intravenous fluids, replete electrolytes. ‚

Medication

  • Atropine: 0.5 mg (peds: 0.02 mg/kg) IV, repeat 0.5 " “1 mg IV
  • Cyanide antidote kit:Inhale amyl nitrite ampule for 30 sec every minute until sodium nitrite given.Sodium nitrite: 10 mL of 3% solution or 300 mg IV over 3 " “5 min (peds: 0.15 " “0.33 mL/kg):Monitor methemoglobin levels to keep <30%.Sodium thiosulfate: 50 mL IV of 25% solution or 12.5 g (peds: 1.65 mL/kg)
  • Digoxin Fab fragments: Empiric dose 5 " “10 vials
  • Hydroxocobalamin: 5 g IV for adults; 70 mg/kg not to exceed 5 g IV for pediatrics
  • Magnesium: 2 " “4 g IV
  • Physostigmine: 0.5 " “2 mg IV
  • Sodium bicarbonate 8.4%: 1 amp IV push until narrowing of QRS complex

Follow-Up

Disposition

Admission Criteria

  • Dysrhythmias for cardiac monitoring
  • Intractable vomiting
  • Refractory hypotension
  • Evidence of end-organ damage (e.g., hepatic dysfunction, acidosis) or concern for potential for end-organ damage
  • Altered mental status

Discharge Criteria

  • Baseline mental status
  • Tolerating oral fluids
  • Normal cardiac activity
  • Delayed sequelae not anticipated

Lower threshold to admit children: ‚

  • Tend to eat more concentrated parts of plants
  • Lower lethal dose
  • Symptoms less specific

Followup Recommendations

Follow-up with medical toxicologist or primary care physician ‚

Pearls and Pitfalls

  • Death from unintentional plant exposures is rare.
  • Intentional exposures from herbal remedies, attempted abuse or therapeutic misadventures can be deadly.
  • Contact your regional poison center if concerned about a patient ingesting a potentially poisonous plant: 1-800-222-1222

A special thanks to Dr. Harry Karydes, who contributed to the previous edition. ‚

Additional Reading

  • Froberg ‚ B, Ibrahim ‚ D, Furbee ‚ RB. Plant poisoning. Emerg Med Clin North Am. 2007;25(2):375 " “433.
  • Nelson ‚ LS, Shih ‚ RD, Balick ‚ MJ. Handbook of Poisonous and Injurious Plants. 2nd ed. New York, NY: Springer; 2007:21 " “34.
  • Palmer ‚ ME, Betz ‚ JM. Plants. In: Goldfrank ‚ LR, Flomenbaum ‚ NE, Lewin ‚ NA, et al., eds. Goldfranks Toxicologic Emergencies. 9th ed. Chicago, IL: McGraw-Hill Medical; 2011:1537 " “1560.

See Also (Topic, Algorithm, Electronic Media Element)

  • Acidosis
  • Cyanide Poisoning
  • Digoxin Poisoning

Codes

ICD9

988.2 Toxic effect of berries and other plants eaten as food ‚

ICD10

  • T62.1X1A Toxic effect of ingested berries, accidental, init
  • T62.2X1A Toxic effect of ingested (parts of) plant(s), acc, init

SNOMED

  • 446686000 Poisoning by ingestion of plant (disorder)
  • 29824007 Atropa belladonna poisoning (disorder)
  • 45328004 Digitalis purpurea poisoning (disorder)