Rosen & Barkin's 5-Minute Emergency Medicine Consult (549 page)

• 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
  

• 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
    

• 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
  

• 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
  

• Genera include
  Alocasia
  ,
  Dieffenbachia
  , and
  Philodendron
  as well as many others
  
• Common names for calcium oxalate–containing plants include elephant’s 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.
    

• Genera include Crotalaria, Heliotropium, Senecio, and Sesbania
  
• Common names of plants with pyrrolizidine alkaloids include scorpion’s 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.
  

• 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.
  

• 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

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

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

• Hypertension
  
• Tachycardia → bradycardia (late)
  
• Diaphoresis
  
• Salivation
  
• Vomiting
  
• Fasciculations
  
• Muscle weakness
  

• Potentially delayed (unlike cyanide gas)
  
• Initial symptoms:
  
  • Abdominal pain, nausea, vomiting
    
  • Lethargy
    
  • Diaphoresis
    
• Followed by:
  
  • Altered mental status
    
  • Lactic acidosis
    
  • Seizures
    
  • Cardiovascular collapse
    
  • Multiorgan system failure
    

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

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

• 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
  

• 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 concentrated
    
  • 100 seeds equal 6 mg of atropine
    
  • Lethal at 4–5 g of leaf
    
• Yellow oleander:
  
  • 2 leaves lethal in 12.5 kg child
    

• Identification of ingested material
  
• Workup depends on plant ingested
  

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

• ECG
  
• CXR
  

• Altered mental status:
  
  • Drug use/alcohol
    
  • Seizures
    
  • Trauma
    
  • Cerebrovascular accident
    
  • Hypoglycemia
    
• Digoxin toxicity
  
• Gastroenteritis
  
• Agents causing metabolic acidosis (see Acidosis chapter)
  
• Cardiotoxic drugs
  

TREATMENT

• Examples of common nontoxic houseplants:
  
  • African violet
    
  • Bird of paradise
    
  • Ficus
    
  • Gardenia
    
  • Grape ivy
    
  • Orchids
    
  • Poinsettia (despite reputation)
    
  • Rubber tree
    
  • Spider plant
    
  • Wandering Jew
    
  • Wax plant
    
  • Zebra plant
    
• Collect seeds, leaves, spores in paper bag.
  
• Contact local botanist.
  
• Syrup of ipecac is not recommended
  

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

• Supportive care
  
• Rare plants necessitate focused/antidotal therapy
  

• Benzodiazepines for agitation
  
• Consider physostigmine for severe agitated delirium
  

Digoxin-specific Fab indicated in:

• Significant bradycardia
  
• Tachydysrhythmia
  
• Hyperkalemia
  

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

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

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

• 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
  

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

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

• 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