Rosen & Barkin's 5-Minute Emergency Medicine Consult (100 page)

• ICU admission for decreased level of consciousness or hemodynamic instability (bradycardia, conduction delays, hypotension)
  
• Observation and monitoring for 24 hr for long-acting or sustained-release preparations owing to the potential delay in symptoms
  

Asymptomatic 8–10 hr after ingestion of short- or immediate-release preparation

• Psychiatric evaluation for all suicidal patients
  
• Poison prevention guidance for parents of pediatric accidental ingestion
  

• Consider β-blocker toxicity in patients who present with hypotension and bradycardia.
  
• Wide complex QRS dysrhythmias should be treated with sodium bicarbonate.
  

• Harvey MG, Cave GR. Intralipid infusion ameliorates propranolol-induced hypotension in rabbits.
  J Med Toxicol
  . 2008;4:71–76.
  
• Pfaender M, Casetti PG, Azzolini M, et al. Successful treatment of a massive atenolol and nifedipine overdose with CVVHDF.
  Minerva Anestesiol
  . 2008;74:97–100.
  
• Shepherd G. Treatment of poisoning caused by β-adrenergic and calcium-channel blockers.
  Am J Health Sys Pharm
  . 2006;63:1828–1835.
  

See Also (Topic, Algorithm, Electronic Media Element)

Calcium Channel Blocker, Poisoning

CODES

971.3 Poisoning by sympatholytics [antiadrenergics]

BASICS

• Defined as naturally occurring organisms or toxins that are purified and prepared for mass dissemination with intent of causing mass morbidity, mortality, and social disruption.
  
• Organisms include bacteria, viruses, and fungi.
  
• Over 400 potential or actualized etiologic agents capable of being used as biologic weapon:
  
  • Characterized by their relatively low cost compared with other weapons of mass destruction (WMD), high potency, and their ability to be delivered in a stealthy manner
    
  • Stealth quality of biologic weapons comes from organism’s natural incubation period.
    
• Easy to conceal and difficult to detect:
  
  • Agents often invisible to naked eye, odorless, and tasteless
    
• Patients typically present to various health care facilities with host of common complaints, adding to delay in recognition of covert release of biologic weapon.
  
• Victims of biologic warfare agents are exposed either via direct cutaneous contact with agent, respiratory inhalation of aerosolized agent, or via GI tract after poisoning of food or water source.
  

• Bacteria:
  
  • Anthrax:
    Bacillus anthracis
    
  • Plague:
    Yersinia pestis
    
  • Cholera: Infection from
    Vibrio cholerae
    :
    
    • Presents with severe GI symptoms and rapidly leads to profound dehydration
      
  • Tularemia:
    Francisella tularensis
    
  • Brucellosis: Organism in the
    Brucella
    genus
    
  • Q fever:
    Coxiella burnetii
    
• Viruses:
  
  • Smallpox: Variola virus
    
  • Viral encephalitides: Members of
    Alphavirus
    genus (Venezuelan equine encephalitis, Eastern equine encephalitis, and Western equine encephalitis)
    
  • Viral hemorrhagic fevers: From 4 families of viruses, includes illnesses such as Ebola, Marburg, Lassa, and dengue fever
    
• Toxins:
  
  • Ricin
    
  • Staphylococcal enterotoxin B
    
  • Botulinum toxin
    
  • Mycotoxins
    

DIAGNOSIS

• Health care providers need to be alert to detect illness patterns and diagnostic clues that indicate biologic weapon release.
  
• Indications of intentional release of agent include:
  
  • Geographic clustering of illnesses with individuals who live, work, or attended event in close proximity (if multiple people who work in same office develop pneumonia, it could potentially represent respiratory pathogen release)
    
  • Unusual age distribution for common illness (chickenpox-like illness among adult patients could represent smallpox release)
    
  • ≥2 patients presenting with similar unexplained illnesses (2 patients presenting with flaccid paralysis could represent botulinum toxin release)
    
  • Single case of illness caused by uncommon agent (smallpox, inhalational anthrax)
    
  • High volume of patients with similar presentation of symptoms associated with escalating morbidity and mortality
    

• Inhalational anthrax:
  
  • Fever
    
  • Chills
    
  • Fatigue, malaise, lethargy
    
  • Cough, usually dry or minimally productive
    
  • Nausea or vomiting
    
  • Dyspnea
    
  • Diaphoresis
    
  • Chest pain
    
  • Myalgias
    
  • Tachycardia
    
  • Fever
    
  • Meningeal signs
    
• Cutaneous anthrax:
  
  • Skin lesion:
    
    • Painless pruritic papule
      
    • Turning into vesicle that ruptures forming necrotic ulcer
      
  • Black eschar
    
  • Surrounding gelatinous nonpitting edema
    

• Abrupt onset
  
• Fever, chills
  
• Cough, hemoptysis, dyspnea
  
• Headache
  
• Vomiting
  
• Swollen tender lymph nodes (buboes)
  
• Skin lesions at site of inoculation (i.e., flea bite)
  
• Confusion
  
• Abdominal pain
  
• Oliguria
  
• Obtundation
  
• Extensive ecchymosis
  
• Acral gangrene (digits, nose, penis)
  

• See “Tularemia” chapter.
  
• Typhoidal:
  
  • Most likely form of disease when weaponized and delivered by aerosol
    
  • Fever, headache, malaise
    
  • Nonproductive cough
    
  • 35% mortality if untreated
    

• Incubation period 10–40 days
  
• Flu-like symptoms and pleuritic chest pain for 2–10 days
  
• CXR shows patchy infiltrates
  
• Definitively diagnosed serologically
  
• Mortality:
  
  • <1% even if untreated
    

• Incubation period 3–60 days
  
• Flu-like symptoms and neuropsychiatric symptoms (headache, depression, fatigue, and irritability)
  
• Focal infection of joints and GU tract may cause localized pain, particularly back pain.
  
• Diagnosis by combination of serologic testing and cultures of blood or bodily fluids.
  
• Mortality: <2%
  

• Incubation period 7–17 days (average is 12 days)
  
• Flu-like symptoms (fever, fatigue, myalgias, headache) for ∼2–3 days followed by characteristic rash:
  
  • Progresses from macules to papules to pustular lesions and crusted lesions
    
  • Starts on face and extremities (including palms/soles) and spreads to trunk in 1 wk
    
  • Scabs over in 1–2 wk
    
• Mortality:
  
  • 30% if untreated
    

• See “Hemorrhagic Fever” chapter
  
• Incubation period 1–3 wk
  
• Starts as flu-like syndrome with fever, malaise, myalgias, headache, and sore throat
  
• Afterward, infectious gastroenteritis syndrome, rash, and renal/hepatic dysfunction
  
• Finally, hemorrhagic symptoms develop around the 5th day followed by shock and death:
  
  • Mortality in 50–90% for Ebola if untreated
    

Suspect bioterrorism if:

• Multiple cases of relatively young, healthy patients who present with flu-like syndrome and within days deteriorate rapidly
  
• Typical cutaneous lesions appear
  

• CBC
  
• Electrolytes, BUN, creatinine
  
• ABG
  
• Cerebrospinal fluid (CSF):
  
  • Anthrax: 50% with inhalation anthrax develop hemorrhagic meningitis.
    
• Coagulation studies:
  
  • Plague: Disseminated intravascular coagulation (DIC)
    
• Blood cultures
  
• Wound cultures
  
• Alert lab personnel to potential concerns of clinicians.
  

CXR:

• Anthrax: Mediastinal widening, pulmonary infiltrate/consolidation, pleural effusion
  
• Plague: Bronchopneumonia