Botulism: Difference between revisions

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==Background==
==Adult Botulism==
# sporeforming,m obligate anaerobe, gram positive
===Background===
# lethal dose 1 ng/kg
#Clostridium botulinum produces toxin that blocks Ach release from presynaptic membrane
# 1 gm can kill 1 million people
#Cases due to:
# blocks release of Ach from presynaptic membrane
##Improper canning
# experimental vaccine
##Black-tar heroin use
##Wound infection (contaminated wounds, C-section, tooth abscess, sinus infection)
#Symptoms begin 6-48hr after exposure


==Symptoms==
===Clinical Features===
# symmetric, desc. paralysis w/B/L cranial nerve neuropathies (diplopia, dysarthria, ptosis)
#GI
# GI sxs: N/V, pain, late constipation
##N/V, abd cramps, diarrhea or constipation
# Respiratory Failure
##Not seen in pts who contract botulism from heroin or contaminated wound
#Paralysis
##Descending, symmetric
##Cranial nerves and bublar muscles are affected first: diplopia, dysarthria, dysphagia
###Will progress to respiratory depression if not treated
#Anticholinergic signs
##Urinary retention, dry skin/eyes, hyperthermia
#Dilated pupils (in contrast to pts w/ MG)


===Infant Botulism===
==Infantile Botulism==
# no honey or corn syrup to < 1 yo
===Background===
# most cases < 1 y/o, 90% < 6mo
*Due to consumption of botulinum spores (usually from honey)
# most common form of botulism
**Higher GI tract pH of infants makes them more susceptible
# relative achlorhydia, poorly developed gut flora
*Most cases occur in <1yr, 90% occur in <6m
# sxs from mild failure to thrive to sudden infant death
# drooling, ptosis, dilated/sluggish pupils, weak cry, feeding difficulties, constipation, resp arrest, poor head control, diminished muscle tone


===Wound Botulism===
===Clinical Features===
# black tar heroin, dirty wounds, C-section, tooth abscess, sinus infections
#GI
# incubation 10 days
##Constipation
# wound may appear benign
##Poor feeding
# GI sxs absent
#Lethargy
 
#Weak cry
==Diagnosis==
#Floppy infant
# clinically
# EMG studies: in botulism and Lambert-Eaton, few AcH released and muscle fibers don't reach threshold for contraction. With rapid nerve stim, can get enough AcH buildup in multiple muscle fibers to get "posttetanic facilitation."
# Nerve Conduction - normal in botulism (unlike GBS)


==DDx==
==DDx==
# Myasthenia Gravis - EMG findings and antibody studies will differentiate (decremental response to repetitive nerve stimulation). CAN see false positive improvement to Tensilon test in botulism
#Myasthenia Gravis
# Lambert-Eaton - spares resp muscles and primarily affects proximal lower limb muscles EMG findings similar to botulism (post-tetanic facilitation) but not identical
#Lambert-Eaton
# Guillain -Barre - Miller Fisher variant has prominent ataxia & areflexia that isn't seen in botulism. Nerve conduction tests are also abnormal
#Guillain-Barre  
# Poliomyelitis - usually have fever and asymmetric weakness. Ascending paralysis and CSF pleocytosis.
#Poliomyelitis
# Tick Paralysis - ascending paralysis, abnl nerve cond tests
#Tick Paralysis
# Diphtheria - proximal to distal spread of weakness 1-3 mo after fever and pharyngitis
#Diphtheria
# Hyperthyroidism
#Hyperthyroidism
# Paralytic fish poisoning - tetrodotoxication (w/in 1 hr of fish eat)
#Paralytic fish poisoning
# Mg, mushroom or chemical (arsenic,thallium, anticholinergic) or meds (antichol, aminogly)
#Magnesium toxicitiy
# Sepsis


==Workup==
==Treatment==
# Anaerobic cxs: emesis, gastric fluid, stool, food, wound, serum
#Ventilatory support
# EPS - EMG shows decr amplitude with post-tetanic facilitation Nerve conduction normal
##Consider intubation when VC <30% predicted or <12cc/kg
#Antitoxin/immune globulin
#Infant
##Supportive care only (no benefit from antitoxin or abx)
#Wound
##Antitoxin, wound irrigation & debridement, Pen G 10-20 mill units/day


==Treatment==
==Dispostion==
# Ventilatory support: Intubate when VC < 30% predicted or < 12 cc/kg
#Admit to ICU
# Foodbrone: antitoxin and AC, consider cathartics
# Infant: supportive care only, no benefit from antitoxin or Abx
# Wound: antitoxin, Td, wound irrigation & debridement even if appears well. Pen G 10-20 mill units/day


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Revision as of 03:46, 6 October 2011

Adult Botulism

Background

  1. Clostridium botulinum produces toxin that blocks Ach release from presynaptic membrane
  2. Cases due to:
    1. Improper canning
    2. Black-tar heroin use
    3. Wound infection (contaminated wounds, C-section, tooth abscess, sinus infection)
  3. Symptoms begin 6-48hr after exposure

Clinical Features

  1. GI
    1. N/V, abd cramps, diarrhea or constipation
    2. Not seen in pts who contract botulism from heroin or contaminated wound
  2. Paralysis
    1. Descending, symmetric
    2. Cranial nerves and bublar muscles are affected first: diplopia, dysarthria, dysphagia
      1. Will progress to respiratory depression if not treated
  3. Anticholinergic signs
    1. Urinary retention, dry skin/eyes, hyperthermia
  4. Dilated pupils (in contrast to pts w/ MG)

Infantile Botulism

Background

  • Due to consumption of botulinum spores (usually from honey)
    • Higher GI tract pH of infants makes them more susceptible
  • Most cases occur in <1yr, 90% occur in <6m

Clinical Features

  1. GI
    1. Constipation
    2. Poor feeding
  2. Lethargy
  3. Weak cry
  4. Floppy infant

DDx

  1. Myasthenia Gravis
  2. Lambert-Eaton
  3. Guillain-Barre
  4. Poliomyelitis
  5. Tick Paralysis
  6. Diphtheria
  7. Hyperthyroidism
  8. Paralytic fish poisoning
  9. Magnesium toxicitiy

Treatment

  1. Ventilatory support
    1. Consider intubation when VC <30% predicted or <12cc/kg
  2. Antitoxin/immune globulin
  3. Infant
    1. Supportive care only (no benefit from antitoxin or abx)
  4. Wound
    1. Antitoxin, wound irrigation & debridement, Pen G 10-20 mill units/day

Dispostion

  1. Admit to ICU