Botulism: Difference between revisions
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# Respiratory Failure | # Respiratory Failure | ||
=== | ===Infant Botulism=== | ||
# no honey or corn syrup to < 1 yo | # no honey or corn syrup to < 1 yo | ||
# most cases < 1 y/o, 90% < 6mo | # most cases < 1 y/o, 90% < 6mo |
Revision as of 14:20, 15 March 2011
Background
- sporeforming,m obligate anaerobe, gram positive
- lethal dose 1 ng/kg
- 1 gm can kill 1 million people
- blocks release of Ach from presynaptic membrane
- experimental vaccine
Symptoms
- symmetric, desc. paralysis w/B/L cranial nerve neuropathies (diplopia, dysarthria, ptosis)
- GI sxs: N/V, pain, late constipation
- Respiratory Failure
Infant Botulism
- no honey or corn syrup to < 1 yo
- most cases < 1 y/o, 90% < 6mo
- most common form of botulism
- relative achlorhydia, poorly developed gut flora
- 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
- black tar heroin, dirty wounds, C-section, tooth abscess, sinus infections
- incubation 10 days
- wound may appear benign
- GI sxs absent
Diagnosis
- 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
- 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
- Lambert-Eaton - spares resp muscles and primarily affects proximal lower limb muscles EMG findings similar to botulism (post-tetanic facilitation) but not identical
- Guillain -Barre - Miller Fisher variant has prominent ataxia & areflexia that isn't seen in botulism. Nerve conduction tests are also abnormal
- Poliomyelitis - usually have fever and asymmetric weakness. Ascending paralysis and CSF pleocytosis.
- Tick Paralysis - ascending paralysis, abnl nerve cond tests
- Diphtheria - proximal to distal spread of weakness 1-3 mo after fever and pharyngitis
- Hyperthyroidism
- Paralytic fish poisoning - tetrodotoxication (w/in 1 hr of fish eat)
- Mg, mushroom or chemical (arsenic,thallium, anticholinergic) or meds (antichol, aminogly)
- Sepsis
Workup
- Anaerobic cxs: emesis, gastric fluid, stool, food, wound, serum
- EPS - EMG shows decr amplitude with post-tetanic facilitation Nerve conduction normal
Treatment
- Ventilatory support: Intubate when VC < 30% predicted or < 12 cc/kg
- 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