CURRENT Essentials of Critical Care.pdf

134 Current Essentials of Critical CareBotulism■ Essentials of Diagnosis• Acute descending paralysis caused by neurotoxin produced byClostridium botulinum; at least three of nausea, vomiting, dysphagia,diplopia, dilated fixed pupils, dry mouth in 90%• Cranial nerves affected first, followed by descending symmetricalflaccid paralysis, respiratory muscle involvement slowly orrapidly progressive• No sensory disturbances, changes in sensorium, fever; cranialnerves I, II spared• Confirm by detection of toxin in serum, stool, vomitus, gastricaspirate, suspected food• Three clinical forms: (1) food-borne from ingestion of preformedtoxin (onset 2 hours to 8 days); (2) wound with toxinproduced by infection with C botulinum (rare, incubation period4–14 days, seen with cutaneous illicit drug use); (3) in infants,ingestion of botulism spores, which germinate in the gut andproduce toxins• Toxin irreversibly blocks acetylcholine release at peripheralneuromuscular junctions leading to flaccid paralysis■ Differential Diagnosis• Myasthenia gravis and Eaton-Lambert syndrome• Tick paralysis• Poliomyelitis• Guillain-Barré syndrome (Miller-Fisher variant)• Stroke• Rabies• Diphtheria■ Treatment• Supportive care with frequent monitoring of vital capacity topredict respiratory failure; intubation, mechanical ventilation• Equine botulinum antitoxin (trivalent or polyvalent); patientsmust be tested for hypersensitivity• Debridement of devitalized tissue for wound botulism; penicillinfor wound infection• Antibiotics to decrease GI colonization with C botulinum controversial■ PearlIf an injection drug user develops descending paralysis, suspect woundbotulism caused by “black tar heroin.”ReferenceRobinson RF: Management of botulism. Ann Pharmacother 2003;37:127.[PMID: 12503947]