CURRENT Essentials of Critical Care.pdf

156 Current Essentials of Critical CareTetanus■ Essentials of Diagnosis• Neurologic disorder caused by neurotoxin produced by Clostridiumtetani; toxin binds to presynaptic inhibitory neurons causinguncontrolled motor neuron activity• Presentations: (1) neonatal tetanus; and (2) generalized; (3) local;or (4) cephalic tetanus in adults; local and cephalic tetanuscan progress to generalized• Trismus (“lockjaw”) most common; advanced tetanus with generalizedspasms, opisthotonos, abdominal rigidity, spastic facialexpression (“risus sardonicus”); involvement of respiratorymuscles leads to hypoventilation; autonomic nervous systemdisturbances common (sweating, tachycardia, arrhythmias, fluctuatingblood pressure); fever notably absent, except in patientswith seizures• 1 to 54 days following wound contaminated with C tetani spores;crush, frostbite wounds with higher risk; wound cultures frequentlynegative for C tetani• Lack of C tetani antibody (no immunization) supports diagnosis• C tetani spores survive years in dust, soil, areas contaminatedby human or animal excreta; common in developing countries;rare in the U.S. (50 cases per year); entirely preventable bytetanus vaccination■ Differential Diagnosis• Strychnine poisoning, phenothiazine overdose• Mandibular or other lesions causing jaw lock• Meningoencephalitis, opioid withdrawal, diphtheria, mumps, rabies■ Treatment• Tetanus immune globulin• Debridement of wound; penicillin G (kills active bacteria; sporesnot affected by antibiotics)• Supportive care with tracheostomy, mechanical ventilation,benzodiazepines, nutritional support, therapy of seizures andcardiac arrhythmias• Active immunization during convalescent phase■ PearlBinding of toxin is irreversible; rapid administration of antitoxin crucialto prevent progression and likelihood of death.ReferenceFarrar JJ et al: Tetanus. J Neurol Neurosurg Psychiatry 2000;69:292–301.[PMID: 10945801]