Intensive Care Management of Severe Tetanus

Tetanus is caused by an exotoxin, tetanospasmin, produced by Clostridium tetani, an anaerobic gram-positive bacillus. Tetanospasmin prevents the release of inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the spinal cord, brainstem motor nuclei, and the brain, producing muscle rigidity and tonic spasms. Trismus (lockjaw), dysphagia, laryngeal spasms, rigidity of limbs and paraspinal muscles, and opisthotonic posture are common. Frequent severe spasms triggered by touch, pain, bright light, or sounds may produce apnea and rhabdomyolysis. Autonomic overactivity occurs in severe tetanus causing labile hypertension, tachycardia, increased secretions, sweating, and urinary retention. Dysautonomia is difficult to manage and is a common cause of mortality; magnesium sulfate infusion is often used. Antibiotics (penicillin or metronidazole) and wound care reduce toxin production and human tetanus immune globulin neutralizes the circulating toxin. Nasogastric tube placement for feeding and medications is needed. Early elective tracheostomy is performed in moderate or severe tetanus to prevent aspiration and laryngeal stridor. Benzodiazepines help reduce rigidity, spasms, and autonomic dysfunction. Large doses of diazepam (0.2-1 mg/kg/h) are administered via nasogastric tube. Neuromuscular blocking agents and mechanical ventilation are used for refractory spasms. Mortality ranges from 5% to 50%.