Acute tetanus
Background
- C. tetani spores enter skin through wound, make tetanospasmin toxin
- Lacs, abrasions, puncture wounds
- Preferentially binds GABA and glycinergic neurons and blocks presynaptic release
- Motor neurons undergo sustained excitatory discharge
- Spores found in soil and human feces
- 2001-2008 in US, 233 cases, 26 deaths
- Mortality as high as 45%
- Incubation is 2 to 56d
- The majority of clinical tetanus happen in the elderly.[1]
Clinical Features
Neonatal
- From umbilical stump infection. Usually protected by passive maternal Abs
- Sx- poor suck, irritability, crying, grimacing
- Usually with in 10 d of birth
Local
- Rigidity of muscles near wound- may progress to generalized
Generalized
- Most common form
- PTs are conscious and alert
- Hypersympathetic state c sweating, HTN, tachycardia, fever
Cephalic
- Follow injuries to head or otitis media
- Get CN dysfunction- usually CN 7
Differential Diagnosis
Jaw Spasms
- Acute tetanus
- Akathisia
- Conversion disorder
- Drug toxicity (anticholinergic, phenytoin, valproate, carbamazepine)
- Dystonic reaction
- Electrolyte abnormality
- Hypocalcemic tetany
- Magnesium
- Mandible dislocation
- Meningitis
- Peritonsillar abscess
- Rabies
- Seizure
- Strychnine poisoning
- Stroke
- Temporomandibular disorder
- Torticollis
Diagnostic Evaluation
- Progressive symptoms[2]
- Alert and able to communicate
- Trismus - lockjaw (50%-75% of patients)
- Sardonic smile (risus sardonicus) - other facial muscles become involved
- Minor stimuli such as touch or noise start tetanic contractions
- Abd, back, diff swallowing
- Long bone fractures, tendon rupture
- Opisthotonus - contractures that resemble decorticate posturing
- DX = clinical
Management
- Before wound debridement, apply immunoglobulin (TIG) directly into the wound and IM
- Dose: 3000-6000 units IM with adequate mL to wound
- Des not reverse toxin already fixed to CNS. Binds circulating toxin
Supportive Care
- Place patient in a quiet room
- Provide sedation with Benzodiazepines or phenobarbital
Antibiotics
- Metronidazole 500mg IV (7.5mg/kg) q6hrs OR
- Clindamycin 600mg IV (7.5mg/kg) q6hrs
Penicillin
- Although once the drug of choice it is now no longer recommended since it may potentiate the effect of tetanus toxin by inhibiting the GABA receptors[3]
See Also
References
- ↑ Talan DA, et al. Tetanus immunity and physician compliance with tetanus prophylaxis practices among emergency department patients presenting with wounds. Ann Emerg Med. 2004 Mar;43(3):305-14.Pubmed
- ↑ Fernandez-Frackelton M: Bacteria, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 127:p 1681-1686
- ↑ Ganesh Kumar AV. Benzathine penicillin, metronidazole and benzyl penicillin in the treatment of tetanus: a randomized, controlled trial .Ann Trop Med Parasitol. 2004 Jan;98(1):59-63 PMID 15000732