Background
- Clostridium tetani spores enter skin through wound, make tetanospasmin toxin
- 2001-2008 in US, 233 cases, 26 deaths
- Mortality as high as 45%
- Incubation is 2 to 56d
- Spores found in soil and human and animal feces
- Tetanus prone wounds include contaminated lacerations, abrasions, puncture wounds; crush, avulsion, or frostbite injuries are also vulnerable to tetanus [1]
- Preferentially binds GABA and glycinergic neurons and blocks pre-synaptic release
- Motor neurons undergo sustained excitatory discharge, producing spasms
- The majority of clinical tetanus happen in the elderly.[2]
Clinical Features
Opisthotonus in a patient suffering from tetanus
Neonatal
- From umbilical stump infection. Usually protected by passive maternal Abs
- Symptoms - poor suck and failure to nurse, irritability, crying, grimacing
- Usually with in 10 d of birth
Local
- Rigidity of muscles near wound- may progress to generalized
Generalized
- Most common form of tetanus
- Usually begins with trismus (spasm of the masticator muscle group) with gradual onset of spasm of muscle groups in the trunk and extremities
- Spasms exacerbated by external stimuli (light or sudden sound)
- Patients can lose ability to breathe during prolonged spasms
- Respiratory failure is main cause of death
- Patients are conscious and alert
- Hypersympathetic state with sweating, hypertension, tachycardia, fever
Cephalic
- Follow injuries to head or otitis media
- Get cranial nerve dysfunction- usually cranial nerve 7
Differential Diagnosis
Jaw Spasms
Evaluation
- Diagnosis is clinical
- Progressive symptoms[3]
- 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
- Difficulty swallowing
- Long bone fractures, tendon rupture
- Opisthotonus - lumbar lordosis with the neck and legs extended and the arms flexed at the elbows
- Laryngospasm
- Autonomic instability
- Sympathetic nervous system hyperactivity, including tachycardia, sweating, arrhythmias, and hypertension
- No laboratory testing is used to diagnose tetanus; wound cultures are often negative
Management
- Before wound debridement, immunoglobulin (TIG) directly into the wound and IM
- Dose: 3000-6000 units IM with adequate mL to wound
- Does not reverse toxin already bound to CNS. Binds circulating toxin
- Tetanus toxoid; patients do NOT develop immunity after tetanus infection
- Give during convalescence, not at initial presentation.Cite error: Closing
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- Acts as a presynaptic neuromuscular blocker by antagonizing calcium in the neuromuscular junction and myocardium
- Blocks the release of catecholamines and has anticonvulsant properties
- Often available in low-resource settings
- 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[4]
See Also
References
- ↑ Auerbach PS. Wilderness Medicine. Philadelphia: Mosby Elsevier; 2007.
- ↑ 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
Moll JL, Carden DL. Tetanus. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e New York, NY: McGraw-Hill; 2016. http://accessmedicine.mhmedical.com/content.aspx?bookid=1658§ionid=109435736. Accessed December 01, 2017.
