OTHER NAMES
lockjaw
DEFINITION
A disease caused by the toxin of the bacterium Clostridium tetani that affects the central nervous system, sometimes resulting in death.
CAUSES, INCIDENCE, AND RISK FACTORS
Spores of the bacterium Clostridium tetani live in the soil and are distributed worldwide. In the spore form, Clostridium tetani may remain dormant in the soil but infectious for periods longer than 40 years. Infection begins when the spores are introduced into an injury or wound. The spores germinate, releasing active bacteria that multiply, and produce a neurotoxin, called tetanospasmin. Tetanospasmin selectively blocks inhibitory nerve transmission from the spinal cord to the muscles, allowing the muscles to go into severe spasm. Spasmodic contractions may be so powerful that they tear the muscles or cause compression fractures of the vertebrae.
Tetanus often begins with mild spasms in the jaw muscles (trismus), neck muscles, and facial muscles. Rigidity rapidly develops in the chest, back and abdominal muscles and sometimes the laryngeal muscles (which then interferes with breathing). Muscular seizures (tetany) cause sudden, powerful, and painful contraction of muscle groups. During these episodes, fractures and muscle tears can occur. Without treatment, 1 out of 3 affected people die. The mortality rate for newboms with untreated tetanus is even higher, 2 out of 3.
The incubation period is 5 days to 15 weeks, with 8 to 12 days as the average.
lockjaw
DEFINITION
A disease caused by the toxin of the bacterium Clostridium tetani that affects the central nervous system, sometimes resulting in death.
CAUSES, INCIDENCE, AND RISK FACTORS
Spores of the bacterium Clostridium tetani live in the soil and are distributed worldwide. In the spore form, Clostridium tetani may remain dormant in the soil but infectious for periods longer than 40 years. Infection begins when the spores are introduced into an injury or wound. The spores germinate, releasing active bacteria that multiply, and produce a neurotoxin, called tetanospasmin. Tetanospasmin selectively blocks inhibitory nerve transmission from the spinal cord to the muscles, allowing the muscles to go into severe spasm. Spasmodic contractions may be so powerful that they tear the muscles or cause compression fractures of the vertebrae.
Tetanus often begins with mild spasms in the jaw muscles (trismus), neck muscles, and facial muscles. Rigidity rapidly develops in the chest, back and abdominal muscles and sometimes the laryngeal muscles (which then interferes with breathing). Muscular seizures (tetany) cause sudden, powerful, and painful contraction of muscle groups. During these episodes, fractures and muscle tears can occur. Without treatment, 1 out of 3 affected people die. The mortality rate for newboms with untreated tetanus is even higher, 2 out of 3.
The incubation period is 5 days to 15 weeks, with 8 to 12 days as the average.
. SYMPTOMS
- spasms and tightening of the jaw muscle (hence the name lockjaw)
- stiffening of the neck and other muscles
- spasms of the neck and other muscles
- rigidity of the chest muscles
- rigidity of the abdominal muscles (abdominal rigidity)
- spasms and rigidity of the back muscles, often causing arching (opisthotonos)
- tetanic seizures (painful, powerful bursts of muscle contraction)
- irritability
- fever
Additional symptoms that may be associated with this disease:
- sweating, excessive
- swallowing difficulty
- hand or foot spasms
- drooling
- uncontrolled urination
- uncontrolled defecation
SIGNS AND TESTS
Diagnosis of tetanus is based on the history and physical findings that are characteristic of the disease. Diagnostic studies generally are of little value. Cultures of the wound site are negative for clostridia two-thirds of the time. When the culture is positive it is diagnostic.
Tests that may sometimes be performed include:
- culture of the wound site
- tetanus antibody test
- other tests to rule-out meningitis, rabies, strychnine poisoning or other diseases with similar symptoms
- spasms and tightening of the jaw muscle (hence the name lockjaw)
- stiffening of the neck and other muscles
- spasms of the neck and other muscles
- rigidity of the chest muscles
- rigidity of the abdominal muscles (abdominal rigidity)
- spasms and rigidity of the back muscles, often causing arching (opisthotonos)
- tetanic seizures (painful, powerful bursts of muscle contraction)
- irritability
- fever
Additional symptoms that may be associated with this disease:
- sweating, excessive
- swallowing difficulty
- hand or foot spasms
- drooling
- uncontrolled urination
- uncontrolled defecation
SIGNS AND TESTS
Diagnosis of tetanus is based on the history and physical findings that are characteristic of the disease. Diagnostic studies generally are of little value. Cultures of the wound site are negative for clostridia two-thirds of the time. When the culture is positive it is diagnostic.
Tests that may sometimes be performed include:
- culture of the wound site
- tetanus antibody test
- other tests to rule-out meningitis, rabies, strychnine poisoning or other diseases with similar symptoms
Treatment
The wound must be cleaned. Dead and infected tissue should be removed by surgical debridement. Metronidazole treatment decreases the number of bacteria but has no effect on the bacterial toxin. Penicillin was once used to treat tetanus, but is no longer the treatment of choice because of a theoretical risk of increased spasms. It should still be used if metronidazole is not available. Passive immunization with human anti-tetanospasmin immunoglobulin or tetanus immune globulin is crucial. If specific anti-tetanospasmin immunoglobulin is not available, then normal human immunoglobulin may be given instead. All tetanus victims should be vaccinated against the disease or offered a booster shot.
Mild tetanus
Mild cases of tetanus can be treated with:
Severe tetanus
Severe cases will require admission to intensive care. In addition to the measures listed above for mild tetanus:
Lock-jaw in a patient suffering from tetanus.
- human tetanus immunoglobulin injected intrathecally (increases clinical improvement from 4% to 35%)
- tracheostomy and mechanical ventilation for 3 to 4 weeks,
- magnesium, as an intravenous (IV) infusion, to prevent muscle spasm,
- diazepam (known under the common name Valium) as a continuous IV infusion,
- the autonomic effects of tetanus can be difficult to manage (alternating hyper- and hypotension, hyperpyrexia/hypothermia) and may require IV labetalol, magnesium, clonidine, or nifedipine.
Drugs such as chlorpromazine or diazepam, or other muscle relaxants can be given to control the muscle spasms. In extreme cases it may be necessary to chemically paralyze the patient with curare-like drugs and use a mechanical ventilator.
In order to survive a tetanus infection, the maintenance of an airway and proper nutrition are required. An intake of 3500-4000 Calories, and at least 150g of protein, is often given in liquid form through a tube directly into the stomach, or through a drip into a vein. This high-caloric diet maintenance is required due to the increased metabolic strain brought on by the increased muscle activity.
Prevention
Tetanus is completely preventable by active immunization. Immunizations for children include tetanus toxoid, usually as DTP (see Table 30–4 for schedule). For primary immunization of adults, tetanus toxoid is administered as two doses 4–6 weeks apart, with a third dose 6–12 months later. Booster doses are given every 10 years or at the time of major injury if it occurs more than 5 years after a dose.
Passive immunization should be used in nonimmunized individuals and those whose immunization status is uncertain whenever a wound is contaminated or likely to have devitalized tissue. Tetanus immune globulin, 250 units, is given intramuscularly. Active immunization with tetanus toxoid is started concurrently. Table 33–1 provides a guide to prophylactic management.
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| 1Such as, but not limited to, wounds contaminated with dirt, feces, soil, saliva, etc; puncture wounds; avulsions; and wounds resulting from missiles, crushing, burns, and frostbite. 2Td indicates tetanus toxoid and diphtheria toxoid, adult form. Tdap indicates tetanous toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine, which may be substituted as a single dose for Td. Unvaccinated individuals should receive a complete series of three doses, once of which is Tdap. 3Human tetanus immune globulin, 250 units intramuscularly. 4Yes if more than 10 years have elapsed since last dose. 5Yes if more than 5 years have elapsed since last dose. (More frequent boosters are not needed and can enhance side effects.) Tdap has been safely administered within 2 years of Td vaccination, although local reactions to the vaccine may be increased. | |||||||||||||||||||
EXPECTATIONS (PROGNOSIS)
The death rate is high in children and in the elderly. Wounds on the head or face seem to be more dangerous than those on the body. If the person survives the acute illness, recovery is generally complete. Uncorrected episodes of hypoxia (lack of oxygen) caused by muscle spasms in the larynx throat may lead to irreversible brain damage.
COMPLICATIONS
- airway obstruction
- respiratory arrest
- heart failure
- pneumonia
- fractures, vertebra
The death rate is high in children and in the elderly. Wounds on the head or face seem to be more dangerous than those on the body. If the person survives the acute illness, recovery is generally complete. Uncorrected episodes of hypoxia (lack of oxygen) caused by muscle spasms in the larynx throat may lead to irreversible brain damage.
COMPLICATIONS
- airway obstruction
- respiratory arrest
- heart failure
- pneumonia
- fractures, vertebra
Courtesy:
Compiled and Shared By: Habib Anwar
habib.anwar@hotmail.com
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