Etiology:
Tetanus is a special infection usually associated with trauma. Various types and sizes of wounds may be contaminated, especially open fractures, wounds containing rust, small and deep stab wounds, blind tube injuries, firearm injuries, and more easily contaminated by Clostridium tetanus. It is common for children to be stabbed by their hands and feet. If the wound is applied with soil, incense ashes, firewood ashes and other soil methods, it is more likely to cause disease.
It can occur not only after all kinds of trauma, but also after maternal and neonatal unclean conditions and irregular induced abortion. Otitis media, pressure ulcers, tooth extraction and intrauterine devices can all cause this disease. The number of people suffering from tetanus due to intravenous injection of drugs with unclean syringes is also increasing.
The absolute anaerobic bacterium Clostridium tetanus is Gram-positive. Both livestock and human feces can contain bacteria. After bacteria are excreted from the body, especially from the soil, they are distributed in nature in the form of spores and survive in the soil for several years. This bacterium is very resistant to the environment and can boil for 15 ~ 90 minutes. Clostridium tetanus produces a highly toxic exotoxin, namely neurotoxin. After the toxin is produced, it does not cause inflammation locally, but spreads around, invades muscle tissue, passes upward in the opposite direction to nerve impulse, and finally enters the anterior horn of spinal cord or the motor nucleus of brain stem.
Although the wound contamination rate is high, and the battlefield contamination rate can reach 25% ~ 80%, the incidence of tetanus only accounts for 1% ~ 2% of the polluter, suggesting that there must be other factors, the main factor is the anoxic environment. Clostridium tetanus can contaminate deep tissues (such as blind tube trauma and deep stab wounds). ) during the trauma. If the external opening of the wound is small, there are necrotic tissues and blood clots in the wound, or the wound is too tightly packed and ischemic, an anoxic environment suitable for bacterial growth and reproduction is formed. If there is aerobic bacterial infection at the same time, the latter will consume the residual oxygen in the wound, making the disease more prone to occur.
Treatment:
Tetanus is an extremely serious disease with high mortality, especially for newborns and drug addicts. Therefore, active comprehensive treatment measures should be taken, including eliminating the source of toxin, neutralizing free toxin, controlling and relieving spasm, keeping respiratory tract unobstructed and preventing complications. Treatment measures mainly include:
1. Wound treatment
All necrotic tissues and foreign bodies must be removed from the wound. After antitoxin treatment, the wound should be treated under good anesthesia and spasm control, thoroughly debrided and fully drained. The local area can be washed with 3% hydrogen peroxide solution, and the wound does not need to be stitched and bandaged after debridement. Some wounds seem to have healed, so it is necessary to carefully check whether there is sinus or dead space under the scab.
2. Application of antitoxin
The purpose is to neutralize free toxins, so it is only effective in the early stage. If the toxin has been combined with nerve tissue, it is difficult to achieve the effect. However, because the allergy rate of antitoxin is as high as 5% ~ 30%, intradermal allergy test must be done before taking medicine. Early application of tetanus immunoglobulin is effective, generally only once.
Control spasm
After admission, patients should live in isolation wards to avoid light, sound and other stimuli; Avoid harassing patients and reduce spasms. Sedative and antispasmodic drugs can be used alternately according to the situation to relieve the spasm and pain of patients. Available drugs are: diazepam (which can block the conduction between neurons and relax muscles), intramuscular injection or intravenous drip, and similar drugs are lorazepam and midazolam; Chlorpromazine (which can inhibit the central nervous system and relieve muscle spasm), intramuscular injection or intravenous drip, is used alternately with diazepam, but it is contraindicated when the blood volume is low; Intramuscular injection of phenobarbital (sedation) every 8 ~ 12 hours; 10% chloral hydrate (suitable for severe spasm) is reserved orally or by enema. If spasms are frequent and difficult to control, thiopental sodium can be injected slowly intravenously, but it is safer for people who have done tracheotomy to prevent laryngeal spasms and respiratory depression. However, neonatal tetanus should be carefully treated with sedative and antispasmodic drugs, such as lobeline and colamin.
4. Pay attention to the prevention and treatment of complications
The main complications are respiratory tract, such as asphyxia, atelectasis and lung infection. Therefore, for severe patients with frequent convulsions and uncontrollable drugs, tracheotomy should be performed as soon as possible to improve ventilation. Remove respiratory secretions in time, turn over and pat your back frequently to prevent pneumonia; Patients with tracheotomy should pay attention to respiratory tract management, including airway atomization, humidification and washing. When necessary, special attention should be paid to prevent accidents; Strict aseptic technique to prevent cross infection. Antibiotics should be selected according to the strains of patients with pulmonary infection. Using indwelling catheter to improve urinary retention and installing anal canal to improve abdominal distension.
5. Nutritional support
Because patients have spasms and sweating, they lose more calories and water every day. Therefore, we should pay great attention to the supplement of nutrition (high calorie, high protein and high vitamin) and the adjustment of water-electrolyte balance. Parenteral nutrition with central vein can be used when necessary.
6. Antibiotic therapy
Antibiotics can be intramuscular injection of penicillin, or high-dose intravenous drip, which can inhibit Clostridium tetanus. Metronidazole can also be administered orally or intravenously for 7 ~ 10 days. If the wound has mixed infection, antibacterial drugs should be used accordingly.