Methylene blue is mainly used clinically in the treatment of methemoglobinemia caused by nitrite and aromatic amines (acetanilide, acetaminophen, finasteride, etc.) poisoning. In recent years, a number of new clinical uses have been discovered. 1.Treatment of trigeminal neuralgia The specific method of methylene blue treatment of trigeminal neuralgia: after routine disinfection according to the pain site and nerve positioning, use a No. 7 needle to find the affected nerve hole (with a sense of falling), inject 0.75% bupivacaine 1 ml after the tip of the needle enters the hole about 0.3-0.5 cm, and then keep the needle for 10-15 minutes for observation, and inject methylene blue 10 to 20 mg when the pain disappears and numbness in the patient’s touch pain area. ~ 20 mg. 2, for some post-operative pain relief Methylene blue as a long-acting analgesic can be used for anal surgery pain relief. It has a strong affinity with nerve tissue and acts on the nerve endings after local injection, damaging the peripheral nerve myelin, and the new myelin sheath needs about 30 days to be repaired, so it can play the role of long-acting pain relief. There is a transitional period of about 4 hours before its effect, when there can be pain and foreign body sensation, which gradually turns into numbness and painlessness, it is because the peripheral nerve is first stimulated, and then the nerve myelin is damaged, so it is generally necessary to add lidocaine, which has fast action and strong permeability to nerve endings, and the maintenance time is about 2 to 3 hours, which also happens to be in the blank period of methylene blue analgesia, playing an early analgesic effect. The application of the two together can block the conduction of perianal nerve endings, mildly relax the anal canal, and prevent the sphincter from spasm, which can help reduce the pain of patients, reduce complications and facilitate wound healing. When methylene blue is used for anal surgery pain relief, several points should be noted: the concentration of methylene blue should be 0.1%~0.2% of low concentration liquid; when injecting, it is appropriate to superficially infiltrate the base of the trauma, avoid injecting too deep, and back aspiration must be done before injection to prevent direct injection of the drug into the blood vessels; the amount of injection is best when the trauma is light blue, about 15~20 ml, avoid over-injection. The application of methylene blue and bupivacaine mixture can also be used for post-operative analgesia after dissection. Specific treatment method: Before closing the chest in the lateral position after surgery, make an intercostal nerve block at each of the upper and lower rib corners of the incision, and inject 6 ml of the above mentioned solution respectively. 3.Treatment of Lysol poisoning Lysol, a soap solution of 50% cresol, can lead to methemoglobinemia, with a lethal amount of 50-100 grams. There is no special antidote for Lysol poisoning, but methylene blue can treat methemoglobinemia, which is beneficial to the patient’s recovery. It can inactivate or reduce NO (diastolic factor) activity, reverse hypotension, inhibit inflammatory mediator-induced increase in cGMP resulting in cardiovascular diastolic dysfunction, thus improving cardiovascular function. 4.Treatment of hemangioma Methylene blue treatment of hemangioma, tumor elimination fast, no obvious pain, no side effects, short course of treatment, scar is not obvious, the cure rate is very high. Specific treatment method: After disinfection of the tumor site, a homemade retractable metal or plastic auxiliary ring (sterilized) is placed on the tumor, with the inner side of the ring 0.5 cm from the tumor border, and appropriate pressure is applied. The amount of methylene blue was decided according to the size of the tumor, and the general dose was 10-20 mg/time for 1% solution. The syringe is pierced from the center of the tumor, and the drug is injected evenly in all directions until the tumor becomes blue with a sense of tension. After withdrawing the needle, compress the needle hole with sterile cotton to prevent extravasation of the drug, and withdraw the backup ring and cotton after 5 minutes. Inject once a week for 4 weeks as a course of treatment. If it does not heal, the next course of treatment will be carried out after a 10-day interval. 5, the prevention of intestinal adhesions after surgery Specific application method: the sterile liquid of 1% methylene blue that has been made ampoule, before closing the abdomen at 0.3 mg/kg body weight, evenly coated on the surface of the intestinal tube. Superoxide, peroxide and hydroxyl groups generated locally in the intestine are potential oxidants of poly-saturated fatty acids, which can damage cell membranes and induce the formation of intestinal adhesions. Methylene blue can inhibit the generation of oxygen free radicals, has the effect of antagonizing nitric oxide to relax smooth muscle, and can penetrate cells and tissues. Methylene blue and inhibition of peptidase both combined with the role of more significant. 6.Application in the treatment of deep burns of hands Methylene blue staining early scabbing with full-thickness skin grafting, to obtain timely repair and functional reconstruction of the trauma double efficacy. Application method: In order to prevent excessive removal of healthy tissue or residual necrotic tissue during surgery, methylene blue staining is used 24 hours before surgery to color the necrotic tissue, i.e. necrotic tissue is dyed blue, while healthy tissue is not colored, so that the depth of scab can be correctly judged during surgery. Application of methylene blue intradiscal injection after percutaneous laser disc decompression OBJECTIVE To investigate the clinical efficacy of methylene blue intradiscal injection in the treatment of lumbar disc herniation after percutaneous laser disc decompression (PLDD). Methods: 60 patients with lumbar disc herniation were treated by PLDD and divided into observation group and control group, 30 patients in each group. In the observation group, 1 ml of 1% methylene blue and 1 ml of 2% lidocaine were injected into the lumbar disc after PLDD, and in the control group, PLDD was used alone, and strenuous lumbar activities were avoided for 3 weeks after the operation. The efficacy was compared with the VAS score and clinical examination at a follow-up of 6 to 26(15±2) months. In the observation group, except for one case with no significant improvement in lumbar and leg pain symptoms after surgery and another case with mild improvement in lumbar and leg pain symptoms after surgery, the remaining 28 cases were cured in 24 cases and improved in 4 cases, with an effective rate of 93.3%. In the control group, 12 cases were cured and 9 cases were improved, with an effective rate of 70%. It was concluded that the treatment of lumbar disc herniation with intra-vertebral disc injection of methylene blue after PLDD has the advantages of minimally invasive, low cost, significant efficacy and few complications. The effectiveness rate was 97%, and 57 cases were followed up after 6 months, with 4 cases of symptom recurrence and a recurrence rate of 7%, and 50 cases were followed up at 3 years, with 11 cases of pain recurrence and a recurrence rate of 22%. Conclusion: Methylene blue treatment for trigeminal neuralgia is a simple, safe and effective method, and the nerve damage is reversible.