Local anesthesia is used to numb sensations in a specific part of the body. This prevents pain during surgical procedures.
An anesthetic is applied to the part of the body that is undergoing surgery.
Can be used for sedation, which calms the patient and reduces stress levels. Together, they allow the surgeon to perform the procedure without pain or distress.
Local anesthesia does not last long, so it is mainly used for small outpatient procedures where the patient can leave the clinic the same day.
Benefit
Local anesthesia provides pain relief for dental surgery and other outpatient procedures.
Local anesthesia is used when:
- the operation is minor and does not require general or regional anesthesia
- the procedure can be performed quickly and the patient does not have to stay overnight
- the operation does not require muscle relaxation or loss of consciousness of the patient
Examples include dental surgery, removal of warts, moles or cataracts, and biopsy.
Local complications and errors during the anesthesia procedure
Before any surgical intervention in the maxillofacial region, it is necessary to carry out complete tissue analgesia, since anesthesia in dentistry is not only a humane attitude towards the patient, but also a method of pathogenetic therapy, which is used in the treatment of any inflammatory process and diseases of a traumatic nature that develop in shock zone.
The doctor cannot expect that the disease will proceed without complications if he performed the intervention without providing complete anesthesia in the area of injury or inflammation.
Inadequate pain relief is one of the most common mistakes made by clinic doctors when treating patients in all areas of their specialty.
Another common mistake doctors make is administering the anesthetic too quickly. Under no circumstances should it be allowed during infiltration anesthesia of soft tissues. The anesthetic is injected under high pressure, so a depot of anesthetic solution, which is necessary for tissue infiltration near the needle tip, is not formed. Instead, the solution is shot into the depths in the form of a jet and disperses. The desired analgesic effect is not achieved.
When introducing an anesthetic into the bone, for example, when performing intraligamentary anesthesia, the desired effect is achieved precisely when the drug is administered under high pressure. However, even in this case, it must be taken into account that too rapid administration of the drug can cause rupture of the periodontal ligaments of the tooth and its displacement from the socket.
Another type of complication is damage to the vessel by the injection needle and the formation of a hematoma. This complication is common with intraoral “tuberal” anesthesia. In rare cases, it occurs during anesthesia of the infraorbital nerve. Taking into account the fact that anesthesia of the area near the tubercle of the upper jaw almost always leads to the formation of a hematoma, and its suppuration leads to the formation of phlegmon of the pterygopalatine fossa and infratemporal space, which seriously threatens the patient’s health, it is necessary to abandon the use of this method of anesthesia. In addition, infiltration anesthesia using modern means ensures the achievement of the desired anesthetic effect for any type of dental intervention in the area of the anatomical structures of the upper jaw.
In order to prevent the occurrence of a hematoma during anesthesia at the lower orbital foramen, it is necessary to advance the needle in the direction of distribution of the solution. You should not insert a needle into the canal, since modern anesthetics have diffusion capabilities that allow the injected drug to quickly spread and block the nerve trunk. If there is a suspicion of the development of a hematoma, then it is necessary to clamp the area of tissue with a tampon for several minutes. After the analgesic effect is achieved, the planned intervention can begin. You can also use hypothermia, and after three days - resorption therapy.
A rare, but more serious complication is the breaking off of an injection needle. Most often this happens if the anesthesiologist makes too sudden a movement when the syringe needle is already in the muscle tissue. The risk of complications increases if the needle is completely immersed in the tissue. In order to avoid complications, it is necessary to control the quality of the needles used for injections, as well as the extent to which the doctor adheres to the rules of anesthesia. Do not allow the needle to be completely immersed in the tissue or make sudden movements with the injector. If the needle does break off, it can be removed on an outpatient basis only if the end is visible above the surface. If tissue dissection is necessary to remove a broken needle, the patient must be hospitalized. An X-ray examination must be done before surgery. X-rays should also be taken at the stage of the operation, the volume of which can be significant.
Damage to the nerve trunk by an injection needle is relatively common, resulting in the development of traumatic neuritis, which is accompanied by paresthesia or severe pain. To prevent this from happening, the needle must be advanced in the direction of the anesthetic flow. If paresthesia or pain appears, it can last from 3 days to a week and even up to several months. In this case, taking B vitamins and analgesics, as well as physiotherapeutic procedures, are indicated.
If the fibers of the internal pterygoid muscle are damaged by an injection needle, its contracture may develop and the function of the lower jaw may be impaired. In order to prevent complications from developing during anesthesia of the inferior alveolar nerve, you must carefully follow the technique of advancing the needle to the bone of the inner surface of the jaw branch to the mandibular foramen. Most often, contracture can be eliminated within a few days using physical therapy and painkillers. If its course is prolonged, then mechanotherapy should be performed. Even more severe damage to the nerve trunk or muscle fibers can occur when the tip of the injection needle is bent; for this reason, syringes with a deformed needle should not be used.
Post-injection pain and swelling can occur due to trauma to the periosteum, or as a result of too intense injection of anesthetic into the soft tissue. Another cause of complications lies in the use of expired painkillers. Prevention of such complications comes down to compliance with the rules of anesthesia. It is necessary to exclude subperiosteal and too intense injection of an anesthetic solution into the tissue, as well as the use of anesthetics that have been certified and have not expired.
Treatment of complications is reduced to physiotherapeutic procedures. It is also recommended to use painkillers and antiallergic drugs, such as diphenhydramine and suprastin.
Paresis of facial muscles develops as a result of blocking the branches of the facial nerve with an anesthetic drug. This can be observed during extraoral anesthesia on the maxillary tubercle and during anesthesia of the inferior alveolar nerve. The paresis of individual facial muscles that develops as a result goes away after the painkiller wears off and does not require treatment.
The development of diplopia (double vision) is possible when the anesthetic solution spreads into the infraorbital canal with appropriate anesthesia, resulting in paresis of the extraocular muscles. This complication goes away on its own after the effect of the anesthetic wears off.
The most serious complication that threatens the health and even the life of the patient is tissue necrosis; it develops as a result of the introduction of a non-isotonic solution by mistake. This could be alcohol, calcium chloride, gasoline, or some other drug. The first sign of necrosis is severe pain that occurs at the beginning of solution administration. It is necessary to immediately stop administering the drug, infiltrate the tissues with a diluted anesthetic and, if possible, cut the tissues wide to allow intensive drainage. If a non-isotonic solution was injected into deep tissues, then after first aid the patient should be immediately hospitalized. This is necessary because severe tissue swelling may soon develop, possibly spreading to the neck, causing difficulty breathing and requiring emergency resuscitation.
When observing patients who were mistakenly injected with aggressive liquids during anesthesia, in one of the patients, due to the administration of a non-isotonic solution near the mandibular foramen, necrosis of the pterygomaxillary, perimaxillary space and the lateral surface of the neck began to rapidly develop. On the eleventh day, bleeding appeared, which is why the external carotid artery had to be ligated. Another patient was mistakenly injected with alcohol into the pterygomaxillary space, which resulted in persistent contracture of the lower jaw and extensive tissue scarring. This required extensive surgical intervention. The erroneous administration of 2 ml of a vasoconstrictor drug to a teenager ended tragically.
For preventive purposes, to avoid such complications, carpule technology is used. This eliminates errors when selecting an anesthetic drug.
Types of Local Anesthesia
The type and dose of anesthesia will depend on many factors. These include patients' age, weight, allergies, body part being operated on, and any current health conditions.
Various drugs are used to block pain. They can be applied by injection or by applying a spray or ointment.
The drug works by targeting specific nerve pathways to prevent the nerves in the area of application from sending signals to the brain.
Typically, the drug takes effect within a few minutes and wears off within a few hours. A stronger and higher dose will last longer.
Cocaine was the first anesthetic, but is now rarely used. Lidocaine is currently the most widely used local anesthetic, but different drugs are used for different purposes.
For longer procedures, bupivacaine is more suitable, but it may be more painful when first used. Therefore, the anesthesiologist may use lidocaine first and then administer bupivacaine if numbness is required for a longer period.
Synthetic anesthetics are similar in structure to cocaine, but these drugs do not have the same potential for abuse.
Types of local anesthetics
All medications used by dentists are based on substances from one of two chemical groups:
- Esters: novocaine, tetracaine (dicaine), benzocaine (anesthesin). These compounds are not very stable and are quickly destroyed in body tissues, so their effect is short-lived.
- Amides: lidocaine, trimecaine, melivacaine, bupivacaine, ultracaine (articaine). They are stable, penetrate deep into tissues and, accordingly, provide more effective pain relief [1].
Preparing for local anesthesia
If the patient is undergoing surgery with local anesthesia, the doctor should explain in advance how to prepare.
Patients should tell their doctor if they are using any medications, especially if they are blood thinning agents such as aspirin or warfarin.
Your doctor may instruct you not to eat anything for several hours before surgery. It is also important not to drink alcohol for 24 hours before taking the anesthetic.
In the doctor's office, the doctor applies a local anesthetic to the appropriate area of the body. It will start to feel numb.
The doctor will not act if the patient does not feel numb.
The anesthetic will prevent any pain, but the patient may still feel pressure during surgery.
Depending on what the procedure is and how anxious the patient feels, a sedative may be prescribed at the same time. This will help the patient feel calm and less anxious.
The doctor will monitor the amount of oxygen in your blood using a small device placed on your finger. In rare cases, a plastic nasal tube will be used to provide supplemental oxygen.
The dangers of additives to anesthetics
Many adverse reactions are caused not by the active substance itself, but by additives in the drug. They perform important functions, but at the same time they increase the risks of anesthesia.
Vasiconstrictors
They slow down the penetration of the painkiller into the blood, thereby increasing its effectiveness. This ability is possessed by:
- adrenalin;
- norepinephrine;
- filipressin.
The following complications are typical for vasoconstrictors:
- rise in blood pressure;
- rapid heartbeat (tachycardia);
- heart rhythm disturbance;
- angina attacks;
- headache.
Preservatives
Thanks to the antibacterial and antifungal action, the drug is protected from microorganisms. However, they can cause sensitization of the body and anaphylactic shock.
Stabilizers
Prevents oxidative processes, increasing the shelf life of the painkiller. They are dangerous due to the appearance of urticaria, edema, nervous and vagal reflexes [2].
Risks and complications
Local anesthesia is generally considered very safe. For minor surgeries it is safer than general anesthesia.
There may be tingling and pain, and there may be bruising as you take the drug and wear it off, but this is usually minor.
A person who has had local anesthesia must be careful not to get hurt when they cannot feel pain, such as when biting their cheek after dental treatment.
Temporary side effects that affect some people include:
- blurred vision, dizziness and vomiting
- headache
- muscle twitching
- persistent numbness, weakness, or tingling
Some people may have an allergic reaction. The patient may experience hives, itching, and difficulty breathing.
Cyanosis may occur, in which the skin turns bluish due to poor circulation or insufficient oxygenation of the blood.
In very severe cases, a person may experience CNS depression, in which the central nervous system slows down too much, resulting in a decrease in breathing and heart rate. This can lead to cardiac arrest if blood stops pumping to the heart.
An overdose of local anesthetic can lead to seizures. This can be life-threatening.
Contraindications to sedation
We said earlier that not all patients may be suitable for sedation, let's look again at the factors that are contraindicated for sedation.
So these factors are:
- patient's age,
- characteristics of the body, including allergic reactions to drugs that will be administered, that is, incompatibility with sedative drugs in a given patient,
- bad experience that the patient previously had during sedation, and in him it can also cause fear and, accordingly, panic attacks (that “having gone half asleep” the patient may not control himself).
Regarding bad experiences with sedation - yes, such cases are rare, but unfortunately they do occur. Naturally, these characteristics of the body and circumstances will also affect the effect of the drug itself, accordingly, this is a contraindication. For such patients, more careful preparation for sedation is recommended. Or vice versa - we work with such a patient in terms of organizing his treatment under local anesthesia. First, the psychologist communicates with the patient and prepares him. We also work with the patient: we explain that these procedures are for treatment and they are painless, that the quality of anesthetics is now quite high and some patients will not experience pain.
All work during treatment, if we are considering therapeutic treatment, is carried out under a rubber dam,
that is, the patient does not experience any fear that something might get into the oral cavity. And after the first two manipulations in consciousness under local anesthesia, he understands that dentistry has nevertheless made great strides forward, and that it is possible to be treated without sedation without feeling fear.
Other applications
Local anesthesia may also be used to diagnose some chronic conditions and to relieve pain after surgery.
Research has shown that local anesthesia may be more useful than opioids such as morphine for treating pain after total knee replacement surgery.
In 2010, results from a rodent study in Turkey showed that local anesthetics may reduce some symptoms of inflammatory bowel disease (IBD).
Anyone administering any type of anesthetic should be appropriately trained and qualified.
Allergic reactions to painkillers
Allergies are an example of a side effect of anesthetics that is primarily associated with additives. Occasionally, the reaction is provoked by esters and much more often by preservatives (methylparaben, propylparaben, parabenzoic acid) or the bisulfite stabilizer.
There are two types of allergic reactions:
- Immediate hypersensitivity. It appears within one hour, in severe cases - almost immediately.
- Delayed hypersensitivity. Deterioration of the condition is observed 24–72 hours after injection [3].
What you need to know about anesthesia for dental treatment
10-30% of people do not go to the dentist because of pain. Delaying treatment makes the problem worse. Pain management helps patients feel comfortable during dental procedures.
Types of dental anesthetics
Anesthesia means absence or loss of sensation. With light anesthesia, the person is conscious. In severe cases, the patient is put to sleep. The doctor at the Nika Dentistry clinic uses medications separately or in combination. Selects medications for a safe procedure. The type of anesthetic used also depends on the person's age, health, length of the procedure, and previous negative reactions to anesthetics.
Short-term medications are applied directly to the tooth area. Long-acting is used when complex jaw surgery is performed.
The success of dental anesthesia depends on:
- drug;
- areas of anesthesia administration;
- type of procedure;
- time of the operation;
- severity of inflammation.
Local anesthesia in the lower jaw is not as strong as in the upper jaw.
Doctors give three types of anesthesia: local, sedative and general. The choice depends on the location of the manipulation, the severity of the problem and the combination with other medications.
Local anesthesia
Local anesthesia is used for simple procedures such as tooth filling, which require a short time to complete and are less complex. The person is conscious and talking when local anesthesia is given. The area is numb so that the patient does not feel pain. A popular local anesthetic is lidocaine.
Local anesthetics will numb the pain within 10 minutes, and the best anesthesia for dental treatment wears off between 30 and 60 minutes. Sometimes a vasopressor such as epinephrine is added to enhance the effect and prevent the anesthetic effect from spreading to other parts of the body.
Local anesthetics are available in the form of gel, ointment, cream, spray, patch, liquid and ampoules. Use topically (apply directly to the area to numb it) or inject into the area being treated.
Sometimes sedatives are added to anesthetics to help you relax. The patient remains fully conscious and responds to commands after slight sedation. If the drug is moderate, the person is semi-conscious or almost unconscious if the sedation is deep.
Sedatives are administered orally (tablet or liquid), inhaler, intramuscularly, or intravenously. During moderate to deep sedation, the doctor monitors your heart rate, blood pressure, and breathing.
General anesthesia
General anesthesia is used for long procedures or when the client is nervous and interferes with treatment. The person is unconscious, does not feel pain, the muscles are relaxed, and does not remember how the operation took place. The medicine is administered by putting a mask on the face or intravenously. The dose depends on the procedure and the patient's condition.
What are the side effects
The side effects of dental anesthesia depend on the type of anesthetic used. General anesthesia has more risks than local anesthesia. Reactions also vary:
- nausea or vomiting;
- headache;
- sweating or shaking;
- hallucinations, delusions, or confusion;
- slurred speech;
- dry mouth or throat;
- pain at the injection site;
- dizziness;
- fatigue;
- numbness;
- trismus caused by trauma from surgery.
Vasoconstrictors such as epinephrine added to anesthetics also cause heart and blood pressure problems. These are some side effects of anesthetics. Ask your dentist about the medicine and any problems that may arise after use.
Precautions when prescribing
A person gives consent to treatment before sitting in the dentist's chair. Ask your doctor questions about the risks and precautions to take for a positive outcome.
Pregnancy
The dentist or surgeon will discuss the risks and benefits of anesthetics for the expectant mother and fetus.
Special Needs
For children and people with special needs, the type and dose of anesthetic is adjusted to avoid adverse reactions or overdose.
Aged people
Seniors with health problems will require dosage adjustments and monitoring during and after surgery. Some people become delirious or experience confusion and memory problems after surgery.
Liver, kidney, lung, or heart problems
People with liver, kidney, lung, or heart disease require a dose adjustment because the medicine will take longer to leave the body or will have a strong effect.
Neurological diseases
If you have a history of stroke, Alzheimer's disease, Parkinson's disease, thyroid disease or mental illness, the risk of general anesthesia is increased.
Other conditions
Tell your dentist if you have a hiatal hernia, acid reflux, infections or open sores in your mouth, allergies, severe nausea and vomiting, or are taking medications that cause drowsiness.
The risks are higher for those who:
- sleep apnea;
- epilepsy;
- obesity;
- hypertension;
- heart problems;
- attention or behavior disorder;
- chronic obstructive pulmonary disease;
- gastric bypass;
- Substance abuse.
What are the risks of dental anesthesia
Most people do not experience adverse reactions with local anesthesia. There is a higher risk with general anesthesia, especially in older people and people with medical complications. There is an increased risk of abnormal bleeding while taking blood thinning medications such as aspirin. If you are taking painkillers or nerve medications, tell your dentist or surgeon so they can select an anesthetic.
Anesthesia risks:
- seizures;
- coma;
- respiratory arrest;
- heart failure;
- heart attack;
- stroke;
- hypotension;
- hyperthermia;
- muscle stiffness;
- breathing problems;
- tachycardia.
Allergic reaction
Tell your dentist about any allergies, including reactions to dyes or other substances: rash, itching, swelling of the tongue, lips, mouth, or throat, and difficulty breathing; The anesthetics articaine and prilocaine at a concentration of 4% damage nerves and cause paresthesia;
Conclusion
Discuss concerns about the procedure with your dentist. Ask questions about medications used for pain and what to expect during and after treatment. Get a medical history from your physician, including information about allergies and other medications you take, including over-the-counter and prescription medications and dietary supplements.
Ask for instructions on how to behave before and after, including eating and drinking before and after oral procedures. Ask if transportation home needs to be arranged and see if all questions have been asked of the dentist. The dentist will provide instructions to follow before and after the procedure, and will provide a phone number to contact them in case of complications or questions.
At-risk groups
Some categories of patients are hypersensitive to local anesthesia. The table lists the main risk groups and possible solutions for them.
| Risk group | Recommendations |
| Pregnancy |
|
| Elderly age |
|
| Anorexia nervosa |
|
| Bronchial asthma |
|
| Chronical bronchitis |
|
| Hepatitis |
|
| Hypertension (high blood pressure) |
|
| Heart rhythm disturbances |
|
| Cardiac ischemia |
|
| Heart failure |
|
| Kidney failure |
|
| Porphyria |
|
| Cirrhosis of the liver |
|
| Glaucoma |
|
| Emphysema and chronic obstructive pulmonary disease |
|
| Peptic ulcer |
|
