Operations in aesthetic surgery are classified as simple or complex. The duration of the operations can vary substantially: from several minutes to several (7-8) hours. The operations are carried out both in inpatient and outpatient settings, and the share of outpatient surgeries is about 3 5%, according to the Center for Plastic and Reconstructive Surgery.
Most patients in aesthetic surgery belong to class I-II in physical condition, and the risk of anesthesia and surgery is usually in the IA-PB range (ASA I-II). Preoperative examination is conducted in accordance with generally accepted standards and necessarily includes routine laboratory tests, electrocardiography and anesthesiologist examination.
It is important to assess the patient's psychological status, as this, among other things, influences the choice of anesthesia, although in most cases patients in the aesthetic surgery clinic prefer to be in a state of medical sleep even during small outpatient surgeries.
Mutual understanding and mutual trust between the anesthesiologist and the patient are of great importance for the choice of the method of anesthesia and assessment of the quality of the patient's anesthesia.
As you know, the choice of this or that method of anesthesia is influenced by many factors:
- traumatism of the operation;
- the area of the body on which the intervention is performed;
- the duration of the operation;
- position of the patient on the operating table;
- the degree of influence of the operation and anesthesia on blood circulation, respiration and other vital systems of the patient;
- conducting operations in outpatient or inpatient settings.
Local infiltration anesthesia
Local infiltration anesthesia is the simplest and safest method of anesthesia, it has less impact on the activities of the patient's vital functions than other types of anesthesia.
In addition, local anesthesia reduces afferent impulses, prevents the development of pathological reactions associated with pain and tissue trauma during surgery.
Infiltration of tissues with a solution of local anesthetic can be used in various versions: alone, with intravenous administration of sedatives, and as an analgesic component of general anesthesia.
The introduction of the first portions of a local anesthetic causes painful or unpleasant sensations. Therefore, narcotic analgesics or sedatives are used for premedication or intravenous sedation for the period of anesthesia.
As a topical anesthetic, the most commonly used solutions are lidocaine in a concentration of 0.25-0.5% (maximum dose of 2000 mg of 0.25% solution and 400 mg of 0.5% solution).
The use of 0.25% bupivacaine solution for prolonged postoperative analgesia is possible, but limited due to its high toxicity (maximum dose is 175 mg, with adrenaline added at a dilution of 1: 200,000 to 225 mg).
Adding adrenaline to local anesthetic solutions significantly increases the duration of local anesthesia, slows the drug's entry into circulating blood and, therefore, reduces the effects of resorptive action.
Even when the recommended doses of injectable local anesthetics are exceeded, manifestations of their toxicity are rare. Thus, according to C.Gumicio et al., When lidocaine was administered at a dose of 8.5 mg / kg (average for an adult is 600 mg) with adrenaline, the concentration of lidocaine in the blood plasma did not exceed 1 m kg / ml.
It is known that a toxic effect is observed at a concentration of 5 μg / ml and above. It should be borne in mind that the usual doses used for adults can be toxic to children.
Local anesthesia with intravenous administration of sedatives and without them can be used for aesthetic operations on the face, small corrective operations on the mammary glands and extremities, liposuction of small volume.
As an analgesic component of general anesthesia, the introduction of local anesthetics is advisable to use in complex aesthetic operations on the head and rhinoplasty, volume mammaplasty, operations on the anterior abdominal wall. The amount of the drug administered should not exceed the maximum permissible doses.
Intravenous introduction of eating remedies
In plastic surgery, intravenous sedation combined with local anesthesia is not a simple procedure. This method is most suitable for calm and balanced patients without serious co-morbidities.
Intravenous sedation allows to provide immobility and calmness of the patient during the operation under local anesthesia, reduces the unpleasant sensations associated with the presence in the operating room and the introduction of a local anesthetic.
Most often in the operating room use benzodiazepines. Midazolam has some advantages. It is 2 times more active than diazepam in sedative-hypnotic effect, it starts to act faster and causes more pronounced amnesia, provides early and full awakening and less prolonged sedative effect after the operation. In addition, diazepam causes pain and irritation of the vein when injected.
The antagonist of benzodiazepines, flumazenil, allows to remove all effects of benzodiazepines, which is especially important for outpatients. However, the high price of flum-zenyl, apparently, will for a long time limit its use in clinical practice.
Combined use of benzodiazepines with narcotic analgesics significantly improves the comfort of patients during local anesthesia. Widely used midazolam (2-5 mg intravenously) followed by the introduction of fentanyl (25-50 μg intravenously). However, this combination can cause a significant depression of respiration and a high probability of hypopnea and apnea. Using instead of fentanyl agonist-antagonist butorphanol (stadol, moradol) at a dose of 0.03-0.06 mg / kg causes depression of respiration to a much lesser degree. When a more pronounced sedative effect is required, barbiturates can be used.
The combination of benzodiazepines with ketamine is another good combination for providing a short period of deep analgesia during the infiltration of the operation area with a local anesthetic.
The advantage of ketamine is that it causes less relaxation of the muscles, which prevents the tongue from twisting and ensures the patency of the upper respiratory tract. This property of ketamine allows to carry out operations with a high level of safety on the head and neck of a patient with additional use of local anesthesia.
The introduction of ketamine can cause complications in some patients, so contraindications for its use may be angina pectoris, heart failure, hypertension, cerebral circulation disorder, convulsive syndromes, mental disorders, thyroid disease with its hyperfunction, increased intraocular pressure.
Midazolam significantly alleviates cardiovascular and psychosomatic reactions to the administration of ketamine. For induction, the dose of midazolam is 0.03-0.075 mg / kg and ketamine -0.5-1 mg / kg. If necessary, it is possible to administer ketamine by continuous infusion - 10-20 mg / (kg-min). To prevent salivation and prevent other unwanted reactions, it is necessary to use atropine.
Patients are advisable to warn about possible dreams after the operation. If you use ketamine is highly undesirable, then analgesia can be carried out with narcotic analgesics.
The drug of choice as hypnotics is increasingly becoming propofol (Diprivan - Zeneca). Its main advantages are: quick and full awakening even after long operations, well-being and good mood of patients, lower frequency of nausea and vomiting than after using other drugs. Disadvantages of propofol are pain when administered and lowering blood pressure. Pain during the introduction of hypnotics is reduced after a preliminary intravenous injection of lidocaine or narcotic analgesic. Reduction of blood pressure can be prevented by varying the effect of the action.
With long operations, the advantages of a very expensive propofol sometimes "compete" with the costs of the entire anesthesia. Therefore, in such situations it is advisable to use midazolam as a basis for anesthesia, but to maintain it with nitrous oxide and continuous administration of propofol in small doses.
Despite the high costs, it is necessary to take into account that propofol reduces the duration of postoperative follow-up and the number of medical personnel necessary for this. Its use provides the possibility of rapid discharge and, what is very important, leaves a good impression on the patient from anesthesia.
Among other sedatives in plastic surgery are droperidol, benzodiazepines, antihistamines and phenothiazines.
The main negative property of all these drugs is a long duration of action, which allows them to be used only for long-term operations and for patients in a hospital setting. Consequently, successful intravenous sedation requires a correct choice of the drug and a variation in the effect of the action in accordance with the patient's response.
The method of intravenous sedation combined with local anesthesia can be used in most aesthetic operations, except in cases when it is not possible to provide adequate independent ventilation of the lungs, as well as for operations with more significant blood loss and in patients with serious comorbidities.
Operations on the trunk and on the face can be performed with or without intubation of the trachea. Induction into anesthesia and intubation of the trachea is carried out as standard with the use of barbiturates.
Anesthesia can be maintained by various methods. Due to the fact that cosmetic operations frequently infiltrate the area of operation with solutions of local anesthetic with epinephrine, the need for the introduction of narcotic analgesics can be limited by the period of induction and the time of infiltration of the operation zone by a local anesthetic. Repeated narcotic analgesics are administered before the infiltration of the next operation zone or continuously in small doses to relieve the patient's reaction to the intubation tube.
The use of local anesthesia can significantly reduce the consumption of analgesics both during the operation and after its termination. This significantly reduces the frequency of nausea and vomiting in the postoperative period.
Propofol in combination with narcotic analgesics can be used for both induction and maintenance of anesthesia. These drugs can be combined with nitrous oxide, midazolam or low concentrations of inhalation anesthetics. Propofol with nitrous oxide (in comparison with barbiturates) provides faster awakening and the possibility of patient self-service. Intravenous drip introduction of drugs can reduce the required dose and provide a faster exit from anesthesia.
General anesthesia with artificial ventilation is indicated in plastic surgery on the anterior abdominal wall, extensive mammaplasty, large volume liposuction, rhinoplasty, and in elderly patients with concomitant diseases.
Use of adrenaline-containing solutions
Extensive cosmetic operations and liposuction of large volume can be accompanied by significant blood loss, which requires restoring the fluid balance during surgery and in the postoperative period. Significantly reduce blood loss allows the use of the technique of infiltration of the operation zone with solutions containing adrenaline (1: 200 000). It is desirable for many cosmetic operations and becomes an indispensable condition for liposuction.
The use of freshly prepared solutions with adrenaline, thorough infiltration, aging time before the action of adrenaline (10-15 min) are important rules for the work of surgeons.
When plastic surgery is often used infiltration of subcutaneous fat tissue with a large amount of local anesthetic with adrenaline, therefore, control over the total dose of the local anesthetic is mandatory.
Since adrenaline-containing solutions are administered subcutaneously, a local vasoconstrictor effect is observed after the initial absorption period, which limits the further delivery of the drug to the circulating blood. Nevertheless, transient tachycardia, sometimes with hypertension and arrhythmia, is observed frequently. Attempts to treat tachycardia, hypertension and arrhythmia with the help of appropriate drugs can lead to a prolonged effect of the latter, which persists after the end of adrenaline, causing, in turn, bradycardia and hypotension. If the patient has risk factors, such as arrhythmias, coronary circulation disorders, cerebral vascular diseases, small doses of β-blockers of ultrashort action can be used to prevent tachycardia and hypertension. But in such situations it is better to abandon the introduction of solutions of adrenaline, and maybe from the operation.
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