Sedative during premedication. Preparation for anesthesia (premedication)

In fact, it is the least developed section of modern anesthesiology. Anesthesiologists approached the solution to this seemingly simple problem in different ways. Some researchers were looking for new effective drugs, others combined drugs with multidirectional effects, and others, without delving into the problem, began to use promedol and atropine as standard in all patients. This method of premedication, oddly enough, many anesthesiologists still continue to call “conventional premedication,” although it has been proven that it is practically ineffective.

The complexity of the problem of premedication is that the administered drugs, while giving the desired effect, should not simultaneously disrupt compensatory mechanisms and constant homeostasis. The complexity is further aggravated by the fact that it is difficult to select the right dose of drugs, focusing only on the body weight or age of the patient. Special studies undertaken jointly by anesthesiologists and psychiatrists have shown that the key to solving the problem of premedication should be sought in prescribing individual targeted premedication based on establishing the characteristics of the patient’s mental reaction to the upcoming operation. It is known that people with a normal psyche experience certain mental disorders while awaiting surgery. For some they manifest themselves in the form of anxiety, excitement, restlessness, for others - euphoria, for others - depression, apathy, for others - isolation, anger, melancholy, etc.

This is certainly reflected during anesthesia and surgery, because they are accompanied by pronounced neuroendocrine disorders, which in turn affect the stability of the function of vital organs. It should be emphasized that in most cases these mental disorders are transient. However, there are cases when preoperative mental stress is so great that the patient, even after a successful operation, develops psychoses in the postoperative period that require specific treatment and analgesics.

It is clear that individual targeted premedication is incomparably more effective than any standard method, however, unfortunately, its use in wide clinical practice is still limited by its somewhat cumbersome nature and the lack of the required minimum knowledge in psychiatry among many practical anesthesiologists.

For everyday In practical activities, standard premedication can be recommended, consisting of the drugs indicated above. Experience shows that children under 11-12 years of age do not need to be prescribed any medications the night before surgery, since they are not informed about the upcoming operation. The remaining patients are prescribed tranquilizers and sleeping pills in normal dosages. In the morning, 3-2 hours before surgery, tranquilizers are prescribed again (1-2 tablets of seduxen or elenium), and 45-60 minutes later suprastin (pipolfen) is administered intramuscularly at a dose of 1 mg/kg, but not more than 30 mg, atropine (0.3-0.6 mg) and promelol (0.2-0.3 mg/kg). A good result was observed with the introduction of 0.5-2.5 ml of talamonal (1 ml of talamonal contains 2.5 mg of droperilol and 0.05 mg of fentaiyl) against the background of preliminary administration of atropine at a dose of 0.3-0.6 mg. In case of emergency surgery, it is more advisable to administer these drugs intravenously. In this case, it is better to reduce the dose of atropine to 0.1-0.3 mg.

After premedication the patient should not get out of bed. He should only be taken to the operating room on a gurney. If for one reason or another the premedication does not achieve the desired effect and the patient experiences severe fear and anxiety, then before taking him to the operating room, it is advisable to additionally administer half the dose of these drugs intravenously. Children are often given a base anesthetic intramuscularly in the ward and taken to the operating room while asleep.

Premedication is the preparation of a patient with medication for surgery and anesthesia. Depending on the purpose, premedication can be specific or nonspecific. Specific premedication is used in patients with concomitant pathologies and is aimed at preventing exacerbation of chronic diseases before, during surgery and in the early postoperative period. For this purpose, various medications are used - glucocorticoids and bronchodilators in patients with bronchial asthma, antiarrhythmics in patients with cardiac arrhythmias, antihypertensives in patients with arterial hypertension, and so on. Specific premedication can be prescribed both a month before surgery (for planned interventions) and 10 minutes before surgery (for emergency interventions). Nonspecific premedication is used in all patients undergoing surgery and anesthesia. The purpose of nonspecific premedication is to relieve mental stress, provide rest to the patient before surgery, normalize the level of metabolic processes, which reduces the consumption of general anesthetics, prevents unwanted neurovegetative reactions, side effects of narcotic substances, general and local anesthetics, reduces salivation, bronchial secretion and sweating. This is achieved by using a complex of pharmacological drugs that have a potentiating effect - sleeping pills, antihistamines, narcotic analgesics, tranquilizers, M-anticholinergic drugs. Nonspecific premedication can be prescribed both 3 days before surgery (for planned interventions) and 10 minutes before surgery (for emergency interventions). Premedication can also be either planned (before a planned operation) or emergency (before emergency operations).

It should immediately be noted that in case of a compensated state of the main organs and systems, their special preparation for surgery is not required.

The cardiovascular system requires preparation if available

1. Arterial hypertension

circulatory failure

heart rhythm disturbances.

The respiratory organs must be specially prepared for

chronic bronchitis (smokers' bronchitis)

emphysema

pneumosclerosis

bronchial asthma

pneumonia

Urinary system requires preparation for chronic kidney diseases (pyelonephritis, glomerulonephritis; urolithiasis), prostate diseases (prostatitis; adenoma, cancer), because this can lead to acute urinary retention in the early postoperative period.

Gastrointestinal tract. Some chronic diseases: gastric and duodenal ulcers, complicated by stenosis, tumors are often accompanied by disorders of protein, water-electrolyte, acid-base status and circulating blood volume. In cases of stenosis, the passage of food through the gastrointestinal tract may be impaired - then enteral tube nutrition or adequate parenteral nutrition, and gastric lavage through a tube with its subsequent complete emptying are necessary.

An enema is performed to prepare the bowels. An enema is the introduction of various liquids into the large intestine through the anus. They are used to remove intestinal contents or introduce a substance into the intestines. To prepare the intestines before a planned operation, there are other methods of preparation, in which the patient takes a special solution with microelements, such as Fortrans and Forlax, by mouth.

After premedication and appropriate preparation, the patient is taken to the operating room in a horizontal position on a gurney, accompanied by a nurse.

Highlight direct And indirect premedication. Indirect premedication most often consists of two stages. In the evening, on the eve of the operation, sleeping pills are prescribed orally in combination with tranquilizers and antihistamines. For particularly excitable patients, these drugs are repeated 2 hours before surgery.

Direct premedication is carried out for all patients 30-40 minutes before surgery. It is mandatory to include M-cholinergic blockers, narcotic analgesics and antihistamines in premedication.

M – anticholinergics It must be remembered that if you plan to use cholinergic drugs (succinylcholine, fluorotane) or instrumental irritation of the respiratory tract (tracheal intubation, bronchoscopy) during anesthesia, then there is a risk of bradycardia with possible subsequent hypotension and the development of more serious heart rhythm disturbances. In this case, premedication with anticholinergic drugs (atropine, metacin, glycopyrrolate, hyoscine) to block vagal reflexes is mandatory.

Atropine.Metacin. Scopolamine. The anticholinergic properties of atropine can effectively block vagal reflexes and reduce the secretion of the bronchial tree. However, drugs in this group are potentially dangerous in case of rhythm disturbances and thyrotoxicosis. For premedication, atropine is administered intramuscularly or intravenously at a dose of 0.01-0.02 mg/kg, the usual dose for adults is 0.4-0.6 mg. In children, atropine is used in the same doses. To avoid the negative psycho-emotional impact of intramuscular injection on the child, atropine at a dose of 0.02 mg/kg can be given per os 90 minutes before induction. In combination with barbiturates, atropine can also be administered per rectum when using this method of induction of anesthesia.

Narcotic analgesics. Recently, the attitude towards the use of narcotic analgesics for premedication has changed somewhat. The use of these drugs began to be abandoned if the goal is to achieve a sedative effect. This is due to the fact that when using opiates, sedation and euphoria occur only in some patients. But others may experience unwanted dysphoria, nausea, vomiting, hypotension, or respiratory depression to varying degrees. Therefore, opioids are included in premedication when their use may be beneficial. This primarily applies to patients with severe pain syndrome. In addition, the use of opiates can enhance the potentiating effect of premedication.

Antihistamines. To prevent allergic reactions, histamine H1 receptor blockers are used. Diphenhydramine- has a pronounced antihistamine effect, sedative and hypnotic effects. As a component of premedication, 1% solution is used at a dose of 0.1-0.5 mg/kg intravenously and intramuscularly.

Suprastin- has pronounced antihistamine and peripheral anticholinergic activity, the sedative effect is less pronounced. Doses - 2% solution - 0.3-0.5 mg/kg intravenously and intramuscularly.

Tavegil- compared to diphenhydramine, it has a more pronounced and long-lasting antihistamine effect and has a moderate sedative effect. Doses - 0.2% solution - 0.03-0.05 mg/kg intramuscularly and intravenously.

According to indications, it is possible to introduce premedication sleeping pills (barbiturates and benzodiazepines). Phenobarbital(luminal, sedonal, adonal). Long-acting barbiturate 6-8 hours. Depending on the dose, it has a sedative or hypnotic effect, and an anticonvulsant effect. In anesthesiological practice, phenobarbital is prescribed as a hypnotic on the eve of surgery at night in a dose of 0.1-0.2 g orally, in children a single dose of 0.005-0.01 g/kg.

Tranquilizers – have psychosedative, hypnotic and potentiating effects. Diazepam(Valium, Seduxen, Sibazon, Relanium). The dose for premedication is 0.2-0.5 mg/kg. It has a minimal effect on the cardiovascular system and respiration, and has pronounced sedative, anxiolytic and anticonvulsant effects. However, in combination with other depressants or opioids, it can depress the respiratory center. It is one of the most commonly used sedatives in children. Prescribed 30 minutes before surgery at a dose of 0.1-0.3 mg/kg intramuscularly, 0.1-0.25 mg/kg orally, 0.075 mg/kg rectally. As an option for premedication on the table, intravenous administration is possible immediately before surgery at a dose of 0.1-0.15 mg/kg along with atropine.

Neuroleptics, giving a psychosedative effect. Droperidol. Neuroleptic from the butyrophenone group. Neurovegetative inhibition caused by droperidol lasts 3-24 hours. The drug also has a pronounced antiemetic effect. For the purpose of premedication, use in a dose of 0.05-0.1 mg/kg IM. Standard doses of droperidol (without combination with other drugs) do not cause respiratory depression: on the contrary, the drug stimulates the reaction of the respiratory system to hypoxia. Although patients appear calm and indifferent after premedication with droperidol, they may actually experience feelings of anxiety and fear. Therefore, premedication cannot be limited to the administration of droperidol alone.

The basis of modern premedication is the use of a tranquilizer that has all the properties listed above. An example of such a drug is Midazolam(dormicum, flormidal). For premedication it is used at a dose of 0.05-0.15 mg/kg. After intramuscular administration, plasma concentrations reach a peak after 30 minutes. Midazolam is a drug widely used in pediatric anesthesiology. Its use allows you to quickly and effectively calm the child and prevent psycho-emotional stress associated with separation from parents. Oral administration of midazolam at a dose of 0.5-0.75 mg/kg (with cherry syrup) provides sedation and relieves anxiety by 20-30 minutes. After this time, the effectiveness begins to decrease and after 1 hour its effect ends. The intravenous dose for premedication is 0.02-0.06 mg/kg, intramuscular - 0.06-0.08 mg/kg. Combined administration of midazolam is possible - at a dose of 0.1 mg/kg intravenously or intramuscularly and 0.3 mg/kg rectally. Higher doses of midazolam may cause respiratory depression.

PRE-MEDICATION:
PHARMACOLOGICAL RATIONALE

PAUL F. WHITE PH D MD

The clinic traditionally uses specific medications to ensure the proper condition of the patient before anesthesia. As Beecher noted over 25 years ago: "Empirical procedures, which are the habit of a good doctor, are alive and will live."
In those days when almost all anesthetics were inhalational, the foundations for the rational use of premedication were laid. In order to minimize the side effects of these drugs, the patient was taken to the operating room after the administration of sedatives and drugs that block the secretion of the oral glands. Today, the main reason for prescribing premedication is to make anesthesia and surgery the least traumatic for the patient’s psyche.
Indications for premedication are a feeling of anxiety and restlessness in the patient, the creation of amnesia and analgesia, vagolytic effect and prevention of aspiration of acidic gastric contents and/or postoperative nausea and vomiting.
Oral administration of drugs is used; they are also administered per rectum, intramuscularly or intravenously. Alternative routes of drug administration are described in the anesthesiology literature (eg, mucous or nasal). Based on his own clinical experience, the anesthesiologist may use sedatives, hypnotics, major tranquilizers, narcotic analgesics, anticholinergics, drugs that affect gastric motility, or antihistamines.
Most often, a combination of two or more drugs from different groups is used. An important reason for this is that doctors have not yet developed a consensus regarding premedication.
In general, it is believed that the patient's anxiety and nervousness are the leading factor that needs to be controlled in the preoperative period. The frequency of these manifestations ranges from 40 to 80%. Physiological stress caused by upcoming anesthesia and surgery negatively affects the patient’s psyche and promotes the production of stress hormones. The incidence of severe preoperative stress is higher in women than in men, as well as in all those patients who constantly receive sedatives. The most common causes of preoperative stress are: fear for one's health, fear for the outcome of the operation, separation from family, an unclear future, fear of anesthesia and discomfort in the postoperative period.

Psychological preparation

The psychological aspect of preoperative preparation is largely determined by the visit of the anesthesiologist and his conversation with the patient. Even a brief description of the anesthesia plan and the course of the operation removes the fear of the unknown and unconsciousness in the patient. In 1963, Egberg et al. reported that patients who were seen by an anesthesiologist before surgery

on the day of surgery they were much calmer. Preoperative preparation in the form of conversation and explanation is very effective in eliminating anxiety in patients. Moreover, it is reported that a special booklet on anesthesia was much less effective than a personal conversation between the anesthesiologist and the patient. Although a visit to an anesthesiologist significantly reduces the patient's anxiety, in most cases drug premedication is also necessary, consisting of sedatives and antihistamines (for example, barbiturates, hydroxazine and promethacin). However, the most commonly used drugs are those that have both a sedative and anxiolytic effect (i.e., benzodiazepines).

Pharmacological preparation

The rational use of premedication drugs can provide the patient with minimal anxiety and fear when taken to the operating room, and it is highly desirable that these drugs do not have uncomfortable side effects.
From the patient's point of view, absence of memories (amnesia) and reduction of anxiety are the main goals of premedication. However, most patients want to remember everything that happened to them before and after the operation. Therefore, prolonged amnesia may even increase anxiety.
The most controversial issues in terms of premedication are: the drugs themselves, the route and time of their administration to the patient. Most often, oral medications are given to the patient 60-90 minutes before anesthesia. Even with intramuscular administration of drugs, it takes at least 30-60 minutes for their effect to fully develop. Most often, drugs are administered in such a way that the staff has some time left to deliver the patient to the operating room.
This review discusses the comparative clinical pharmacology of the drugs most widely used for premedication. After reviewing the many studies on premedication that have emerged over the past 25 years, one can agree with Forest et al that "most clinical studies on premedication drugs have lost their accuracy and relevance."

Sedatives, hypnotics and "major" tranquilizers

The most popular drugs among anesthesiologists remain sedatives and hypnotics, which include barbiturates and benzodiazepines. These drugs inhibit central nervous system activity in a dose-dependent manner. Although this process may differ in detail when using different drugs, in principle their effect on the central nervous system is similar. Secobarbital and phenobarbital are widely used for premedication, since they have a fairly pronounced sedative effect without serious depression of the cardiovascular system and respiration. However, after the advent of benzodiazepines, barbiturates became less popular. Comparative studies have shown that benzodiazepines are more effective for premedication and are easier to accept by patients than barbiturates. For many years, chloral hydrate, triclovos and barbiturates were the most popular sleeping pills. Recent studies have shown that benzodiazepines (flurazepam, lorazepam, triazolam, temazepam) are much preferable to barbiturates as hypnotics prescribed the night before surgery.
Benzodiazepines have effects that make them the most preferred for premedication (sedative effect, anticonvulsant activity, amnesia, sedation and even muscle relaxation). In addition, there is a specific benzodiazepine antagonist - flumazenil, which is suitable if it is necessary to quickly relieve the effects of benzodiazepine overdose.
There are also a large number of drugs in this group for oral use.
Diazepam, a typical representative of the group of benzodiazepines, causes a decrease in the patient’s anxiety depending on the dose, has a sedative effect and the ability to cause amnesia. How does diazepam compare to lorazepam? Although both drugs have approximately the same ability to cause sedation and have the same anxiolytic effect, when using diazepam, patients more often report pain at the injection site and more often develop thrombophlebitis, while when using lorazepam, patients wake up longer after anesthesia. However, the most important differences between the two drugs are the time-effect relationship for each.
Compared to lorazepam, the effect of diazepam on the central nervous system develops almost immediately after intravenous administration and lasts 30-60 minutes after it. The experiment also revealed that benzodiazepine receptors have a higher affinity for diazepam than for lorazepam. So, although diazepam has approximately twice the half-life of lorazepam (20-40 hours compared to 10-15 hours), its duration of clinical action is shorter because it binds to benzodiazepine receptors very quickly. The main metabolite of diazepam, dismethyldiazepam, has some pharmacological activity, while lorazepam is immediately converted to inactive metabolites. Finally, the distribution and metabolism of lorazepam is minimally affected by the liver, whereas diazepam is metabolized primarily in the liver. Despite this, in elderly people, the dose of benzodiazepines during premedication should be reduced, since even a relatively small excess of the dose can cause central nervous system depression in them. As an alternative to these widely used drugs, both triazolam (0.125 - 0.5 mg orally) and temazepam (15-30 mg orally) can be used, and in many situations they have undoubted advantages. These benzodiazepines are rapidly absorbed when administered orally and are rapidly metabolized to inactive metabolites.
Midazolam is a new drug with a short half-life (2-4 hours) and is approximately twice as potent as diazepam. As a sedative, it is about three to five times more powerful than the others.
Since midazolam is poorly soluble in water, a solvent (propylene glycol) is required for its administration, which can irritate the vein wall and affect the absorption of the drug when administered intramuscularly. Due to the rapid development of the sedative and anxiolytic effect, midazolam seems to be a good drug for premedication both orally and intramuscularly and rectally in pediatric patients. In addition, its short half-life reduces the risk of drug accumulation when used multiple times. Midazolam is rapidly metabolized in the liver to inactive metabolites. Therefore, when administered orally, the use of the drug is somewhat limited by its high metabolism in the liver. Similar to diazepam, the clearance of midazolam is slightly reduced in elderly and geriatric patients, so its dose in such patients must be reduced.
Clinical studies have shown that midazolam, compared to other sedative drugs, has a certain advantage when administered intramuscularly, and its action develops somewhat faster than that of other drugs, and the awakening of patients after anesthesia also occurs faster.
Compared with benzodiazepines, major tranquilizers (phenthiazines and butorphenones) and antihistamines (hydroxazine and diphenhydramine) provide only sedation. Although the sedative effect of these antipsychotic drugs is very strong, this can also have negative sides (too strong sedation and the inability for the patient to explain his thoughts). Interestingly, many doctors are mistaken in terms of the presence of anxiolytic effects in these drugs.
Droperidol is an antipsychotic of the butorphenene class, which is very popular among anesthesiologists and is used for premedication due to its strong antiemetic effect. Obese patients, patients undergoing ophthalmic and gynecological procedures, patients receiving narcotic analgesics or etomidate, and those patients with a history of nausea and vomiting from previous anesthesia often report that the administration of droperidol significantly improved their condition. Low (0.25-1.25 mg) doses of droperidol can relieve patients from postoperative nausea and vomiting. However, even very low doses of droperidol can cause extrapyramidal symptoms due to its ability to block histamine receptors.
Hydroxazine is a unique non-phenothiazine tranquilizer that has an antihistamine effect, depresses the central nervous system, has a sedative, anxiolytic effect, and has an antiemetic, bronchodilator and anticholinergic effect. Compared to benzodiazepines, it has a more pronounced anxiolytic effect and also causes amnesia. Although its analgesic capabilities are limited, when used together with narcotic analgesics, fairly effective pain relief can be obtained. Interestingly, compared with droperidol as a prophylactic antiemetic, hydroxazine is more effective in doses that have approximately the same sedative effect and the time of awakening of patients after surgery is the same.
Diphenylhydramine (0.5-1.0 mg per kg orally) is another antihistamine that is recommended for premedication to prevent intraoperative allergic reactions in patients with a history of chronic allergic reactions, as well as for those patients undergoing manipulations that are known to lead to to allergic reactions (scintigraphic studies, chemotherapy). In patients with an increased risk of allergic reactions, an H-2 receptor locator is prescribed along with diphenhydramine.

Opioids - narcotic analgesics

In the past, narcotic analgesics have been used as premedication to facilitate induction and to reduce the need for inhalational anesthetic. However, the ability of narcotic analgesics to reduce the need for inhalational anesthetic is very clinically insignificant. Indeed, the traditional use of narcotic analgesics as premedication has been questioned by many researchers. Coheen and Beecher noted many years ago that "as long as there is no pain, there is no need to use drugs for premedication." Interestingly, when morphine alone is prescribed, patients experience some feeling of dysphoria in about 80% of patients who do not experience pain, and only 10% experience a feeling of euphoria. For patients with pain syndrome or dependence on narcotic analgesics, the situation can be very different. The main problem associated with the use of narcotic analgesics is the huge number of their side effects: nausea, vomiting, itching, respiratory depression, agitation and others. Recently published studies have reported that nausea following narcotic analgesic administration occurs in 40 to 57 percent of cases.
When narcotic analgesics are prescribed either alone or in combination with sedatives, the risk of preoperative respiratory depression is further increased. Premedication with a combination of morphine and scopolamine can significantly reduce saturation during transport of the patient to the operating room and during preparation for invasive monitoring. Adding lorazepam to reduce anxiety does not increase respiratory depression as does the combination of morphine and scopolamine. However, the use of lorazepam in cardiac surgery patients (compared to the combination of morphine with scopolamine) significantly more depresses the patient's blood circulation during induction.
Many drugs are used in an attempt to reduce the side effects of narcotic analgesics and increase their effectiveness. Scopolamine, which has central anticholinergic activity, increases the anxiolytic and sedative effects of narcotic analgesics, however, it does not reduce the side effects of morphine. Although droperidol reduces the incidence of nausea and vomiting associated with the use of narcotic analgesics, the incidence of dysphoric reactions with this combination is unpredictable. Some strange reports claim that there is potentiation of their analgesic properties between narcotic analgesics and sedatives. These observations do occur because a calm person is less sensitive to pain, but this does not mean that there is any pharmacodynamic interaction. Promethacin is a popular phenothiazine drug that improves the anxiolytic and sedative effects of morphine during premedication. At the same time, the analgesia obtained by combining morphine with hydroxazine is much more effective than the analgesia obtained by using morphine alone. Most often, these combinations are safe, but it is known that the combination of benzodiazepines and narcotic analgesics can cause hypoxemia and apnea.

Anticholinergics

The use of anticholinergic drugs as a standard part of premedication is associated with their ability to sharply reduce salivary production and have a vagolytic effect. Although most researchers do not consider this to be decisive, the use of these drugs as a component of premedication has long been a tradition. During induction with inhalational anesthetics they do reduce salivary gland secretion, in addition to this, atropine prevents reflex bradycardia and circulatory depression in young children. Glycopyrollate, a drug with a peripheral anticholinergic effect, is also used for premedication. In adults, a dose of glycopyrollate of 0.2 mg IM and a dose of atropine of 1.5 mg IM have the same effect, but glycopyrollate does not have a significant effect on the patient’s heart rate. In addition, none of these drugs affects the volume and acidity of gastric contents. Preoperative administration of glycopyrollate does not reduce the risk of developing aspiration pneumonitis in patients at risk. Awakening from anesthesia is faster with glycopyrrolate because it does not cross the blood-brain barrier.
Another centrally acting anticholinergic drug, scopolamine, is approximately eight to ten times more active than atropine, but is much weaker in its peripheral effect. Recent studies have shown that scopolamine at a dose of 0.5-1.5 mg per 72 hours transdermally has a sedative and antiemetic effect, and also inhibits the secretion of the salivary glands. However, this effect is less predictable in patients with muscle weakness and episodes of nausea and vomiting after previous anesthesia. Unfortunately, even small doses of scopolamine can cause delirium, weakness, speech impairment, hallucinations and coma, which is collectively called "central cholinergic syndrome" .

Drugs affecting gastric motility

Metoclopramide increases the tone of the lower esophageal sphincter, reduces intragastric pressure and improves motility of the stomach, esophagus and initial parts of the small intestine. It has peripheral cholinergic and central antidopaminergic effects. The most common side effects of metoclopramide should be considered dystonic reactions (that is, extrapyramidal symptoms). Some researchers claim that metoclopramide has an antiemetic effect, while others dispute its existence. However, the use of metoclopramide in combination with intravenous droperidol prevents the development of postoperative nausea and vomiting even better than low-dose droperidol alone. In addition, metoclopramide can be used as an adjuvant to H-2 histamine blockers to prevent aspiration. A new drug in this class, clebopride, has an effect on gastric motility and an antiemetic effect, however, its role in clinical anesthesia is not yet great.

H-2 histamine blockers

Anticholinergics, drugs that affect gastric motility, and, more recently, H-2 histamine blockers, are often prescribed to patients who are at increased risk of developing postoperative pneumonitis. Patients with impaired consciousness, swallowing abnormalities or gastrointestinal motility disorders, as well as patients with a “full stomach,” benefit from the use of these drugs. Pregnant, obese and diabetic patients also require preoperative administration of these drugs. The use of H-2 histamine blockers increases the pH of gastric contents in the preoperative period, depending on the dose, and also reduces basal gastric secretion. In general, multiple doses (the evening before surgery and the morning of surgery) are more effective than a single dose in reducing gastric acidity and volume.
Both commonly used H-2 histamine blockers (cimetidine and ranitidine) significantly increase gastric pH within an hour of parenteral administration. Although these drugs can reduce the risk of aspiration, none of them can completely eliminate this risk. Thus, the use of these drugs in no way reduces the importance of careful intraoperative monitoring and protection of the patient's airway during intubation. In addition, cimetidine has the potential to inhibit hepatic oxidase enzyme activity, thereby prolonging the elimination time of some drugs used during anesthesia (diazepam, chlordiazepoxide, theophylline, propranolol and lidocaine). Ranitidine, a more modern H-2 histamine blocker, is more powerful, specific, and longer lasting than cimetidine. Ranitidine at a dose of 100-200 mg orally is as effective as cimetidine at a dose of 200-400 mg orally, and its use significantly reduces the risk of postoperative pneumonitis and there are practically no side effects or negative interactions between it and other drugs.
What do anesthesiologists themselves think about this? Research data suggests that 40 to 80 percent of patients undergoing elective surgery have pH< 2.5 и или объем желудочного содержимого более 25 мл во время интубации трахеи. Эти данные могут рассматриваться как факторы риска развития синдрома Мендельсона. Итак, необходимо проводить профилактику аспирации, так как после нее развивается тяжелейшее осложнение - аспирационная пневмония. Что же использовать в качестве профилактического средства? Большинство исследователей утверждают, что помочь в данной ситуации могут антациды. К сожалению, коллоидные суспензии антацидов при их аспирации вызывают серьезные повреждения легких и только широко распространенные твердые лекарственные формы антацидов (цитрат натрия) могут помочь, однако они менее эффективны. Предоперационное назначение цитрата натрия поднимает рН желудочного содержимого выше 2.5 у 64-84 процентов больных, однако, этот препарат увеличивает объем желудочного содержимого. По сравнению с циметидином цитрат гораздо менее эффективен в плане предупреждения аспирационного пневмонита. Предоперационное назначение 300 мг циметидина или 150 мг ранитидина перорально в комбинации с метоклопрамидом значительно снижают риск развития послеоперационного аспирационного пневмонита. O Sullivan et al продемонстрировали, что комбинированное применения метоклопрамида и ранитидина является наиболее эффективными в плане предупреждения тяжелого аспирационного пневмонита.

Premedication in an outpatient setting

We often see and hear statements that premedication in outpatients should be minimal, since massive premedication increases the time it takes for the patient to awaken. The information we obtained from the anesthesiological literature refutes this belief. Clarke and Hurtig reported that intramuscular premedication with meperidine and atropine did not increase the patient's time to awakening after outpatient surgery. More recent studies have shown that premedication with short-acting narcotic analgesics (eg fentanyl intravenously) may even reduce the time it takes to awaken patients due to their analgesic properties and reduced need for anesthetic. In a retrospective study, Meridy reported that preoperative administration of diazepam or hydroxazine did not significantly increase patient awakening time. In pediatric outpatients, oral administration of diazepam or hydroxazine very little increases the patient's time to awakening. Premedication with a combination of diazepam, meperidine and atropine also showed its potential in terms of ensuring the safety of anesthesia and practically did not increase the time of awakening in pediatric practice. In a double-blind study, Jackobsen et al found that oral diazepam significantly reduced preoperative discomfort without any significant wake-up time.
Midazolam is one of the most suitable drugs for outpatient premedication due to the fact that its effect after intramuscular administration develops very quickly. Midazolam reduces anxiety in patients before surgery and does not affect the time of awakening after short-term outpatient procedures. Compared to the combination of morphine and scopolamine, midazolam has a much smaller range of side effects. As oral drugs, temazepam and lormetazepam have proven themselves well, and are superior to all other benzodiazepines when used in outpatient practice.
Are antiemetics needed in outpatient practice? Nausea and vomiting are two of the most common problems in ambulatory anesthesiology. Etiological factors may include the patient's condition (for example, pregnancy), assisted breathing (air in the stomach) and drugs (fentanyl, etomidate, isoflurane, nitrous oxide). Some researchers believe that droperidol is an effective antiemetic, however, the use of droperidol can dramatically prolong the time awakening the patient due to its rather pronounced sedative effect. Despite this, droperidol should be used in those outpatients in whom a high risk of postoperative nausea and vomiting is expected (laparoscopy, abortion). On the other hand, metoclopramide can be used alone or in combination with droperidol, either orally or parenterally.
Thus, in outpatient surgery it is impossible to do without premedication, since it is always necessary to minimize the risk of aspiration, as well as create an appropriate psychological background for the patient.

Conclusions

Traditionally, premedication is those medications that are prescribed to a patient who is undergoing surgery. However, preoperative preparation should not be limited only to the medication component; it should also include a psychological component. The psychological moment is provided by a conversation between the anesthesiologist and a conversation with the patient. A wide range of pharmacological agents are used for premedication, which have a variety of effects.
Most anesthesiologists agree that the goal of modern premedication is an anxiolytic effect. Prevention of aspiration also remains relevant. The choice of drug depends on the weight, age of the patient, the severity of his condition and the upcoming surgical treatment.
The point of view of some doctors who use “standard premedication” is extremely erroneous, since there are no two identical patients and no two identical anesthesiologists.

Premedication is the medical preparation of the patient before anesthesia and surgery using various drugs. Premedication can also be carried out before various painful examinations (bronchoscopy) and in dentistry.

The main goals of premedication are to eliminate the patient's anxiety, adjust indicators, and suppress unwanted reactions.

Tasks

Premedication before surgery is carried out to solve important problems and has sedative and potentiating effects.

Sedative (calming) effect. Fear of anesthesia and pain, fear of surgery, white coats, the operating room, all this leads to the patient’s anxiety, which means the pulse quickens, blood pressure rises, the nervous system is excited - all this can complicate the work of the anesthesiologist and prolong the recovery period of the body after anesthesia and surgery.

The potentiating effect means that premedication can enhance the analgesic effect of anesthesia and anesthesia drugs.

Preventing unwanted reflex reactions.

Suppression of bronchial secretion.

Drugs

Preparations for premedication before anesthesia prescribed by a doctor are used at night and 1.5-2 hours before surgery. They can be administered orally, intravenously, rectally, and possibly also intravenously, but this is only in extreme cases.

Sleeping pills: for example, Elenium, Relanium, Seduxen, etc.

Antihistamines - tavegil, diphenhydramine, suprastin and analogues.

Painkillers according to indications.

To suppress unwanted reflex reactions, reduce mucous secretion and prevent bronchospasm, atropine or analogues are used.

It is important to remember that types of premedication are prescribed strictly individually after a preliminary conversation between the anesthesiologist and the patient. Some features and advice from an anesthesiologist for premedication.

Young children do not need premedication at all, because... they are not afraid and simply do not know what awaits them. The anesthesiologist comes, administers, for example, ketamine intramuscularly in the required dosage, the child falls asleep after 3-5 minutes, takes him in his arms and into the operating room.

Sleeping pills at night should be given to elderly patients with caution, or particularly anxious ones, and at the request of the patient.

Narcotic analgesics such as promedol are recommended to be used extremely rarely, because There is always a threat of respiratory arrest in elderly and weakened patients. Moreover, promedol is a very weak analgesic.

Technique

Sequence of actions for premedication:

1. Operating team: the operating nurse, surgeon and assistant are ready, the nurse anesthetist begins to administer premedication drugs at the command of the anesthesiologist. There are various premedication regimens, for example, atropine + diphenhydramine + seduxene + fentanyl, in appropriate dosages;

3. After this, induction anesthesia is done, muscle relaxants are administered;

5. The anesthesiologist gives permission to the surgeon to begin the operation.

In conclusion, it is worth saying that it is more convenient, more effective and safe to carry out premedication right before surgery on the operating table. This is also done when the anesthesia-respiratory equipment and monitoring systems are fully ready.

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anesthesiologist Medical On Group (Odintsovo, International Medical Center)

Dentists often invite an anesthesiologist to help them see a patient who is afraid of treatment. At the same time, they say that the patient requires premedication. Obviously, the concepts of premedication and sedation are confused here. It would be more correct to say that the patient requires anesthesiological assistance, simply the participation of an anesthesiologist in treatment.

What is premedication? This is the definition given by the “Guide to practical training in anesthesiology, resuscitation and intensive care”, edited by N. M. Fedorovsky, 2002:

Premedication(from Lat. pre - before; Lat. medicamentum - medicine) - preliminary medicinal preparation of the patient for general anesthesia and surgery. The purpose of this training is to reduce the patient’s anxiety level, reduce gland secretion, and enhance the effect of anesthesia drugs.

In other words, premedication is preparation for treatment, usually surgical. The concepts of surgical and therapeutic treatment in general medicine and dentistry are very different, if only in that the internist, as a rule, does not use anesthesia for therapeutic treatment. In dentistry, on the contrary, therapeutic treatment often requires local anesthesia.

What is premedication, what components does it consist of? The above-mentioned “Guide” provides a classic set of premedication components:

“Premedication is a combination of drugs and in most cases includes a narcotic analgesic, a sedative and an antihistamine.”

Premedication - preliminary medical preparation of the patient for general anesthesia and surgery

An example of this combination is the famous “troika” from hospitals during the times of developed socialism: promedol, diphenhydramine, atropine. I will not dwell in detail on the disadvantages and advantages of this set of drugs, I will only say that this standard was not suitable for all patients, and the effect of using the “triad” was sometimes completely opposite. At the present stage of development of medical science, given the peculiarities of domestic legislation on the circulation of medicines, a doctor’s capabilities in the field of using medicines have changed significantly, so let’s take a break from the classical schemes and move on to the realities of today.

First, let's determine what effect we need to get from premedication. The general goal of drug preparation for intervention is the stable condition of the patient, which can be divided into several components; accordingly, measures affecting each of them can be divided.

Anxiolytic treatment can confidently be placed in first place. Any patient experiences varying degrees of stress when visiting a doctor. An appointment with a dentist often causes fear and anxiety than with other specialists, so the patient should be prescribed anxiolytics, which will reduce the intensity of the experience of waiting for an appointment. It is recommended to prescribe anxiolytics in two stages: at night, on the eve of treatment, and one to two hours before the start of treatment, taking into account the duration of action of the drug.

Given the extensive list of registered drugs, it is possible to use herbal-based anxiolytics, for example the following scheme:

• Persen, one tablet in the morning and one tablet in the afternoon the day before treatment.
• On the same day, take Sanoson, two tablets two hours before bedtime.
• An hour before treatment, take two sanoson tablets.

However, if the dentist has the opportunity to prescribe benzodiazepines to the patient, preference should be given to them. The mechanism of action of benzodiazepines is based on their effect on GABAergic receptors found in various brain structures, primarily in limbic (emotiogenic) structures. Under the influence of benzodiazepines, the sensitivity of these receptors to GABA, which is an inhibitory transmitter, increases, which leads to changes in the functioning of the nervous system.

In this regard, benzodiazepines have the following spectrum of action:

• Anxiolytic effect (anti-anxiety), due to the influence of benzodiazepines on the amygdala complex of the limbic system. This leads to a decrease in emotional lability, mental stress, fear, and anxiety.
• Sedative effect due to the influence of benzodiazepines on the corresponding receptors localized in the reticular formation and nonspecific nuclei of the thalamus. The result of this action is a decrease in the speed and accuracy of reactions to external stimuli, drowsiness occurs, and a decrease in mental performance, so the prescription of benzodiazepines to people in specific professions should be done with caution.
• A hypnotic effect that is not true, but is due to an anxiolytic effect and is proportional to psychosedation. Accelerates the process of falling asleep, increases the duration of sleep, which is close to physiological.

The dosage should be selected individually, taking into account the type of nervous system of the patient, the degree of anxiety, weight, height and age. When prescribing benzodiazepines, it is necessary to warn the patient, or better yet, get a signature from him that he will not drive a car or operate dangerous machinery, conduct important negotiations, take exams, etc. for the entire duration of the drug’s effect (about 24 hours).

The use of antihistamines, which is offered by the “Guide to practical training in anesthesiology, resuscitation and intensive care” edited by N. M. Fedorovsky, and was previously prescribed routinely in hospitals, according to modern views on the mechanism of development of allergic reactions is not recommended: they do not prevent anaphylactic shock can . However, their use is advisable, given the side sedative effect and potentiation of the action of anxiolytics by almost all anti-allergy drugs. Therefore, antihistamines should not be excluded in anxious patients.

The next component of premedication should be medications that stabilize the patient’s somatic condition. In a healthy person, the anxiolytic component will cope with this perfectly, but in a person who is compromised in certain organs and systems, drugs should be prescribed based on anamnesis morbi and vitae.

Premedication is a combination of drugs and in most cases includes a narcotic analgesic, a sedative and an antihistamine.

Before treating patients suffering from a serious chronic disease (chronic ischemic heart disease, heart failure of various origins, stage 2-4 hypertension, conditions after myocardial infarction, cerebrovascular accidents, etc.), it is recommended to schedule a consultation with a specialist who will give recommendations on premedication and adjust the patient’s chronic treatment before visiting the dentist. It is quite possible to involve an anesthesiologist to prescribe premedication and adjust the patient’s physical condition during treatment (therapeutic support of the intervention).

Here we should especially focus on patients who are constantly taking antiplatelet agents and anticoagulants. As a rule, there is no need to cancel or change the regimen of anticoagulant or antiplatelet therapy before performing minor surgical operations in the oral cavity. In this case, you need to focus on the severity of the patient’s condition, the result of a blood test for coagulation and the presence of concomitant diseases.

Antiplatelet agents

Although a number of dentists recommend that their patients stop taking medications several days before surgery to prevent the possibility of bleeding, studies show that there is no need to stop taking low doses of the drug (75-100 mg/day). In most cases, the time to stop bleeding did not differ between patients who took antiplatelet agents and those who stopped taking them. In addition, according to one study, there is also no need to stop high doses (325 mg/day) before removing a single tooth. Thus, it is necessary to eliminate the practice of discontinuing low (and in some cases high) doses of antiplatelet drugs before minor oral surgery.

In fact, discontinuation of antiplatelet drugs itself may provoke a higher risk of complications (for example, an attack of acute heart failure) than the risk of intra- and postoperative bleeding.

Anticoagulants

Most authors believe that if the INR (International Normalized Ratio) or INR (International Normal Ratio), a coagulation test that determines the clotting time of a patient's blood plasma after adding a mixture of tissue thromboplastin and calcium to it, is below four, it is necessary to cancel or There is no change in anticoagulant intake, since hemostasis can be achieved by local means. However, if the patient’s INR goes beyond the therapeutic corridor, the dentist, before performing surgery and adjusting treatment, is obliged to consult with the doctor who prescribed these drugs, with a view to discontinuing them several days before treatment. Typically, medications that affect blood clotting are discontinued at least 5 days before the dentist appointment.

Separately, it should be said about the prevention of side effects of drugs used by dentists in the treatment of patients. In first place here are anesthetics that contain adrenaline; second place in frequency of use, but not in the effect produced, is occupied by retraction threads impregnated with adrenaline, used by orthopedists, since the generalized effect of the adrenaline contained in them often exceeds the effect of the general effect of anesthetics on the body of adrenaline. Another factor that plays a role here is that dentists do not take into account the generalized effect of adrenaline contained in the threads, because the doctor does not inject any drugs under the patient’s mucous membrane and it seems to him that the drug does not enter the body. Meanwhile, the ability of the oral mucosa to absorb substances exceeds the ability of the gastrointestinal mucosa: many tablet drugs are recommended to be dissolved under the tongue to speed up and enhance the effect. Most modern anesthetics used in dentistry are based on articaine. Compared to other modern anesthetics, this drug has less overall effects on the body as a whole. However, it should be taken into account that articaine exhibits antagonism in the effects on skeletal muscles with antimyasthenic drugs such as kalimine and prozerin, especially when used in high doses, which requires additional correction of the treatment of myasthenia gravis by the attending physician before visiting the dentist. In addition, like other local anesthetics, it lowers blood pressure and slows the rhythm of contraction of the heart muscle, so to possible objections that the drug is used locally, one can argue that from such a generously supplied tissue as the oral mucosa, it works quite well absorbed into the bloodstream and has a general effect on the body.

Withdrawal of antiplatelet agents may result in a higher risk of complications than the risk of intra- and postoperative bleeding.

The same thing happens with adrenaline contained in the anesthetic capsule. In addition, most dentists do not use the spear-shaped plunger tip of a carpule syringe to pull back to determine if the needle is in a blood vessel, so direct injection of part or even the entire carpule into the bloodstream cannot be ruled out. However, the generalized effect of an anesthetic on the body is not as dangerous as a similar effect of adrenaline.

Often, the generalized side effects of adrenaline are not taken into account by dentists, but this should be done, since it not only causes anxiety in the patient, but also provokes a change in the somatic state: it causes an increase in blood pressure, tachycardia followed by bradycardia, rhythm disturbances (including atrial fibrillation and ventricles), coldness and pallor of the skin, vomiting, headache, metabolic acidosis. It can provoke myocardial infarction, cerebral hemorrhage (especially in elderly patients) and pulmonary edema, which for obvious reasons can be fatal.

It should be noted here that retraction threads impregnated with adrenaline, used simultaneously for several teeth, release the adrenaline they contain to the body in much greater quantities.

To prevent the generalized effects of adrenaline, adrenaline antagonists should be included in premedication. They are alpha and beta adrenergic receptor blockers.

Separately, I would like to dispel the myth about the possibility of reducing the gag reflex with antiemetic drugs.

Dentists trying to solve this patient’s problem with medication are divided into two groups: some advise including tablets used to treat transport sickness in the premedication, others recommend centrally acting antiemetic drugs. Both recommendations are erroneous, because they do not take into account the mechanism of development of vomiting.

Nausea and vomiting - a protective reflex of the body - occurs for various reasons, and, accordingly, various reflex circuits are involved in its manifestation.

Specific drugs are designed to interrupt specific, different mechanisms of vomiting, and not all at once.

To prevent the generalized effects of adrenaline, adrenaline antagonists should be included in premedication. They are alpha and beta adrenergic receptor blockers

Thus, locomotion vomiting (transport disease) is provoked by a change in the position of the body in space and, accordingly, disruption of the entire chain of the human balance apparatus, from the balance organ located in the inner ear to the parts of the brain that perceive its signals.

The mechanism for the development of vomiting, triggered by irritation of the gastric mucosa, differs not only from the mechanism mentioned above, but also from the mechanism of vomiting caused by irritation of the posterior wall of the pharynx.

Irritation of the posterior pharyngeal wall can be relieved with superficial anesthesia applied to the pharyngeal mucosa by spraying.

But in patients, with rare exceptions, vomiting at a dentist’s appointment is caused by fear of treatment, so in this case it is necessary to influence precisely this reason. The best drug to prevent the occurrence of such a gag reflex is an anxiolytic.

Dentists often use atropine to treat increased salivation.

In many cases, premedication with an anticholinesterase drug is justified, but we should not forget that anticholinesterase drugs provoke tachycardia, the occurrence of which can be dangerous for patients compromised by the cardiovascular system. When prescribing atropine, some caution should be exercised and it should be replaced with less aggressive drugs, for example platyphylline.

Analgesics occupy a special place in premedication. Non-steroidal anti-inflammatory and antipyretic drugs are used, which cause a number of possible complications, therefore their prescription is justified only if the patient has pain and only if the use of these drugs significantly reduces or relieves pain.

We should not forget about the importance of such a component of premedication as a preliminary conversation with the patient. Although verbal influence is not medicinal, it cannot be discounted. A calm, friendly conversation, a detailed explanation to the patient of the stages of treatment, indicating the moments at which he may experience pain or discomfort, indicating their duration and intensity (local anesthesia, pulp extraction, etc.), sometimes helps the action is more effective than a set of well-chosen medications for premedication.

So, modern premedication before an outpatient dental appointment should include the following components and be carried out at least 24 hours before treatment:

• Verbal influence on the patient in the form of a conversation with the doctor, explaining in a friendly tone in a simple and understandable form the stages of treatment and indicating the patient’s possible unpleasant sensations during this treatment. It is best to talk with the patient in detail during the initial examination and briefly before each subsequent appointment, repeating the main points of the initial conversation.
• Anxiolytic drugs prescribed at least twice: the night before treatment and an hour or two before the dentist appointment.
• Antihistamines to potentiate the effect of anxiolytic drugs, also prescribed at night and an hour or two immediately before treatment.
• Correction of the treatment of concomitant chronic somatic conditions, which, of course, is not carried out overnight, but takes the period necessary to achieve the result.
• Taking alpha- and beta-adrenergic receptor blockers if the patient is suspected of having possible adverse reactions from the administration of adrenaline.
• Anticholinesterase drugs, if necessary, affect the increased production of the salivary glands.
• If there is pain, only analgesics can significantly reduce or stop it.

Literature

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5. Do antiplatelet agents and anticoagulants need to be discontinued before minor oral surgery? Dr. Al-Harkan, Dr. Al-Ayoub.
6. Pathways of drug absorption. Receipt of drugs into the oral cavity and stomach(resident of KazNMU named after S. D. Asfendiyarov Gasanov A.).
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