All About Premedication in Anesthesia

Introduction

The administration of more analgesics during surgery and undesirable postoperative behavioral changes like sleep disruption, separation anxiety, food issues, and frequent urination have all been linked to perioperative anxiety. Ages between one and three years, inhibited, dependent temperament, nervous parents, and previous unpleasant hospital experiences are indicators for preoperative anxiety. For instance, a child with behavioral conditions or is at risk of aspiration, the anesthetic plan requires modifications specifically for that child.

Adolescents have a greater demand for privacy, independence, and bodily awareness. Giving this age group a sense of influence over anesthesia plans can help them feel less anxious. Relationship building is challenging for kids with psychological, developmental, or behavioral issues since these kids commonly fear and distrust others. At the time of induction of anesthesia, they are more likely to be combative and hostile, necessitating sedation, restraint, or both. Hence, consideration of the child's age and temperament is essential to a successful approach to the induction of anesthesia.

What Is Premedication in Anesthesia?

Prescription drugs are typically administered intramuscularly; however, youngsters and people with bleeding issues are better off taking them orally. Preoperative medicine is often administered 20 minutes to three hours before surgery. Before cannulation, pediatric patients are frequently provided topical anesthetic creams. Premedication with sedatives, analgesia, antimuscarinics, antiemetics, or anti-acidity are the categories of pre-induction techniques for anxiety management.

1. Sedatives Premedication: The intravenous and inhalational anesthetic agents, which have far fewer side effects and a faster start of the action, has resulted in the discontinuation of the use of powerfully sedative medications (such as morphine and hyoscine) to promote smooth induction and reduce salivation. The main purpose of premedication in children is to reduce anxiety, which helps with painless separation from the parents and makes inducing anesthesia easier. Premedication may also have the following additional effects: antiemesis, analgesia, forgetfulness, prevention of physiologic stress, vagolysis, reduction in total anesthetic requirements, lower likelihood of aspiration, decreased salivation, and secretions. The most common sedative premedication are:

• Midazolam: The most used sedative premedication in children is Midazolam, a water-soluble benzodiazepine. Amnesia with minimal respiratory depression is one of the advantages of Midazolam. The 0.05 to 0.2 mg/kg of Midazolam can be administered in the preoperative state. However, effective sedation and anxiolysis are commonly achieved orally at a dose of 0.5 to 0.75 mg/kg, up to a maximum of 20 mg.

• Alpha 2–Adrenergic Agonists: Alpha 2–adrenergic agonists are being increasingly utilized preoperatively to reduce anxiety in recalcitrant youngsters. The use of recovery analgesia, emergence agitation, postoperative nausea and vomiting (PONV), and postoperative shivering are all clinically significant advantages of this class of medications. An alpha 2-adrenergic agonist, Clonidine, can be given intravenously at 2 g/kg or orally (3 to 4 g/kg). Premedication with Clonidine is better than Midazolam in producing sedation and lowering postoperative pain, PONV, and emergence agitation. The alpha 2: alpha 1 affinity ratio of Dexmedetomidine is 1600:1, making it a more powerful and highly selective alpha 2-adrenoreceptor agonist than Clonidine, with a shorter terminal half-life (about two hours in children). Dexmedetomidine has been used intranasally in 1 g/kg doses given 45–60 min before induction.

• Ketamine: Long used as a premedical, Ketamine is an NMDA (N-methyl-D-aspartate) receptor antagonist. It can be given intravenously, orally, or intramuscularly with the major advantage of analgesic effects and sedative effects without respiratory depression. However, some of the adverse effects include increased salivation, the appearance of delirium, and delayed recovery.

• Fentanyl: It is used to reduce anxiety and induce sedation. Fentanyl is readily absorbed through the transmucosal route.

• Topical Anesthetics: A suitable amount of topical anesthesia for an IV (intravenous) catheter placement can be achieved by applying EMLA cream (a eutectic blend of two local anesthetics: 2.5 % Lidocaine and 2.5 % Prilocaine) to undamaged skin with an occlusive dressing one hour beforehand. However, EMLA produces skin blanching and vasoconstriction, making IV cannulation more challenging.

• Melatonin: Melatonin, a hormone produced in the pineal gland, has a variety of effects, including hypnosis, anxiolysis, drowsiness, and anti-inflammatory properties. It results in a night of restful sleep and could lower the likelihood of emergency agitation.

• Triclofos: The pharmacologically active metabolite of chloral hydrate, trichloroethane, is present in triclosan syrup as its monophosphate sodium salt. Because Triclofos tastes better and causes less gastrointestinal discomfort than chloral hydrate, it has been widely used as a sedative.

2. Analgesia: The immediate postoperative period is made more comfortable for patients by analgesic medications that are administered earlier. Opioids, Paracetamol, non-steroidal anti-inflammatory medications (NSAIDs), and gabapentin are some of the available options.

• NSAIDs: It is frequently used, especially during surgery.

• Opioids: It also results in cardiorespiratory depression and varying sedation. The possibility of nausea and vomiting from all opioids may outweigh any positive advantages. Opioids can also cause anaphylaxis (a severe allergic reaction that might turn out to be fatal) or bronchospasm (muscle constriction throughout the bronchi or lungs).

• Clonidine: Children's postoperative pain has been demonstrated to decrease when Clonidine is administered as a premedication.

3. Antimuscarinics: They can be administered to minimize vagally mediated bradycardia and hypotension as well as dry up secretions in the mouth and airways.

• Hyoscine: The sedative, amnesic, and anti-salivation effects are all exhibited by Hyoscine. It enhances opioids while providing an antiemetic effect. Due to this, an opioid is frequently prescribed along with intramuscular atropine or hyoscine.

• Anti Sialagogues: Anti-sialagogues, such as intramuscular or intravenous Glycopyrrolate, are mostly recommended before Ketamine anesthesia or during awake fiber-optic intubation with an adverse effect of dry mouth may result from anti sialagogues.

4. Antiemetics or Anti-acidity: Antiemetics are used to improve stomach emptying or lessen the emetic effects of anesthetic drugs. These kinds of drugs lessen stomach acidity and should be given to people who are at risk of regurgitation of gastric contents or who are having procedures with a high incidence of nausea and vomiting. It is not advised for people who are not at risk to take antiemetics and agents to lower acidity regularly. An H2-receptor antagonist may be used 1 to 2 hours preoperatively, and oral non-particulate antacids such as Sodium citrate 15 to 30 minutes before induction.

Conclusion

Anesthesia induction is a combination of art and science. There are long-term behavioral effects of pre-induction anxiety and turbulent anesthetic inductions. The anesthesiologist must support patient-friendly techniques and have a thorough understanding of psychology. The patient's age and temperament must be taken into consideration while developing behavioral strategies and sedative premedication.