From the Guidelines
Propofol is the most widely used and recommended induction agent for anesthesia due to its rapid onset, short duration, and smooth recovery profile. Common anesthetic drugs used for induction of anesthesia include propofol, etomidate, ketamine, and sodium thiopental.
Key Characteristics of Induction Agents
- Propofol (1.5-2.5 mg/kg IV) has a rapid onset (30-40 seconds) and short duration, making it a popular choice for induction, although it can cause hypotension 1.
- Etomidate (0.2-0.3 mg/kg IV) maintains hemodynamic stability, making it valuable for cardiovascularly compromised patients, but may cause adrenal suppression.
- Ketamine (1-2 mg/kg IV or 4-5 mg/kg IM) provides dissociative anesthesia with analgesic properties and maintains blood pressure, making it useful in hypovolemic patients, though it can increase intracranial pressure and cause emergence reactions.
- Sodium thiopental (3-5 mg/kg IV), a barbiturate, is less commonly used today but still available in some regions.
Considerations for Induction
These medications are typically administered intravenously by anesthesia providers who carefully select the appropriate agent based on the patient's medical condition, the surgical procedure, and hemodynamic goals. Dosing adjustments are necessary for elderly patients, those with significant comorbidities, or when combined with other sedatives or opioids to prevent oversedation and respiratory depression. The choice of induction agent should prioritize minimizing risks and optimizing outcomes, considering factors such as the patient's health status and the nature of the surgical procedure, as emphasized in recent guidelines 1.
From the FDA Drug Label
Induction of General Anesthesia Adult Patients Most adult patients under 55 years of age and classified as ASA-PS I or II require 2 mg/kg to 2.5 mg/kg of propofol injectable emulsion for induction when unpremedicated or when premedicated with oral benzodiazepines or intramuscular opioids.
Pediatric Patients Most patients aged 3 years through 16 years and classified ASA-PS I or II require 2.5 mg/kg to 3.5 mg/kg of propofol injectable emulsion for induction when unpremedicated or when lightly premedicated with oral benzodiazepines or intramuscular opioids.
The common anesthetic drugs used for induction of anesthesia include:
- Propofol: 2 mg/kg to 2.5 mg/kg for adult patients and 2.5 mg/kg to 3.5 mg/kg for pediatric patients. Other anesthetic drugs that may be used for induction are not mentioned in the provided drug labels. 2
From the Research
Common Anaesthetic Drugs for Induction
The following are common anaesthetic drugs used for induction of anesthesia:
- Propofol: a short-acting induction agent with good anesthetic properties, commonly used for induction of anesthesia 3, 4, 5, 6
- Ketamine: often used in combination with other anaesthetic agents, such as propofol, for induction of anesthesia 3, 7, 5, 6
- Etomidate: an anesthetic that induces only minor cardiovascular changes, often used for induction of anesthesia in critically ill patients 3, 4, 5, 6
- Midazolam: a benzodiazepine that can be used as a single induction hypnotic drug, but is often used in combination with other anaesthetic agents 4, 7
- Thiopental: a barbiturate that produces negative inotropic effects, often used for induction of anesthesia in certain clinical situations 4
- Methohexital: a barbiturate that is only administered in very few clinical situations, due to its negative inotropic effects 4, 7
Comparison of Anaesthetic Drugs
Studies have compared the hemodynamic effects of different anaesthetic drugs, including propofol, ketamine, etomidate, midazolam, thiopental, and methohexital 3, 4, 7, 5, 6. The choice of anaesthetic drug depends on various factors, including the patient's medical condition, the type of surgery, and the desired level of sedation.
Clinical Applications
These anaesthetic drugs are used in various clinical settings, including: