General Anesthetics Overview

A class of drugs that induce a state of calm and drowsiness, often used to prepare patients for surgery or medical procedures.

A type of sedative agent given intravenously (IV) that works by activating alpha-2 receptors in the brain.

A pre-procedure medication given to patients to reduce anxiety, pain, and other side effects related to anesthesia or surgery.

A class of drugs used to block the effects of acetylcholine, a neurotransmitter involved in muscle contractions and other bodily functions.

Medication given to reduce anxiety and promote sleep.

Drugs that have a calming effect on the brain and body.

A class of drugs that lower blood pressure.

Drugs that block the effects of histamine, a substance in the body involved in allergic reactions.

A type of anesthesia that is administered intravenously.

A common intravenous anesthetic known for its quick onset and short duration of action. It modulates GABA receptors, inducing sedation and sleep.

Used to induce general anesthesia and maintain sedation. It works by modulating GABA receptors.

A unique intravenous anesthetic that blocks NMDA receptors. Its effects include analgesia and a 'dissociative' state where the patient is aware but unresponsive.

Inhaled anesthetics are liquids that evaporate easily and are breathed in by the patient. They are preferred for maintaining general anesthesia.

A common inhaled anesthetic often used in mixtures with oxygen or oxygen and nitrous oxide. It affects GABA receptors to induce anesthesia.

Anesthetics work by modulating GABA receptors, ultimately leading to a state of unconsciousness.

Anesthetics are used to maintain a stable state of anesthesia during surgery or procedures.

A quantitative measure of how potent an inhalation anesthetic is. A lower MAC value indicates a more potent anesthetic, meaning less of the drug is needed to achieve the desired effect.

The ratio of an inhalation anesthetic's concentration in the blood to its concentration in the alveoli (air sacs in the lungs). A low blood/gas partition coefficient means the anesthetic quickly moves from the lungs into the blood, leading to faster induction and recovery.

The stage of general anesthesia where the patient loses consciousness and becomes unaware of their surroundings.

The stage of surgical anesthesia where the patient is fully unconscious, relaxed, and ready for surgery.

A type of anesthesia that uses drugs delivered by breathing in a gas or vapor.

A type of drug used to relax muscles, often used alongside general anesthesia.

A method of monitoring the brain's electrical activity during anesthesia to assess the depth of anesthesia.

The state of being unconscious and unresponsive to stimuli.

A class of drugs that relax muscles by directly affecting the central nervous system.

Drugs that relax muscles by acting on the peripheral nervous system.

A type of peripheral action muscle relaxant that mimics acetylcholine's actions, causing muscle contraction.

A type of peripheral action muscle relaxant that blocks the action of acetylcholine, causing muscle relaxation.

Drugs that temporarily block the transmission of nerve signals, preventing pain and movement.

Application of local anesthetic directly to skin or mucous membranes to block sensory receptors.

Injection of local anesthetic into tissues like skin, subcutaneous tissue, or muscles.

Injection of local anesthetic into the spinal canal, blocking nerve roots of the spinal cord. Two types: spinal and epidural.

Amides, a type of local anesthetic, are broken down by enzymes in the liver, making their effects last longer compared to esters.

Lidocaine, a common amide local anesthetic, can also be used as a class 1B antiarrhythmic drug to treat irregular heartbeats.

Bupivacaine, another amide local anesthetic, is often used for long-lasting pain relief, including in labor and chronic pain management.

Local anesthetics like lidocaine and bupivacaine work by blocking the flow of signals through nerves, preventing pain sensations.

Esters, a second type of local anesthetic, are broken down quickly by enzymes in the body, leading to shorter effects.

Benzocaine, a common ester local anesthetic, is typically used for surface anesthesia on the skin or mucous membranes.

Allergic reactions are more common with esters due to the breakdown product PABA, which can cause sensitivity.

Amides are generally considered safer than esters, as they are less likely to cause allergic reactions.

The ability of local anesthetics to block nerve conduction by interfering with sodium ion (Na+) channels in the nerve membrane.

The non-ionized form of a local anesthetic can easily cross the cell membrane due to its lipid solubility, while the ionized form binds to and blocks the sodium channels.

The acidity of the tissue environment can influence the effectiveness of local anesthetics. Infected tissues tend to have a lower pH, which can decrease the ionized form and reduce the anesthetic effect.

Many local anesthetics cause blood vessel dilation, which can lead to faster absorption and increased risk of systemic side effects.

Combining a local anesthetic with a vasoconstrictor, such as epinephrine, can reduce blood vessel dilation, allowing for a smaller dose and more localized effect.

The pKa of a drug and the pH of the tissue determine the proportion of ionized and non-ionized forms present. Different local anesthetics have varying pKa values, influencing their effectiveness in different tissue environments.

The ability of a local anesthetic to block nerve conduction is affected by its chemical structure and the length of the molecule.

Some local anesthetics, like bupivacaine, have a longer duration of action compared to others, like lidocaine. This is related to their chemical properties and how they interact with the sodium channels.