Anesthetics Flashcards
What are the four types of Anesthesia?
General Anesthesia (this is a drug induced loss of consciousness of the entire body where patients are not able to feel any pain) Usually they are used in conjunction with neuromuscular blockades.
Neuraxial Anesthesia - injection of anesthetic with an opioid around the nerves. This can be split into two main types of anesthesia.
Epidural - (single dose or continuous infusion) this is when the anesthesia is injected outside the dura (skin like covering around the spinal cord) into the epidural space.Gives more of a local effect. You can also administer this type of anesthesia as an analgesic for post treatment recovery.
Subarachnoid - (single dose) this is when it is injected into the dura, directly into the spinal cord. This will provide waist down numbing of pain and areflexia.
Regional Anesthesia- Is an injection of an anesthetic around a specific nerve to block sensation of pain to an ENTIRE limb. Examples include an arm/leg or for the teeth during dental work.
Local Anesthesia: injection of anesthetics in the area of surgery rather than around a specific nerve. Often used for very minor surgeries. For example, a mole removal or skin tag.
What are the goals of Anesthesia?
Amnesia - provide of sedation
Areflexia - (prevent reflexes from moving) for example: coughing, muscle tension, and cardiovascular reflexes like increased BP
Analgesia - inability to feel pain
What are the two types of intravenous anesthetic agents?
Propofol and Ketamine.
How does Propofol work?
They increase the GABA in the body, hence providing sedation.
What can Propofol not do?
Propofol cannot provide analgesic affects alone, and hence must be used in conjunction with an analgesic.
They can provide amnesia and the maintenance.
What are the side effects of Propofol?
Respiratory depression and potential hypotension.
How does Ketamine work?
It interacts with NDMA receptors as an antagonist.
This anesthetic can be given intravenously or intramuscularly.
What effects does Ketamine provide?
They have both amnestic and analgesic properties.
In high does they work for amnesia (dissociative), and low doses they have pain management.
What are the side effects of Ketamine?
Increased sympathetic nervous system activity, hallucinations (this is why its used recreationally) and minimal respiratory depression (this drug helps maintain muscle tone and keep BP stable).
What are volatile anesthetic agents?
Anesthetics that are delivered through inhalation, and are ether based compounds.
How are they delivered?
Through an anesthetic mask or a endotracheal tube.
What are the most common drugs names?
Desflurane and Sevoflurane.
What is the mechanism of action?
Increases GABA agonism, but the full mechanism is unclear.
What effects to volatile agents provide?
Amnesia and Areflexia in the spinal cord.
What are the side effects of volatile agents?
Hypotension, mild respiratory depression, nausea/vomiting, and Malignant hyperthermia.
What is malignant hyperthermia? CFAM
rare clinical condition of hyper metabolism that leads to fever, muscle breakdown, acidosis and cardiovascular collapse. This can result in death is not promptly treated.
What are muscle relaxants?
Medications that cause paralysis of skeletal muscles that are used to facilitate surgery and endotracheal intubation.
What effects do they produce?
They are areflexia agents but they do not provide analgesic, amnestic, or hypnotic properties.
What are the two broad categories for muscle relaxants?
Depolarizing agents, and non-depolarizing agents.
What are depolarizing muscle relaxants?
IHM^2
Drug name: Succinylcholine
What this drug does is binds to the ACh receptor as an agonist. Acetylcholine is a neurotransmitter that sends signals that causes skeletal muscle fibers to be unresponsive. By binding and increasing the affinity, the muscles can be relaxed for a period of time. This causes a prolonged depolarization period.
