Ketamine Flashcards
What is Ketamine and its primary use in medicine?
Ketamine is an anesthetic agent used for its dissociative anesthesia, analgesia, and hemodynamic stability, especially useful in emergency, pediatric, and psychiatric settings.
Describe the dissociative anesthesia provided by Ketamine.
Ketamine induces a unique state where the patient remains unconscious but maintains spontaneous respiration, suitable for scenarios where mechanical ventilation is undesired.
How does Ketamine provide analgesia?
Ketamine’s strong analgesic properties are effective at sub-anesthetic doses for acute and chronic pain management, owing to its NMDA receptor antagonism.
Explain Ketamine’s impact on cardiovascular stability.
Ketamine stimulates the sympathetic nervous system, increasing blood pressure and heart rate, beneficial in hypotensive or shock states.
Discuss Ketamine’s bronchodilatory effects.
Ketamine induces bronchodilation, making it advantageous for patients with asthma or other respiratory conditions by reducing the risk of bronchospasm.
Why is Ketamine suitable for pediatric anesthesia?
Due to its rapid onset, short duration, and minimal respiratory depression, Ketamine is effectively used in pediatric sedation and anesthesia.
What psychiatric applications does Ketamine have?
Low doses of Ketamine show rapid antidepressant effects in treating severe depression and suicidal ideation, offering a novel approach in psychiatry.
Detail Ketamine’s mechanism of action.
Ketamine blocks NMDA receptors, inhibiting glutamate’s excitatory effects, leading to dissociation, analgesia, and potentially rapid antidepressant effects.
How does Ketamine affect cerebral functions?
Ketamine increases cerebral blood flow and oxygen consumption, considerations crucial in neurosurgical and critically ill patients.
Describe Ketamine’s pharmacological profile.
As a phencyclidine derivative and NMDA antagonist, Ketamine is supplied as a racemic mixture, inducing dissociation, analgesia, and amnesia.
What side effects are associated with Ketamine use?
Ketamine may cause nystagmus, increased intraocular pressure, maintain reflexes, and lead to psychotomimetic effects like hallucinations or delirium.
Address Ketamine’s utility in low-resource settings.
Its versatility in administration routes (IV, IM, oral) makes Ketamine valuable in settings lacking advanced medical equipment.
What are the anti-inflammatory effects of Ketamine?
Ketamine inhibits inflammatory mediators like TNF-alpha and IL-6, contributing to its anti-inflammatory effects.
Discuss the metabolic fate of Ketamine.
Ketamine is metabolized to norketamine, which retains 20-30% of Ketamine’s activity, and further metabolism affects its analgesic efficacy and side effects.
Explain Ketamine’s effects on pulmonary compliance.
Ketamine increases pulmonary compliance and decreases resistance, acting as a potent bronchodilator and making it a good induction agent for asthmatic patients.
How does Ketamine influence the sympathetic nervous system?
Ketamine stimulates the sympathetic nervous system and inhibits norepinephrine reuptake, contributing to its cardiovascular effects.
What considerations should be taken with repeated Ketamine doses?
Repeated Ketamine use can lead to tolerance, hepatic enzyme induction, and uncover direct myocardial depressant effects in certain conditions.
Detail the precautions with Ketamine concerning ocular effects.
Ketamine may increase intraocular pressure, requiring caution in patients with glaucoma or eye injuries.
How does Ketamine maintain reflexes during anesthesia?
Patients under Ketamine maintain cough, corneal, and swallow reflexes, differentiating it from other anesthetics.
Discuss Ketamine’s role in inducing a catatonic state.
Ketamine can induce a catatonic state where the patient appears conscious but is unable to respond to sensory stimuli, characterized by eye opening, swallowing, and muscle contracture.
Address the issue of increased salivation with Ketamine.
Ketamine increases lacrimation and salivation, which can increase the risk of laryngospasm, often managed by premedication with anticholinergic agents.
Alpha-adrenergic and beta-adrenergic antagonists properties?
Alpha-adrenergic and beta-adrenergic antagonists may unmask the direct myocardial depressant effects of ketamine.
Effects of depleted catecholamine stores ?
Sympathetic blockade or depleted catecholamine stores may unmask the direct myocardial depressant effects of ketamine
