What is the pharmacokinetics of inhaled anesthetics?

What is the pharmacokinetics of inhaled anesthetics?

The uptake and distribution of inhalational anaesthetics depends on inhaled concentration, pulmonary ventilation, solubility in blood, cardiac output and tissue uptake. Inhalational anaesthetics are mainly eliminated by pulmonary exhalation, but significant amounts of halothane are removed by hepatic metabolism.

How are volatile anesthetics metabolized?

The elimination of any anesthetic from the body is by metabolism and excretion. Metabolism involves catabolic phase I reactions, i.e. hydrolysis, oxidation and anabolic phase II reactions involves addition of a glucuronyl or methyl group to the metabolite.

How is sevoflurane metabolized?

Relatively little biotransformation, only 5% is metabolized by cytochrome P450 CYP2E1 to hexafluoroisopropanol (HFIP) with release of inorganic fluoride and CO2. No other metabolic pathways have been identified for sevoflurane. The low solubility of sevoflurane facilitates rapid elimination via the lungs.

How is sevoflurane absorbed?

As a consequence, more sevoflurane is absorbed into the CO 2 absorber than is observed with other inhalational anesthetics. The production and subsequent inhalation of compound A correlate inversely with the inflow rate 60 and directly with the absorbent temperature 61.

Is nitrous oxide a volatile anesthetic?

The volatile anesthetics (halothane, isoflurane, desflurane, and sevoflurane) are liquids at room temperature and require the use of vaporizers for inhalational administration. Nitrous Oxide is already under normal conditions of temperature and pressure.

What the body does to drug?

Pharmacokinetics, sometimes described as what the body does to a drug, refers to the movement of drug into, through, and out of the body—the time course of its absorption.

What is minimum alveolar concentration in anesthesia?

The minimum alveolar concentration (MAC) value is the concentration of an inhalation anesthetic agent in the lung alveoli required to prevent movement in response to a surgical stimulus in 50% of patients.

What is the difference between sevoflurane and desflurane?

Sevoflurane has a blood: gas partition coefficient of 0.65, which is slightly greater than desflurane. The major advantage over desflurane is the better scent. It is considered to be less airway irritation in LMA anesthesia with smooth induction and recovery.

What percentage of sevoflurane is metabolized?

The extent of metabolism of sevoflurane and desflurane is 2-5% and 0.02-0.2% of the dose taken up, respectively. Peak serum fluoride concentrations occur within one hour after sevoflurane anesthesia, are usually in the range of 20-40 microM, and decline rapidly.

What is the Iupac name of sevoflurane?

methyl isopropyl ether
Sevoflurane is a sweet-smelling, nonflammable, highly fluorinated methyl isopropyl ether used as an inhalational anaesthetic for induction and maintenance of general anesthesia….Sevoflurane.

What stage of anesthesia is nitrous oxide?

Nitrous oxide is a weak inhalational anesthetic. Because 105% alveolar concentration is needed to induce general anesthesia when nitrous oxide is used as a sole anesthetic agent, it is ineffective as a single agent for general anesthesia.

What are inhalation anesthetics used for?

Inhalation anesthetics (nitrous oxide, halothane, isoflurane, desflurane, sevoflurane, most commonly used agents in practice today) are used for induction and maintenance of general anesthesia in the operating room.

Are inhaled anesthetics FDA approved?

Inhaled anesthetics are commonly used in combination with IV anesthetic agents. These agents have FDA approval for use as a general anesthetic and sedation agent in the operating room. Inhaled anesthetic agents have also had use in the intensive care unit, but this is not an FDA-approved indication.

What is nitrous oxide inhalation anesthetic?

Nitrous Oxide is already under normal conditions of temperature and pressure. All inhalational anesthetics provide amnesia and immobility, except for nitrous oxide, which also provides analgesia. Inhaled anesthetics are commonly used in combination with IV anesthetic agents.

Is halothane an acceptable inhalation agent for paediatric anaesthesia?

Inhalational agents currently in use have acceptable pharmacokinetic characteristics, and clinical acceptance depends on their potential for adverse effects. Induction of anaesthesia with halothane is rapid and relatively pleasant and it is the agent of choice for paediatric anaesthesia.