130 likes | 234 Views
The Use and Abuse of Nitrous Oxide: No Laughing Matter. Erica Helfer LEAP Independent Study Summer 2008. What do you know about . laughing gas ?. History of anesthetics. 1846 – Ether first demonstrated as a surgical anesthetic. . CH 3 CH 2 OCH 2 CH 3.
E N D
The Use and Abuse of Nitrous Oxide:No Laughing Matter Erica Helfer LEAP Independent Study Summer 2008
What do you know about laughing gas ?
History of anesthetics 1846 – Ether first demonstrated as a surgical anesthetic. CH3CH2OCH2CH3
What does an anesthetic drug need to be able to do? • Relieve pain (analgesia) • Induce memory loss (amnesia) • Relax muscles • Reduce consciousness (if necessary)
What makes a good anesthetic? • Chemical stability • Minimal irritation upon inhaling (if gaseous) • Rapid and pleasant onset of anesthesia (time to loss of consciousness) • Speed and safety of emergence from anesthesia • Rapid changes in depth of anesthesia • Minimal metabolism • Absence of toxic effects in normal doses, especially cardiovascular and respiratory and toxicity to the liver • Wide margin of safety
Two types of modern anesthetics • Intravenous (drugs used in anesthesia) • Hypnotics (e.g. Etomidate) • Opioids (e.g. Morphine) • Other (e.g. Ketamine) • Inhalational (true anesthetics) • Desflurane • Enflurane • Halothane • Isoflurane • NITROUS OXIDE
Synthesis of nitrous oxide Nitrous oxide is commonly prepared by heating solid ammonium nitrate to make water vapor and gaseous nitrous oxide. • What type of reaction is this? • Write the balanced chemical equation for this reaction. + =
Pros and cons of nitrous oxide as an anesthetic • PROS: nonflammable, nonirritating, powerful analgesic agent, rapid onset and recovery (due to low blood/gas solubility), little or no toxicity, not metabolized, ease in regulation of the depth of action • CONS: N2O is not a strong enough anesthetic for the use in large operations. It is uncomfortable for people who have trouble breathing through their nose. It is also a greenhouse gas with potential to cause global warming when released into the environment (310 times the ability to trap heat in atmosphere than CO2).