Februari 06, 2017
nitrous oxide is a very common inhalationalanesthetic. it's capable of providing analgesia, someanesthesia, and amnesia. because of its euphoric and hysterical effects,it's also known as "laughing gas." some aspects of its pharmacology are concerningif the drug is used for long periods, whether that's in recreational or medical settings. as always, there will be more informationand links to references on thedrugclassroom.com which you can find using the link below. among the potential positive effects are dissociation,euphoria, anxiolysis, mood lift, sedation, analgesia, laughter, and a dream-like state.
the negatives can include amnesia, dizziness,nausea, vomiting, and headache. some of its benefits in anesthesia are thatit generally offers stable cardiorespiratory function, reduces anxiety, offers some painrelief, and doesn't irritate the respiratory tract. a key part of its widespread medical and recreationaluse has been its perceived safety. although the drug is generally quite safe,precautions should be taken. it shouldn't be used directly from a whippedcream charger or nitrous oxide tank. it's best to use a balloon. the drug should only be inhaled when sittingor laying down.
you should never take it in a way that doesn'tlet you disconnect from the nitrous source or that deprives you of oxygen. this means, for example, you shouldn't usea mask. even opening a container in a small, enclosedarea should be avoided. when taken recreationally, the substance canprovide a short-lasting euphoric state with reduced or altered perception of your surroundings. dream-like hallucinations are sometimes reportedand it's possible to feel depersonalization and derealization. the physical sensations may include feelingsof warmth or cold as as well as sensations
of body distortion, like stretching, pulling,compression, and disintegration. its physical euphoria has been reported toenhance orgasm, according to some users. often there's an element of amnesia that impairsyour memory of the core effect period. users sometimes become significantly detachedfrom the outside world and even their bodies. this leads to traveling internally in a seeminglylocation-less or time-less space, which could feel profound. that kind of experience isn't the most typicalresponse to nitrous oxide. most of the perceptual effects involve distortions. your vision might get blurry and it can bepulsating.
pulsating auditory changes may also occur. other auditory effects include high pitchedsounds, echoes, muffled hearing, and an incorrect sense of distance. some closed eye visuals can occur, such aspatterning. the open eye visuals mainly involve distortionsof color and depth. occasionally there are more complex dream-likehallucinations, such as thinking you're interacting with a person or someone is touching you. it's possible to experience confusion, paranoia,and anxiety. those feelings aren't the most common responseand typically only last for a short period.
sexual effects are sometimes reported, suchas increased arousal and sexual feelings. because of its euphoric and short-lastingnature, there's typically a big impulse to use the drug again. another recreational aspect is that it cansynergize with drugs like psychedelics, mdma, and cannabis. nitrous oxide isn't a very potent anesthetic. as such, it's generally used for conscioussedation in cases like dental procedures or labor. it's frequently an adjunct to local anesthesiain dental cases.
it can also be used in general anesthesiawhen combined with a more potent inhalational anesthetic or an iv anesthetic. the drug is always administered with oxygen,with the nitrous being at a concentration of 30 to 70%. nitrous oxide does provide some pain reliefand a reduction in anxiety, which can be quite useful. it's often used in a way that still allowspain to technically be felt, but the pain is much easier to handle. it's not very good or practical as a singleanesthetic.
because of its low solubility in blood, there'sa rapid clearance of the gas. this makes it easy for medical personnel toacutely control what state the patient is in. nitrous oxide is sometimes administered inthe pre-hospital setting, including in areas where opioids aren't available for emergencymedicine. it's been used in labor since the late 1800s,with the practice becoming more common in the 1900s. the drug allows a woman to maintain consciousnesswhile experiencing analgesia and anxiolysis. epidural analgesia appears more effective,but nitrous is often sufficient to meet the
demands of a patient. more research should be done on its efficacyand safety in this setting. nitrous oxide has also been studied for otherpotential medical uses. there's some evidence it could be used similarlyto ketamine in the treatment of depression. one study found that it offered antidepressanteffects without hallucinations or loss of consciousness. it could potentially be used as a neuroprotectantin ischemic brain injury, although there's more interest in utilizing xenon. some use of the drug for reducing cravingand withdrawal symptoms in drug dependence
has appeared. it's primarily been used in alcohol withdrawal,with nitrous being compared to benzodiazepines. some evidence suggests it might quickly reducewithdrawal symptoms and reduce the need for sedatives. this use has been greatest in south africa. nitrous oxide works in a matter of secondsand only lasts for about 2 to 5 minutes. this is why it is continuously administeredalong with oxygen in medical settings. once administration ends, the effects quicklyend as well. nitrous oxide is a simple compound made ofnitrogen and oxygen which can be described
as an oxide of nitrogen. it's a colorless gas with a somewhat sweettaste. a few mechanisms for nitrous oxide seem toexist. the primary one is nmda antagonism. some of the other possible contributing factorsare inhibition of low-voltage activated calcium channels, activation of trek-1, weak gaba-cantagonism, weak 5-ht3 antagonism, increase in nitric oxide activity, and potentiationof gaba-a receptors. endogenous opioid peptides might play a rolein pain relief. there may be a release of proenkephalin anda rise in metenkephalin.
this leads to activation of descening inhibitorypathways and a modulation of nociception. variable effects of opioid antagonists havebeen seen on nitrous oxide's activity. nitric oxide plays a possible role in thedrug's action and nitric oxide synthase inhibitors have been shown to inhibit nitrous oxide'santinociception. an average dose during a session of nitrousoxide use is the equivalent of 1 to 5 chargers or 1 to 5 balloons. the substance should never be used directlyfrom a charger or tank. joseph priestley, an english chemist, is believedto have isolated nitrous oxide for the first time in 1772.
it's may have been prepared before, such asby joseph black, but the honor is generally given to priestley. priestley and others though it was a highlydangerous substance. it was observed to cause death when mice wereplaced in a jar of the gas. the first publication about it was in 1776,as part of a volume of priestley's experiments and observations on different kinds of air. around the same time, samuel mitchill of theus proclaimed nitrous oxide to be very dangerous. he stated it was the "principle of contagionand capable of producing the most terrible effects when respired by animals."
"if full inspiration of the gaseous azotebe made there will be sudden extinction of life." this view quickly changed. in 1798, thomas beddoes of the pneumatic institutemade 20-year-old humphry davy the superintendent of the medical pneumatic institution. he quickly got to work investigating nitrousoxide and first took the substance in april 1799. davy found it could produce brief intoxicationwith euphoria and distortions of sensation, time, and space.
his discoveries were announced to the nicholson'sjournal in 1799, with davy writing that he had overturned mitchill's hypothesis. many experiments were conducted by davy andhe also give it to other individuals, including samuel taylor coleridge. an example of people's response to nitrousoxide is found in a letter from robert southey to thomas southey. "davy has actually invented a new pleasure,for which language has no name. oh tom! i am going for more this evening; it makesone strong, and so happy!.
. .tom, i am sure the air in heaven must bethis wonder-working gas of delight!" davy went on to coin the term "laughing gas." he published a book that, among other things,mentioned its potential role in medicine in 1800. it was found the substance seemingly alleviatedheadaches and toothaches. in a practically throwaway statement at theend of the book, davy said: "as nitrous oxide in its extensive operationappears capable of destroying physical pain, it may probably be used with advantage duringsurgical operations in which no great effusion of blood take place."
the significance of this statement shouldn'tbe understated. had davy and others actually pursued thatbelief, they could have kickstarted the age of anesthesia. this could have saved people a lot of painand enabled medical procedures that simply weren't being done due to the pain issue. another interesting set of statements fromdavy concerned nitrous oxide's compulsive nature. "i ought to observe that a desire to breathethe gas is always awakened in me by the sight of a person beathing, or even by that of anair bag or an air holder."
"the desire of some individuals acquaintedwith the pleasures of nitrous oxide for the gas has been so strong as to induce them tobreathe with eagerness, the air remaining in the bags after the respiration of others." important individuals like astley cooper,a famous surgeon, soon learned of and experienced nitrous oxide. yet the drug failed to move much beyond recreationaluse for years. davy's work began to be discussed in medicaland chemistry settings. nitrous oxide was mentioned in british textbooksin the 1800s to 1820s. professor silliman wrote in the american journalof science in 1819 that more attention should
be given to gases like nitrous oxide. it was brought the attention of the publicthrough demonstrations at the royal institution, at private parties, and as part of publicentertainment. its use in england became fairly signifiacant. public entertainment involving nitrous oxideseemed to kick off around the 1820s and 1830s. although it'd still be a while before medicaluse really began, it might have been used to relieve pain after dental extractions asearly as 1820 in paris. it was also considered for other medical useslike relieving asthma. some poisonings by what was believed to beimpure nitrous oxide did occur.
there was a bit of use in america. one account noted that it became "the customof some of our medical schools--at the university of pennsylvania, for one--for students tobreathe "laughing gas", as it was then called, for a diversion." traveling showmen demonstrated its propertiesin the us as early as the 1830s. one of those showmen was samuel colt, designerof the first mass produced revolver. in 1832, at the age of 18, he toured the eastcoast from canada to maryland showing nitrous oxide's effects. horace wells, an american dental surgeon,briefly introduced the gas into his medical
practice in 1844. he learned about its pain blocking propertiesduring a "grand exhibition" organized by gardner quincy colton in connecticut. on december 10, 1844, wells noticed that oneof the participants in the show inhaled the gas and then injured his leg while staggeringaround. yet he didn't seem notice the pain until theeffects wore off. wells insisted colton also give him the drug. he didn't want to just experience nitrousand instead went a step further, asking for one of his wisdom teeth to be extracted whileunder the influence of the gas.
the next day, that's exactly what was done. wells reported being pain free during theprocedure. he proclaimed it was "a new era in tooth pulling." wells carried out successful trials of thesubstance in dental procedures from december 1844 to january 1845. he decided he should present his findingsduring a demonstration in boston in january 1845. when he arrived, his work was publicized indaily papers such as the boston bee. those papers also publicized the apparentutility of the gas during dental procedures.
most of the people wells met in boston doubtednitrous oxide's usefulness. he was allowed to address students at harvardmedical school sometime in late january. that address was followed by a well-knowndemonstration elsewhere in boston on the same evening. in front of students and physicians, wellsfailed to fully show nitrous oxide was useful during a dental procedure. the patient somewhat cried out and reportedpain in the beginning. some reports claim the patient ended up reportingless pain than usual, but his initial response was enough for many to consider it a failure.
wells attributed the failure to withdrawingthe nitrous bag too soon. some of the spectators reportedly laughedat him. although he would eventually be recognizedby some as the "discoverer of anesthesia," interest temporarily turned to other anestheticslike ether and chloroform. this was ultimately a tragic story. wells became ill shortly after the failurein boston, possibly in connection to a deep sense of humiliation and failure. he tried to get public and official recognitionas the discoverer of anesthesia, but was largely unsuccessful.
in january 1848, wells committed suicide byinhaling chloroform and cutting his left femoral artery. little did he know, just a few weeks earlierthe parisian medical society had recognized him as the inventor of anesthesia and madehim an honorary member. gardner quincy colton, the same man who organizedthe event that introduced wells to nitrous oxide's efficacy, firmly established the useof nitrous in dentistry in 1863. by the late 1860s, use was fairly widespread. a successful demo in london in 1868 triggereda spread of its use in europe. the same year, multiple cases of a safer formutilizing both nitrous oxide and oxygen were
published. from the 1860s forward, nitrous oxide waspopularized as an anxiolytic and analgesic tool for procedures like tooth extractions. prolonged administration wasn't really reporteduntil around the 1890s. in 1895, herbert paterson began giving thegas through the nose in long dental procedures. paterson showed this method to others. though medical use was expanding, nonmedicalwas still taking place in the mid to late 1800s. william james, a famous philosopher, publishedaccounts of its activity late in the century.
the use of nitrous oxide for labor was gainingground by the 1920s, mainly in the us. all through this time, nitrous oxide was treatedas a basically harmless substance, but things started to shift. in april 1956, the lancet published a caseseries from bledgam hospital in denmark showing megaloblastic bone marrow changes from extendedinhalation. physicians at the hospital thought it couldbe used for days on end in patients with severe tetanus infections. two of the first five patients, a 15-year-oldboy and a 53-year-old female, died from sepsis following agranulocytosis after the firstweek.
this prompted a trial in two more cases. both patients showed marked hematologicalchanges on day 4, and bone-marrow biopsies showed megaloblastic changes. a b12 inactivation report then appeared in1968. however, this paper largely went unnoticedfor about 10 years. when reports began appearing of high miscarriagerates in anesthesia personnel, concerns about occupational exposure increased. some reports indicated a correlation betweenworking around nitrous oxide and reporting irritability, fatigue, headache, and fetalmalformation.
papers detailing nitrous oxide-related neuropathyand myelopathy contributed to occupational exposure concerns and also made people wonderif it should even be used. neurological problems appeared in a case seriesin 1978. most of the patients were dentists and presentedwith what appeared to be subacute combined degeneration of the spinal cord. the initial symptoms were numbness and tinglingin the hands and legs. and some of them eventually couldn't walkwithout assistance. most of the symptoms slowly declined whenuse ended, but not all of the symptoms resolved. the same year, an editorial suggested thatif nitrous oxide were a new drug, it probably
wouldn't be used. some usage patterns were affected, but a lotof medical professionals weren't even aware of these issues. in the 1960s and 70s, there was a rise inrecreational use, often among those with access to large amounts of nitrous oxide, such asdentists and hospital workers. a 1979 paper indicated up to 20% of dentaland medical students had experimented with the drug. we learned more about its pharmacology inthe 1980s and 1990s. papers showed it could affect opioid peptidesand was an nmda antagonist.
in 2002, a review found it was widely usedin labor. upwards of 50% of women in the uk and 60%of women in finland were given nitrous oxide. in 2010, the american college of nurse-midwivespublished a statement endorsing the increased availability of nitrous oxide for women inthe us. from the 2000s to 2010s, thetre was an apparentdecline in the medical use of nitrous oxide. at the same time, recreational use was stableor higher. currently, it's one of the most common inhalants. there's been some decline in the use of nitrousoxide in some countries, but use is still significant.
nitrous oxide is unscheduled in the us. some states, such as california, florida,and oregon have laws that prohibit the sale or use of nitrous oxide for recreational purposes. it's typically uncontrolled in other countries,but there might be some laws pertaining to recreational use. the primary safety concerns are hypoxia andb12 inactivation. hypoxia is mainly an issue if someone usesnitrous oxide too much and too quickly, or if they can't separate from the administrationdevice upon losing consciousness. it's best to avoid using multiple balloonsin quick succession.
even when you're hypoxic, you may not feellike you need to breathe or that you're even being deprived of oxygen. nitrous oxide is always given with oxygenin medical settings, but that wasn't always the case, so asphyxia would sometimes occur. fatalities still rarely occur nowadays fromequipment malfunction, inaccurate gas cylinder labeling, and other human error. b12-related concerns are relevant when useis very high or someone is deficient in b12. the substance oxidizes the cobalt core ofcobalamin, thereby infringing upon methionine synthase.
this inhibition may persist for days and couldbe cumulative with repeated use. inhibited methionine synthase raises homocysteinelevels and can impair the synthesis of dna. with the resulting lack of methionine ands-adenosyl methionine, methylation of myelin sheath phospholipids will be impaired. this diminishes myelin formation, eventuallyleading to neurological issues. when neurological issues appear, treatmentmainly consists of abstinence from nitrous oxide and b12 administration. to prevent these issues, you shouldn't frequentlyuse the drug and you should keep up your b12 levels.
in medical settings, it's typically fine whenused for less than 6 hours. the neurological issues will include thingslike weakness, clumsiness, numbness, and tingling. it can eventually become difficult to movearound. and it's also possible for there to me memoryimpairment and mood changes. neurotoxicity has been mentioned as a possibleconcern, but it's not clear how relevant the animal models are to humans. increases in gas volume or pressure can leadto problems. it is potentially contraindicated, at leastin some cases, in bowel, laparoscopic, middle ear, and eye surgery.
caution is advised in neurosurgery. modern evidence indicates occupational exposureis probably not a concern, especially if there's proper ventilation and scavenger devices. death is very rare with nitrous oxide. most fatalities have occurred from oxygendeprivation, generally from using a system that doesn't allow for enough oxygen whensomeone loses consciousness.
Tidak ada komentar
Posting Komentar