出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/11/21 13:48:59」(JST)
| Vomiting | |
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Miracle of Marco Spagnolo by Giorgio Bonola (Quadroni of St. Charles)
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| Classification and external resources | |
| Specialty | Gastroenterology |
| ICD-10 | R11 |
| ICD-9-CM | 787 |
| MeSH | D014839 |
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[edit on Wikidata]
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Vomiting, also known as emesis and throwing up, among other terms, is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.[1]
Vomiting can be caused by a wide variety of conditions; it may present as a specific response to ailments like gastritis or poisoning, or as a non-specific sequela of disorders ranging from brain tumors and elevated intracranial pressure to overexposure to ionizing radiation. The feeling that one is about to vomit is called nausea, which often precedes, but does not always lead to, vomiting. Antiemetics are sometimes necessary to suppress nausea and vomiting. In severe cases, where dehydration develops, intravenous fluid may be required.
Vomiting is different from regurgitation, although the two terms are often used interchangeably. Regurgitation is the return of undigested food back up the esophagus to the mouth, without the force and displeasure associated with vomiting. The causes of vomiting and regurgitation are generally different.
Vomiting can be dangerous if the gastric content enters the respiratory tract. Under normal circumstances the gag reflex and coughing prevent this from occurring; however, these protective reflexes are compromised in persons under the influences of certain substances such as alcohol or anesthesia. The individual may choke and asphyxiate or suffer an aspiration pneumonia.[citation needed]
Prolonged and excessive vomiting depletes the body of water (dehydration), and may alter the electrolyte status. Gastric vomiting leads to the loss of acid (protons) and chloride directly. Combined with the resulting alkaline tide, this leads to hypochloremic metabolic alkalosis (low chloride levels together with high HCO−
3 and CO
2 and increased blood pH) and often hypokalemia (potassium depletion). The hypokalemia is an indirect result of the kidney compensating for the loss of acid. With the loss of intake of food the individual may eventually become cachectic. A less frequent occurrence results from a vomiting of intestinal contents, including bile acids and HCO−
3, which can cause metabolic acidosis.[citation needed]
Repeated or profuse vomiting may cause erosions to the esophagus or small tears in the esophageal mucosa (Mallory–Weiss tear). This may become apparent if fresh red blood is mixed with vomit after several episodes.[citation needed]
Recurrent vomiting, such as observed in bulimia nervosa, may lead to destruction of the tooth enamel due to the acidity of the vomit. Digestive enzymes can also have a negative effect on oral health, by degrading the tissue of the gums.[citation needed]
Receptors on the floor of the fourth ventricle of the brain represent a chemoreceptor trigger zone, known as the area postrema, stimulation of which can lead to vomiting. The area postrema is a circumventricular organ and as such lies outside the blood–brain barrier; it can therefore be stimulated by blood-borne drugs that can stimulate vomiting or inhibit it.[2]
There are various sources of input to the vomiting center:
The vomiting act encompasses three types of outputs initiated by the chemoreceptor trigger zone: Motor, parasympathetic nervous system (PNS), and sympathetic nervous system (SNS). They are as follows:[citation needed]
The neurotransmitters that regulate vomiting are poorly understood, but inhibitors of dopamine, histamine, and serotonin are all used to suppress vomiting, suggesting that these play a role in the initiation or maintenance of a vomiting cycle. Vasopressin and neurokinin may also participate.[citation needed]
The vomiting act has two phases. In the retching phase, the abdominal muscles undergo a few rounds of coordinated contractions together with the diaphragm and the muscles used in respiratory inspiration. For this reason, an individual may confuse this phase with an episode of violent hiccups. In this retching phase nothing has yet been expelled. In the next phase, also termed the expulsive phase, intense pressure is formed in the stomach brought about by enormous shifts in both the diaphragm and the abdomen. These shifts are, in essence, vigorous contractions of these muscles that last for extended periods of time - much longer than a normal period of muscular contraction. The pressure is then suddenly released when the upper esophageal sphincter relaxes resulting in the expulsion of gastric contents. Individuals who do not regularly exercise their abdominal muscles may experience pain in those muscles for a few days. The relief of pressure and the release of endorphins into the bloodstream after the expulsion causes the vomiter to feel better.[citation needed]
Gastric secretions and likewise vomit are highly acidic. Recent food intake appears in the gastric vomit. Irrespective of the content, vomit tends to be malodorous.[citation needed]
The content of the vomitus (vomit) may be of medical interest. Fresh blood in the vomit is termed hematemesis ("blood vomiting"). Altered blood bears resemblance to coffee grounds (as the iron in the blood is oxidized) and, when this matter is identified, the term coffee-ground vomiting is used. Bile can enter the vomit during subsequent heaves due to duodenal contraction if the vomiting is severe. Fecal vomiting is often a consequence of intestinal obstruction or a gastrocolic fistula and is treated as a warning sign of this potentially serious problem (signum mali ominis).[citation needed]
If the vomiting reflex continues for an extended period with no appreciable vomitus, the condition is known as non-productive emesis or "dry heaves", which can be painful and debilitating.[citation needed]
Vomiting may be due to a large number of causes, and protracted vomiting has a long differential diagnosis.[citation needed]
Causes in the digestive tract
Causes in the sensory system:[citation needed]
Causes in the brain:[citation needed]
Metabolic disturbances (these may irritate both the stomach and the parts of the brain that coordinate vomiting):[citation needed]
Pregnancy:[citation needed]
Drug reaction (vomiting may occur as an acute somatic response to):[citation needed]
Illness (sometimes colloquially known as "stomach flu"—a broad name that refers to gastric inflammation caused by a range of viruses and bacteria):[citation needed]
An emetic, such as syrup of ipecac, is a substance that induces vomiting when administered orally or by injection. An emetic is used medically when a substance has been ingested and must be expelled from the body immediately (for this reason, many toxic and easily digestible products such as rat poison contain an emetic). Inducing vomiting can remove the substance before it is absorbed into the body. Ipecac abuse can cause detrimental health effects.[citation needed]
Salt water and mustard water have been used since ancient times as emetics.[8] Care must be taken with salt, as excessive intake can potentially be harmful.[9][10]
Copper sulfate was also used in the past as an emetic.[11][12] It is now considered too toxic for this use.[13]
Hydrogen peroxide is used as an emetic in veterinary practice.[14][15]
It is quite common that, when one person vomits, others nearby become nauseated, particularly when smelling the vomit of others, often to the point of vomiting themselves. It is believed that this is an evolved trait among primates. Many primates in the wild tend to browse for food in small groups. Should one member of the party react adversely to some ingested food, it may be advantageous (in a survival sense) for other members of the party to also vomit. This tendency in human populations has been observed at drinking parties, where excessive consumption of alcoholic beverages may cause a number of party members to vomit nearly simultaneously, this being triggered by the initial vomiting of a single member of the party. This phenomenon has been touched on in popular culture: notorious instances appear in the films Monty Python's The Meaning of Life (1983) and Stand By Me (1986).[16]
Intense vomiting in ayahuasca ceremonies is a common phenomenon. However, people who experience "la purga" after drinking ayahuasca, in general, regard the practice as both a physical and spiritual cleanse and often come to welcome it.[17] It has been suggested that the consistent emetic effects of ayahuasca—in addition to its many other therapeutic properties—was of medicinal benefit to indigenous peoples of the Amazon, in helping to clear parasites from the gastrointestinal system.[18]
There have also been documented cases of a single ill and vomiting individual inadvertently causing others to vomit, when they are especially fearful of also becoming ill, through a form of mass hysteria.[citation needed]
Most people try to contain their vomit by vomiting into a sink, toilet, or trash can, as vomit is difficult and unpleasant to clean. On airplanes and boats, special bags are supplied for sick passengers to vomit into. A special disposable bag (leakproof, puncture-resistant, odorless) containing absorbent material that solidifies the vomit quickly is also available, making it convenient and safe to store until there is an opportunity to dispose of it conveniently.[citation needed]
People who vomit chronically (e.g., as part of an eating disorder such as bulimia nervosa) may devise various ways to hide this disorder.[citation needed]
An online study of people's responses to "horrible sounds" found vomiting "the most disgusting". Professor Trevor Cox of the University of Salford's Acoustic Research Centre said that "We are pre-programmed to be repulsed by horrible things such as vomiting, as it is fundamental to staying alive to avoid nasty stuff." It is thought that disgust is triggered by the sound of vomiting to protect those nearby from possibly diseased food.[19]
An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of medications such as opioids and chemotherapy.[citation needed]
Antiemetics act by inhibiting the receptor sites associated with emesis. Hence, anticholinergics, antihistamines, dopamine antagonists, serotonin antagonists, and cannabinoids are used as antiemetics.[22]
Evidence to support the use of antiemetics for nausea and vomiting among adults in the emergency department is poor.[23] It is unclear if any medication is better than another or better than no active treatment.[23]
Nausea and/or vomiting are the main complaints in 1.6% of visits to family physicians in Australia.[24]
| Wikimedia Commons has media related to Vomiting. |
| Wikiquote has quotations related to: Vomiting |
| Look up vomiting in Wiktionary, the free dictionary. |
Symptoms and signs: digestive system and abdomen (R10–R19, 787,789)
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| Defaecation |
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English, FrenchÉtude rétrospective des empoisonnements canins à la strychnine de 1998 à 2013 dans l’Ouest canadien. Cette étude décrit les observations se rapportant à 93 cas d’empoisonnement à la strychnine chez des chiens pendant une période de 16 ans en Saskatchewan, en Albert
| リンク元 | 「100Cases 60」「嘔吐」「嘔吐物」 |
| 関連記事 | 「vomit」 |
・BUN
| 中枢性刺激 | 化学受容器引金帯刺激 | 薬物 | アポモルヒネ、モルヒネ、ジギタリス、抗菌薬、抗癌薬、降圧薬、アミノフイリン、コルヒチン、アルコール |
| 毒物 | 重金属、ガス | ||
| 放射線 | 各種癌治療後 | ||
| 感染症 | 細菌毒素 | ||
| 内分泌疾患 | 肝性脳症、糖尿病性ケトアシドーシス/高血糖高浸透圧症候群、尿毒症、妊娠悪阻、妊娠高血圧症候群 | ||
| 代謝疾患 | 甲状腺クリーゼ、副腎不全、Addison病 | ||
| 直接刺激 | 脳圧亢進 | 頭部外傷、脳腫瘍、脳出血、くも膜下出血、髄膜炎、脳への放射線療法後 | |
| 脳循環障害 | ショック、低酸素脳症、脳梗塞、片頭痛、脳炎、髄膜炎 | ||
| 上位中枢刺激 | 神経性食思不振症、不快感、てんかん、ヒステリー、抑うつ状態、うつ病、過度の嫌悪感、不快感、拘禁反応による恐怖、ストレス、視覚・嗅覚・味覚的刺激 | ||
| 末梢性刺激 | 消化管疾患 | 舌咽頭疾患 | アデノイド、咽頭炎 |
| 食道疾患 | 胃食道逆流症、食道裂孔ヘルニア、食道癌 | ||
| 胃腸疾患 | 急性胃炎、急性胃十二指腸粘膜病変、急性腸炎、急性虫垂炎、消化性潰瘍、食中毒、消化管腫瘍、寄生虫、食中毒、Mallory-Weiss症候群 | ||
| 消化管通過障害 | 腸閉塞、胃幽門部狭窄、輸入脚症候群 | ||
| 腹膜疾患 | 腹膜炎 | ||
| 胆膵疾患 | 急性胆嚢炎、急性胆管炎、急性膵炎、膵癌、胆管癌 | ||
| 肝疾患 | 急性肝炎 | ||
| 循環器疾患 | うっ血性心不全、狭心症、急性心筋梗塞 | ||
| 泌尿器科疾患 | 尿路結石、腎結石、急性腎炎、腎盂腎炎、腎不全 | ||
| 耳鼻咽喉科疾患 | 中耳炎、Meniere病、乗り物酔い | ||
| 眼科疾患 | 緑内障 | ||
| 呼吸器科疾患 | 肺結核、胸膜炎、肺癌、咳嗽発作 | ||
| 婦人科疾患 | 子宮付属器炎、月経前症候群、更年期障害 | ||
| 脊髄疾患 | 脊髄癆、多発性硬化症 | ||
| 膠原病 | 結節性多発動脈炎、強皮症、側頭動脈炎 | ||
| 新生児 | 乳児 | 幼児～学童 | |
| 消化器疾患以外で見・落とさないよう注意する疾患 | 敗血症・髄膜炎・水頭症・脳奇形・尿路感染症 | 髄膜炎・脳炎・脳症・虐待児・尿路感染症・呼吸器感染症・心疾患・薬物中毒・誤嚥 | 脳炎・脳症・脳腫瘍・肺炎・中耳炎・頭部外傷・薬物中毒・心筋炎・不整脈 |
| よくある消化器疾患 | 溢乳・空気嚥下・哺乳過誤・初期嘔吐・胃食道逆流現象・胃腸軸捻転・腸管感染症・壊死性腸炎 | 食事過誤・空気嚥下・便秘・腸管感染症・幽門狭窄症・腸重積症・胃食道逆流現象・胃長軸捻転・食事アレルギー | 腸管感染症・急性虫垂炎・肝・腹部外傷・肝炎・胆嚢炎・膵炎・腹部外傷・食事アレルギー・好酸球性胃腸症 |
| 主な代謝性疾患 | 先天性副腎過形成・ガラク卜ース血症 | 先天性副腎過形成・Reye症候群 | アセトン血性嘔吐症・ケトン性低血糖症・糖尿病性ケトアシドーシス・Reye症候群 |
| その他 | 起立性調節障害・神経性食思不振症 | ||
| 外科的疾患 | 食道閉鎖・狭窄症・胃軸捻転・十二指腸閉鎖・狭窄症・腸回転異常・捻転・小腸閉鎖症・Hirschsprung病・胎便性イレウス・稀に腸重積・肥厚性幽門狭窄・特発性腸管偽性閉鎖症 | 肥厚性幽門狭窄症・腸重積・腸回転異常・捻転・Hirschsprung病・虫垂炎 | 虫垂炎・腸重積・腸回転異常・捻転・上腸間膜動脈症候群・腫瘍・嚢胞 |
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