breath holding

• 息こらえ

WordNet

1. a short respite (同)breather, breathing place, breathing space, breathing spell, breathing time
2. a slight movement of the air; "there wasnt a breath of air in the room"
3. the air that is inhaled and exhaled in respiration; "his sour breath offended her"
4. the process of taking in and expelling air during breathing; "he took a deep breath and dived into the pool"; "he was fighting to his last breath"
5. passing or able to pass air in and out of the lungs normally; sometimes used in combination; "the boy was disappointed to find only skeletons instead of living breathing dinosaurs"; "the heavy-breathing person on the telephone" (同)eupneic, eupnoeic
6. the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation (同)external_respiration, respiration, ventilation
7. uttered without voice; "could hardly hear her breathed plea, `Help me"; "voiceless whispers" (同)voiceless

PrepTutorEJDIC

1. 〈U〉『息』,『呼吸』;UC〉1回の吸気(め気) / 〈C〉(風の)そよぎ;(…の)かすかなかおり《+『of』+『名』》 / 〈C〉(…の)ささやき(whisper)《+『of』+『名』》
2. 〈U〉呼吸;一息 / 〈C〉一呼吸の間,瞬時 / 〈C〉休息,休止
3. 〈U〉しっかり握ること,保持 / 〈C〉《しばしば複数形で》所有地,持ち株 / 〈U〉ホールディング(バスケットボール・フットボールなどで腕や手で相手をじゃますね反則行為)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/05/01 00:20:02」(JST)

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[Wiki en表示]

Apnea

A 32s breathing pause in a sleep apnea patient.
ICD-9	786.03

Apnea, apnoea, or apnœa (Greek: ἄπνοια, from ἀ-, privative, πνέειν, to breathe), is a term for suspension of external breathing. During apnea there is no movement of the muscles of respiration and the volume of the lungs initially remains unchanged. Depending on the patency of the airways there may or may not be a flow of gas between the lungs and the environment; gas exchange within the lungs and cellular respiration is not affected.

Causes

Apnea can be voluntarily achieved, drug-induced (such as opiate toxicity or tryptamine toxicity), mechanically induced (for example, by strangulation or choking), or it can occur as a consequence of neurological disease or trauma. During sleep in patients who are suffering from sleep apnea, these events will occur up to 20-30 times per hour, every night.

Voluntary apnea can be achieved by closing the vocal cords, simultaneously keeping the mouth closed and blocking the nasal vestibule, or constantly activating expiratory muscles.

Complications

Under normal conditions, humans cannot store much oxygen in the body. Prolonged apnea leads to severe lack of oxygen in the blood circulation. Permanent brain damage can occur after as little as three minutes and death will inevitably ensue after a few more minutes unless ventilation is restored. However, under special circumstances such as hypothermia, hyperbaric oxygenation, apneic oxygenation (see below), or extracorporeal membrane oxygenation, much longer periods of apnea may be tolerated without severe consequences.

Untrained humans cannot sustain voluntary apnea for more than one or two minutes^{[citation needed]}. The reason for the time limit of voluntary apnea is that the rate of breathing and the volume of each breath are tightly regulated to maintain constant values of CO₂ tension and pH of the blood. In apnea, CO₂ is not removed through the lungs and accumulates in the blood. The consequent rise in CO₂ tension and drop in pH result in stimulation of the respiratory centre in the brain which eventually cannot be overcome voluntarily.

When a person is immersed in water, physiological changes due to the mammalian diving reflex enable somewhat longer tolerance of apnea even in untrained persons. Tolerance can in addition be trained. The ancient technique of free-diving requires breath-holding, and world-class free-divers can hold their breath underwater up to depths of 214 metres and for more than four minutes. Apneists, in this context, are people who can hold their breath for a long time.

Hyperventilation

Voluntary hyperventilation before beginning voluntary apnea is commonly believed to allow the person involved to safely hold their breath for a longer period. In reality, it will give the impression that one does not need to breathe, while the body is actually experiencing a blood-oxygen level that would normally, and indirectly, invoke a strong dyspnea. Some have incorrectly attributed the effect of hyperventilation to increased oxygen in the blood, not realizing that it is actually due to a decrease in CO₂ in the blood and lungs. Blood leaving the lungs is normally fully saturated with oxygen, so hyperventilation of normal air cannot increase the amount of oxygen available. Lowering the CO₂ concentration increases the pH of the blood, thus increasing the time before the respiratory center becomes stimulated, as described above. While hyperventilation will yield slightly longer breath-holding times, any small time increase is at the expense of possible hypoxia. One using this method can suddenly lose consciousness—a shallow water blackout—as a result. If a person loses consciousness underwater, especially in fresh water, there is a considerable danger that they will drown. An alert diving partner would be in the best position to rescue such a person.

Apneic oxygenation

Because the exchange of gases between the blood and airspace of the lungs is independent of the movement of gas to and from the lungs, enough oxygen can be delivered to the circulation even if a person is apneic. This phenomenon (apneic oxygenation) is explained as follows:

With the onset of apnea, an underpressure develops in the airspace of the lungs, because more oxygen is absorbed than CO₂ is released. With the airways closed or obstructed, this will lead to a gradual collapse of the lungs. However, if the airways are patent (open), any gas supplied to the upper airways will follow the pressure gradient and flow into the lungs to replace the oxygen consumed. If pure oxygen is supplied, this process will serve to replenish the oxygen stored in the lungs. The uptake of oxygen into the blood will then remain at the usual level and the normal functioning of the organs will not be affected.

However, no CO₂ is removed during apnea. The partial pressure of CO₂ in the airspace of the lungs will quickly equilibrate with that of the blood. As the blood is loaded with CO₂ from the metabolism, more and more CO₂ will accumulate and eventually displace oxygen and other gases from the airspace. CO₂ will also accumulate in the tissues of the body, resulting in respiratory acidosis.

Under ideal conditions (i.e., if pure oxygen is breathed before onset of apnea to remove all nitrogen from the lungs, and pure oxygen is insufflated), apneic oxygenation could theoretically be sufficient to provide enough oxygen for survival of more than one hour's duration in a healthy adult.^{[citation needed]} However, accumulation of carbon dioxide (described above) would remain the limiting factor.

Apneic oxygenation is more than a physiologic curiosity. It can be employed to provide a sufficient amount of oxygen in thoracic surgery when apnea cannot be avoided, and during manipulations of the airways such as bronchoscopy, intubation, and surgery of the upper airways. However, because of the limitations described above, apneic oxygenation is inferior to extracorporal circulation using a heart-lung machine and is therefore used only in emergencies and for short procedures.

In 1959, Frumin described the use of apneic oxygenation during anesthesia and surgery. Of the eight test subjects in this landmark study, the highest recorded paCO2 was 250 millimeters of mercury, and the lowest arterial pH was 6.72 after 53 minutes of apnea.

Apnea test in determining brain death

A recommended practice for the clinical diagnosis of brain death formulated by the American Academy of Neurology hinges on the conjunction of three diagnostic criteria: coma, absence of brainstem reflexes, and apnea (defined as the inability of the patient to breathe unaided, that is, with no life support systems). The apnea test follows a delineated protocol.

See also

• List of terms of lung size and activity
• Sleep apnea
• Expiratory apnea
• Mechanical ventilation
• Free-diving
• Shallow water blackout
• Deep water blackout
• Respiratory arrest
• Apnea of prematurity

References

• Nunn, J. F. (1993). Applied Respiratory Physiology (4th ed.). Butterworth-Heinemann. ISBN 0-7506-1336-X. 
•  This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. 

External links

• http://healthysleep.med.harvard.edu/sleep-apnea, a resource from the Harvard Division of Sleep Medicine on Obstructive Sleep Apnea
• http://apneacalculator.com/, information about Apnea and the apnea-calculator for clinical treatment of Obstructive Sleep Apnea
• http://www.freedivers.co.uk , information about learning the sport of Freediving, the club is called Apneists UK

UpToDate Contents

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• 1. 幼児における非てんかん性発作性障害 nonepileptic paroxysmal disorders in infancy
• 2. 小児および思春期における失神の原因 causes of syncope in children and adolescents
• 3. 小児におけるチアノーゼの病因および評価 etiology and evaluation of cyanosis in children
• 4. 小児および思春期におけるの失神の緊急評価 emergent evaluation of syncope in children and adolescents
• 5. 幼児および小児における痙攣発作の臨床検査診断 clinical and laboratory diagnosis of seizures in infants and children

English Journal

• Oral Levosimendan Increases Cerebral Blood Flow Velocities in Patients with a History of Stroke or Transient Ischemic Attack: A Pilot Safety Study.

• Kivikko M1, Kuoppamäki M2, Soinne L3, Sundberg S4, Pohjanjousi P2, Ellmen J2, Roine RO5.
• Current therapeutic research, clinical and experimental.Curr Ther Res Clin Exp.2015 Jan 29;77:46-51. doi: 10.1016/j.curtheres.2015.01.001. eCollection 2015.
• BACKGROUND: Intravenous levosimendan is indicated for acute heart failure. The compound has shown promising beneficial effects in ischemic stroke models.OBJECTIVE: We evaluated the efficacy and safety of oral levosimendan in patients with a history of cerebral ischemia.METHODS: In a randomized, doub
• PMID 26082815

• Breathing Inhibited When Seizures Spread to the Amygdala and upon Amygdala Stimulation.

• Dlouhy BJ1, Gehlbach BK2, Kreple CJ3, Kawasaki H4, Oya H4, Buzza C5, Granner MA6, Welsh MJ7, Howard MA4, Wemmie JA8, Richerson GB9.
• The Journal of neuroscience : the official journal of the Society for Neuroscience.J Neurosci.2015 Jul 15;35(28):10281-9. doi: 10.1523/JNEUROSCI.0888-15.2015.
• Sudden unexpected death in epilepsy (SUDEP) is increasingly recognized as a common and devastating problem. Because impaired breathing is thought to play a critical role in these deaths, we sought to identify forebrain sites underlying seizure-evoked hypoventilation in humans. We took advantage of a
• PMID 26180203

• Time-frequency dynamics of intra- and extracerebral hemodynamic functional connectivity during resting-state and respiratory challenges assessed by multimodal functional near-infrared spectroscopy.

• Holper L1, Scholkmann F2, Seifritz E3.
• NeuroImage.Neuroimage.2015 Jul 11. pii: S1053-8119(15)00630-8. doi: 10.1016/j.neuroimage.2015.07.021. [Epub ahead of print]
• Monitoring respiratory processes is important for evaluating neuroimaging data, given their influence on time-frequency dynamics of intra- and extracerebral hemodynamics. Here we investigated the time-frequency dynamics of intra- and extracerebral hemodynamic functional connectivity states during hy
• PMID 26169319

Japanese Journal

• 生後1か月で発症し鉄剤投与が有効であった頻回憤怒けいれんの1例

• 早野 聡,久保田 哲夫,澤井 潤,伊藤 祥絵,松井 照明,北瀬 悠磨,鈴木 俊彦,林 直子,松沢 要,大江 英之,城所 博之,竹本 康二,加藤 有一,宮島 雄二,小川 昭正,久野 邦義
• 日本小児科学会雑誌 115(3), 644-646, 2011-03-01
• NAID 10029385224

• Postoperative cyanotic breath-holding spells in a child with Worster-Drought syndrome

• CHHABRA Anjolie,BAIDYA Dalim K.
• Journal of anesthesia 24(6), 982-983, 2010-12-20
• NAID 10027741838

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関連記事

「breath」

「breath」

　　[★]

• n.

• 息、一呼吸、呼吸

関

breathe、breathing、respiration、respiratory