WordNet

reckoned, situated or tending in the direction which naturally or arbitrarily is taken to indicate increase or progress or onward motion; "positive increase in graduating students"
a film showing a photographic image whose tones correspond to those of the original subject
the primary form of an adjective or adverb; denotes a quality without qualification, comparison, or relation to increase or diminution (同)positive degree
indicating existence or presence of a suspected condition or pathogen; "a positive pregnancy test" (同)confirming
having a positive charge; "protons are positive" (同)electropositive, positively charged
formally laid down or imposed; "positive laws" (同)prescribed
characterized by or displaying affirmation or acceptance or certainty etc.; "a positive attitude"; "the reviews were all positive"; "a positive benefit"; "a positive demand"
greater than zero; "positive numbers"
of a function or curve; extending without break or irregularity
continuing in time or space without interruption; "a continuous rearrangement of electrons in the solar atoms results in the emission of light"- James Jeans; "a continuous bout of illness lasting six months"; "lived in continuous fear"; "a continuous row of warehouses"; "a continuous line has no gaps or breaks in it"; "moving midweek holidays to the nearest Monday or Friday allows uninterrupted work weeks" (同)uninterrupted
the force applied to a unit area of surface; measured in pascals (SI unit) or in dynes (cgs unit); "the compressed gas exerts an increased pressure" (同)pressure level, force per unit area
an oppressive condition of physical or mental or social or economic distress
the somatic sensation that results from applying force to an area of skin; "the sensitivity of his skin to pressure and temperature was normal" (同)pressure_sensation
a force that compels; "the public brought pressure to bear on the government"

PrepTutorEJDIC

『肯定した,同意の』 / 『実際的な,』積極的な,建設的な / 《補語にのみ用いて》『確信のある』,自信のある / (事が)疑問の余地がない,明確な;(言葉が)はっきりした / 《名詞の前にのみ用いて》《話》全くの,文字どおりの / (生体の反応が)陽性の / (数が)正の,プラスの;(気電が)陽の;(写真で)陽画の / (形容詞・副詞の比較変化で)原級の / 明確(明白)なもの / (形容詞・副詞の)原級 / (写真の)陽画,ポジ / (数学で)正数
(時間的・空間的に)『切り目なく続く』;続けざまの,途切れない
〈U〉『押すこと』,『押しつけること』,圧搾,圧縮;〈C〉〈U〉『圧力』,圧力の強さ / 〈U〉『圧迫』,『強制』 / 〈U〉(不快な)圧迫感 / 〈C〉〈U〉(精神的な)重荷,苦脳;(時間・金銭的)切迫 / 〈U〉多忙,あわただしさ / 《おもに米》…‘に'圧力をかける,強制する(《英》pressurise)
〈C〉航空路 / 〈C〉(鉱山などの)通風路 / 《複数形》航空会社
(17,8世紀音楽での)通奏低音

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/03/09 11:30:58」(JST)

wiki en

Continuous positive airway pressure (CPAP) is the use of continuous positive pressure to maintain a continuous level of positive airway pressure. It is functionally similar to P_EEP, except that PEEP is an applied pressure against exhalation and C_PAP is a pressure applied by a constant flow. The ventilator does not cycle during C_PAP, no additional pressure above the level of C_PAP is provided, and patients must initiate all of their breaths. Nasal C_PAP is frequently used in neonates though its use is controversial. Studies have shown nasal C_PAP to reduce ventilator time but an increased occurrence of pneumothorax was also prevalent.^[1]

As a treatment or therapy, CPAP uses mild air pressure to keep an airway open. CPAP typically is used for people who have breathing problems, such as sleep apnea.

CPAP also may be used to treat preterm infants whose lungs have not yet fully developed. For example, physicians may use CPAP to treat infants who have respiratory distress syndrome or bronchopulmonary dysplasia. In some preterm infants whose lungs haven't fully developed, CPAP improves survival and decreases the need for steroid treatment for their lungs.

CPAP at home utilizes machines specifically designed to deliver a constant flow or pressure. Some CPAP machines have other features as well, such as heated humidifiers. CPAP is the most effective treatment for obstructive sleep apnea, in which the mild pressure from CPAP prevents the airway from collapsing or becoming blocked.

Settings and measurements

C_pap — This is the pressure applied without pause or end to the airway. Generally utilizing flow to generate the pressure.
PEEP — PEEP is sometimes also called CPAP however the pressure generated in PEEP is by a backpressure valve forcing increased pressure on exhalation, ultimately creating a sustained (continuous) pressure.
FiO₂ — The fractional O2 percentage that is being added to the delivered air.

High flow therapy

Illustration of a patient using HFT device

Humidified high flow nasal airway respiratory support is a method of delivering a high minute volume of respiratory gas via nasal cannula. The respiratory gas is heated to near body temperature and humidified, usually to saturation vapor pressure. This form of respiratory support is generally referred to as High Flow Therapy (HFT). HFT is also referred to as Transnasal Insufflation (TNI) ^[2], especially when used for treatment of sleep apnea.

Nasal cannula usually used for oxygen delivery usually deliver 1–6 liters of oxygen per minute. The FiO2; the percent oxygen inhaled by the patient, usually ranges roughly from 24% to 35% as 100% O2 delivered from the cannula is diluted with air at about 21% oxygen. Flow rates for delivery of oxygen using typical nasal cannula are limited because medical oxygen is anhydrous, and when delivered from a pressurized source the gas cools as it expands with the drop to atmospheric pressure. Delivery of cold dry gas is irritating to the respiratory mucosa, can cause drying and bleeding of the nasal mucosa, trigger bronchospasm in asthmatics, and can increase metabolic demand by cooling the body. Thus oxygen delivery by nasal cannula is limited to less than 6 liters per minute^[3].

Even with quiet breathing, the inspiratory flow rate at the nares of an adult usually exceeds 12 liters a minute, and can exceed 30 liters a minute for someone with mild respiratory distress. The typical upper limit of oxygen delivery via nasal cannula of six liters a minute does not meet the inspiratory flow rates of the average adult and therefore the oxygen is then diluted with room air during inspiration. Prior to the advent of HFT, when high FiO2 was required for respiratory support special face masks or intubation was required. With HFT, respiratory gas flow volume is delivered which meets or exceeds the patient's inspiratory flow rate, and is heated and humidified, allowing for comfortable delivery of respiratory support.

For HFT, a source of oxygen is usually blended with compressed air. Hospitals usually have 50 psi compressed O2 and air available for therapeutic use. This allows the delivery of air, blends of air and O2 from 22% to 99%, or delivery of 100% oxygen with the use of an oxygen blender. The gas is then heated, generally to about 37°C, and humidified to near 100% RH using a humidifier. The gas is transported to the patient through a heated delivery tube to prevent cooling and condensation of the water vapor which has been added to the respiratory gas(es).

HFT requires the use of special nasal cannula and tubing large enough to deliver flow rates of respiratory gas, up to 50 liters per minute in adults. At the same time the nasal cannula must be small enough that they do not seal inside the nares, as this allows flow during exhalation and excess gas flow during inhalation to escape. If the cannula did seal, the high flow volume could produce excessive pressure in the airway and might provoke barotrauma.

Benefits

Since the delivered flow rate of HFT can meet the inspiration flow rate, the delivered gases is not diluted by room air. The FiO2 is controlled by the clinician, and can be set from 21% to 100% oxygen. Nasal high flow therapy reduces respiratory dead space and generates some positive airway pressure resulting from the expiratory resistance generated by continuous high flow gas delivery. Flow rates exceeding inspiratory demand may also provide positive pressure during inspiration. Heated humidification of the respiratory gas facilitates secretion clearance and decreases the development of bronchial hyper-response symptoms^[4]. Some patients requiring respiratory support for bronchospasm benefit using air delivered by HFT without additional oxygen ^[5]. HFT is useful in the treatment of sleep apnea^[6]. During use of HFT the patient can drink, and speak. Most patients find HFT more comfortable than using oxygen masks. As this is a non-invasive therapy, it avoids the risk of ventilator-associated pneumonia in situations where it can supplant the use of a ventilator.

Use in neonates

Nasal HFT has shown to be useful in neonatal intensive care settings for premature infants with Infant respiratory distress syndrome,^[7] as it prevents many infants from intubation, and allows safe respiratory management at lower FiO2 levels, and thus reduces the risk of retinopathy of prematurity or other forms of oxygen toxicity.

Criticism

Critics of HFT point out that while there are many reports of the positive outcomes, little is known about the mechanisms of action of HFT and what levels may be unsafe. There has been concern that HFT delivery settings prescribed are largely empiric, with large variation of pressure produced by HFT between individuals^[8].

Development

HFT was originally developed for use in race horses.

References

^ Colin J. Morley, Peter G. Davis, Lex W. Doyle, Luc P. Brion, Jean-Michel Hascoet & John B. Carlin (February 2008). "Nasal CPAP or intubation at birth for very preterm infants". The New England journal of medicine 358 (7): 700–708. doi:10.1056/NEJMoa072788. PMID 18272893.
^ McGinley B, Halbower A, Schwartz AR, Smith PL, Patil SP, Schneider H. Effect of a high-flow open nasal cannula system on obstructive sleep apnea in children. Pediatrics. 2009 Jul;124(1):179-88. PMID 19564298
^ Waugh JB, Granger WM. An evaluation of 2 new devices for nasal high-flow gas therapy. Respir Care. 2004 Aug;49(8):902-6. PMID=15271229 PubMed
^ Roca O, Riera J, Torres F, Masclans JR. High-flow oxygen therapy in acute respiratory failure. Respir Care. 2010 Apr;55(4):408-13. PMID 20406507
^ Waugh JB, Granger WM. An evaluation of 2 new devices for nasal high-flow gas therapy. Respir Care. 2004 Aug;49(8):902-6. PMID 15271229
^ McGinley BM, Patil SP, Kirkness JP, Smith PL, Schwartz AR, Schneider H. A nasal cannula can be used to treat obstructive sleep apnea. Am J Respir Crit Care Med. 2007 Jul 15;176(2):194-200. Epub 2007 Mar 15. PMID 17363769
^ Shoemaker MT, Pierce MR, Yoder BA, DiGeronimo RJ. High flow nasal cannula versus nasal CPAP for neonatal respiratory disease: a retrospective study. J Perinatol. 2007 Feb;27(2):85-91. PMID 17262040
^ Kubicka ZJ, Limauro J, Darnall RA. Heated, humidified high-flow nasal cannula therapy: yet another way to deliver continuous positive airway pressure? Pediatrics. 2008 Jan;121(1):82-8. PMID 18166560

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 成人における閉塞性睡眠時無呼吸に対する陽圧気道療法の導入 initiation of positive airway pressure therapy for obstructive sleep apnea in adults
2. 持続的気道陽圧（CPAP）のアドヒアランス adherence with continuous positive airway pressure cpap
3. 機械的人工換気のモード modes of mechanical ventilation
4. 成人における閉塞性睡眠時無呼吸のマネージメント management of obstructive sleep apnea in adults
5. 成人の急性呼吸不全における非侵襲的陽圧換気 noninvasive positive pressure ventilation in acute respiratory failure in adults

English Journal

Obstructive sleep apnea syndrome.

Mannarino MR, Di Filippo F, Pirro M.AbstractObstructive sleep apnea (OSA) syndrome is a common but often unrecognized disorder caused by pharyngeal collapse during sleep and characterized by frequent awakenings, disrupted sleep and consequent excessive daytime sleepiness. With the increasing epidemic of obesity, the most important risk factor for OSA, prevalence of the disease will increase over the coming years thus representing an important public-health problem. In fact, it is now recognized that there is an association between OSA and hypertension, metabolic syndrome, diabetes, heart failure, coronary artery disease, arrhythmias, stroke, pulmonary hypertension, neurocognitive and mood disorders. Diagnosis is based on the combined evaluation of clinical manifestations and objective sleep study findings. Cardinal symptoms include snoring, sleepiness and significant reports of sleep apnea episodes. Polysomnography represents the gold standard to confirm the clinical suspicion of OSA syndrome, to assess its severity and to guide therapeutic choices. Behavioral, medical and surgical options are available for the treatment. Continuous positive airway pressure (CPAP) represents the treatment of choice in most patients. CPAP has been demonstrated to be effective in reducing symptoms, cardiovascular morbidity and mortality and neurocognitive sequelae, but it is often poorly tolerated. The results of clinical studies do not support surgery and pharmacological therapy as first-line treatment, but these approaches might be useful in selected patients. A better understanding of mechanisms underlying the disease could improve therapeutic strategies and reduce the social impact of OSA syndrome.
European journal of internal medicine.Eur J Intern Med.2012 Oct;23(7):586-93. Epub 2012 Jun 24.
Obstructive sleep apnea (OSA) syndrome is a common but often unrecognized disorder caused by pharyngeal collapse during sleep and characterized by frequent awakenings, disrupted sleep and consequent excessive daytime sleepiness. With the increasing epidemic of obesity, the most important risk factor
PMID 22939801

Feasibility of continuous positive airway pressure by primary care paramedics.

Cheskes S, Thomson S, Turner L.SourceFrom the Sunnybrook-Osler Centre for Prehospital Medicine (SC, ST, LT) , Toronto, Ontario , Canada ; the Division of Emergency Medicine, Department of Family and Community Medicine, University of Toronto (SC) , Toronto, Ontario , Canada ; and the Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital (SC) , Toronto, Ontario , Canada .
Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors.Prehosp Emerg Care.2012 Oct;16(4):535-40. Epub 2012 Jun 11.
Abstract Introduction. Continuous positive airway pressure (CPAP) has been used effectively in the prehospital environment for a wide range of respiratory emergencies. The feasibility of CPAP when used by primary care paramedics (PCPs) has not been established. Objective. We sought to study the fea
PMID 22686168

Japanese Journal

携帯型機器(PBSM)で記録したスペクトルエントロピーによるCPAP使用時の睡眠の質的評価

大久典子,小川浩正,色川俊也,黒澤一,吉田克己
自律神経 = The Autonomic nervous system 47(3), 271-276, 2010-06-15
NAID 10026905862

術後にブーシナク持続気道陽圧装置の使用で低酸素血症が改善した1症例

岩下耕平,濱田孝光,岩切重憲,香取清,仁田原慶一,比嘉和夫
福岡大学医学紀要 37(2), 79-82, 2010-06
NAID 110007581273

Related Pictures

★リンクテーブル★

リンク元	「人工呼吸」「持続的気道陽圧法」「持続陽圧呼吸療法」「CPAP」
拡張検索	「nasal continuous positive airway pressure」
関連記事	「continuous」「positive」「pressure」「airway」

「人工呼吸」

　　[★]

英: artificial respiration, artificial ventilation

概念

1. 人工的に呼吸を行わせること。このため、伝統的なmouth to mouthからバックアンドバルブマスク、あるいは人工呼吸器を用いて行う。
2. 一次救命処置の中における処置　→　人工呼吸#一次救命処置

人工呼吸適応

SAN.422

肺活量 < 10ml/kg, PaO2 < 55 mmHg(50%以上の酸素投与下), 呼吸回数 > 35/min, 努力呼吸, 吸引圧 < -25cmH2O

人工呼吸のモード

送気制御パターンによる分類

量規定換気 volume controlled ventilation VCV
圧規定換気 [[]] PCV

換気モード

調節換気 controlled mechanical ventilation CMV

間欠的陽圧呼吸 IPPV：間欠的に定容量のガスを換気する
持続的陽圧呼吸 CPPV：間欠的に定容量のガスを換気する　＋　呼気終末陽圧の付加

同期型間欠的強制換気 synchronized intermittent mandatory ventilation SIMV = 間欠的強制換気 intermittent mandatory ventilation IMV：自発呼吸が不十分な場合に、陽圧呼吸が強制的に行われる。
圧支持換気 pressure suppot ventilation
持続気道内陽圧 continuous positive airway pressure CPAP：自発呼吸をしている患者に呼気・吸気を通じて陽圧を欠ける。
非侵襲的陽圧換気法 noninvasive positive pressure ventilation NPPV