HFJV

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1. high frequency 短波,高周波

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/12/18 16:52:49」(JST)

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Modes of mechanical ventilation are one of the most important aspects of the usage of mechanical ventilation. The mode refers to the method of inspiratory support. Mode selection is generally based on clinician familiarity and institutional preferences since there is a paucity of evidence indicating that the mode affects clinical outcome. The most frequently used forms of volume-limited mechanical ventilation are IMV and CMV. Substantial changes in the nomenclature of mechanical ventilation over the years but more recently has become standardized by many respirology/pulmonology groups.

Cycle

Cycling is the method for how a ventilator knows to give a breath and stop a breath. Cycling is the governing system for how a breath will ultimately be applied. Parameters vary but rate (), I:E and other similar parameters are almost always set by the clinician along side the cycle.

Volume controlled

Flow-volume loop

Volume controlled systems of ventilation are based on a measured volume variable which is set by the clinician. When the ventilator detects the set volume having been applied the ventilator cycles to exhalation. This is measured various ways by each brand and model. Some ventilators measure using a flow sensor at the circuit wye while some measure where the expiratory circuit plugs into the expiratory port on the ventilator body.

Pressure controlled

Pressure controlled cycling is based on an applied positive pressure that is set by the clinician. In pressure controlled modes the total volume is variable as the ventilator is using only the pressure as a measurement for cycling. Most ventilators calculate pressure at the expiratory circuit though some measure near the circuit with a proximal pressure line.

Spontaneously controlled

Spontaneously controlled cycling is a flow sensed mode dependent on a spontaneously breathing patient to cycle. Spontaneously controlled ventilation is typically only in reference to continuous spontaneous ventilation, also called continuous positive airway pressure (CPAP).

Negative pressure controlled

Negative pressure ventilation cycles by producing a negative pressure around the chest and abdomen. Negative pressure moves across the chest and diaphragm and causes air to move into the lungs in the normal fashion. When the negative pressure stops being applied, the chest returns to atmospheric pressure and the inspired air then is exhaled.

Strategy

Airway pressure release ventilation

Airway pressure release ventilation graph

Airway pressure release ventilation is a time-cycled alternant between two levels of positive airway pressure, with the main time on the high level and a brief expiratory release to facilitate ventilation. This is a type of inverse ratio ventilation. The exhalation time (T_low) is shortened to usually less than one second to maintain alveoli inflation. Fundamentally this is a continuous pressure with a brief release. APRV currently the most efficient conventional mode for lung protective ventilation.

Different perceptions of this mode may exist around the globe. While 'APRV' is common to users in North America, a very similar mode, biphasic positive airway pressure (BIPAP), was introduced in Europe. The term APRV has also been used in American journals where, from the ventilation characteristics, BIPAP would have been perfectly good terminology. But BiPAP(tm) is a trademark for a noninvasive ventilation mode in a specific ventilator (Respironics Inc.). Other manufacturers have followed with their own brand names (BILEVEL, DUOPAP, BIVENT). Although similar in modality, these terms describe how a mode is intended to inflate the lung, rather than defining the characteristics of synchronization or the way spontaneous breathing efforts are supported.

Continuous mandatory ventilation

Continuous mandatory ventilation (formerly known as Assist Control or AC) is a mode of ventilation where breaths are delivered based on set variables. The patient may initiate breaths by attempting to breathe. Once a breath is initiated, either by the patient or by the ventilator the set tidal volume is delivered. Continuous mandatory ventilation used to also be called Volume Control or Assist Control Volume Control (AC/VC), though this is no longer recommended. Since nomenclature of mechanical ventilation is only recently standardized there are many different names that historically were used to reference CMV but now reference Assist Control. Names such as: volume control ventilation, and volume cycled ventilation in modern usage refer to the Assist Control mode.

Controlled mechanical ventilation in its original form had no patient sensitivity. A breath set was a breath delivered. Continuous mandatory ventilation was created out of the need for patient-initiation in breaths. Fundamentally, Continuous mandatory ventilation is controlled mechanical ventilation (CMV) with a sensitivity for patient breathing. The use of controlled mechanical ventilation requires the patient be completely unconscious, either pharmacokinetically or otherwise in a coma.

Continuous mandatory ventilation (formerly Assist Control or AC) is associated with profound diaphragm muscle dysfunction and atrophy. Continuous mandatory ventilation is no longer the preferred mode of mechanical ventilation.

Intermittent mandatory ventilation

Intermittent mandatory ventilation is similar to continuous mandatory ventilation in two ways: the minute ventilation (V_E) is determined (by setting the respiratory rate and tidal volume); and the patient is able to increase the minute ventilation. However, IMV differs from continuous mandatory ventilation in the way that the minute ventilation is increased. Specifically, patients increase the minute ventilation by spontaneous breathing, rather than patient-initiated ventilator breaths. The ventilator breaths are synchronized with patient inspiratory effort. IMV with pressure support is the most efficient and effective mode of mechanical ventilation.

Intermittent mandatory ventilation has not always had the synchronized feature, so the division of modes were understood to be SIMV (synchronized) vs IMV (not-synchronized). Since the American Association for Respiratory Care established a nomenclature of mechanical ventilation the "synchronized" part of the title has been dropped and now there is only IMV.

Mandatory minute ventilation

Mandatory minute ventilation (MMV) allows spontaneous breathing with automatic adjustments of mandatory ventilation to the meet the patient’s preset minimum minute volume requirement. If the patient maintains the minute volume settings for V_T x f, no mandatory breaths are delivered. If the patient's minute volume is insufficient, mandatory delivery of the preset tidal volume will occur until the minute volume is achieved. The method for monitoring whether or not the patient is meeting the required minute ventilation (V_E) differs by ventilator brand and model, but generally there is a window of monitored time, and a smaller window checked against the larger window (i.e., in the Dräger Evita® line of mechanical ventilators there is a moving 20-second window, and every 7 seconds the current tidal volume and rate are measured) to decide whether a mechanical breath is needed to maintain the minute ventilation. MMV is the optimal mode for weaning in neonatal and pediatric populations and has been shown to reduce long term complications related to mechanical ventilation.

Pressure regulated volume control

Pressure regulated volume control is an IMV based mode. Pressure regulated volume control utilizes pressure-limited, volume-targeted, time-cycled breaths which can be either ventilator or patient initiated. The peak inspiratory pressure delivered by the ventilator is varied on a breath-to-breath basis to achieve a target tidal volume which is set by the clinician. For example, if a target tidal volume of 500 mL is set but the ventilator delivers 600 mL, the next breath will be delivered with a lower inspiratory pressure to achieve a lower tidal volume. Though PRVC is regarded as a hybrid mode because of its tidal-volume (VC) settings and pressure-limiting (PC) settings fundamentally PRVC is a volume-control mode.

Adaptive support ventilation

Adaptive support ventilation (ASV) is a positive pressure mode of mechanical ventilation that is closed-loop controlled. The frequency and tidal volume of breaths of a patient on the ventilator are automatically adjusted based on the patient's requirements. The lung mechanics data are used to adjust the depth and rate of breaths to minimize the work rate of breathing. In this mode, every breath is synchronized with patient effort if such an effort exists, and otherwise, full mechanical ventilation is provided to the patient. ASV is a patented technology originally described as one of the embodiments of US Patent No. 4,986,268.. In this invention, the control algorithm computes the optimal rate of respiration to minimize the work rate of breathing. The rationale is to make the patient's breathing comfortable and natural within safe limits, and thereby stimulate spontaneous breathing and reduce the weaning time.

Continuous positive airway pressure

continuous positive airway pressure (CPAP) is a non-invasive positive pressure mode of ventilation (NPPV). CPAP is simply a pressure applied at the end of exhalation to keep the alveoli open and not fully deflate. This mechanism for maintaining inflated alveoli helps increase partial pressure of oxygen in arterial blood, an appropriate increase in CPAP increases the PaO₂.

Bilevel positive airway pressure

Bilevel positive airway pressure (BPAP) is a mode used during noninvasive positive pressure ventilation (NPPV). First used in 1988 by Professor Benzer in Austria, it delivers a preset inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP). BPAP can be described as a Continuous Positive Airway Pressure system with a time-cycled change of the applied CPAP level. CPAP, BPAP and other non-invasive ventilation modes have been shown to be effective management tools for chronic obstructive pulmonary disease and acute respiratory failure.

Often BPAP is incorrectly referred to as "BiPAP". BiPAP® is the name of a portable ventilator manufactured by Respironics Corporation; it is just one of many ventilators that can deliver BPAP.

High-frequency ventilation (Active)

The term active refers to the ventilators forced expiratory system. In a HFV-A scenario, the ventilator uses pressure to apply an inspiratory breath and then applies an opposite pressure to force an expiratory breath. In high-frequency oscillatory ventilation (sometimes abbreviated HFOV) the oscillation bellow and piston force positive pressure in and apply negative pressure to force an expiration.

High-frequency ventilation (Passive)

The term passive refers to the ventilators non-forced expiratory system. In a HFV-P scenario, the ventilator uses pressure to apply an inspiratory breath and then simply returns to atmospheric pressure to allow for a passive expiration. This is seen in High-Frequency Jet Ventilation, sometimes abbreviated HFJV.

Ventilation systems for weaning

Proportional assist ventilation

Proportional assist ventilation (PAV) is a mode in which the ventilator guarantees the percentage of work regardless of changes in pulmonary compliance and resistance. The ventilator varies the tidal volume and pressure based on the patients work of breathing, the amount it delivers is proportional to the percentage of assistance it is set to give.

Positive-end expiratory pressure

Positive end expiratory pressure is pressure applied upon expiration. PEEP is applied either using a valve that is connected to the expiratory port and set manually or a valve managed internally by a mechanical ventilator. PEEP is simply a pressure that an exhalation has to bypass, effectively causing alveoli to remain open and not fully deflate. This mechanism for maintaining inflated alveoli helps increase partial pressure of oxygen in arterial blood, an increase in PEEP increases the PaO₂.

Pressure support

Pressure support is a spontaneous mode of ventilation also named Pressure Support Ventilation (PSV). The patient initiates every breath and the ventilator delivers support with the preset pressure value. With support from the ventilator, the patient also regulates their own respiratory rate and their tidal volume.

In Pressure Support, the set inspiratory pressure support level is kept constant and there is a decelerating flow. The patient triggers all breaths. If there is a change in the mechanical properties of the lung/thorax and patient effort, the delivered tidal volume will be affected. The user must then regulate the pressure support level to obtain desired ventilation.

Pressure support improves oxygenation, ventilation and decreases work of breathing.

Also see adaptive support ventilation.

Other ventilation modes and strategies

Liquid ventilation

Liquid ventilation is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury, including:

• Reducing surface tension by maintaining a fluid interface with alveoli
• Opening of collapsed alveoli by hydraulic pressure with a lower risk of barotrauma
• Providing a reservoir in which oxygen and carbon dioxide can be exchanged with pulmonary capillary blood
• Functioning as a high efficiency heat exchanger

Despite its theoretical advantages, efficacy studies have been disappointing and the optimal clinical use of LV has yet to be defined.

Total liquid ventilation

In total liquid ventilation (TLV), the entire lung is filled with an oxygenated PFC liquid, and a liquid tidal volume of PFC is actively pumped into and out of the lungs. A specialized apparatus is required to deliver and remove the relatively dense, viscous PFC tidal volumes, and to extracorporeally oxygenate and remove carbon dioxide from the liquid.

Partial liquid ventilation

In partial liquid ventilation (PLV), the lungs are slowly filled with a volume of PFC equivalent or close to the FRC during gas ventilation. The PFC within the lungs is oxygenated and carbon dioxide is removed by means of gas breaths cycling in the lungs by a conventional gas ventilator.

See also

• Table of modes of mechanical ventilation
• Mechanical ventilation
• Respiratory therapy

References

UpToDate Contents

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• 1. 新生児における機械的人工換気 mechanical ventilation in neonates
• 2. 成人における高頻度人工呼吸 high frequency ventilation in adults

English Journal

• The effects of high-frequency jet ventilation (HFJV) on pneumoperitoneum-induced cardiovascular changes during laparoscopic surgery.

• Bickel A, Trossman A, Kukuev I, Eitan A.SourceDepartment of Surgery, Western Galilee Hospital, 22100, Nahariya, Israel, amitai@netvision.net.il.
• Surgical endoscopy.2011 Jun 3. [Epub ahead of print]
• PMID 21638187

• Medical intelligence article: novel uses of high frequency ventilation outside the operating room.

• Raiten J, Elkassabany N, Gao W, Mandel JE.SourceDepartment of Anesthesiology and Critical Care, University of Pennsylvania School of Medicine, 3400 Spruce St., Dulles 6, Philadelphia, PA 19104, USA. j.raiten@gmail.com
• Anesthesia and analgesia.2011 May;112(5):1110-3. Epub 2011 Mar 3.
• High frequency jet ventilation (HFJV) is a technique that is most frequently used in the intensive care unit and during tracheal and otorhinolaryngologic surgery. The utility of HFJV for procedures performed outside of the intensive care unit and operating room is currently being explored. The abili
• PMID 21372275

Japanese Journal

• OR1-6 当科におけるPCPS/HFJV併用気道ステント留置症例に対する検討(ステント,一般口演1,第31回日本呼吸器内視鏡学会学術集会)

• 常塚 宣男,清水 陽介,田中 伸佳
• 気管支学 : 日本気管支研究会雑誌 30(増刊), S136, 2008-05-20
• NAID 110006835423

• V09-06 左肺全摘術後患者の胸腔鏡下右上葉肺部分切除術 : selective HFJVの有用性(肺癌2,第25回呼吸器外科学会総会)

• 永島 明,稲葉 義平,岩波 崇嗣,小野 憲司
• 日本呼吸器外科学会雑誌 22(3), 403, 2008-04-18
• NAID 110006806262

Related Links

• 高頻度ジェット換気（HFJV）① 人工呼吸の開始から初期設定まで | NICU ...

HFJVを始める前に a)診療部の方針に従って器械のセットアップ及び ...

• High-frequency ventilation - Wikipedia, the free encyclopedia

High frequency jet ventilation (HFJV) is provided by the Bunnell Life Pulse High- Frequency Ventilator. HFJV employs an endotracheal tube adaptor in place for the normal 15 mm ET tube adaptor. A high pressure "jet" of gas flows out of the ...

Related Pictures

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★リンクテーブル★

リンク元	「高頻度ジェット換気」「高頻度人工換気法」
関連記事	「HF」

「高頻度ジェット換気」

　　[★]

英

high-frequency jet ventilation HFJV

同

高周波ジェット換気

• 平均気道内圧を低く維持しつつ換気が可能なため、気道が開放している状態(カフの無い気管チューブ、気管損傷、気管支瘻)において利用される。

• http://www2.synapse.ne.jp/insomnia/resp/contents/word3.html#high_frequency_ventilation

• 高圧のガス減を高速度で遮断および解放を繰り返して（およそ1～6Ｈｚ）ジェット流を作り換気を行う。
• 1回換気量は約2－4ml/kgとなる。
• 気道が開放する、ラリンゴマイクロ手術、気管気管支手術などで適応となる。

「高頻度人工換気法」

　　[★]

英

high frequency ventilation, HFV

関

HFJV

「HF」

　　[★]

• 心不全 heart failure
• 血液濾過法 hemofiltration