Airway management

The terms airway management, airway management or Airway management is called in medicine all the actions and knowledge that serve to secure an airway for spontaneous breathing or external respiration, so that enough oxygen for a sufficient gas exchange reaches the lungs, while a laying by the tongue or the inhalation (aspiration ) of blood, vomit or foreign matter is prevented.

An airway management is always necessary if respiratory function is disturbed by threatening accident or illness or if the natural breathing through sedation or anesthesia artificially ( iatrogenic) is restricted. In this respect, airway management is part of emergency medicine, anesthesia and intensive care.

• 2.1 Areas of application
• 2.2 Advantages and disadvantages
• 2.3 Technology and Application

Methods

Serve to secure the airway

• Specific storage measures such as the recovery position
• Handles ( hyperextension of the head, jaw thrust, cricoid pressure, BURP maneuver, C- handle)
• The use of different airway devices and ventilation masks
• The insertion of tubes into the airways ( intubation ), mostly as endotracheal intubation or by alternative means ( laryngeal mask, laryngeal tube, Combitube )
• The creation of alternative airways through a cricothyroidotomy or tracheotomy.

Storage measures

The recovery position serves as a life-saving measure of the layman to avoid linings of the respiratory tract by the tongue or aspiration of vomit.

While medical measures to secure the airway, the patient is positioned supine.

Manual mask ventilation

The manual mask ventilation is indicated in anesthesia, when ventilation is of short duration, such as anesthesia or short to bridge the time until the actual intubation for longer anesthesia. In emergency medicine it is used for oxygenation of the patient without adequate breathing until a further airway management can be done as endotracheal intubation. The mask ventilation is usually by respiratory bag and mask ventilation, as an emergency measure by the layman, the oxygen supply is done by artificial respiration. A respiratory mask offers no protection against aspiration.

The airways of unconscious patients are kept open either by manipulation of the mandible or by using nasopharyngeal ( Wendl tube) or oropharyngeal tubes ( Guedel ). These guarantee a flow of air through the nose or mouth to the throat and prevent the falling back of the tongue, which can also be caused by the overstretching of the head and the jaw thrust.

Intubation

As the insertion of an intubation tube, a hollow probe, designated in the respiratory tract. The standard method of endotracheal intubation is now supplemented by a number of alternative methods ( laryngeal tube, laryngeal mask airway, Combitube ).

Endotracheal intubation

When endotracheal intubation ( shortened often referred to as intubation in the narrower sense) an endotracheal tube (hollow tube made ​​of plastic) through the mouth ( orotracheal ) or nose ( nasotracheal ) between the vocal folds of the larynx ( larynx ) into the windpipe ( trachea) is introduced. By means of a sealing balloon (cuff ) prior to entering the respiratory tract secretions ( aspiration) are largely protected, and an external ventilation possible. Intubation is now regarded as the standard method of airway management. It is used in patients during general anesthesia for surgical interventions, with loss of consciousness or acute disorders of breathing. The insertion of the ventilation tube is tolerated only in unconsciousness or deep sedation or anesthesia.

The insertion of a tube with two lumens ( " double-lumen " ) allows the page separate ventilation of the lung, which is required for some procedures in thoracic surgery. This is partially described as endobronchial intubation, as the tip of the tube comes to rest in a main bronchus.

Non- invasive ventilation (NIV ) as an alternative

As non-invasive ventilation is a mostly automatic ventilation through masks or helmets understood where no tubes are inserted into the body.

NIV requires an airtight connection as possible between the ventilator and respiratory tract, so that face masks, mouth / nose masks, nose masks are used ( with the mouth closed ) or full- head helmets.

Areas of application

Acute shortness of breath from COPD, pulmonary edema, pneumonia, asthma

CPAP therapy, for example, with sleep apnea syndrome can be counted in the broadest sense, to NIV, which technically CPAP is only a passive upright posture Unger of overpressure in the exhalation phase. A ventilation in terms of active support of Inhalation is not CPAP.

Pros and Cons

As can be seen from the table, the advantage of the NIV is that no hoses have to be introduced into the airways and in complications such as especially the lung inflammation can be reduced. The main disadvantage of the NIV the lack of protection of the lungs is to call before Magensaftaspiration why NIV should not be used in patients with risk of aspiration.

Table adapted by

Technology and application

In acute exacerbation of COPD or asthma can usually consists overtaxing the Atmungsmusukulatur due to high resistances by inhalation. Therefore, should be actively supported with NIV inhalation. The pressure support in the inhalation should be set on the ventilator so that the total inspiratory pressure is in the air passages 15-25 cmH20. In the exhalation pressure between 3-6 cmH20 (PEEP ) should be kept. Thus, the patient is assisted in the inhalation and compensates the existing by the disease intrinsic PEEP.

In an acute deterioration of respiratory function by pulmonary edema or pneumonia, the alveoli are not ventilated and fall together. Therefore, a pressure between 10-15 cm H20 in the exhalation phase (PEEP ) should be kept in order to open or keep open the alveoli in the NIV. A pressure support during inhalation is then only necessary when it comes secondary to fatigue of the respiratory muscles.

For intensive care and specialized nursing homes are different ventilators with NIV function. So far on the use of NIV outside the hospital in the emergency service only individual special ventilation devices: These are eg Dräger Oxylog ® 2000 / 3000, Weinmann Medumat Transportation ®, Cardinal Health LTV ® 1200. As a pure CPAP system without the ability to print support high-flow systems exist which produce a PEEP about a high gas flow (eg from Vygon CPAP Boussignac valve).

Supraglottic airway devices as an alternative

Alternatives to endotracheal intubation aids such as laryngeal mask, laryngeal tube and Combitube, often the inability to place the tube properly ( difficult intubation, see below) are used. They are called supraglottic airway devices, as their end above the glottis ( glottis ) comes to rest. They come in the difficult airway management used when endotracheal intubation is not possible; However, their aspiration is inferior to the endotracheal tube significantly. In laryngeal masks and Larynxtuben however exist models that provide a relief of the stomach by a nasogastric tube may be inserted through a special channel. Supraglottic airway devices are also suitable for hard to reach patients, for example, after a traffic accident.

In the case of cardiac resuscitation supraglottic airway devices for helper without Intubationsexpertise are recommended as the first choice to allow ventilation. Endotracheal intubation should be performed in the context of cardiac resuscitation only from Intubationsexperten and should thereby only lead to a short, timed interruption of Herzdruckassage or ideally be performed under continuous chest compressions.

The laryngeal mask airway (LMA, synonym laryngeal mask ) is a means to hold open the airways, which was developed by the British anesthetist Archibald Brain in 1981 and introduced into clinical practice. It consists of a bead-like mask which is connected to a hose. The laryngeal mask airway is blind until shortly before the larynx inserted into the throat and sealed there. It is used on the one hand, the oxygen supply to general anesthesia when endotracheal intubation is not necessary ( small interventions without the involvement of body cavities ). On the other hand, it serves as an easy to platzierendes instrument securing the difficult airway.

The laryngeal tube (LT ) is a tube with two block cuffs ( cuffs ), which is placed as the laryngeal mask airway in the throat largely blind. Between the cuff the lumen terminates at the level of the larynx, so that up and down the introduced air can flow into the lungs through the sealing of the cuffs. In the use, handling and profile of adverse events similar to the Larynxtubus the laryngeal mask, but he's not as gentle on tissue. Since the sealing of the esophagus also is slightly better, it is usually used in emergency medicine and little in routine anesthesia.

When Combitube is a double lumen tube, which can be blindly pushed forward and so either in the esophagus ( 90% probability) or comes to lie in the trachea. It represents another alternative to endotracheal intubation and is mainly used in emergencies, if the latter fails. In this framework, the application in the policies of various professional societies is provided, such as during resuscitation. In routine clinical practice of anesthesia, however, the Combitube does not matter. Disadvantages are high costs and the lack of opportunity to introduce a feeding tube.

Surgical Atemwegsicherung

If a respiratory protection with the various existing methods is not possible ( Can not ventilate - cannot- intubate - situation), a cricothyroidotomy may be made by the physician. In this case, access to the respiratory tract at the level of the larynx is formed by the diaphragm ( conicum ligament, also called the cricothyroid ligament ) is opened between the cricoid and thyroid cartilage. This can be done by a puncture set, or by means of a scalpel. The cricothyrotomy is a medical emergency life-saving measure that is rarely and only as a last resort, but never as a measure of a first aider in the first aid for use.

The tracheostomy surgical procedure in which the neck of a soft tissue access to the trachea is provided. Indications for tracheostomy may be, for example, the need for long-term ventilation after accidents or surgery, neurological disorders with disturbances of swallowing reflex, radiation treatment to the head or neck or laryngeal paralysis. Also, patients after complete removal of the larynx wear a tracheostomy.

Difficult airway management

As difficult airway management is defined as the situation when the airway maintenance is not possible with the methodology used. The definitions relate to the skills of a trained, trained through alternative means of securing airway anesthesia specialist (definition of DGAI ). It consists of:

• Difficult mask ventilation - The manual bag - mask ventilation is possible not suffizient.
• Difficult pharyngeal airway maintenance - The insertion and sealing supraglottic airway devices not succeed.
• Difficult tracheal intubation - There are several attempts to intubation required.
• Endotracheal intubation is not possible.

To control a " difficult airway " a number of alternative methods are used in addition to standard procedures. If it is an anticipated difficult airway management during planned anesthesia, fiberoptic intubation with preserved spontaneous breathing of the patient is the drug of choice. It works under local anesthesia by means of a flexible endoscope, the bronchoscope, by which the vocal folds can be displayed and passes. A tube is then inserted through the instrument. Evidence of difficult airway management ( overbite, receding chin, small mouth, small reclination of the head, Mallampati grade 3 or 4, and others) are diagnosed in the informed consent discussion with the anesthesiologist. A reliable forecast of difficulties in airway management is thus not possible.

An unexpected difficult airway management arises despite previously inconspicuous evaluation, particularly in the emergency situation when the patient was not previously known. There are in addition to the aforementioned method, among other special laryngoscope types ( according to Miller, Dörges, McCoy, Bullard, etc.), Videolaryngoskope, different guide rods for intubation, the Intubationslarynxmaske ( Fasttrach ) through which a tube can be inserted, a rigid Intubationstracheoskop ( " Notrohr " ), other special aids and as a last resort coniotomy used to ensure the oxygenation of the patient.

Algorithms for mastery of difficult airway management often exist in medical facilities.