Airway Equipment (PDF)

Wondershare PDFelement AIRWAY EQUIPMENT (AIRWAYS) ‫الطبيب االستشاري‬ ‫الدكتور‬ ‫معتز فؤاد األغا‬  Introduction Wondershare...

Wondershare PDFelement AIRWAY EQUIPMENT (AIRWAYS) ‫الطبيب االستشاري‬ ‫الدكتور‬ ‫معتز فؤاد األغا‬  Introduction Wondershare PDFelement Anaesthetists must have a sound understanding and firm knowledge of the functioning of all anaesthetic equipment in common use. It is essential that anaesthetists check that all equipment is functioning correctly before they proceed to anaesthetise a patient. AIRWAYS are devices that can be passed orally or through nose to maintain the patency of air passages. Unlike other maneuvers to maintain a patent airway, including chin lift, jaw thrust and tracheal intubation, insertion of an airway does not affect the stability of the cervical spine. Oral and nasopharyngeal airways constitute an important mandatory accessory in airway management. Types of Airways They can be: oropharyngeal, nasopharyngeal, modified-laryngeal mask airway, cuffed oropharyngeal airway (COPA) , etc. Wondershare PDFelement  Wondershare Oropharyngeal Airways PDFelement Components Oropharyngeal airway has a flange to prevent over insertion, a straight bite block portion and a curved section. It is a curved apparatus made of metal, plastic or hard rubber. The curved body of the oropharyngeal airway contains the air channel. It is flattened anteroposteriorly and curved laterally. It also serve as a means to fix the airway in place. It has a flange at the proximal (buccal) end which limits the depth of insertion & prevent the oropharyngeal airway from falling back into the mouth so avoiding further posterior displacement into the pharynx. The flange may or may not rest on the patients lips depending on whether the particular airway being used is the correct size. The bite portion is straight and fits between the teeth or gums. It should be firm, so that the patient can’t close the air channel by biting. The air channel should be as large as possible to pass suction catheters. Wondershare PDFelement  The pharyngeal end is the curved portion of the airway that extends Wondershare PDFelement upward and backward to correspond to the shape of the tongue and palate. It separates the tongue from posterior pharyngeal wall and by pressures along the base of the tongue pulls the epiglottis slightly forward. When inserted, the distal end should lie just above the epiglottis so as to not irritate the laryngeal inlet. The oropharyngeal airways are oval or circular in cross section and are produced in varying lengths and diameters to suit different sizes of patients (from neonates to large adults). Uses It prevents obstruction of the upper air passage by lifting the tongue and epiglottis away from the posterior pharyngeal wall, to reverse the effects of gravity on the tongue & maintain the patency of the upper airway in cases of obstruction caused by a decreased level of consciousness. Decreased consciousness can lead to loss of pharyngeal tone that can result in airway obstruction by the tongue, epiglottis, soft palate or pharyngeal tissues. Wondershare PDFelement  Wondershare It prevents biting and occlusion of the orotracheal tube PDFelement It protects the tongue during biting and seizure activity It facilitates oropharyngeal suctioning It provides a better mask fit for ventilation It helps insertion of tubular devices into pharynx or esophagus Insertion Technique The appropriate size of the airway is obtained by selecting it with the vertical distance between the patient’s incisor (midline of the lips) and the angle of the jaw, or the corner of the patient’s mouth to tragus of the ear. Too small airway may cause kinking of the tongue and obstructing gas movement. Too large airway may cause obstruction by displacing the epiglottis and may traumatize the larynx. The patient’s mouth is opened and a well-lubricated airway is inserted into the oral cavity in the upside down position, with the curvature facing caudad, as far as the junction between the hard and the soft palate and then rotated through 180°, and advanced until the bite block rests between the incisors,& the airway lies in the oropharynx.  Wondershare This rotation technique minimizes the chance of pushing the tongue PDFelement backward and downward into the pharynx, causing further obstruction. Correct placement is shown by improvement in airway patency and by seating of the flattened reinforced section between the patient’s teeth or alveolar margins if the patient is edentulous. In children, it is recommended that the airway is inserted the right way round, tongue blade or laryngoscope may be used to depress the tongue. The airway is held horizontal as the tip is inserted into the mouth. As the airway is advanced it is rotated into a vertical position. This causes it to slide around behind the tongue. This is done to minimize the risk of trauma to the oropharyngeal mucosa. The same technique can be used in adults. Problems in practice and safety features 1. Airway obstruction: Appropriate size must be used. If larger sized or long airway is used, it may act as an foreign body in the airway & can cause laryngospasm.  The degree to which airway patency has been increased after Wondershare PDFelement insertion of the airway should be assessed, not assumed. It should also always be remembered that a badly inserted airway can make patency worse rather than better. 2. The airways must be inserted after lubrication. 1. Trauma to the tongue, nose, uvula, & pharynx during insertion. 2. Trauma to the teeth, crowns/caps if the patient bites on it. 3. If inserted in a patient whose pharyngeal and laryngeal reflexes are not depressed enough, the gag reflex can be induced that might lead to vomiting, coughing and laryngospasm. 4. They confer no protection against aspiration. Types of Oropharangial Airways Guedel Airway The most common airway that is used. It is available in up to nine sizes, which have a standardized number coding ( the smallest ‘000’ to the largest ‘6’). Wondershare PDFelement Wondershare PDFelement  The bite portions are color coded to provide easy identification of size. Wondershare PDFelement It has a gentle curve that follows the contour of the tongue and has a tubular channel for air exchange and suction. Waters Airway It is available in sizes 00, 0, 1–7. It is a metallic oropharyngeal airway with two holes at the pharyngeal end. It is hollow and has a nipple on the flange for oxygen and suction. It can be cleaned with soap and water. Safar’s Airway It is available in sizes for adult and pediatric. It is an “S” shaped airway that looks like two airways joined together. It is made of non traumatic soft rubber. It is mainly used for artificial resuscitation. Connell Airway It is available in sizes 00, 0, 1–7. It is a metallic hollow oropharyngeal airway and is similar to waters airway but has no insufflation nipple. It can be cleaned with soap and water. It is used in management of a patient’s Wondershare PDFelement Wondershare PDFelement Wondershare PDFelement  Wondershare PDFelement Berman Intubation Airway Berman airway is designed to assist with oral fibreoptic intubation. It acts to guide the fibrescope around the back of the tongue to the larynx, with the purpose of both maintaining the patient’s airway and acting as a bite block, thus preventing damage to the fibrescope. Unlike a Guedel airway, It has no enclosed air channel. The sides are cut open and there is support through the center. The center have openings in it to permit suction if the airway becomes lodged sideways. The sides allow passage of suction catheters and provide air channels. The side opening allows it to be removed from the fibrescope, prior to the railroading of the tracheal tube into the trachea. Sizes are available for infant, small child, child, medium adult, and large adult. It has a flange at the buccal end. It is easier to clean and is less likely to become obstructed with foreign body or mucus. However, the anterior jaw lift was more effective than the Berman device for assisting fibreoptic orotracheal intubation. Wondershare PDFelement Wondershare PDFelement  Wondershare Williams Airway Intubator and Berman Oropharyngeal Airway are PDFelement superior to Ovassapian airway regarding visualization of the vocal cords, provided that Berman airway is of an adequate size & positioned in the midline. Completing the tracheal intubation is more difficult with the Berman airway than the Ovassapian airway. Ovassapian Fiberoptic Intubating Airway It is used during fiberoptic intubation. The proximal end is tubular and narrow that gradually widens at the distal end. The distal part does not have any posterior wall. Hence, the distal end of the fiberscope can be maneuvered in this open space in the oropharynx. The lingual surface is flat. There are two side walls and two pairs of curved guide walls between the side walls. The guide walls curve toward each other, leaving a space for a tracheal tube up to size 9 and are flexible so that the airway can be removed from around the tracheal tube after intubation has been completed. It is not necessary to remove the tracheal tube connector during fibreoptic intubation. Wondershare PDFelement Wondershare PDFelement  Wondershare Williams Airway Intubator PDFelement It was designed for blind orotracheal intubations. It can also be used in fiberoptic intubations or as oral airway. It is made of plastic and available in two sizes, 9 & 10, which will admit up to 8.0 & 8.5 (ID) tracheal tube, respectively. The tracheal tube connector should be removed during intubation, because it will not pass through the airway. The proximal half is cylindrical, while the distal half is open on its lingual surface. Nasopharyngeal Airway It is an alternative device that can be used to maintain the airway by inserting it through the nose, into the nasopharynx, bypassing the mouth and the oropharynx. Components 1. The rounded curved body of this airway, made of soft plastic, rubber or polyurethane. It curves to fit the curvature of the nasopharynx. Wondershare PDFelement  Wondershare 2. Bevelled distal end. The bevel is left-facing. PDFelement 3. The proximal end has either a fixed or adjustable flange. A ‘safety pin’ is provided to prevent the airway from migrating into the nose. It is available in different lengths and internal diameters. Mechanism of action 1. It is an alternative to the oropharyngeal airway when the mouth cannot be opened or having limited mouth opening or pathology of oral cavity that makes it difficult to insert oral airway or an oral airway does not relieve the obstruction. 2. Nasotracheal suction is performed using a catheter passed through it. 3. During pharyngeal surgery, fiberoptic bronchoscopy, & to apply CPAP. 3. It is better tolerated by semi-awake patients than the oral airway. 4.It is less likely to be accidentally displaced or removed. Insertion Technique The size inserted is size 6 for an average height female and size 7 for an average height male. Wondershare PDFelement Wondershare PDFelement  Wondershare After lubricating it along its entire length, it can be inserted through PDFelement either nares, bevel end first, although the left-facing bevel is designed to ease insertion into the right nostril.It is held in the hand on the same side as it is to be inserted. It is passed vertically along the floor of the nose ,backwards through the nasopharynx, with slight twisting action and the curve of the airway should be directed toward the patient’s feet. Do not proceed further if resistance is encountered. Either it should be redirected or passed through the other nostril or a smaller sized airway should be used. If placed appropriately, the pharyngeal end lies just above the epiglottis and below the base of the tongue. It’s distal end lies beyond the pharyngeal border of the soft palate but not beyond the epiglottis, with the flange just outside the nostrils. Problems in practice and safety features 1. Its use is not recommended when the patient has a bleeding disorder, is on anticoagulants, has nasal deformities( nasal polyps or adenoidal tissue) or sepsis. Trauma to septal mucosa, can cause epistaxis. 2. Excess force should not be used during insertion as a false passage PDFelement Wondershare may be created. There is a potential risk of intracranial placement in cases of basal skull fracture. 3. Too large airway can result in pressure necrosis & ulceration of nasal mucosa, whereas too small airway may be ineffective at relieving airway obstruction. 4. Latex allergy 5. Tissue oedema 6. Retention, aspiration or swallowing. TYPES OF NASAL AIRWAY Bardex Airway It is made of rubber, with large flange at nasal end & bevel at pharyngeal end. Binasal Airway It consists of two nasal airways joined together by a connection that has a 15 mm adaptor for attachment to the breathing system. Wondershare PDFelement Wondershare PDFelement Epistaxis Airway Wondershare PDFelement It is inserted into the nose and inflated. It is useful in epistaxis by providing local pressure and is available in several sizes. Rusch Airway It is made of red rubber. It has an adjustable flange at the nasal end. The pharyngeal end has a short bevel. Cuffed Oropharyngeal Airway (COPA) It could be an alternative to the face mask use during spontaneous ventilation anesthesia. It is color-coded according to sizes and is available in sizes 8–11. It is a modified Guedel type of oropharyngeal airway with an integral bite portion. The proximal end has a standard 15 mm connector for attachment to the breathing circuit. At its proximal end it has two posts for attaching a non-latex elastic fixation strap which is used to stabilize the COPA device in the mouth. Wondershare PDFelement Wondershare PDFelement Wondershare PDFelement  Wondershare It is made of polyvinyl chloride (PVC). PDFelement The inflatable cuff (capacity of 25–40 mL of air) at the distal end seals the oropharynx. It is inflated through a one way valve attached to a pilot balloon which emerges at the tooth lip guard. When inflated the cuff is broad and flattened posteriorly and shorter and more pointed anteriorly. On inflation, it displaces the base of the tongue, forms a low pressure seal with the pharynx and passively elevates the epiglottis from the posterior pharyngeal wall to provide a clear airway. The cuffed oropharyngeal airway can be inserted easily by inexperienced users with a high first-attempt success rate (>90%); manipulations of the device may be required to maintain a patent airway. COPA is less reliable for “hands- free” ventilation than the laryngeal mask airway. However, the incidence of laryngopharyngeal discomfort and salivation is less with the COPA.