Tracheal intubation , usually referred to as intubation , is the placement of flexible plastic tubes to the trachea (trachea) to maintain open airways or to serve as a conduit through which to regulate drugs Certain medications. This is often done in patients who are severely injured, sick, or anesthetized to facilitate lung ventilation, including mechanical ventilation, and to prevent possible airway asphyxiation or obstruction.
The most widely used route is orotracheal, in which the endotracheal tube is passed through the mouth and the vocal tool into the trachea. In the nasotracheal procedure, the endotracheal tube is passed through the nose and vocal apparatus into the trachea. Other intubation methods involve surgery and include cricothyrotomy (used almost exclusively in emergencies) and tracheotomy, used primarily in situations where the long-standing need for airway support is anticipated.
Because it is an invasive and uncomfortable medical procedure, intubation is usually performed after administration of general anesthesia and neuromuscular inhibitors. However, it can be performed on a conscious patient with local or topical anesthesia or in an emergency with no anesthesia at all. Intubation is usually facilitated by using conventional laryngoscopy, flexible fiber-optic bronchoscopy, or a video laryngoscope to identify the vocal cords and pass the tubes between them to the trachea rather than to the esophagus. Other tools and techniques can be used interchangeably.
After the trachea has been intubated, the balloon balloon usually rises just above the end of the tube to help secure it, to prevent gas leak breathing, and to protect the tracheobronchial tree from receiving unwanted substances such as stomach acid. The tube is then secured to the face or neck and connected to a T-piece, anesthetic respiratory circuit, bag pouch bag device, or mechanical ventilator. After there is no longer need for ventilation and/or airway protection, the tracheal tube is removed; this is referred to as tracheal extubation (or decannulation, in the case of a surgical airway such as cricothyrotomy or tracheostomy).
For centuries, tracheotomy was considered the only reliable method for tracheal intubation. However, since only a small proportion of patients survive surgery, doctors perform tracheostomy only as a last resort, in patients who are near death. However, it was only in the late nineteenth century that progress in understanding anatomy and physiology, as well as respect for the germ theory of disease, had improved the results of this operation to the point that it could be considered an acceptable treatment option. Also at the time, advances in endoscopic instrumentation have increased in such a way that direct laryngoscopy has become a viable means of securing airway by non-surgical orotracheal routes. In the mid-20th century, tracheostomy and endoscopy and non-surgical tracheal intubation have evolved from a rarely used procedure to be an important component of anesthetic practice, critical care remedies, emergency medicine, and laryngology.
Tracheal intubation may be associated with mild complications such as tooth decay or upper respiratory tract laceration. It may also be associated with potentially fatal complications such as pulmonary aspiration of the abdominal contents which can cause severe and sometimes fatal chemical aspiration pneumonitis, or an unknown esophageal intubation that can cause potentially fatal anoksia. Because of this, potential difficulties or complications due to the presence of anatomy of the unusual airway or other uncontrollable variables are carefully evaluated prior to tracheal intubation. An alternative strategy to secure the airway should always be available.
Video Tracheal intubation
Indication
Tracheal intubation is indicated in various situations when a disease or medical procedure prevents a person from maintaining a clear airway, breathing, and blood oxygenation. In these circumstances, oxygen supplementation using a simple face mask is inadequate.
Depressed consciousness
Perhaps the most common indication for tracheal intubation is for placement of channels through which nitrous oxide or volatile anesthetics may be administered. General anesthesia agents, opioids, and neuromuscular inhibitors may reduce or even eliminate respiratory impulses. While this is not the only way to maintain a patent airway during general anesthesia, tracheal intubation provides the most reliable means of oxygenation and ventilation and the greatest level of protection against lung regurgitation and aspiration.
Damage to the brain (such as large strokes, penetrating head injury, poisoning or poisoning) can cause a decreased level of consciousness. When this becomes severe to the point of fainting or coma (defined as a score on the Glasgow Coma Scale of less than 8), the extrinsic dynamic collapse of the airways may block the airway, impeding the flow of free air to the lungs.. In addition, reflexes of airway reflexes such as coughing and swallowing may be reduced or absent. Tracheal intubation is often required to restore patency (absence of relative blockage) of the airways and to protect the tracheobronchial tree from lung aspiration in gastric contents.
Hypoxemia
Intubation may be necessary for patients with reduced oxygen content and oxygen saturation from the blood caused when their respiration is inadequate (hypoventilation), suspended (apnea), or when the lungs can not adequately transfer gas to the blood. Such patients, who may be alert and alert, are usually critically ill with multisystem disease or many severe injuries. Examples of such conditions include cervical spine injury, multiple rib fractures, severe pneumonia, acute respiratory distress syndrome (ARDS), or near-drowning. Specifically, intubation is considered if the arterial oxygen partial pressure (PaO 2 ) is less than 60 millimeters of mercury (mm Hg) when inhaling the O-sub-inspired <2> concentration (FIO). 2 ) by 50% or greater. In patients with elevated arterial carbon dioxide, the arterial partial pressure of CO 2 greater than 45 mm Hg in the setting of acidemia will encourage intubation, especially if a series of measurements shows worsening respiratory acidosis. Regardless of laboratory values, these guidelines are always interpreted in a clinical context.
Airway obstruction
Actual or future airway obstruction is a common indication for tracheal intubation. A life-threatening airway obstruction can occur when a foreign object is caught in the airway; this is very common in infants and toddlers. Severe blunt or penetrating injuries to the face or neck may be accompanied by swelling and extensive hematoma, or injury to the larynx, trachea or bronchi. Airway obstruction is also common in people who have suffered from inhaling smoke or burns in or near the airway or epiglottitis. Ongoing generalized seizure activity and angioedema are another common cause of life-threatening airway obstruction that may require tracheal intubation to secure the airway.
Airway manipulation
Diagnostic or therapeutic manipulations of the airways (such as bronchoscopy, laser therapy or bronchial fitting) may intermittently interfere with the ability to breathe; intubation may be necessary in such situations.
Maps Tracheal intubation
Tools
Laryngoscopes
Most tracheal intubations involve the use of a viewing instrument of one kind or another. Modern conventional laryngoscope consists of a handle that contains a battery that moves light and a set of interchangeable, straight or curved knives. This device is designed to allow laryngoscopy to view the larynx directly. Because of the availability of such tools, the technique of blind intubation of the trachea is rarely done today, although it may still be useful in certain emergency situations, such as natural or man-made disasters. In pre-hospital emergency settings, digital intubation may be necessary if the patient is in a position that makes direct laryngoscopy impossible. For example, digital intubation may be used by paramedics if the patient is trapped in the inverted position in the vehicle after a motor vehicle crash with a long expansion time.
The decision to use a straight or curved laryngoscope blade partly depends on the specific anatomical features of the airway, and in part on personal experience and laryngoscopy preferences. The Macintosh blade is the most widely used curved laryngoscope blade, while the Miller blade is the most popular blade style. Both Miller and Macintosh laryngoscope blades are available in 0 (baby) sizes up to 4 (large adults). There are many other straight and curved blade styles, with accessories such as mirrors to enlarge the field of view and even ports for oxygen administration. This particular knife is especially designed for use by anesthesiologists and otolaryngologists, most commonly in the operating room.
Fiber layoposcopes have become increasingly available since the 1990s. Unlike the conventional laryngoscope, this device allows the laryngoscopy to indirectly see the larynx. This provides a significant advantage in situations where operators need to look around an acute corner to visualize the glottis, and handle difficult intubations. Video laryngoscopy is a special optical fiber that uses digital video camera sensors to allow operators to see glottis and larynx on a video monitor. Another "non-invasive" device that can be used to assist tracheal intubation is the laryngeal mask airway (used as a conduit for placement of the endotracheal tube) and Airtraq.
Stylet
An intubation stylet is a soft metal wire designed to be inserted into an endotracheal tube to make the tube more suited to the upper airway anatomy of a particular individual. This aid is usually used with difficult laryngoscopy. Just like with the laryngoscope bar, there are also some stylet types available, such as the Verathon Stylet, specially designed to follow the 60 Â ° blade angle of the GlideScope video laryngoscope.
The Eschmann tracheal tube introducer (often mistakenly referred to as "elastic bougie gum") is a special type of stylet used to facilitate difficult intubation. This flexible device is 60 cm (24 inches) in length, 15 French (5 mm in diameter) with the angle of "small hockey stick" at the far end. Unlike traditional intubation styles, the Eschmann tracheal tube introduction is usually inserted directly into the trachea and then used as a guide where the endotracheal tube can be passed (in the same way as the Seldinger technique). As the introduction of the Eschmann tracheal tube is much more rigid than conventional stilettes, this technique is considered to be a relatively atraumatic tracheal intrakaroid device.
The tracheal tube exchanger is a hollow catheter, 56 to 81 cm in length (22.0 to 31.9 inches), which can be used to remove and replace the tracheal tube without the need for laryngoscopy. The Cooked Air Exchange Catheter (CAEC) is another example of this type of catheter; this device has a central lumen (hollow channel) where oxygen can be given.
Stylet lit is a tool that uses the principle of transillumination to facilitate blind orotracheal intubation (intubation technique in which the laryngoscopy does not see the glottis).
Tracheal tube
The tracheal tube is a catheter inserted into the trachea for the primary purpose of building and maintaining a patent airway (open and unobstructed). The tracheal tube is often used for airway management in general anesthesia settings, critical care, mechanical ventilation and emergency medicine. Many types of tracheal tubes are available, suitable for different specific applications. The endotracheal tube is a type of specific tracheal tube that is almost always put through the mouth (orotracheal) or nasal (nasotracheal). It is a respiratory passage designed to be placed into the respiratory tract of a severely injured, sick or anesthetized patient for ventilation of the mechanical positive pressure of the lungs and to prevent possible aspiration or airway obstruction. The endotracheal tubes have fittings designed to be connected to pressurized gas sources such as oxygen. At the other end is a hole through which the gas is directed to the lungs and may also include a balloon (referred to as a cuff). The end of the endotracheal tube is positioned above the carina (before the trachea is divided into each lung) and sealed inside the trachea so that the lungs can be ventilated equally. The tracheostomy tube is another type of tracheal tube; metal or plastic tubes curved along 2-3 inches (51-76 mm) are inserted into the tracheostomy or a cricothyroid incision.
The tracheal tube may be used to ensure adequate oxygen and carbon dioxide exchange, to provide oxygen in concentrations higher than that found in air, or to manage other gases such as helium, nitrous oxide, nitrous oxide, xenon, or certain volatile anesthetic agents such as as desflurane, isoflurane, or sevoflurane. They can also be used as routes for administration of certain drugs such as bronchodilators, inhaled corticosteroids, and drugs used in treating cardiac arrest such as atropine, epinephrine, lidocaine and vasopressin.
Originally made of latex rubber, modern endotracheal tubes are currently made of polyvinyl chloride. Tubes made of silicone rubber, silicone rubber reinforced wire or stainless steel are also available for special applications. For human use, the tubes have sizes ranging from 2 to 10.5 mm (0.1 to 0.4 inches) in internal diameter. The size is chosen based on the size of the patient's body, with smaller sizes used for babies and children. Most endotracheal tubes have an inflatable cuff to cover the tracheobronchial tree against respiratory gas leak and lung aspiration of the contents of the stomach, blood, secretions and other fluids. Uncuffed tubes are also available, although their use is limited primarily to children (in young children, the cricoid cartilage is the narrowest part of the airway and usually provides sufficient seal for mechanical ventilation).
In addition to handcuffed or extruded, preformed endotracheal tubes are also available. Oral and nasal RAE tubes (named after Ring inventors, Adair and Elwyn) are the most widely used of tubes already formed.
There are a number of endo-bronchial double-lumen endo-bronchial tubes that have endobronchial and endotracheal tubes (Carlens, White and Robertshaw tubes). These tubes are usually coaxial, with two separate channels and two separate openings. They combine endotracheal lumen that ends in the trachea and endobronchial lumen, a distal end positioned 1-2 cm to the right or left trunk bronchus. There is also a Univent tube, which has a single tracheal lumen and an integrated endobronchial blocker. These tubes allow a person to ventilate either the lungs, or the lungs independently. Single lung ventilation (enabling the lung on the surgical side for collapse) may be useful during thoracic surgery, as it may facilitate the surgeon's view and access to other relevant structures within the thoracic cavity.
Armored "armored" endotracheal tube, silicone rubber tube reinforced with wire. They are much more flexible than polyvinyl chloride tubes, but they are difficult to compress or strain. This can make them useful for situations where the trachea is anticipated to remain intubated for long durations, or if the neck remains flexed during surgery. Most armored tubes have Magill curves, but ready-made armored RAE tubes are also available. Another type of endotracheal tube has four small holes just above the blowing cuff, which can be used for suctioning trachea or intratracheal drug delivery if necessary. Other tubes (such as the Bivona Fome-Cuf tube) are specially designed for use in laser operations in and around the respiratory tract.
Method to confirm placement of the tube
There is no single method to confirm the placement of tracheal tubes has proven to be 100% reliable. Thus, the use of several methods to confirm correct tube placement is now widely regarded as the standard of care. Such methods include direct visualization when the tip of the tube passes through the glottis, or indirect visualization of the tracheal tube in the trachea using a tool such as a bronchoscope. With a properly positioned tracheal tube, the same bilateral breath sound will be heard after listening to the chest with a stethoscope, and no sound when listening to the area above the abdomen. The same bilateral rise and fall from the chest wall will be evidenced by ventilation visits. A small amount of water vapor will also be visible inside the tube lumen with each breath and there will be no contents of the stomach in the tracheal tube at all times.
Ideally, at least one of the methods used to confirm the placement of a tracheal tube would be a measuring instrument. Capnography waves have emerged as the gold standard for confirmation of placement of tubes in the trachea. Other methods that rely on instruments include the use of an end-tidal colorimetric carbon dioxide detector, a self-inflated balloon esophagus, or an esophageal detector. The distal end of a properly placed tracheal tube will lie mid-trachea, approximately 2 cm (1 inch) above the carina bifurcation; This can be confirmed with a chest x-ray. If inserted too far into the trachea (outside of the carina), the end of the tracheal tube may be in the main right bronchus - a situation often referred to as "right main trunk intubation". In this situation, the left lung may not be able to participate in ventilation, which can lead to decreased oxygen content due to ventilation/perfusion mismatch.
Custom situations
Emergency
Tracheal intubation in emergencies can be difficult with fiberoptic bronchoscopy because of blood, vomit, or secretions in the respiratory tract and poor patient cooperation. Therefore, patients with massive facial injuries, complete upper airway obstruction, considerably reduced ventilation, or large multiple airway bleeds are poor candidates for fiber-optic intubation. Fiberoptic intubation under general anesthesia usually requires two skilled individuals. A success rate of only 83-87% has been reported using fiberoptic techniques in the emergency department, with significant nasal bleeding occurring in up to 22% of patients. This weakness limits the use of fiberoptic bronchoscopy in urgent and emergency situations.
Personnel experienced in direct laryngoscopy is not always available in certain settings requiring emergency trachea intubation. For this reason, specific devices have been designed to act as a bridge to the definitive airway. Such devices include the air duct laryngeal mask, cuffed oropharyngeal ducts and esophageal-tracheal combitube (Combitube). Other devices such as rigid stylet, lightwand (blind technique) and indirect fiberoptic rigid style, such as Bullard's scope, Upsher scope and WuScope can also be used as an alternative to direct laryngoscopy. Each of these devices has its own set of benefits and shortcomings, and nothing is effective in all circumstances.
Fast induction and intubation
Fast sequence induction and intubation (RSI) are specific methods for induction of general anesthesia, commonly used in emergency surgery and other situations where the patient is assumed to have a "full fill". The objective of RSI is to minimize the likelihood of regurgitation and lung aspiration of gastric contents during induction of general anesthesia and subsequent tracheal intubation. RSI traditionally involves lung preoxygenation with a very fitting oxygen mask followed by sequential administration of an intravenous induced sleeping agent and rapid-acting neuromuscular inhibitors, such as rocuronium, succinylcholine, or cisatracurium besilate, prior to tracheal intubation.
One important difference between RSI and routine tracheal intubation is that the practitioner does not manually assist ventilation of the lungs after the onset of general anesthesia and respiratory arrest, until the trachea has been intubated and the cuff has increased. Another key feature of RSI is the manual application of 'cricoid pressure' to the cricoid cartilage, commonly referred to as the "Sellick maneuver", before airway instrumentation and tracheal intubation.
Since the introduction of the RSI, there has been controversy over almost every aspect of this technique, including:
- choice of drug induction, dosage and administration methods.
- avoid manual ventilation before tracheal intubation.
- optimal position and head-up, head-down or horizontal position of supine is the safest for induction of anesthesia in patients with full stomach.
- application of cricoid pressure (Sellick maneuver).
Named for the English anesthesiologist Brian Arthur Sellick (1918-1996) who first described the procedure in 1961, the aim of cricoid pressure was to minimize the likelihood of regurgitation and lung aspiration in the contents of the stomach. Cricoid pressure has been widely used during RSI for nearly fifty years, although there is no solid evidence to support this practice. The initial article by Sellick is based on a small sample size at high tidal volume, head down position and barbiturate anesthesia is the rule. Beginning around 2000, a large amount of evidence has been accumulated that questioned the effectiveness of cricoid pressure. The application of cricoid pressure can in fact replace the esophagus laterally instead of compressing it as described by Sellick. Cricoid pressure can also suppress the glottis, which can block the laryngoscopy view and actually cause delays in securing the airway.
Cricoid pressure is often confused with "BURP" maneuvers (Backwards Upwards Rightwards Pressure). While both of these involve digital pressure to the anterior (front) aspect of the larynx, the latter purpose is to enhance the glottic view during laryngoscopy and tracheal intubation, rather than to prevent regurgitation. Both CRP pressure and BURP maneuver have the potential to aggravate laryngoscopy.
RSI can also be used in a pre-hospital emergency situation when a patient is aware but respiratory failure is imminent (as in extreme trauma). This procedure is usually performed by aviation paramedics. Paramedics often use RSI to intubate before transportation because intubation in fixed wing aircraft or moving wings is extremely difficult due to environmental factors. The patient will be paralyzed and intubated in the soil before being transported by plane.
Cricothyrotomy
Cricothyrotomy is an incision made through the skin and cricothyroid membrane to form a patent airway during certain life-threatening situations, such as airway obstruction by a foreign object, angioedema, or massive facial trauma. Cryothyrotomy is almost always done as a last resort in cases where orotracheal and nasotracheal intubation is unlikely or contraindicated. Cricothyrotomy is easier and faster to perform than a tracheostomy, requiring no cervical spine manipulation and associated with fewer complications.
The easiest method for performing this technique is needle cricothyrotomy (also called percutaneous percutaneous cricothyrotomy), in which large intravenous catheters (12-14) are used to puncture the cricothyroid membrane. Oxygen can then be supplied through this catheter through jet insufflation. However, while needle cricothyrotomy may save lives in extreme circumstances, this technique is only meant to be a provisional measure until a definitive airway can be determined. While a cricothyrotomy needle can provide adequate oxygenation, a small diameter cricothyrotomy catheter is insufficient to remove carbon dioxide (ventilation). After one hour of apnea oxygenation through needle cricothyrotomy, one can expect PaCO 2 greater than 250 mm Hg and an arterial pH less than 6.72, although oxygen saturation is 98% or greater. A more definitive airway can be formed by performing a surgical cricothyrotomy, in which a 5 to 6 mm (0.20 to 0.24 inch) endotracheal tube or tracheostomy tube can be inserted through a larger incision.
Some manufacturers market packaged cricothyrotomy kits, which allow one to use a guided wire-guided dilation technique (Seldinger), or a classical surgical technique to insert a polyvinylchloride catheter through a cricothyroid membrane. The device can be stored in hospital emergency rooms and operating rooms, as well as ambulances and other pre-selected hospital settings.
Tracheostomy
The tracheostomy consists of making an incision on the front of the neck and opening the air passage directly through an incision in the trachea. The resulting opening can function independently as the airway or as a site for the tracheostomy tube to be inserted; This tube allows a person to breathe without using his nose or mouth. Opening can be done with a scalpel or a needle (referred to as a surgical and percutaneous technique respectively) and both techniques are widely used in current practice. To limit the risk of damage to the recurrent laryngeal nerves (the nerves that control voicebox), tracheotomy is performed as high as possible in the trachea. If only one of these nerves is damaged, the patient's voice may be disturbed (dysphonia); if both nerves are damaged, the patient will not be able to speak (aphonia). In acute settings, the indications for tracheotomy are similar to those for cricothyrotomy. In chronic settings, indications for tracheotomy include the need for long-term mechanical ventilation and tracheal secretion removal (eg, coma, or extensive surgery involving head and neck).
Children
There are significant differences in airway anatomy and respiratory physiology between children and adults, and this is carefully considered before tracheal intubation in every pediatric patient. The difference, which is quite significant in infants, gradually disappears as the human body approaches adulthood and body mass index.
For infants and young children, orotracheal intubation is easier than the nasotracheal route. Nasotrakeal intubation risks removing adenoid and nose bleeding. Despite the greater difficulty, nasotracheal intubation routes are better than orotracheal intubation in children undergoing intensive care and require long intubation because these routes allow for safer tube fixation. Like adults, there are a number of devices designed specifically for help with difficult tracheal intubation in children. Confirm the exact position of the tracheal tube performed as in adult patients.
Because a child's airway is narrow, a small amount of glottic or tracheal swelling can cause a critical obstruction. Inserting a tube that is too large relative to the tracheal diameter can cause swelling. Conversely, inserting a tube that is too small can cause an inability to achieve effective positive pressure ventilation due to escape of the gas through the glottis and out of the mouth and nose (often referred to as "leak" around the tube). Excessive leakage can usually be fixed by inserting larger tubes or cuffed tubes.
The tip of the properly placed tracheal tube will be in the mid-trachea, between the collarbone in anteroposterior chest radiography. The true diameter of the tube is that it produces a small leak at a pressure of about 25 cm (10 inches) of water. The corresponding internal diameter for the endotracheal tube is estimated to be approximately the same diameter as the little finger of the child. The appropriate length for the endotracheal tube can be estimated by doubling the distance from the corner of the child's mouth to the ear canal. For premature infants, the internal diameter of 2.5 mm (0.1 inches) is the appropriate size for the tracheal tube. For babies with normal gestational age, 3 mm inner diameter (0.12 in) is the appropriate size. For children who were given normal nutrition at age 1 and older, two formulas were used to estimate the exact diameter and depth for tracheal intubation. The internal diameter of the tube in mm is (patient age in 16)/4, while the exact depth of insertion cm is 12 (patient age in year/2).
Newborns
In newborns, free flow oxygen is used to be recommended during intubation, but since there is no useful evidence, the 2011 NRP guidelines no longer apply.
Predicting difficulty
Tracheal intubation is not a simple procedure and the consequences of failure are grave. Therefore, patients are carefully evaluated for possible adversity or prior complications. This involves taking a patient's medical history and performing a physical examination, a judgmental result against one of several classification systems. Surgical procedures proposed (eg surgery involving head and neck, or bariatric surgery) can cause a person to anticipate difficult intubation. Many individuals have unusual airway anatomies, such as those with restricted movement to their neck or jaw, or those with tumors, deep swelling due to injury or allergies, developmental abnormalities of the jaw, or excess fat tissue of the face and neck.. Using conventional laryngoscopy techniques, tracheal intubation can be difficult or even impossible in such patients. This is why all people who do tracheal intubation should be familiar with alternative techniques to secure the airway. The use of flexible fiber-optic bronchoscopy and similar tools has become one of the preferred techniques in the management of such cases. However, these devices require different skills than those used for conventional and expensive laryngoscopy to be purchased, maintained and repaired.
When taking a patient's medical history, the subject is asked for significant signs or symptoms, such as difficulty speaking or difficulty in breathing. This may indicate a blocking lesion at various locations in the upper airway, larynx, or tracheobronchial. Previous surgery history (eg, previous cervical fusion), injury, radiation therapy, or tumors involving the head, neck, and upper chest may also provide clues to potentially difficult intubations. Previous experience with tracheal intubation, especially difficult intubation, long duration intubation (eg, intensive care unit) or prior tracheotomy is also noted.
Examination of the respiratory tract in detail is important, in particular:
- neck of the spine: the subject should be able to tilt the head back and then move forward so that the chin touches the chest.
- range of motion of the jaw (temporomandibular joint): the three subject fingers should be able to fit between the upper and lower incisors.
- the size and shape of the maxillary and mandible, primarily looking for problems such as maxillary hypoplasia (maxillary undeveloped jaw), micrognathia (abnormally small jaw), or retrognathia (misalignment of the upper and lower jaws).
- thyromental distance: the three subject fingers should fit between the Adam's apple and chin.
- the size and shape of the tongue and the palate relative to the size of the mouth.
- teeth, especially note the presence of prominent maxillary incisors, loose or damaged teeth, or crowns.
Many classification systems have been developed in an attempt to predict the difficulties of tracheal intubation, including the Cormack-Lehane classification system, Intubation Difficulty Scale (IDS), and Mallampati scores. Mallampati score was taken from the observation that the basic size of the tongue affects difficult intubation. This is determined by looking at the anatomy of the mouth, and in particular the basic visibility of the palatine uvula, faucial pillars and soft palate. Although such medical assessment systems may be helpful in patient evaluation, no single score or combination of scores can be trusted to specifically detect all and only patients who are difficult to perform intubation. In addition, one study of experienced anesthesiologists, on the widely used Cormack-Lehane classification system, found that they did not get the same patient scores consistently over time, and only 25% could correctly define all four classes from the widely used Cormack-Lehane classification system.. In certain emergencies (eg, severe head trauma or suspected cervical spine injury), it may not be possible to fully exploit a physical examination and various classification systems to predict difficult tracheal intubation. In such cases, alternative techniques to secure the airway should be available.
Complications
Tracheal intubation is generally considered the best method for airway management under various circumstances, as it provides the most reliable means of oxygenation and ventilation and the greatest level of protection against lung regurgitation and aspiration. However, tracheal intubation requires a lot of clinical experience to be mastered and serious complications can occur even when done right.
Four anatomical features must be present for direct orotracheal intubation: adequate mouth opening (various temporomandibular joint movements), adequate pharyngeal space (determined by examining the back of the mouth), sufficient submandibular space (the distance between the thyroid cartilage and the chin, the space at which the tongue should be removed for laryngoscopy to see the glottis), and adequate extension of the cervical spine in the atlanto-occipital joint. If any of these variables are in any way compromised, intubation should be expected to be difficult.
Minor complications usually occur after laryngoscopy and insertion of orotracheal tubes. These are usually short-duration, such as sore throat, lip or gum laceration or other structures in the upper airway, peeling, cracked or dislodged teeth, and nasal injuries. Other common but potentially more serious complications include accelerated or irregular heartbeat, high blood pressure, high intracranial and introcular pressure, and bronchospasm.
More serious complications include laryngospasm, tracheal or esophageal perforation, lung aspiration of the contents of the stomach or other foreign objects, fractures or dislocations of the cervical spine, temporomandibular joints or aryltenoid cartilages, decreased oxygen content, increased arterial carbon dioxide, and weakness of the vocal cords.. In addition to these complications, tracheal intubation through the nasal route carries the risk of adenoid release and potentially severe nose bleeding. New technologies such as flexible fiberoptic laryngoscopy have a better value in reducing the incidence of some of these complications, although the cause of intubation trauma is most often still a lack of skill in the laryngoscopist section.
Complications can also be severe and durable or permanent, such as vocal cord damage, esophageal perforation and retrofaring abscess, bronchial intubation, or nerve injury. They can even be life-threatening, such as laryngospasm and negative pulmonary edema pressure (lung fluid), aspiration, unrecognized esophageal intubation, or unintentional disconnection or retraction of the tracheal tube. Potentially fatal complications are more commonly associated with prolonged intubation and/or tracheotomy including abnormal communication between the trachea and nearby structures such as the innominate artery (tracheoinnominate fistula) or esophagus (tracheoesophageal fistula). Other significant complications include airway obstruction due to loss of stiffness of the trachea, ventilator-related pneumonia and narrowing of the glottis or trachea. Cuff pressure is carefully monitored to avoid complications of over-inflation, much of which can be traced to excessive cuff pressures that limit the blood supply to the tracheal mucosa. A Spanish study 2000 percutaneous bedside tracheostomy reported an overall complication rate of 10-15% and a procedural 0% death, which is comparable to that of other series reported in the literature of the Netherlands and the United States.
Inability to secure the airway, with failure of oxygenation and subsequent ventilation are life-threatening complications that, if not promptly corrected, result in decreased oxygen content, brain damage, cardiovascular collapse, and death. When done incorrectly, the associated complications (eg, unrecognized esophageal intubation) can be fatal. Without adequate training and experience, the incidence of such complications is high. The case of Andrew Davis Hughes, of the Emerald Isle, NC is a widely known case where the patient is intimately intubated and, due to lack of oxygen, suffers severe brain damage and dies. For example, among paramedics in some urban communities of the United States, unknown esophageal or hypopharyngeal intubation has been reported 6% to 25%. Although not common, where basic emergency medical technicians are allowed to intubate, the reported success rate is as low as 51%. In one study, nearly half of patients with the wrong tracheal tube died in the emergency room. Therefore, the latest issue of the American Heart Association's Guide to Cardiac Heart Resuscitation has not emphasized the role of tracheal intubations that support other airway management techniques such as bag-valve-mask ventilation, laryngeal air mask and Combitube.
One complication - intentional and unconscious intubation intubation - are common (as often as 25% in the hands of inexperienced personnel) and tend to produce damaging or even fatal outcomes. In such cases, oxygen is inadvertently given to the abdomen, from which it can not be taken by the circulatory system, not the lungs. If this situation is not immediately identified and corrected, death will result from anoxia of the brain and heart.
Of 4,460 claims in the American Society of Anesthesiologists (ASA) Closed Claims Project database, 266 (about 6%) are for airway injury. Of these 266 cases, 87% of injuries were temporary, 5% permanent or disabled, and 8% resulted in deaths. Difficult intubation, age over 60 years, and female sex are associated with claims for esophageal or pharyngeal perforation. The initial signs of perforation present only 51% of perforation claims, whereas late sequelae occur in 65%.
Alternative
Although it offers the greatest level of protection against lung regurgitation and aspiration, tracheal intubation is not the only way to maintain a patent airway. Alternative techniques for airway management and oxygen delivery, volatile anesthesia or other respiratory gases include respiratory tract, i-gel, oropharyngeal airway, continuous positive airway pressure (CPAP mask), BiPAP nose mask, simple facial mask, and nasal cannula.
General anesthesia is often given without tracheal intubation in certain cases where the procedure is brief in duration, or a procedure in which the depth of anesthesia is insufficient to cause a significant compromise in ventilation function. Even for longer duration or more invasive procedures, general anesthesia may be given without tracheal intubation, provided the patient is carefully selected, and a beneficial-benefit-risk ratio (ie, the risk associated with unprotected airways is believed to be less than risk of tracheal intubation).
Airway management can be classified into closed or open techniques depending on the ventilation system used. Tracheal intubation is a typical example of a closed technique when ventilation occurs using a closed circuit. Some open techniques exist, such as spontaneous ventilation, apnea ventilation or jet vents. Each has its own special advantages and disadvantages that determine when it should be used.
Spontaneous ventilation is traditionally performed by inhalation agents (ie gas induction or inhaled induction using halothane or sevoflurane) but can also be performed using intravenous anesthesia (eg propofol, ketamine or dexmedetomidine). SponTaneous Respiration using IntraVEnous anesthesia and High Flow nose oxygen (STRIVE Hi) is an open airway technique that uses titration onto propofol that maintains ventilation at a deep level of anesthesia. It has been used in airway operations as an alternative to tracheal intubation.
History
- Tracheostomy
The earliest known tracheotomy depiction was found in two Egyptian tablets dating from about 3600 BC. The 110-page Ebers Papyrus, an Egyptian medical papyrus dated around 1550 BC, also makes reference to the tracheotomy. Tracheostomy is described in Rgveda, a Sanskrit text of ayurvedic medicine written about 2000 BC in ancient India. Sushruta Samhita from about 400 BC is another text of the Indian subcontinent about ayurvedic medicine and an operation that mentions tracheotomy. Asclepiades of Bithynia (c. 124-40 BC) is often credited as the first physician to perform non-emergency tracheotomy. Galen Pergamon (129-199 AD) clarified the anatomy of the trachea and was the first to show that the larynx formed a sound. In one of his experiments, Galen used a bellows to inflate the lungs of dead animals. Ibn S? N? (980-1037) describes the use of tracheal intubation to facilitate breathing in 1025 in the 14 volume medical encyclopaedia, The Canon of Medicine. In the 12th century medical text book Al-Taisir , Ibn Zuhr (1092-1162) - also known as Avenzoar - from Al-Andalus gives a correct description of tracheostomy surgery.
The first detailed description of tracheal intubation and subsequent artificial respiration came from Andreas Vesalius (1514-1564) from Brussels. In his monumental book published in 1543, De humani corporis fabrica , he describes an experiment in which he passed the reed into a dying animal trachea whose thorax has been opened and retained the vents by blowing into the reeds intermittently. Antonio Musa Brassavola (1490-1554) of Ferrara managed to treat a patient suffering from a peritonsillar abscess by tracheotomy. Brassavola published his account in 1546; this operation has been identified as the first recorded successful tracheostomy, despite many previous references to this surgery. Toward the end of the 16th century, Hieronymus Fabricius (1533-1619) describes a useful technique for tracheotomy in his writings, though he never actually performed the operation himself. In 1620, the French surgeon Nicholas Habicot (1550-1624) published a report on four successful tracheostomies. In 1714, the anatomist Georg Detharding (1671-1747) of the University of Rostock tracheotomized the drowning victim.
Although many examples are recorded in its use since antiquity, it was not until the early 19th century that tracheotomy has finally begun to be recognized as a legitimate means of treating severe airway obstruction. In 1852, the French physician Armand Trousseau (1801-1867) presented a series of 169 tracheotomy to the Acadà ©  © nie Impà © à © riale de MÃÆ'  © decine. 158 of these were performed for croup treatment, and 11 were performed for "chronic laryngeal disease". Between 1830 and 1855, more than 350 tracheotomies were performed in Paris, mostly at HÃÆ'Â'pital des Enfants Malades, a public hospital, with an overall survival rate of only 20-25%. This compares with 58% of 24 patients in private practice Trousseau, who fared better due to greater postoperative care.
In 1871, German surgeon Friedrich Trendelenburg (1844-1924) published a paper describing the first elective successful human tracheostomy to be performed for the purpose of general anesthesia. In 1888, Sir Morell Mackenzie (1837-1892) published a book that discusses indications for tracheotomy. At the beginning of the 20th century, tracheotomy became the lifesaving treatment of patients suffering from paralytic polio paralysis requiring mechanical ventilation. In 1909, the Philadelphia laryngologist, Chevalier Jackson (1865-1958) described the technique for tracheotomy used to this day.
- Laryngoscopy and non-surgical techniques
In 1854, a Spanish singing teacher named Manuel GarcÃÆ'a (1805-1906) became the first to see a glottis that functioned in living humans. In 1858, the French pediatrician EugÃÆ'¨ne Bouchut (1818-1891) developed a novel technique for non-surgical orotracheal intubation to bypass laryngeal obstruction caused by diphtheria-associated pseudomembrane. In 1880, Scottish surgeon William Macewen (1848-1924) reported the use of orotracheal intubation as an alternative to tracheotomy to allow patients with glottic edema to breathe, as well as in general anesthesia settings with chloroform. In 1895, Alfred Kirstein (1863-1922) of Berlin first described the direct visualization of the vocal cords, using the esophagoscope he had modified for this purpose; he calls this tool an autoscope.
In 1913, Chevalier Jackson was the first to report a high success rate for direct laryngoscopy as a means for tracheal intubation. Jackson introduced a new laryngoscope blade that incorporates components that the operator can slide out to allow space to pass through the endotracheal tube or bronchoscope. Also in 1913, New York surgeon Henry H. Janeway (1873-1921) published the results he obtained using a laryngoscope that he recently developed. Another pioneer in this field was Sir Ivan Whiteside Magill (1888-1986), who developed the novel nasotracheal intubation technique, Magill pliers, Magill laryngoscope blades, and some clothing for the administration of volatile anesthetic agents. The Magill curve of the endotracheal tube is also named for Magill. Sir Robert Reynolds Macintosh (1897-1989) introduced a curved laryngoscope knife in 1943; The Macintosh blade remains to this day the most widely used laryngoscope blade for orotracheal intubation.
Between 1945 and 1952, optical engineers built on the earlier work of Rudolph Schindler (1888-1968), developed the first gastrocamera. In 1964, optical fiber technology was applied to one of these early gastrocameras to produce the first fiber-optic endoscope. Originally used in upper GI endoscopy, it was first used for laryngoscopy and tracheal intubation by Peter Murphy, an anesthesiologist of England, in 1967. The concept of using a stylet to replace or replace an orotracheal tube was introduced by Finucane and Kupshik in 1978, using a catheter central vein.
By the mid-1980s, flexible fiber-optic bronchoscopy had become an indispensable instrument in the pulmonology and anesthesia communities. The digital revolution of the 21st century has brought new technology to the art and science of tracheal intubation. Some manufacturers have developed video laryngoscopes that use digital technology such as CMOS active pixel sensors (CMOS APS) to produce a glottic view so trachea may be intubated.
See also
- instrat Intratrakeal
Note
References
External links
- Direct laryngoscopy video recorded with Airway Cam (TM) imaging system
- Examples of some devices to facilitate tracheal intubation
- Rich free image sources describe different types of endotracheal tubes
Source of the article : Wikipedia
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