Cricoid cartilage

Introduction In the last two decades, clinical application of ultrasound technology has expanded, not only for visualization of anatomical structures and identification of pathology, but also to facilitate medical procedures. Recently, the use of point-of-care-ultrasound (POCUS) has gained popularity for a variety of perioperative procedures and guidance in high-acuity settings. Another area of interest is the use of POCUS for evaluation of upper airway structures. This has proved to be a valuable and noninvasive tool for anesthesiologists, critical care and emergency physicians. Training and understanding of applied airway sonoanatomy will enable physicians to identify abnormal or difficult airway and perform procedures such as percutaneous cricothyroidotomy or tracheostomy, confirmation of endotracheal tube (ETT) placement, and performance of regional blocks for airway management. Training and understanding of applied airway sonoanatomy will enable physicians to identify abnormal or difficult airway and perform procedures such as percutaneous cricothyroidotomy or tracheostomy, confirmation of endotracheal tube placement, and performance of regional blocks for airway management. Sonoanatomy of the Upper Airway The important airway structures that can be visualized using ultrasound are tongue, hyoid bone, epiglottis, thyrohyoid membrane, thyroid cartilage, cricothyroid membrane, cricoid cartilage, trachea, and esophagus. 1 (Table 1, Figures 1-9) The POCUS airway scanning t...

Cricothyrotomy, whether traditional surgical cricothyrotomy or percutaneous cricothyrotomy using a guidewire, uses an incision through the skin and cricothyroid membrane through which an artificial airway is inserted into the trachea. Cricothyrotomy is typically done emergently, when endotracheal intubation is contraindicated or unachievable by other methods of tube insertion, and non-definitive methods of airway management and ventilation (eg, extraglottic devices such as a laryngeal mask airway) fail to adequately ventilate and oxygenate the patient. Cricothyrotomy using a guidewire is similar to the How To Do Femoral Vein Cannulation Percutaneous cannulation of the femoral vein uses anatomic landmarks to guide venipuncture and a Seldinger technique to thread a central venous catheter through the femoral vein and into the... read more (catheter over guidewire) of central venous line insertion and may be more suitable for operators with limited surgical experience. Needle cricothyrotomy, a temporary method that uses a 12- to 14-gauge angiocatheter attached to a bag-valve-mask device (or a jet ventilator if available), is the preferred cricothyrotomy method for children < 10 years old. This apparatus can be easily assembled by attaching the angiocatheter to a 3-mL syringe with the plunger removed. The adapter from a 6.5-mm endotracheal (ET) tube is then attached to the syringe, and the patient is ventilated using a bag-valve-mask device attached to the ET tube adapter. Ind...

The larynx (voice box) is an organ located in the anterior neck. It is a component of the respiratory tract, and has several important functions, including phonation, the cough reflex, and protection of the lower respiratory tract. There are nine cartilages located within the larynx; three unpaired, and six paired. They form the laryngeal skeleton, which provides rigidity and stability. In this article, we shall examine the anatomy of the laryngeal cartilages. Unpaired Cartilages The three unpaired cartilages are the epiglottis, thyroid and cricoid cartilages. Thyroid Cartilage The thyroid cartilage is a large, prominent structure which is easily visible in adult males. It is composed of two sheets (laminae), which join anteriorly to form the laryngeal prominence (Adam’s apple). The posterior border of each sheet project superiorly and inferiorly to form the superior and inferior horns (also known as cornu). The superior horns are connected to the hyoid bone via the lateral thyrohyoid ligament, while the inferior horns articulate with the cricoid cartilage. Cricoid Cartilage The cricoid cartilage is a complete ring of hyaline cartilage, consisting of a broad sheet posteriorly and a much narrower arch anteriorly (said to resemble a signet ring in shape). The cartilage completely encircles the airway, marking the inferior border of the larynx at the level of C6. It articulates with the paired arytenoid cartilages posteriorly, as well as providing an attachment for the inferi...

Subglottic stenosis (SGS) is a narrowing of the airway below the vocal cords (subglottis) and above the trachea. Subglottic stenosis will involve narrowing of the cricoid, the only complete cartilage ring in the airway. This narrowing is often caused by scarring inthe larynx just below the vocal cordsbut may also involve the vocal cords and affect the voice as well. Subglottic stenosis comes in two forms: acquired and congenital. Endoscopic view of congenital subglottic stenosis. • Acquired subglottic stenosis often occurs after long periods of intubation and ventilation for respiratory problems. • Congenital subglottic stenosis occurs as a rare birth defect and may be associated with other genetic syndromes and conditions. The airway remains narrow because the airway cartilage did not form properly before birth. Causes The exact cause of the scarring is not known at this time. Individual neonatal intensive care units only have small numbers of infants who develop this condition and not enough patients in each individual unit to have statistically significant data. Multicenter studies are needed to better understand the cause of subglottic stenosis. However, current evidence suggests a number of important risk factors include prolonged intubation, low birth weight, reflux, sepsis and others. Furthermore, a tracheostomy may cause stenosis or malacia (softening) at the tracheostomy site especially if it is placed high in the trachea. Signs and symptoms Neck radiograph showin...

Ranu R. Jain, Mary F. Rabb, in Benumof and Hagberg's Airway Management, 2013 CSubglottis The cricoid cartilage is the narrowest portion of the infant's airway, about 5 mm in diameter, compared with the vocal cords of the adult airway. 6 The infant's larynx is funnel shaped with a narrow cricoid cartilage, whereas the adult airway is cylindrical. Tight-fitting endotracheal tubes that compress the mucosa at this level may cause edema and increase resistance to flow. Resistance to flow is inversely proportional to the radius of the lumen to the fourth power (r 4). One millimeter (1 mm) of edema can reduce the cross-sectional area of the infant trachea by 75%, versus 44% in the adult trachea. Lee Coleman, ... Sivam Ramanathan, in Benumof and Hagberg's Airway Management, 2013 bCricoid Cartilage The cricoid cartilage (see Fig. 1-9) represents the anatomic lower limit of the larynx and helps support it. 35 The name cricoid is derived from the Greek words krikos and eidos, meaning shaped like a ring, and it is frequently said to have a signet-ring shape. It is thicker and stronger than the thyroid cartilage and represents the only complete cartilaginous ring in the airway. For this reason, cautious downward pressure on the cricoid cartilage to prevent passive regurgitation is possible without subsequent airway obstruction. Traditionally, it was thought that the pediatric airway was narrowest at the level of the cricoid, and recommendations for ETT size were made based on the size ...

JazzIRT / E+ / Getty Images What are the Important Acronyms to Understand? CICO is an acronym representing "cannot intubate, cannot oxygenate". This is a critical moment when your healthcare provider is not able to provide oxygen to you during an emergency situation. In this situation, non-invasive ( FONA is an acronym representing "front of neck airway". FONA forms of airway management include both tracheostomy (surgically placing a hole in the trachea) and cricothyrotomy (surgically placing a hole through the cricothyroid membrane into the trachea). FONA methods are only used when other forms that are less invasive have failed. • Bag-mask involves a facemask connected to a bag that can be squeezed to push oxygen through your nose and mouth into your lungs. This is the least invasive form of airway management. AMBU bag is a common example that you may hear. • Extraglottic airway devices (also known as supraglottic airway devices) are breathing tubes that are placed above the vocal cords. Laryngeal airway mask (LMA) is a common example. • Intubation places a breathing tube past the vocal cords. This can be inserted by either direct visualization or using video laryngoscopy. • Cricothyrotomy What Is the Cricothyroid Membrane? The cricothyroid membrane is a ligament that attaches the thyroid cartilage to the cricoid. The thyroid cartilage is located above your thyroid and in front of your larynx that houses your voice box. The top-middle part of the thyroid cartilage forms a...

a specialized, fibrous connective tissue present in adults, and forming most of the temporary skeleton in the embryo, providing a model in which most of the bones develop, and constituting an important part of the organism's growth mechanism; the three most important types are hyaline cartilage, elastic cartilage, and fibrocartilage. Also, a general term for a mass of such tissue in a particular site in the body. The thyroid and cricoid cartilages can fracture, buckle and dislocate with respect to each other (Figure 4) Paraglottic hemorrhage and/or edema as well as abnormal endolaryngeal contour or configuration are findings at CT that often accompany cartilage injuries (Figure 4) In newer management paradigms, laryngeal cartilage fractures are surgical lesions, reduced and fixed with adaptation plating to restore the skeletal anatomy necessary for proper phonation (Figure 5).