2. Anatomy of Trachea and Bronchi

tube of cartilage with a membranous lining which is continuous inferiorly with the larynx. The trachea proper is 10–11 cm long, extending downwards from the cricoid cartilage at the level of the sixth cervical vertebra, as far as the sixth thoracic vertebra (in full inspiration). diameter in the adult is around 20 mm. year of life its diameter is 3 mm or less,

Structure: it comprises 16–20 C-shaped cartilages attached vertically by fibroelastic connective tissue, which helps explain the mobility of the structure. displaced slightly rightwards by the arch of the aorta @ Bifurcation

the isthmus of the thyroid overlying the second to fourth tracheal rings. sternohyoid and sternothyroid muscles, the oesophagus lies posteriorly, and the recurrent laryngeal nerves run in grooves between the trachea and oesophagus its lower course, it is related on the right to the lung and pleura, to the brachiocephalic artery and veins, On the left, it is related to the arch of the aorta and the left common carotid and subclavian arteries

T5 R = shorter (3 cm long), wider and angled more vertically than the left hat foreign bodies and tracheal tubes are more likely to enter its orifice than the left left main bronchus is more obliquely placed and is some 5 cm in length. In children, the angles of the bronchi at the carina are equal.

within about 2.5 cm of the bifurcation, the right main bronchus gives off the right upper lobe bronchus It is this right upper lobe bronchus that is most at risk from inadvertent occlusion by a tracheal tube or a right-sided double-lumen endobronchial tube The right main then gives off the middle lobe bronchus, which is directed downwards and forwards The medial, anterior, lateral and posterior basal segments arise in due course from the main stem of the lower lobe bronchus, which continues in its downward direction.

the longer left main bronchus gives off the left upper lobe bronchus after about 5 cm, this then divides into a superior division from which arise apical, posterior and anterior segments of the upper lobe, The anatomy of the left lower lobe is similar to the right in that the left lower lobe bronchus gives off superior, anterior basal, lateral basal and posterior basal segments

Right upper lobe Apical Lateral Apical Left upper lobe Apical Left lower lobe Anterior Lingula Superior Posterior RML Lateral Medial RLL Apical Medial basal Anterior basal Lateral basal Posterior basal LLL Apical Medial basal Anterior basal Lateral basal Posterior basal

• If the patient is supine, it is more likely that the apical segments of the lower lobes will be affected because of the direct posterior projection of the bronchus of the apical segment. • lateral position, then aspiration is more likely to affect the upper lobes. • Prone. RML + Lingula • sitting, it will be the posterior or lateral basal segments of the lower lobes that are contaminated

the cardinal sign will be otherwise unexplained desaturation. In a patient who has not received neuromuscular blockers this may be preceded by coughing which fails to settle as anaesthesia deepens Auscultation may reveal rhonchi and/or crepitations. Chest X-ray changes often occur early enough to support the diagnosis of significant aspiration, although they can be delayed for 6 hours or more. Management is essentially expectant. Does not need supplemental oxygen to maintain a normal SpO2 after 2 hours, then it is unlikely that there will be significant sequelae patient remain oxygen-dependent, then he or she will need supportive therapy which in severe cases may include intubation and ventilation. There is no evidence of any benefit from the administration of prophylactic antibiotics or steroids

You will see first the trachea; the anterior wall, which is composed of complete cartilaginous bands; and the posterior wall, which is membranous. The carina separates the right and left main stem bronchi Rght main bronchus is wider than the left and is shorter at ~3 cm long. It is also angled more vertically than the left. Within ~2.5 cm of the bifurcation can be seen the right upper lobe bronchus middle lobe bronchus, which is directed downwards and forwards. Just below the origin of the middle lobe bronchus and opposite to it is the bronchus of the apical segment of the lower lobe; beyond this the main stem of the lower lobe bronchus continues downwards.

Left side view: the left main bronchus is more obliquely placed and is about 5 cm in length. It gives off the left upper lobe bronchus near its termination at about 5 cm, which then divides into a superior division and a lingular bronchus. The anatomy of the left lower lobe bronchus is similar to the right.

pulmonary resection, oesophagogastrectomy, surgery of the thoracic aorta, anterior spinal fixation and thoracoscopic sympathectomy. A left-sided tube is almost always favoured because this avoids the risk of inadvertently occluding the origin of the right upper lobe bronchus. double-lumen tube is positioned correctly when the upper surface of the bronchial cuff lies immediately distal to the bifurcation of the carina. The position of the tube should be checked endoscopically.

this may be caused by external trauma but has also been reported not infrequently as a complication of tracheal intubation. Clinical features may include alteration of phonation and stridor (if the larynx is involved), hoarseness, subcutaneous emphysema, pain on external palpation and pain on movement of the tongue.