Figure 3-3. View of the lateral chest wall showing an intercostal space and layers. Note their relation to pleura and lung. Tube and diagram indicate the positioning for tube thoracostomy. Needle and diagram indicate the positioning for an intercostal nerve block. (Adapted with permission from Moore KL: Clinically Oriented Anatomy 3rd ed. Baltimore, Williams & Wilkins, 1992 p 57; upper inset reprinted with permission from Scott DB: Techniques of Regional Anaesthesia. East Norwalk, CT, Appleton & Lange, 1989, p 147; lower inset adapted with permission from Chen H, Sonneday CJ, Lille-moe KD, eds: Manual of Common Bedside Surgical Procedures, 2nd ed. Philadelphia, Lippincott Williams & Wilkins, 2000, p 123.)
3. The tube is inserted near the upper border of the rib to avoid the intercostal vein, artery, and nerve, which run in the costal groove between the internal intercostal muscle and the innermost intercostal muscle.
Intercostal nerve block (see Figure 3-3)
1. Intercostal nerve block may be necessary to relieve pain associated with a rib fracture or herpes zoster (shingles). A needle is inserted at the posterior angle of the rib, along the lower border of the rib, to bathe the nerve in anesthetic.
3. Several intercostal nerves must be blocked to achieve pain relief because of the presence of nerve collaterals (i.e., overlapping of contiguous dermatomes; see Figure 2-3).
IV. POSTERIOR CHEST WALL. Fractures of the lower ribs (Figure 3-4)
A. A rib fracture on the right side may damage the right kidney and liver.
B. A rib fracture on the left side may damage the left kidney and spleen.
C. A rib fracture on either side may damage the pleura as it crosses rib 12.
Figure 3-5. Mediastinum. (/A) Superior, anterior, middle, and posterior divisions of the mediastinum. (B) Lateral radiograph demarcating the superior (S), anterior (A), middle (M), and posterior (P) divisions of the mediastinum. (B adapted with permission from Freundlich IM, Bragg DG: A Radiologic Approach to Diseases of the Chest, 2nd ed. Baltimore, Williams & Wilkins, 1997, p 610.)
Figure 3-4. Posterior chest wall. Note that the kidneys are located from vertebrae T12 to L3 and that the right kidney is lower than the left. The pleura extends across rib 12 (dotted line). Note the structures that may be injured by fractures to the lower ribs. During splenectomy, the left kidney may be damaged because of its close anatomic relation and connection through the splenorenal ligament. K-kidney. (Adapted with permission from Moore KL: Clinically Oriented Anatomy, 3rd ed. Baltimore, Williams & Wilkins, 1992, p 213.)
V. MEDIASTINUM (Figure 3-5) is the space between the pleural cavities in the thorax. It is bounded laterally by the pleural cavities, anteriorly by the sternum, and posteriorly by the vertebral column. It is divided into superior, anterior, middle, and posterior sections.
1. The superior mediastinum contains the trachea, esophagus, thymus, phrenic nerVes, azygous vein, SVC, brachiocephalic artery and veins, aortic arch, left common carotid artery, left subclavian artery, and thoracic duct.
2. Pathologies commonly found in this area include: aortic arch aneurysm, esophageal perforation from endoscopy or an invading malignancy, and traumatic rupture of the trachea.
B. Anterior mediastinum
1. The anterior mediastinum contains the thymus, fat, lymph nodes, and connective tissue.
C. Middle mediastinum
1. The middle mediastinum contains the heart, pericardium, phrenic nerves, ascending aorta, SVC, IVC, and coronary arteries and veins.
2. Pathologies commonly found in this area include: pericardial cysts, bronchiogenic cysts, and sarcoidosis.
1. The posterior mediastinum contains the descending aorta, esophagus, thoracic duct, azygous vein, splanchnic nerves, vagus nerves (cranial nerve X), and sympathetic trunk.
2. Pathologies commonly found in this area include: ganglioneuromas, neuroblastomas, and esophageal diverticula or neoplasms.
Was this article helpful?
If Pregnancy Is Something That Frightens You, It's Time To Convert Your Fear Into Joy. Ready To Give Birth To A Child? Is The New Status Hitting Your State Of Mind? Are You Still Scared To Undergo All The Pain That Your Best Friend Underwent Just A Few Days Back? Not Convinced With The Answers Given By The Experts?