tailieunhanh - Ebook The ABSITE review (4/E): Part 2

Part 2 book “The ABSITE review” has contents: Cardiac, gastrointestinal hormones, statistics and patient safety, pediatric surgery, orthopedics, neurosurgery, gynecology, hernias, abdomen, and surgical technology, biliary system, pancreas, small bowel, and other contents. | CHAPTER 25. THORACIC ANATOMY AND PHYSIOLOGY Azygous vein runs along the right side and dumps into superior vena cava Thoracic duct runs along the right side, crosses midline at T4–5, and dumps into left subclavian vein at junction with internal jugular vein Phrenic nerve – runs anterior to hilum Vagus nerve – runs posterior to hilum Right lung volume 55% (3 lobes: RUL, RML, and RLL) Left lung volume 45% (2 lobes: LUL and LLL and lingula) Quiet inspiration – diaphragm 80%, intercostals 20% Greatest change in dimension superior/inferior Accessory muscles – sternocleidomastoid muscle (SCM), levators, serratus posterior, scalenes Type I pneumocytes – gas exchange Type II pneumocytes – surfactant production Pores of Kahn – direct air exchange between alveoli PULMONARY FUNCTION TESTS Need predicted postop FEV1 > (or > 40% of the predicted postop value) • If it is close → get qualitative V/Q scan to see contribution of that portion of lung to overall FEV1 → if low, may still be able to resect Need predicted postop DLCO > 10 mL/min/mm Hg CO (or > 40% of the predicted postop value) • Measures carbon monoxide diffusion and represents oxygen exchange capacity • This value depends on pulmonary capillary surface area, hemoglobin content, and alveolar architecture No resection if preop pCO2 > 50 or pO2 3 cm but > 2 cm away from carina. T3: invasion of chest wall, pericardium, diaphragm, or cm or subcarinal > cm) on chest CT • Does not assess aorto-pulmonary (AP) window nodes (left lung drainage) • Assesses ipsilateral (N2) and contralateral (N3) mediastinal nodes • If mediastinal nodes are positive, tumor is unresectable • Looking into middle mediastinum with mediastinoscopy • Left-side structures – RLN, esophagus, aorta, main pulmonary artery (PA) • Right-side structures – azygous and SVC • Anterior structures – innominate vein, innominate artery, right PA Chamberlain procedure (anterior thoracotomy or parasternal mediastinotomy) – assesses enlarged AP window .