Thorax Clinical Supplement

pectus excavatum

a depression of the sternum, associated with exercise intolerance, dyspnea, chest pain; funnel chest

Pectus Carinatum

an anterior protrusion of the sternum, associated with dyspnea, frequent respiratory tract infections, common in scoliosis; pigeon chest

Sternal Angle of Louis

the union of the manubrium and the body fo the sternum; associated with the sternal end of the 2nd ribs, landmark for T4, approximates the superior border of the mediastinum, arch of the aorta and bifurcation of the trachea

What can be produced by the sternum?

Red bone marrow.

Sternal Biopsy for bone marrow

can result in sternal fracture, pneumomediastinum, pneumothorax or cardiac tamponade

Thoracic Outlet Syndrome

bony issues with a cervical rib or hypo plastic first rib, soft tissue changes with hypertrophic/spastic muscles and a fibrous CT band or trauma or tumors; associated with compression of C8 and T1 and vascular compression (subclavian a)
SS: cold fingers, color changes in hands, claudication, pain

Costovertebral articulation information

With vertebral body or with transverse processes. Ribs articulate with the superior facet of the same number vertebra and the inferior facet of the superior vertebra and the intervening intervertebral disc.

Ribs 1, 11 and 12 articulate only with the thoracic vertebra of the same number.

Ribs 11 and 12 do not articulate with transverse processes

Costochondral Articulation

primary cartilaginous

What type of joint is costovertebral

synovial, plane/gliding

interchondral

synovial, plane/gliding; found between costal cartilages of ribs 6/7, 7/8 and 8/9. Contact between ribs 9 and 10 is never synovial.

Sternocostal

rib 1 - primary cartilaginous, when rib 1 moves the rest of the cage comes; ribs 2-7 are synovial, plane/gliding

Sternoclavicular

synovial, saddle

manubriosternal

secondary cartilaginous

xiphisternal

primary cartilaginous

Rib Fractures lead to...

flail chest, pneumo or hemothorax, spleen injury or liver injury, and lacerations of the aorta/great vessels (1st/2nd rib)
Diaphragmatic hernia (if diaphragm is pierced)

Key Dermatomes

T4-nipple, T6-xyphoid

herpes zoster

infection of the posterior root ganglion; produces pain/burning and blisters along the cutaneous distribution of the affected ganglion

most common ganglion affected by herpes zoster?

T5-T10 - ~66% of cases of herpes zoster eruptions

intercostal nerve block

injection of anesthesia into the intercostal space; anesthesia should be directed between internal and innermost intercostals muscles; nerves are most at risk of iatrogenic injury

Lymphatic drainage

generally follows the arterial supply backwards to lymph nodes around the main arterial truks

Exceptions to lymph drainage

lungs, parts of the liver, oral cavity and tongue (drain bilaterally)

Metastasis of cancerous cells from a primary tumor occurs by three mechanisms

local spread/invasion: includes seeding of pleura and peritoneum, via lymphatic channels or by blood vessels

mesothelioma

local spread/invasion of cancerous cells from a primary tumor that seeds the pleura and perineum

lymphadenopathy

cancer can spread through the lymphatic channels to the lymph nodes to the lungs (via jugulo-venous angle) causing this condition

Liver and Lung Cancer

metastasis can move via the blood vessels and seed the organ at next major capillary bed which is often these 2; most sarcomas spread predominantly by blood vessels

Most common site of metastasis

lymph nodes, liver, and lung

Where does a majority of the breast tissue lymph drain to?

axillary nodes (anterior/pectoral)

What is a secondary site of lymph drainage in the breast, especially medial quadrants?

parasternal nodes

Lymph from lower quadrants drains...

Drains to inferior phrenic nodes (route for mets to liver)

parasternal lymph nodes

provide a route for breast cancer to the liver. The liver is a major lymph producing organ which has a variety of routes and relevant lymph channels.

signs/symptoms of breast cancer

breast mass/focule nodule, axillary lump, skin dimpling, impaired lymphatic drainage, nipple inverts, retracts or has blood dishcharge, skin ulceration (advanced) or metastasis (difficulty breathing, bone/back pain, jaundice, neurological).

Structures at risk during mastectomy or radical dissection of diseased axillary lymph nodes

Long thoracic nerve, winged scapula
Intercostobrachial nerve, sensory loss in medial arm; axilla
Pectoral nerves, weakness in medial rotation; adduction of humerus

Where do most malignant breast tumors arise from?

~60% from superior lateral quadrant

Route of lymph from skin of breast

axillary, inferior deep cervical, infraclavicular and parasternal nodes (lymph from nipple/areola is not included)

Path of breast metastasis to lungs

venous channels -\> intercostal veins -\> azygos system -\> lungs or pleura

path of breast metastasis to lungs

venous channels -\> intercostal veins -\> azygos system -\> bastion's intervertebral plexus -\> vertebrae or brain.

Pleura space

a potential space between the visceral and parietal layers of pleura

what is maintained in the pleura space

a vacuum for negative pressure that is needed for breathing. If this space is disrupted the lung cannot function properly

pleural effusion

accumulation of fluid in the pleural sac

pneumothorax

air in the pleural cavity

spontaneous pneumothorax

rupture of visceral pleura, air enters the pleural cavity. Risk Factors: Marfan or Ehlers-Danlos syndrome, tall, thin stature, young (20-30s), smoker. Acute onset chest/shoulder pain (worse with inspiration), shortness of breath. Chest x-ray is a line of visceral pleura (collapsed lung), mediastinal shift AWAY from the affected lung; such mediastinal shift reduces the size the pulmonary cavity on the contralateral side, resulting in impaired pulmonary function and impairs venous return to the heart which leads to diminished atrial filling and reduced cardiac output

Open/Traumatic Pneumothorax

Anatomy: results from traumatic injury to parietal pleura (rib fx, stabbing), permitting air to enter the pleural cavity from outside (during inspiration)
S/S \= chest trauma, shortness of breath, decreased breath sounds
Chest x-ray \= chest wall defect (e.g. broken ribs) line of visceral pleura

Tension Pneumothorax

rupture of the visceral pleura, lung tissue forms a 1-way valve so that each breath more air enters the pleural cavity from the lung; air is trapped under positive pressure and displaces the trachea and mediastinum AWAY from affected lung - such mediastinal shift reduces the size of the pulmonary cavity on the contralateral side, resulting in impaired pulmonary function and compresses the diaphragm and vena cava which diminished atrial filling and leads to reduced cardiac output (hypotension)
S/S: sudden onset chest pain, dyspnea, reduced breath sounds, hypotension, hypoxia, jugulovenous distension, tachycardia, anxiety, fatigue
Requires immediate decompression (emergency \= no time for radiographs) - thoracostomy @ 2nd intercostal space at midclavicular line, then chest tube

what are the three types of pneumothorax?

spontaneous, traumatic, tension

Needle location for therapeutic pleural tapping

Superior to 12th rib, posteriorly

hydropneumothrax

air and fluid

hemopneumothorax

blood + air

chylothorax

lymph (milky white fluid); injury to thoracic duct

pyopneumothorax

pus and air

empyema

pus without air, from infection (commonly bacterial pneumonia, abscess)

pleurisy

inflammation of the pleura

thoracocentesis, thoracentesis

used for treatment of pleural effusions or empyemas; is most commonly done at the 8th of 9th intercostal space near the midaxillary line and the needle is inserted along the inferior aspect of the intercostal space

intercostal nerve block location

superior aspect of the intercostal space

Chest tubes

commonly inserted to drain large amounts of air, fluid, etc from the pleural space - tube is inserted at 4th or 5th intercostal space near the midaxillary line

parietal pleura innervation

GSA, costal and peripheral diaphragmatic - intercostal nerves, mediastinal and central diaphragmatic is phrenic nerve

Visceral pleura innervation

GVA- no pain innervation

Phrenic nerve irritation

inflammation can "refer" pain to shoulder

Visceral Pleura innervation

GVA \= no pain innervation

Oblique Fissures

scapular line (4th rib), midaxillary line (5th rib), midclavicular line (6th rib)

Horizontal Fissure

midaxillary line (4th rib), midclavicular rib (4th rib)

How to listen to breath sounds from superior lobes

anterior chest wall at the costochondral junction. Right (3rd rib), Left (5th rib)

Breath sounds from middle lobe

along the anterior chest wall, under the 4th rib; Right lung only

breath sounds from inferior lobes

below the 5th rib

inferior limit of visceral and parietal pleura

Visceral: scapular line (10th rib), midaxillary line 8th, midclavicular line 6th. Parietal: scapular line (12th), Midaxillary Line (10th) and Midclavicular line (8th)

Most common sites of lung metastases are

central nervous system, bone (vertebrae), liver and adrenal gland.

how can lung metastases migrate?

by the venous drainage of the lungs, such as the pulmonary veins.

Lymphatic drainage of the right lung

tracheobronchial nodes to the R paratracheal

Lymphatic drainage of the left lung

superior lobe: superior tracheobronchial to Left paratracheal; inferior lobe: inferior tracheobronchial/carinal nodes to R paratracheal \>> Left paratracheal

Where does the left superior lobe rarely drain to?

the carinal nodes

What can enlarged lung nodes do?

displace the carina and this can be detected on bronchoscopy

Where are aspirated foreign objects most likely to go?

right main bronchus (then to middle or inferior lobar branch) because it is shorter, wider and more vertical than the left bronchus

What is the cough reflex?

associated by foreign body aspiration, sensory and motor by cranial nerve 10. Motor is assisted by phrenic and intercostal nerves.

Atelectasis

collapse of lung or lobe resulting from blockage of the airway; the opening to the right middle lobe is the smallest/most narrow, as a result the R middle lobe is the most commonly affected; obstructive atelectasis may cause mediastinal shift towards the affected lung

Pancoast tumor

tumor of the lung apex which can affect a, the lower trunk of the brachial plexus (Klumpke Palsy), b, Cervical sympathetic chain (Horner Syndrome)

Pulmonary embolism definition

blockage of a branch of the pulmonary artery with a blood clot (DVT), fat droplet or air bubble; often from deep veins in the lower extremity

Signs and symptoms of Pulmonary Embolism

from dvt: edema, leg pain/tenderness; chest pain, dyspnea, tachypnea, tachycardia, fever, cyanosis

Risk Factors for Pulmonary Embolism

poor venous flow/stasis, recent travel of four hours or more, immobility, hyper coagulable states, recent surgery, COPD, pregnancy, oral contraceptives, estrogen therapy, smoking

Hemoptysis

"Spitting up blood;" bleeding from the airway from bronchial a \>> pulmonary arteries; compare to hematemesis

Thymic tumors

can compress the trachea or recurrent laryngeal nerve, esophagus, great veins; a significant number of patients with myasthenia graves have thymic tumors

thymic tumor compression of recurrent laryngeal nerve causes...

hoarseness

thymic tumor compression of esophagus causes...

dysphagia

thymic tumor compression of great veins causes..

cyanosis

Borders of the cardiac silhouette

left - aortic arch, pulmonary trunk, left auricle and left ventricle. Right - right brachiocephalic vein, superior vena cava vein, r atrium and the inferior vena cava

heart autonomics - sympathetic

T1-T4, IML preganglion, sympathetic chain

heart autonomics - parasympathetic

medulla CNS, dorsal vagal nucleus preganglion, intramural postganglion

Lung autonomics - sympathetic

T2-7, IML preganglion and sympathetic chain

Lung Autonomics - parasympathetic

medulla CNS, dorsal vagal nucleus preganglion and intramural (post ganglion)

upper esophagus sympathetic

T1-4 CNS, IML (preganglion), sympathetic chain (post ganglion)

upper extremity sympathetic

T2-7 CNS, IML (preganglion), sympathetic chain is postganglion

upper esophagus parasympathetic

medulla CNS level, dorsal vagal nucleus (preganglionic), intramural (postganglionic)

Transverse pericardial sinus

insertion of a finger through this sinus puts the aorta and pulmonary artery anterior to the finger; for CABG surgery

pericarditis

inflammation of the pericardium, characterized by pericardial friction rub

pericardial effusion

accumulation of fluid in the pericardial space

pericardium innervation

vagus nerve, phrenic nerve and sympathetics. Will feel shoulder pain if phrenic nerve is inflamed

pericardiocentesis

performed by insertion of a needle inferior to the thoracic cage at the left xiphisternal junction; the needle is directed towards the pericardium to remove fluid (blood/pus) from between the serious layers of parietal pericardium and the serous layer of the visceral pericardium (epicardium). Care must be taken to avoid branches of the internal thoracic artery

What must you avoid in pericardiocentesis?

branches of the internal thoracic artery

cardiac tamponade

compression of the heart from accumulated fluid in the pericardial sac

What is associated with cardiac tamponade/Beck's triad?

rapid heartbeat and muffled heart sounds, distended neck veins, hypotension or weak pulses

Phrenic n

Innervates fibrous pericardium

What coronary artery is most often dominant

Right coronary (70-75%)