Lecture 16: Clinical anatomy thorax and mediastinum

Question 1

What is thoracocentesis used for?

Answer 1

Either to drain effusion for symptomatic relief or;

To diagnose underlying cause

Question 2

What is the correct location for thoracocentesis?

Answer 2

5th ICS in the mid axillary line

Question 3

What is pleural effusion?

Answer 3

Condition that increases the production of fluid or impairs the drainage of the fluid from the pleural cavities

Question 4

What causes pleural effusion?

Answer 4

Inflammation of the pleura

Irritation of the pleura

Cancer (most common are breast and lung cancer)

Pulmonary embolism (caused by blood clot, blockage of lung arteries)

Open heart surgery complications

Pneumonia

Question 5

Xray of healthy lung vs pleural effusion

Answer 5

See figure

Question 6

How to preform thoracocentesis

Answer 6

Preparation of site

Needle insertion at the marked point in the middle of the appropriate ICS

Avoid blood vessels and nerves that run down the causal edge of each rib

See figure

Question 7

What does the needle have to pass through during thoracocentesis?

Answer 7

Skin

Fat

Intercostal muscles

Do not puncture lung or diaphragm!

Question 8

What is pneumothorax?

Answer 8

Entry of air into the pleural cavity

Results in partial collapse of lung (due to lung’s inherent elasticity)

See figure

Question 9

What causes pneumothorax?

Answer 9

Punctures from external sources (bullets) or from internal sources (broken ribs)

Question 10

Where is the cervical pleura? Clinical significance?

Answer 10

Dome of pleura that extends the superior thoracic aperture

Danger of causing pneumothorax with attempt of venipuncture

Question 11

Parts of the lung pleura

Answer 11

See figure

Question 12

What prevents lungs from collapsing?

Answer 12

Alveolar pressure (= intrapleural pressure + alveolar elastic recoil pressure)

Question 13

What is angina pectoris?

Answer 13

Medical term for chest pain or discomfort due to coronary heart disease

Occurs when the heart muscle doesn’t get as much blood as it needs

Question 14

What can cause angina pectoris?

Answer 14

Usually happens because one or more of the heart’s arteries (coronary arteries) is narrowed or blocked

Question 15

How do coronary arteries become blocked?

Answer 15

Atherosclerosis is common (inflammatory reaction of the vessel wall)

Leads to structural changes in the vessel wall. Fat, cholesterol and other substances collect in the walls

Question 16

What are larger accumulations in the arteries due to atherosclerosis called?

Answer 16

Atheromas or plaque

Can damage artery walls and block blood flow

Question 17

What does severely restricted blood flow in the heart muscle cause?

Answer 17

Symptoms such as chest pain (angina pectoris)

Question 18

How to treat angina pectoris?

Answer 18

Nitroglycerine (vasodilator that opens blood vessels to improve flow)

Surgery (coronary balloon angioplasty or coronary bypass graft)

See figure

Question 19

What materials are needed for coronary bypass graft?

Answer 19

Superficial veins of the leg or internal thoracic artery

Question 20

Symptoms of pericardial effusion

Answer 20

Dyspnea

Chest pain

Pressure and discomfort

Pain relieved by sitting up and leaning forward, intensified by laying supine

Question 21

What is pericardial effusion?

Answer 21

Abnormal accumulation of fluid in the pericardial cavity

There is limited amount of space in the pericardial cavity, so fluid accumulation leads to increased inter pericardial pressure

Can negatively affect heart function

Question 22

What causes pericardial effusion?

Answer 22

Inflammation of the pericardium following heart surgery or heart attack

Autoimmune disorders (rheumatoid arthritis or lupus)

Spread of cancer

Waste products in the blood due to kidney failure (uraemia)

Viral, bacterial, fungal or parasitic infections

Trauma or puncture wound near the heart

Question 23

Xray of normal vs heart with pericardial effusion

Answer 23

See figure

Question 24

How pericardial effusion is treated

Answer 24

Pericardiocentesis

Needle inserted through chest into pericardial effusion area

Catheter put into fluid and suctioned out

See figure

Question 25

Where is the cardiac notch located?

Answer 25

Between the 4th and 6th intercostal space

Question 26

Where is the xiphicostal angle?

Answer 26

Between the diploid process and the thorax