Lecture 16: Clinical anatomy thorax and mediastinum Flashcards
What is thoracocentesis used for?
Either to drain effusion for symptomatic relief or;
To diagnose underlying cause
What is the correct location for thoracocentesis?
5th ICS in the mid axillary line
What is pleural effusion?
Condition that increases the production of fluid or impairs the drainage of the fluid from the pleural cavities
What causes pleural effusion?
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
Xray of healthy lung vs pleural effusion
See figure
How to preform thoracocentesis
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
What does the needle have to pass through during thoracocentesis?
Skin
Fat
Intercostal muscles
Do not puncture lung or diaphragm!
What is pneumothorax?
Entry of air into the pleural cavity
Results in partial collapse of lung (due to lung’s inherent elasticity)
See figure
What causes pneumothorax?
Punctures from external sources (bullets) or from internal sources (broken ribs)
Where is the cervical pleura? Clinical significance?
Dome of pleura that extends the superior thoracic aperture
Danger of causing pneumothorax with attempt of venipuncture
Parts of the lung pleura
See figure
What prevents lungs from collapsing?
Alveolar pressure (= intrapleural pressure + alveolar elastic recoil pressure)
What is angina pectoris?
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
What can cause angina pectoris?
Usually happens because one or more of the heart’s arteries (coronary arteries) is narrowed or blocked
How do coronary arteries become blocked?
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
What are larger accumulations in the arteries due to atherosclerosis called?
Atheromas or plaque
Can damage artery walls and block blood flow
What does severely restricted blood flow in the heart muscle cause?
Symptoms such as chest pain (angina pectoris)
How to treat angina pectoris?
Nitroglycerine (vasodilator that opens blood vessels to improve flow)
Surgery (coronary balloon angioplasty or coronary bypass graft)
See figure
What materials are needed for coronary bypass graft?
Superficial veins of the leg or internal thoracic artery
Symptoms of pericardial effusion
Dyspnea
Chest pain
Pressure and discomfort
Pain relieved by sitting up and leaning forward, intensified by laying supine
What is pericardial effusion?
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
What causes pericardial effusion?
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
Xray of normal vs heart with pericardial effusion
See figure
How pericardial effusion is treated
Pericardiocentesis
Needle inserted through chest into pericardial effusion area
Catheter put into fluid and suctioned out
See figure
Where is the cardiac notch located?
Between the 4th and 6th intercostal space
Where is the xiphicostal angle?
Between the diploid process and the thorax
