Thorax - walls and cavities Flashcards
Indications for ICNB
Analgesia for pts with rib fractures and post surgical pain after chest and upper abdominal surgery
Acute and chronic pain conditions affecting thorax and upper abdomen, including breast and chest wall surgery
Describe ICNB technique
- 20 degrees upwards
- Intercostal space
- Between internal intercostal and innermost intercostal muscles
How do you clinically locate the upper level of the right diaphragm?
Of what clinical relevance is determining this level?
Diaphragm - post. 11th and ant. 6th. Right is higher than left due to liver.
Clinically locate by percussion - resonant = lung and dull = liver.
Clinical relevance:
- Have lungs been pushed down? e.g. pleural effusion, COPD
Contents of superior mediastinum - 3 arteries, veins, nerves and structures
3 branches from arch of aorta
3 veins - L/R brachiocephalic + SVC and azygous
3 nerves = phrenic, sympathetic and vagus
3 structures = oesophagus, trachea and thoracic duct
What separates subclavian artery and vein?
Scalenus anterior
Thoracic outlet syndrome: differentiate pancoast tumour and cervical rib?
Cervical rib compresses subclavian artery = when hand raised, blood flow defect
What are the boundaries of the superior thoracic aperture? Where is it in relation to superior mediastinum?
T1, first rib and superior border of the manubrium of the sternum
It is the upper border of the superior mediastinum
What structure crosses the neck of the first rib?
Sympathetic trunk
Site of ICNB
Anywhere proximal to mid axillary line where the lateral cutaneous branch takes off
- angle of rib (6-8 cm from spinous processes)
What major intra abdominal organs are protected by the thoracic cage?
Liver, stomach, spleen, kidneys
What happens when damage to collateral neurovascular bundle?
nothing
Indications for chest tube drains
Unresolved primary pneumothorax > 2cm after 2 attempts at aspiration
Secondary pneumothorax > 2cm
Unilateral pleural effusion
Empyema (pus in pleural cavity)
Decompensated bilateral pleural effusion
Tension pneumothorax after needle decompression
Where is the neurovascular plane encountered in the anterolateral abdominal wall?
Between internal oblique and transversus abdominis
What nerve sits posterior to subclavian artery?
inferior branch of brachial plexus
Blood supply and venous drainage of thorax
Arterial
- posteriorly = superior intercostal artery (1-2) and superior intercostal arteries from thoracic aorta (3-11)
- anteriorly = internal mammary (1-6) and musculo-phrenic (7-11)
Venous - follows arteries
- posterior = to azygous and on the left, to braciocephalic
- anterior = internal thoracic and musclophrenic
Apart from apical tumour, what is another condition which can cause thoracic outlet syndrome?
Cervical rib
What are the borders of the safety triangle?
Base of axilla
5th intercostal space
Lateral edge of pectoralis major
Lateral edge of latissimus dorsi
borders of superior, anterior, middle and posterior mediastinum
Superior = T1-5
T5-9…
anterior =
middle = fibrous pericardium demarcates
T5-T12 = posterior
- oesophagus
What is unique about the 1st rib?
Does not have a costal groove
Most common indication for chest tube drains
Tension pneumothorax after needle decompression
At what point along the rib is the lateral cutaneous nerve given from the intercostal nerve? Clinical significance?
Angle of the rib
Site of nerve block as this is the point at which posterior and anterior join - nerve block to both branches
Malignancy in apical lung? Clinical outcomes (4)?
Pancoast tumour.
1 Can lead to Horner’s syndrome by compressing T1 stellate ganglion (sns)
- partial ptosis (loss of muscular innervation to eyelid)
- anhidrosis (loss of sweat gland stimulation)
- miosis (loss of sns responsible for pupillary dilation)
2 compress brachial plexus (mainly T1 - hand)
- shoulder pain and weakness
- paraesthesia (numbness and tingling)
3 laryngeal nerve compression
- weak or paralyzed larynx (voice hoarsness)
4 SVC compression
- increase venous pressure (flushing and edema)
- raised JVP
- SOB
Contraindications for ICNB (2)
1 local infection
2 bleeding disorders, coagulopathies
How would you determine where to place an intercostal tube into the pleural cavity?
4th or 5th intercostal space
Between ant. axillary and mid axillary lines
Just above superior rib to avoid damaging neurovascular bundles
