L16 - Surgery Trauma / Pneumothorax / Foreign Body / Cancer / Transplant Flashcards
What is a flail chest?
Movement of segment of chest wall.
Causes of flail chest?
Significant force diffused over large area of thorax.
If patient has osteoporosis: less force required
Describe muscles in chest
Intercostal muscles with fascial attachments.
Includes
- trapezius
- serratus
Describe diagnostic methods to detect a flail chest
2 methods and what do they show
CXR
- demonstrate fractured ribs
- hypovolemia may initially mask underlying pulmonary contusion
ABG
- will show severity of hypoventilation created by pulmonary contusion and pain of rib fractures
Treatment options for a flail chest
- Patient controlled analgesia
- Oral pain medication
- Indwelling epidural catheter
Haemothroax
Collection of blood within pleural cavity.
Haemothorax may be a consequence of…
Blunt, penetrating trauma.
Complication of disease.
Describe extrapleural injury which may cause haemothorax
Extrapleural Injury
- trauma to chest wall tissues with violation of pleural membrane
Sources of significant persistent bleeding which may cause haemothorax
Intercostal and internal mammary arteries.
Describe intrapleural injury which may cause haemothorax
Intrapleural injury
- blunt, penetrating injury involving any intrathoracic structure
Describe major arterial, venous structures within the thorax that may be involved in intrapleural injury
Aorta Brachiocephalic branches Pulmonary arteries SVC Brachiocephalic vein IVC Azygous vein
Haemodynamic response to haemothorax
Heavy blood loss may cause early symptoms of shock:
- tachycardia
- tachypnea
- decrease in pulse pressure
Describe physiologic resolution of haemothorax
- Blood entering pleural cavity exposed to motion of diaphragm, lungs and other intra-thoracic structures
- results in some degree of defibrination of blood
- incomplete clotting occurs
How might small, asymptomatic haemothorax progress into large and symptomatic bloody pleural effusion
- Lysis of existing clot by pleural enzymes
- increase in protein concentration in pleural fluid
- results in increase in osmotic pressure within pleural cavity
- Transudation of fluid into pleural space
Later stages of haemothorax may lead to…
Empyema
Fibrothorax
Empyema
- Bacterial contamination of retained haemothorax
- may lead to bacteremia, or septic shock if left untreated
Fibrothorax
- Fibrin deposition develops in an organised haemothorax.
- Coats both parietal and visceral pleural surfaces.
- Adhesive process traps the lung in position
- Prevents lung expansion
Pneumothorax
Abnormal collection of air in pleural cavity between lung and chest wall
Primary spontaneous pnuemothorax
Occurs without an apparent cause in absence of significant lung disease
Secondary spontaneous pnuemothorax
Occurs in the presence of existing lung disease
Typical symptoms of pneumothorax
- Sudden onset sharp, one sided chest pain.
- Shortness of breath
Describe how a tension pneumothorax occurs?
- There’s an area of damaged tissue.
- One way valve formed.
- Amount of air in chest increases.
- Results in tension pneumothorax.
Differential diagnosis for pneumothorax
lung bullae
haemothorax
Diagnostic method for pneumothorax
CXR, USS, CT
Tactile fremitus
Fremitus: vibration transmitted through body
What may increased tactile fremitus show?
Ask patient to repeat ‘99’ while examiner feels vibrations.
Tactile fremitus increased over areas of consolidation
What may decreased tactile fremitus show?
Decreased in area of pleural effusion / pneumothorax
Describe how haemothorax may develop into large bloody pleural effusion?
- blood entering plueral cavity exposed to motion of diaphragm etc.
- some degree of defibrination of blood
- incomplete clotting occurs
- after cessation of bleeding, lysis of osmotic clots by pleural enzymes
- RBC lysis leads to increased protein concentration of pleural fluid
- causes transduction of fluid into pleural space.
- hence small and asymptomatic haemothroax may progress into large pleural effusion
Describe dangers of tension pneumothorax
- Pressure build up in pleural space, compressing lung.
- Mediastinal shift to opposite side.
- Progressive kinking IVC.
- VC eventual obstruction.
- MEDICAL EMERGENCY*
Tension pneumothorax
- injured tissue forms one way valve
- volume of nonabsorpable intrapleural air increases
- pressure arises within affected hemithorax
- pressure increases
- ipsilateral lung collapses and causes hypoxia
Cardiac tamponade
results in:
- accumulation of fluid in pericardial fluid
- reduced ventricular filling
- subsequent haemodynamic compromise
Management of cardiac tamponade
Emergency subxiphoid percutaneous drainage.
- movement of pericardial fluid
3 Phases of haemodynamic changes in tamponade
- Accumulation of pericardial fluid, impairs relaxation and filling of ventricles.
- Pericardial pressure increases above ventricular filling pressure.
- Decreases in cardiac output.
Beck’s triad
- Increased JVP
- hypotension
- diminished heart sound
Pulsus paradox
Normal inspiratory decrease in systemic BP.
While listening to heart sounds during inspiration, pulse weakens or may not be palpated with certain heart beats.
Subcutaneous emphysema
When gas or air travels under skin
Pathophysiology of subcutaneous emphysema
- injury to parietal pleura that allows for passage of air into pleural space and subcutaneous tissues.
- air from alveolus spreading into endovascular sheath.
Pulmonary contusion
Blunt injury to lungs causing oedema.
Hypoxia.
Treatment supportive
- humidified o2, pain relief, ventilation
