Week 2 Flashcards
What are the three spaces found in the thorax?
The centrally located mediastinum
The right lung cavity
The left lung cavity
What is contained in the mediastinum?
Contains the heart, covered by the pericardium; the thymus gland; parts of the esophagus and trachea; and a network of nerves and blood vessels
What is the inner and outer membranes covering the lungs called?
Parietal pleura (outside) and visceral pleura (inside)
How much pleural fluid is produced in about 24 hours?
0.3mL/kg of body weight or 25mL in the average person
What is the pressure in the pleural space during inhalation and exhalation?
-8 cm H2O during inspiration and -4 cm H2O during expiration
Ventilation?
The mechanical act of moving air into and out of the lungs
Respiration
Gas exchange across the alveolar-capillary membrane
What is the name of the nerve that causes the diaphragm to contract?
The phrenic nerve
What are the characteristics of pleural pain?
SOB and pain
What are two common clinical conditions that require pleural drainage?
Rupture of the surface of the lung (such as a bleb) or tracheobronchial tree, allowing air and possibly serious or serosanguineous fluid into the pleural space while the chest wall remains intact
External penetration of the chest wall resulting from surgical intervention for trauma (eg gunshot) allowing air and blood or serosanguineous fluid from damaged tissues into the pleural space
What is a pneumothorax?
Air in the pleural space and negative pressure between the pleura vanishes
Open pneumothorax?
Wound from external that leaves the pleural space open to the air
Closed pneumothorax?
Enters space through rupture of the lung and visceral pleura but chest wall remains intact
Spontaneous pneumothorax?
Pneumothorax for no particular reason
What is a tension pneumothorax?
When air continues to leak into the pleural space with no means of escape there will be a rapid build-up of pressure in the pleural space
why is a tension pneumothorax dangerous?
If pressure becomes high enough, the lung can completely collapse and the pressure can then be transmitted to the mediastinum, pushing it away from the affected side, compressing great vessels and the heart itself (cardiac output decrease)
Signs and symptoms of a tension pneumothorax
Increases respiratory rate and effort
Dyspnea
Pleuritic chest pain
Decreased movement of the affected side of the chest
Decreased breath sounds on auscultation of the affected side
Falling BP
Rising pulse
Subcutaneous emphysema?
Feeling of crackling on chest palpitation
Hemothorax
Blood collection in the pleural space following thoracic surgery or certain chest injuries
Empyema
Accumulation of pus in the pleural space caused by pneumonia, lung abscess, or contamination of the pleural cavity
Chylothorax?
Accumulation of lymphatic fluid in the pleural space
Cardiac tamponade?
Blood collection in the mediastinal cavity following cardiac surgery or chest trauma, collecting between the pericardium and the heart and externally compressing the heart
How much extra air or fluid can a person usually tolerate in their pleural space (if they don’t have underlying lung disease)?
Less than 10%
What are the goals of chest drainage?
Remove the fluid and/or air as quick as possible
Prevent drained air and/or fluid from re-entering the chest cavity
Re-expand the lungs, restore normal negative intrapleural pressure