General Clinical Flashcards
True or False: There are pain receptors in the lungs
False, they are asensate
Why do people get breathless?
Demand increases and is higher than supply of O2
PND
Paroxysmal Nocturnal Dyspnoea
What are some of the sinister causes of cough?
• Lung cancer • Mesothelioma • Pulmonary metastases • Pulmonary fibrosis • Sarcoidosis • Pneumonitis
What are the ‘big 4’ causes of haemoptysis?
• Infection • Carcinoma • Pulmonary Embolism • Bronchiectasis
Blood
A specialised fluid composed of cells suspended in plasma
What is blood composed of?
- Plasma - White cells - Platelets - Red blood cells
What are the majority of blood cells made?
Bone marrow
What is contained at the centre of the haem group?
Iron atom
True or False: iron deficient red cells are smaller
True, lack of iron leads to a reduction in Hb
Which protein is responsible for the storage of iron?
Ferritin
What causes an increase in neutrophils?
Stress: physiological or pathological (acute infection, trauma, infarction, inflammation)
What causes an increase in eosinophils?
• parasitic infections • hypersensitivity/allergic reactions
What causes an increase in basophils?
Hypersensitivity reactions
What causes an increase in monocytes?
• chronic infections, malignancy, autoimmune disorders
What causes an increase in lymphocytes?
• Viral infections
D-dimer
Fibrin degradation product - if increased suggest increased fibrinolysis following increased fibrin deposition
Plasma viscosity (PV)
an index of changes in plasma proteins (reactant fibrinogen and some globulins). Changes in plasma viscosity can reflect systemic inflammation, and less commonly, haematological malignancies producing an abnormal protein.
Type I Respiratory Failure
A low level of oxygen in the blood (hypoxemia) without an increased level of carbon dioxide in the blood (hypercapnia)
Type II Respiratory Failure
Hypoxemia (PaO2 6.0kPa). Respiratory centre becomes insensitive to CO2 and respiration could be driven by hypoxia, rather than hypercapnia
What are the reasons that people retain carbon dioxide?
- Reduced hypoxic drive: Respiratory centre becomes desensitised to CO2 and respiration could be driven by hypoxia - V/Q mismatching: Normally areas of poor ventilation have reactive vasoconstriction, but if you give them excess oxygen, then reactive vasoconstriction is reversed and this area is perfused so CO2 struggles to leave - Haldane effect: Chronically hypoxaemic patient has low Hb saturation, which increases Hb affinity for CO2
What are 5 underlying causes of hypoxia?
- Circulatory hypoxia: oxygenated blood can’t get to the tissues - Anaemic hypoxia: no Hb to carry the oxygen - Toxic hypoxia: prevention of oxygen binding to Hb - Hyperaemic hypoxia: lungs dont work, can be due to low inspired oxygen concentration (eg. altitude), alveolar hyperventilation or impaired diffusion, shunting, V/Q mismatch or dead space - Alveolar hypoxia: inability to breathe eg. obesity, anaesthesia
Shunting
Good perfusion but bad ventilation eg. lung diseases
Dead space
Good ventilation but bad perfusion eg. circulatory disorders such as PE or hypertension
Ventilation perfusion mismatching
Areas of lung disease have varying degrees of perfusion and ventilation, and perfusion should be directed to areas of best ventilation, though this can be mismatched. • Lung apex: Good V, Poor Q • Lung base: Poor V, Good Q
True or False: Oxygen is the treatment for breathlessness
False, oxygen is the treatment for hyperaemia