SOB Flashcards
What is an ETT
exercise tolerance test
what does thalium show
metabolically active areas taking up more of it, perfusion defects, infarction (fixed defect), ischaemia (reversible defect)
what is the first treatement for a NSTEMI
thrombolysis
why is PO2 normal in anaemia
oxygen still in blood just not enough haemoglobin to carry it
what is haemodynamic instability
perfusion failure represented by clinical features of circulatory shock and advanced heart failure
what does a narrow QRS mean
SVT
what does a wide QRS mean
ventricular tachycardia
what are the factors contributing to production of shortness of breath
increased;
- work of breathing
- ventilatory drive
impaired resp muscle function
what can cause increased work on breathing
airflow obstruction (asthma, chronic bronchitis, tracheal obstruction)
decrease pulmonary compliance (pulmonary oedema, fibrosis)
restricted chest expansion (resp muscle paralysis)
what can cause increased resp drive
physiological dead space (ventilation-perfusion miss match e.g. infection, PE)
stimulation of resp centre
what are the chemical and neural stimulation of respiration
increased:
- aterial hydrogen ion conc (metabolic acidosis)
- arterial PacO2 (resp acidosis)
- central arousal (anxiety, thyrotoxicosis)
decreased:
-aterial PaO2 via aortic, carotid and brain stem chemoreceptors (pneumonia, anaemia)
pulmonary j receptor (in lungs) discharge (pulmonary oedema)
what is after load
force against which left ventricle contracts to eject blood into systemic circulation
what can increase afterload
increased peripheral resistance- which can be raised by high blood pressure
what happens when the left side of the heart fails
the left atrial and left ventricular pressures rise. The increased left-sided
pressures (called preload) produce back pressure on the lungs and cause a rise
in pulmonary capillary hydrostatic pressure resulting in accumulation of fluid
in the interstitial and intraalveolar lung spaces: - a condition known as
pulmonary oedema
how is pulmonary oedema manifested clinically
varying degrees of shortness of breath