Circulation Flashcards
What is the function of plasma + what does it contain
Brings nutrient hormones and vitamins
Keep electrolyte levels constant
What’s a sinus rhythm
Record of spread of depolarisation through the heart on the electrocardiograph
What is the perfusion pressure
difference between arterial and venous pressure
Which vessels have higher resistance and why
Smaller (arterioles and capillaries) as they’ve small radii
Veins have larger diameters , less resistance and less pressure needed to push blood
What is haemorrhaging shock and what are the symptoms and signs
- Inadequate tissue perfusion due to bleeding etc
- Increasing HR
- Triggered fight or flight response cause sweating and paleness
What is a person who is suffering haemorrhage shock at risk of
- Cellular hypoxia
- Anaerobic metabolism
- Cellular dysfunction
- Cell death
- Vital organ failure
How is haemorrhaging shock managed
- Stop bleeding
- Repaid infusion of IV fluids through IV cannula
- Replace blood loss
- Anaesthetise, locate artery and clip, bypass using graph
How to measure the blood pressure?
- Put on cuff and ensure the arrow is overlying the brachial artery
- Find the radial pulse, inflate cuff until radial pulse disappears, deflate cuff slowly until it reappears = estimated systolic pressure
- Reinflate cuff to 20 mmHg above estimated systolic pressure
- Place stethoscope over brachial artery
- Deflate the cuff slowly and note the pressure when the first Korotkoff sounds are heard (systolic) + the pressure when sounds disappear (diastolic)
Shock definition
Inadequate tissue perfusion
How does haemorrhage cause shock?
- CO = HR x SV
- SV is dependent on venous return
- Decreased circulating volume —> decreased venous return to the heart —> fall in CO —> fall in BP —> less pressure to push RBCs through capillary beds in tissues and organs at a rate sufficient to meet metabolic demands —> poor perfusion = SHOCK
What do we find on examination that leads us to suspect shock?
Signs of increased SN activiy and decreased perfusion:
- Tachycardia, pallor, cool peripheries (baroreceptor reflex) and increased respiratory rate
- Measure BP (but it can remain normal initially due to compensatory mechanisms started by baroreceptors)
- Loss of consciousness due to poor brain perfusion
What is the significance of shock if it’s prolonged?
Leads to cellular dysfunction in tissues and organs and later cell death —> multi-organ failure (kidney)
How to manage a patient who is losing a lot of blood?
- Stop the bleeding —> use PEEP if bleeding laceration is the cause
- Establish intravenous (IV) access
- Give IV fluids until blood arrives
- Give group O negative blood and later blood matched to their own blood group and rhesus status (cross-matched blood)
What to do to stop the bleeding of hemorrhage?
PEEP
- Position: keep patient lying down and raise legs to promote venous return
- Examine briefly to identify source of bleeding
- Elevate: raise limb above heart (slows bleeding)
- Pressure: put direct firm pressure over site of bleeding (if bleeding from artery is suspected, compress the artery proximal to site of bleeding)
Risk factors for atherosclerosis
- High BP
- High cholesterol/obesity
- Smoking
- Diabetes
- Family history
- Sedentary lifestyle
