Circulation Flashcards
What disease processes or pathology are you looking for when you assess circulation?
- Primary cardiac diseases - myocardial ischaemia or arrhythmia
- Circulatory failure secondary to problems in other systems - hypoxia, shock
What signs suggest a problem with circulation?
- abnormal pulse rate and rhythm
- reduced central and peripheral perfusion - capillary refill time
- reduced blood pressure
- reduced organ perfusion - chest pain, altered mental state, reduced urine output
- bleeding or other fluid losses
What should be assumed to be the primary cause for shock in all medical and surgical patients unless proven otherwise?
Hypovolaemia - give 500ml 0.9% saline
What are the FOUR main types of shock?
CHOD
- Cardiogenic shock
- Hypovolaemic shock
- Obstructive shock
- Distributive shock
What type of shock results in a low diastolic blood pressure/wide pulse pressure?
Distributive shock - anaphylactic or septic
What does a narrow pulse pressure suggest?
What type of shock results in a narrow pulse pressure?
narrow pulse pressure suggests arterial vasoconstriction (difference between systolic and diastolic is < 35-45 mmHg
this occurs in shock that is not distributive - cardiogenic, hypovolaemic, obstructive
What is shock?
Circulatory failure resulting in inadequate organ perfusion
- SBP <90 or MAP <65
- with evidence of tissue hypoperfusion - reduced GCS, pallor, cool peripheries, increased cap refill, urine output <0.5ml/kg/hr, serum lactate >2mmol/L,
What is meant by obstructive shock?
- Tension pneumothorax
- Cardiac tamponade
- Massive PE
Obstructive shock is caused by physical obstruction to filling and/or emptying of the heart.
What is meant by distributive shock?
- Anaphylactic shock
- Septic shock
- Neurogenic shock - spinal cord injury
Distributive shock is caused by vasodilation (decrease in total peripheral resistance)
What is meant by cardiogenic shock?
- Acute MI
- Serious arrhythmias - profound bradycardia or tachycardia (very likely to lead to a cardiac arrest arrhythmia)
Cardiogenic shock is caused by failure of the heart muscle to pump.
What is meant by hypovolaemic shock?
- Haemorrhage - injuries, aortic dissection, ruptured AAA
- Fluid loss - vomiting, diarrhoea, burns, 3rd space losses
- Addisonian crisis
What are the causes of tachycardia?
What are the causes of bradycardia?
- Regular
- Sinus bradycardia
- Complete AV with junctional escape rhythm
- Irregular
- Second degree AV block
- Mobitz Type 1
- Mobitz Type 2
- Second degree AV block
What are the causes of oliguria?
Oliguria - <0.5ml/kg/hr urine output (for >6 hrs = AKI)
pre-renal causes - SHOCK - usually hypovolaemic or distributive, renal artery stenosis (ACEi, NSAIDs)
renal causes - nephrotoxic drugs, rhabdomyolysis, glomerulonephritis, nephrotic syndrome
post-renal causes - ureteric calculi, pelvic mass, blocked catheter, BPH
Describe how you would approach the Circulation part of the ABCDE assessement.
I would assess the patient’s circulation by feeling the temperature of their peripheries, checking their capillary refill time, peripheral and central pulses, JVP and listening to the chest.
In terms of basic observations I would check HR, BP and urine output.
I would obtain IV access via 2 wide bore cannulae (grey) in each ACF; from here I would obtain necessary bloods (including FBC, U+Es (as a baseline paying particular attention to…), coagulation screen, G+S/X-M, LFTs, cultures) and consider catheterising to monitor urine output, obtaining an ECG to look for dynamic changes and a fluid challenge if BP was low.
