What happens when the body switches to the anaerobic respiration?
-Lactate increases
- change in blood pH- lactic acidosis
What happens in shock?
inadequate oxygen and nutrient supply to the cells
BP= (HR x _____ ______) x Systemic vascular resistance
stroke volume
Put these stages of shock in order:
- progressive shock
- initial stage
- refractory shock
- compensation/nonprogressive
- initial stage, 2. compensation/nonprogressive, 3. progressive shock, 4. refractory shock
What happens in the inital stage of shock?
Cells are being starved of O2, reduced production of ATP for energy, switch to anaerobic metabolism- lactic acid is produced. No clinical signs to observe or document.
What happens in the compensation (non-progressive) stage of shock?
- initial detection of reduced perfusion, activation of compensatory (homeostatic) mechanisms- cardiovascular, renal and endocrine compensation. Outward clinical signs- respiratory, cardiovascular, renal and skin.
Cardiovascular Compensation:
1. __________ respond to stretch of the arterial walls.
2. __________ in the left ventricle output results in activation of baroreceptors.
3. Activates baroreceptor ________
- Baroreceptors
- decrease
- reflex
Name 5 cardiovascular clinical observations of shock
- increased HR (tachycardia)
- pale, clammy, cold skin (vasoconstriction)
- decrease pulse pressure (Weak Pulse)
- NO change in BP (its being compensated)
- all these trying to return the arterial pressure back to normal.
What does the antidiuretic hormone (ADH) do?
water retention, vasoconstrict blood vessels, to maintain or increase BP
Effect of Shock on Gas Exchange:
- efficient gas exchange requires sufficient _______ and _______
- ventilation and perfusion
Shock reduced perfusion= _____ V/Q ratio
high
Clinical Signs of Compensatory Shock:
- Cardiovascular- _______, no change in BP
- Renal- ______, kidneys trying to conserve water in the system.
- Skin- ____, clammy, cool
- Respiratory- _______ RR.
- tachycardia
- oliguria
- pale
- increased
What happens in the progressive (non-compensated) stage of shock?
- compensatory mechanisms begin to fail- BP falls
- perfusion begins to fail
- metabolic acidosis present
- oxygen deprivation in the brain- confusion
- multiple organ failure- organ damage
What happens in refractory shock?
-widespread cell death
- shock cannot be reversed
- death is imminent
What is hypovolaemic shock?
- reduction in circulatory volume- hence decrease cardiac output
- Blood loss- trauma, lower GI bleed, AAA, dehydration, PR bleed, oesophageal varices.
What is cardiogenic Shock?
- failure of the heart as a pump
- loss of CO- (HR and contractility)
Name 3 causes of cariogenic shock
- Major MI
- Severe left ventricular failure
- ischemic heart disease
Name 3 causes of hypovolemic shock
- AAA
- Trauma
- Dehydration
- PR bleed
- Lower GI bleed
- Oesophageal varices
What is distributive shock?
- inadequate tissue perfusion- lack of normal responsiveness to blood vessels to vasoconstrictive agents, direct vasodialation
- drop in systemic vascular resistance and stroke volume
Name 3 examples of distributive shock
- septic- massive vasodilation- less pressure- tissues will not get enough oxygen
- anaphylactic- massive release of histamine from mast cells, increased prostaglandin release, systemic vasodilation
- neurogenic- loss of vasomotor tone and sympathetic activity- e.g spinal cord injury, deep general/spinal anaesthesia, brain damage.
What is obstructive shock?
A blockage in blood flow to the heart or major blood vessels.
Name 3 causes of obstructive shock
PE, Cardiac tamponade, tension pneumothorax etc.
Name 4 symptoms of obstructive shock
- Increased RR
- Tachycardia
- Low BP
- Oliguria
