Shock Flashcards
What is the definition of shock?
The state that results from inadequate perfusion of tissues.
Can be life threatening.
For triage - IV fluids, keep warm, oxygen.
What is the function of the cardiovascular system?
Transport oxygen to cells.
Removes carbon dioxide & other waste products from the body.
Must be able to maintain sufficient flow through capillary beds to meet cell’s oxygen & fuel needs.
When an animal goes into shock, what role does the sympathetic nervous system play?
Results in a message being sent to the sympathetic nervous system, which results in release of hormones.
What are the four hormones that are released when in shock?
Cortisol - a natural hydrocortisone produced in the adrenal cortex.
Angiotensin - controls BP.
Aldosterone - reabsorption of sodium.
Antidiuretic - ADH (post pit.), fluid regulation - increases water & salt reabsorption.
What effect do these hormones have on the body?
Retain salt and water - support BP - support a supply of energy.
When in shock - the sympathetic nervous system is responsible for increasing heart rate and constricting peripheral arteries.
What is needed to maintain perfusion & how can these fail?
The pump (heart), the pipes (blood vessels), and fluid (blood).
Fails by pump failure, pipe failures and loss of volume.
What are the four classifications of shock?
Hypovolaemic - fluid failure.
Cardiogenic - pump failure.
Distributive - neurogenic, septic, anaphylactic - pipe failure.
Obstructive - pump and pipe failure.
What is hypovolaemic shock & its causes?
Low blood volume.
Causes = haemorrhage, vomiting, diarrhoea, burns, diuresis.
What is cardiogenic shock & its causes?
Pump failure = heart failure.
Causes = CHF (congestive heart failure), arrhythmias (abnormal heart rhythms).
What is distributive neurogenic shock & its causes?
A loss of tone bone blood vessels.
Will have a lack of oxygen to vessels.
Causes = spinal cord damage, anaesthesia, pain, drugs & hypoglycaemia.
What is distributive anaphylactic shock & its causes?
A mass release of histamine due to allergic hypersensitivity reaction.
Causes = increased capillary permeability with vasodilation reduces venous return & BP.
What is distributive septic shock & its causes?
Systemic infection (whole of the body) - can be bacterial/viral that goes into bloodstream.
Endotoxin shock - caused by gram negative bacteria going into bloodstream.
Causes = bacterial toxins - wound infections, invasive procedures, UTI, respiratory infections.
What is obstructive shock & its causes?
An obstruction of blood flow.
Causes = thromboembolism, tumour, GDV - any condition that results in obstruction of blood flow.
What are the early signs of shock?
Increased respiratory rate, restlessness, anxiety.
What are the key clinical signs of shock?
Early shock = increased RR, restlessness, anxiety.
BP drop = late sign of shock.
Pallor, tachycardia, slow CRT.
Decreased HR, decreased HR.
What are the four progressive stages of shock?
Non progressive (initial).
Compensated - compensatory mechanisms are successful in maintaining perfusion.
Progressive - compensation mechanisms begin to fail.
Irreversible - complete failure of compensatory mechanisms. Death.
Describe the compensatory shock stage.
Increased RR, restlessness.
Tachycardia.
Falling BP.
Possible delay in CRT.
Pale.
Nausea, vomiting, thirst.
Decreased body temp.
Weakness.
Describe irreversible shock stage.
Loss of peripheral vascular resistance.
Confusion, unconscious.
Slow, irregular, threads pulse.
Falling BP.
Cold, clammy, Cyanotic.
Irregular respirations.
What can irreversible shock lead to?
Renal failure.
Hepatic failure.
Multiple organ system failure.
Respiratory distress syndrome.
Death.
What is the first aid treatment for shock?
Maintain respiration - administer O2.
Control haemorrhage.
Keep patient warm.
Position patient - lower head if possible as encourage blood flow.
IVFT - supports circulating fluids, warm fluids etc.
What are your nursing observations and why?
Monitor urine output
- check renal function affected by low BP.
- normal urine output 1-2ml/kg/hr.
Monitor patient frequently
- q10 mins until stable, then q30-60mins as improves.
- demeanour.
- BP
- temperature.
- HR, RR and quality.
- CRT and MM colour.
