Shock

Question 1

What is shock?

Answer 1

Life-threatening failure of adequate oxygen deliver to the tissue.

Question 2

What is the aetiology of shock?

Answer 2

1. Cardiogenic - failure of pump function
2. Hypovolaemic - loss of intravascular volume
3. Distributive - failure of vasoregulation
4. Obstructive - barriers to cardiac flow or filling

Question 3

What are some examples of causes of these categories of shock?

1. Cardiogenic
2. Hypovolaemic
3. Distributive
4. Obstructive

Answer 3

1. After ACS, due to cardiomyopathy, valvular abnormalities, arrhythmias.
2. Due to haemorrhage (trauma, GI), burns, vomiting, diarrhoea, heat exhaustion.
3. Sepsis, anaphylaxis, poisoning, brainstem injury (neurogenic) or endocrine (adrenal, hypothyroid, hypopituitarism).
4. Pulmonary embolism, cardiac tamponade, tension pneumothorax.

Question 4

What are the clinical features of shock?

Answer 4

1. Stress response - tachycardia, tachypnoea
2. Centralisation of blood via peripheral vasoconstriction - cool extremities, mottled skin, slow CRT
3. Oliguria (<0.5ml/kg/hr) or rise in creatinine (acute)
4. Altered cognition, confusion, agitation
5. Lactate >2
6. Systolic BP <90mmHg or a rapid decline by <40mmHg

Question 5

What investigations are done if you suspect someone is in shock?

Answer 5

1. ECG - ischaemia or arrhythmias
2. FBC, U&Es, CRP - Hb, WCC, AKI, sepsis
3. ABG - oxygenation, acid status, lactate
4. Glucose - DKA
5. USS - tamponade, AAA, dissection
6. Urine pregnancy test (USS for ectopic)
7. JVP/central venous pressure - cardiogenic

Question 6

What is the general rule for management of shock?

Answer 6

Apart from anaphylaxis, give 250ml fluid challenge, if little improvement, suggests cardiogenic.

Question 7

What is the management of cardiogenic shock?

Answer 7

1. Airway, aim O2 94-98%
2. 2 large bore IV cannulas
3. Morphine for pain
4. Fluids if underfilled, caution overfilling (oedema) - GTN infusion
5. If not then inotropic support (dobutamine)
6. Vasopressors and inotropic support needs ICU

Question 8

What is the management of hypovolaemic shock and how can you tell if it has resolved?

Answer 8

1. 250ml fluid challenge

2. Resolved if - HR increases, urine output increases, BP increases, lactate clears.

Question 9

What is the management of a haemorrhagic shock?

Answer 9

1. Fluids first, if still shocked despite 2L, crossmatch blood.
2. Blood products initiated in acute profound haemorrhage.
3. Whole blood never used

Question 10

What are the different types of blood products you can give and what do you give them for?

Answer 10

1. RBCs for anaemia and haemorrhage
2. Platelets for bleeding
3. FFP to correct clotting defects
4. Cryoprecipitate in massive bleeding from excessive anticoagulation
5. Human albumin to replace protein in hypoproteinaemic patient (liver/renal issues) who is fluid overloaded.

Question 11

What is the management of anaphylaxis?

Answer 11

1. 100% O2
2. Adrenaline 0.5mg IM
3. IV access
4. Chlorphenamine 10mg IV
5. Hydrocortisone 200mg IV
6. IV fluids