1.2c Resuscitation (C - Circulation) & Anaphylaxis

Question 1

How does poor circulation manifest clinically?

Answer 1

It depends which major organ is not being perfused.

1. Brain - spectrum of agitation, confusion, stupor, drowsiness, dizziness, coma.
2. Heart - chest pain, angina, dyspnoea, heart failure, dysrhythmias, cardiac arrest.
3. Kidneys - decreased output, acidosis, electrolyte abnormalities, renal failure.

Question 2

How do you assess for poor perfusion?

Answer 2

• Zero survey: first impression, e.g. consciousness, colour, obvious trauma or deformity.
• Primary survey: A + B already assessed, now feel for pulse and check vitals. Feel belly and calves. Insert a large cannula in antecubital fossa.
• Secondary survey: Reassess ABCDE, more thorough examination, e.g. JVP elevation, basal crepitations. Initial response to medication/fluids, etc. PMHx. Ix, e.g. POCUS (point of care USS), recruit more help.
• *

Question 3

Is the patient stable or unstable?

Explain what the 4 defining parameters for answering this question are from a C - Circulation perspective.

Answer 3

1. LOC by GCS and appearance
2. Blood pressure <90mmHg is concerning
3. Chest pain, good indicator of coronary perfusion
4. Shortness of breath

Question 4

Describe the vital signs used to measure circulation.

Answer 4

1. Pulses and BP
   
   • Old guidelines - palpable pulses = systolic BP 50-60mmHg, however this is inaccurate
   • New guidelines - which pulses can be felt, e.g. radial, brachial, subclavian, femoral, popliteal, dorsalis pedis, posterior tibialis and GCS
2. Heart Rate
   
   • One of the earlier signs of deterioration of circulation
   • There is a 10-18 bpm increase per degree celsius increase in temperature
   • Autonomic dysfunction in elderly means they may decompensate a lot more before HR increases to compensate for BP changes
   • Do not assume tachycardia is benign
3. Respiratory Rate
   
   • Early sign of shock
   • Need to consider other causes, e.g. acidosis, pain, anxiety
4. Capillary refill
   
   • Centrally over sternum, or finger at level of heart
   • <2s, 3s is acceptable in neonates, elderly patients have less skin turgor so CR can be prolonged even if well

Question 5

What is shock?

Answer 5

Shock is not the emotional reaction to trauma, but rather the insufficient perfusion for the needs of vital organs.

Question 6

What are the 4 types of shock?

Answer 6

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

+/- Endocine/metabolic

Question 7

What is the most common type of shock?

Answer 7

Hypovolaemic shock.

Question 8

What are the causes of hypovolaemic shock?

Answer 8

Haemorrhagic (internal, external).

Vomiting/diarrhoea in children.

Other causes include burns, sweating, renal disorders (e.g. DKA, diabetes insipidus).

Question 9

What are the causes of cardiogenic shock?

Answer 9

Cardiogenic shock - is the failure of the heart to pump effectively.

Any disease that affects the pump action of the heart can cause cardiogenic shock - e.g. AMI, cardiomyopathies, myocarditis, CHF, valvular dysfunction.

Question 10

What are the causes of obstructive shock?

Answer 10

Obstructive shock is where there is obstruction of blood flow outside of the heart.

Some common causes include:

• Cardiac tamponade
• Tension pneumothorax
• Massive pulmonary embolism
• Aortic stenosis

Question 11

What are the causes of distributive shock?

Answer 11

Distributive shock occurs when vascular space exceeds the volume of blood.

• Sepsis - causes widespread vasodilation
• Anaphylaxis - anti-histamine release causing vasodilation
• Spinal injuries - loss of sympathetic tone to vasculature causing dilation, neurogenic shock

Question 12

What is endocrine/metabolic shock?

Answer 12

It refers to multiple endocrine/metabolic mechanisms which can cause shock - these shocks may all be different mechanisms.

Examples:

1. Hypothyroidism: cardiogenic
2. Thyrotoxicosis: cardiomyopathy which can cause cardiogenic shock
3. Relative adrenal insufficiency: distributive shock, endogenous/exogenous catecholamines don’t work due to lack of steroid

Question 13

What are some key strategies to help manage shock?

Answer 13

Fluid resuscitation, IV antibiotics, Vasopressors…

Question 14

What is the target MAP for shock?

Answer 14

Target MAP = 65mmHg, not the patient’s normal MAP.

Question 15

Describe the general principles of anaphylaxis management.

Answer 15

1. Lie patient flat, do not allow to stand or walk
2. IM adrenaline without delay
   
   • 1:1000 IMI into lateral thigh
   • Dose 0.01mg/kg to max 0.5mg IM per dose every 5 minutes
3. Supplemental oxygen
4. Asthma reliever (always give adrenaline before this)
5. Fluid bolus 20mL/kg IV
6. Oral prednisolone (1mg/kg up to 50mg), IV hydrocortisone (5mg/kg up to 200mg)
7. IV glucagon for persistent hypotension (1-2mg in adults, or 20-30mcg/kg up to 1mg in children)

[Image from ECINSW: https://www.aci.health.nsw.gov.au/networks/eci/clinical/clinical-resources/clinical-tools/anaphylaxis]

Question 16

Outline the basic approach to assessing circulation in a patient.

Answer 16

Appearance, are they well or unwell? –> Vitals -> Warm/cool peripheries? –> Radial pulse –> Hydration –> Heart sounds / breath sounds –> Abdomen –> Calves.

Carotid bruits –> Brachial/subclavian pulses –> Popliteal pulses –> Dorsalis pedis –> Tibialis posterior pulses