Critical Care

Question 1

Define shock

Answer 1

Clinical syndrome caused by inadequate tissue perfusion and oxygenation leading to abnormal metabolic function

Question 2

Name the six types of shock

Answer 2

Cardiogenic
Hypovolaemic
Obstructive
Septic
Anaphylactic
Neurogenic

Question 3

Why should colloids be stopped in anaphylactic shock?

Answer 3

Colloids may be the cause of anaphylaxis

Question 4

How is Systemic Inflammatory Response Syndrome (SIRS) defined?

Answer 4

Present if 2 or more of the following:
HR >90
Temp <36 or >38.3
RR >20 or PaCO2 <4.3kPa
WCC <4 or >12 x 10 to the power of 9/l

Question 5

How is sepsis defined?

Answer 5

SIRS plus known or suspected infection

Question 6

How is severe sepsis defined?

Answer 6

sepsis + signs of hypoperfusion or organ failure including decreased urine output, elevated urea or creatinine, abnormal LFTs, coagulation disturbance, hypoxia or ARDs or a raised serum lactate

Question 7

Define septic shock

Answer 7

Severe sepsis with hypotension (systolic BP <90 or MAP <60) despite adequate fluid resuscitation or the requirement for vasopressors/inotropes to maintain blood pressure

Question 8

What is the treatment given for sepsis?

Answer 8

BUFALO
Blood cultures + septic screen
Urine output – monitor hourly
Fluid resuscitation
Antibiotics IV – see microbiology guideline
Lactate measurement
Oxygen to correct hypoxia

Question 9

What are the clinical signs of shock?

Answer 9

1. Systolic BP <90mmHg (or a 30mm Hg fall in baseline BP)
2. Lactate >3 mmol/L
3. Base excess <4mEq/L
4. Reduced capillary refill time

Question 10

If blood pressure is unrecordable in suspected shock what action should be taken?

Answer 10

Call the cardiac arrest team

Question 11

What is the treatment for anaphylactic shock?

Answer 11

1. A-E assessment
2. Adrenaline 1:1000 solution, 0.5ml (0.5mg) intramuscular
   Repeat after 5 mins if no improvement
3. IV infusion 1L 0.9% saline STAT
4. Chlorphenamine (antihystamine 10mg slow IV
5. Hydrocortisone 200mg slow IV

Question 12

What is MAP?

Answer 12

Mean arterial pressure = Cardiac output x Systemic vascular resistance

Question 13

What assessments should be regularly repeated in assessing perfusion?

Answer 13

Heart rate and respiratory rate trends
Urine output
Repeated ABG and lactate
Conscious level monitoring

Question 14

How do inotropes work?

Answer 14

Inotropes increase the contractility of the heart (and often its rate as well) usually by acting on Beta receptors (increase cardiac output)

Question 15

How do vasopressors work?

Answer 15

Vasopressors cause vasoconstriction of the peripheral vasculature by acting on alpha receptors (increase systemic vascular resistance)

Question 16

If a patient with suspected shock presents as cool and pale what are the most likely causes of shock?

Answer 16

Hypovolaemic (hamorrhage)

Cardiogenic (MI, tamponade, arrhythmias)

Question 17

How is hypovolaemic shock treated?

Answer 17

Identify and treat underlying cause (stop bleeding)
Raise legs
Give fluid bolus 1L 0.9% saline STAT
Crossmatch and group and save
Aim for HR <100 BP >90 and urine output >0.5mL/kg/hr

Question 18

A patient in suspected shocks presents as warm, clammy, vasodilated. What sort of shock could this be?

Answer 18

Distributive:
Sepsis
Anaphylaxis
Neurogenic

Question 19

For which type of shock are inotropes recommended?

Answer 19

Cardiogenic

Question 20

Name three commonly used inotropes?

Answer 20

Dobutamine
Adrenaline
Ephidrine

Question 21

Name two commonly used vasopressors?

Answer 21

Noradrenaline

Metaraminol

Question 22

What is the average fluid requirement of a normal person?

Answer 22

Approximately 2500ml over 24 hours or 25-30ml/kg/24hr

Question 23

What does normal fluid loss occur via?

Answer 23

Urine (1500ml)
Stool (200ml)
Insensible losses, sweat, evaporative water from respiratory tract (800ml)

Question 24

How will a patient that is underfilled (dry) present?

Answer 24

• Tachycardia
• Postural drop in BP
• Increased cap refill time
• Decreased urine output (>0.5ml/kg/hr)
• Cool peripheries
• Dry mucous membranes
• Decreased skin turgor
• Sunken eyes

Question 25

How will a patient that is overfilled present?

Answer 25

• Increased JVP
• Pitting oedema of sacrum, ankles or even legs and abdomen
• Tachypnoea
• Bibasal crepitation’s
• Pulmonary oedema on CXR

Question 26

How much Na+ and K+ is required per 24 hours

Answer 26

100mmol Na+

70mmol K+

Question 27

What sort of patients would require higher fluid requirements?

Answer 27

Those with excess loss, e.g vomiting, diarrhea, drains, fever, (sweating).
Those with decreased demand, e.g. elderly/frail, low BMI, heart problems, renal failure

Question 28

How much bodily fluid does a 70Kg man have

Answer 28

42L (60% body weight)

Question 29

What proportion of bodily fluids are intracellular and extracellular?

Answer 29

2/3rds intracellular (28L)

1/3rd extracellular (14L)

Question 30

How much blood does a 70kg man have on average?

Answer 30

1/3rd of their extracellular compartment (5L)

Question 31

What are third space fluids/fluid sequestration?

Answer 31

inflammation and injury cause capillary permeability to increase so that fluid and protein leak from the blood vessels causing oedema

Question 32

When is fluid sequestration most commonly seen?

Answer 32

Pancreatitis
Sepsis
Post major operations

Question 33

Describe a fluid challenge

Answer 33

A bolus of crystalloid 0.9% saline 500ml (250ml if frail or heart problems, 10ml/kg in children) given over <15 minutes. Reassess immediately.

Question 34

What is the maximum safe rate if potassium administration outside of HDU/ICU?

Answer 34

10mmol/hr

Question 35

What is the daily glucose requirement?

Answer 35

50-100mg/24hr

Question 36

How much glucose is in 500 ml 5% glucose

Answer 36

5g/100ml so 25g in 500ml 5% glucose

Question 37

Why is dextrose (5% glucose) useless for fluid resuscitation?

Answer 37

Contains a small amount of glucose which is quickly metabolized leaving only water. Water then rapidly equilibriates throughout all fluid compartments.providing hydration but not resuscitation.