Ref to critical care

Question 1

fluids in hypovolaemic

Answer 1

30ml/kg crystalloid

Question 2

AVPU correlation to GCS

Answer 2

A 12-15
V 8-11
P 4-7
U 3

Question 3

MAP =

Answer 3

MAP = CO X SVR

Question 4

CO =

Answer 4

CO = HR X SV

Question 5

Factors affecting stroke volume

Answer 5

preload (influenced by venous return and circulating blood volume), contractility, afterload

Question 6

What is CaO2?

Calculation

Answer 6

oxygen concentration of blood
=(O2 in Hb)+(O2 in solution)
=(1.34 x Hb x Sp02 x 0.01) + (0.023 x PaO2)

Question 7

How to calculate DO2

Answer 7

DO2 = CaO2 X CO

Question 8

Why is actual DO2 less in septic shock

Answer 8

Oxygenated blood is mal-distributed in the micro circulation

Question 9

What is Vo2? How to calculate

Answer 9

Oxygen consumption

VO2 = CO X (Ca02 - CvO2)

Question 10

Name 3 reasons for invasive monitoring

Answer 10

Abnormal physiology that fails to normalise quickly with simple measures

Unstable haemodynamic condition or potential for rapid deterioration

Use of drugs (vasopressors and inotropes) that can alter cardiovascular physiology rapidly

Intra-arterial lines are used for frequent blood analysis

Central IV access to enable the delivery of multiple infusions e.g. drugs (including veno-irritant
drugs), fluids and parenteral nutrition

Question 11

Complications of art lines - name 4

Answer 11

Failure,
 disconnection and bleeding,
 thrombosis, 
ischemia, 
haematoma
, infection, 
aneurysm,
inadvertent injection of irritant drugs

Question 12

Types of central line

Answer 12

Multilumen – several lumens exist so that multiple infusions are possible.

Wide bore – may be multilumen. Used for rapid administration of fluid, other catheters may be
passed down the large lumen – e.g. PAF catheter or pacing wires

Single lumen – often tunnelled - usually for parenteral nutrition or chemotherapy. Not often used
in ICU (multiple lumens required, as lines often need to be changed in ICU)

Question 13

Complications central line early vs late - name 3 of each

Answer 13

Early:
Damage to veins or adjacent structures, e.g. artery, nerve or thoracic duct
Pneumothorax (especially subclavian route)
Arrhythmias
Air embolism
Puncture of great vessels or heart

Late
Infection (reduced incidence at subclavian)
Extravasation of irritant drugs
Air embolism (if left open)
Bleeding
Catheter breakage
Catheter knotting
Penetration of vessel wall or heart

Question 14

Ways of monitoring CO in ICU

Answer 14

Pulmonary Artery Flotation Catheter (PAFC)
PiCCO (pulse-induced contour cardiac output)
LiDCO (Lithium)
Oesophageal Doppler Monitor (ODM)

Question 15

Advantages/ limitations of Oesophageal Doppler Monitor (ODM)

Answer 15

Advantages
Ease of use.
Minimally invasive.

Complications and disadvantages
Not easy (but possible) to use in awake patients
Risk of oesophageal damage (small)
Unable to use – oesophageal tear, coarctation and aortic balloon pump
Readings depend on probe position

Question 16

How does LiDCO work

Answer 16

Injection on lithium into vein - then sensor measures lithium as it goes past in artery

Question 17

How does PiCCO work

Answer 17

A special arterial line (with a thermistor to measure temperature) is inserted into the brachial or
femoral artery

intermittent thermodilution (fig. 1) is also performed - cold solution is injected into a central vein,
the temperature is detected by a thermistor in the arterial line and, similar to the PAF catheter, the
temperature change can be used to calculate the cardiac output.

Question 18

What are the levels 0-3 in hospital

Answer 18

Level 0 Patients whose needs can be met through normal ward care in an acute
hospital.

Level 1 Patients at risk of their condition deteriorating, or those recently relocated from
higher levels of care whose needs can be met on an acute ward with additional
advice and support from the critical care team.

Level 2 Patients requiring more detailed observation or intervention including support for
a single failing organ system or postoperative care, and those stepping down
from higher levels of care.

Level 3 Patients requiring advanced respiratory support alone or basic respiratory
support together with support of at least two organ systems. This level included
all complex patients requiring support for multi-organ failure.

Question 19

Frank starling law basically means ?

Answer 19

increase preload -> increased ventricular stretch -> increase contractility -> increase CO

Question 20

What is CVP essentially measure? Easiest way to measure ? usual value ?

Answer 20

preload

Use lumen on central line

2-10mmHg

Question 21

When do you see increased CVP ?

Decreased?

Answer 21

R heart dysfunction
fluid over load
tamponade

hypovolemia
venodilation

Question 22

Causes of increased Pul artery pressure ? usual reading

Answer 22

L heart failure
pulm HTN
mitral stenosis / regurg
Atrial septal defect

20-30 / 10-20 mmHg