Data interpretation 2

Question 1

Describe how a thrombo-elastogram works

Answer 1

An activator is added to the patients blood sample
The blood sample is then added into a heated cup.
A pin is suspended down into the heated cup filled with whole blood
The cup rotates 4.45 deg every 5 seconds.

As the clot develops, more rotational force is transmitted to the pin.

An electromagnetic transducer detects the rotational force.

The information is electronically conveyed to a computer that then produces a characteristic graph

Question 2

What 3 causes are associated with excessive platelet bleeding and a normal TEG.

What are actions to be taken for each of these causes

Answer 2

1. Surgical injury to blood vessel with insufficient repair
2. vWF deficiency
3. Presence of platelet inhibitors

Actions:

1. Surgical repair
2. DDAVP (desmopressin)
3. Run PlateletMapping (on the machine)

Question 3

How does coagulation factor deficiency/dysfunction/inhibition (heparin/warfarin) effect the TEG

Answer 3

1. Prolonged R-time (reaction time) > 10
2. Decreased alpha-angle < 47
3. Low normal MA ± 55

Question 4

What are the causes of coagulation factor deficiency

Answer 4

Haemodilution
Significant blood loss (trauma)
Blood Salvage
Liver disease or congestion
Congenital condition (haemophilia)

Factor consumption > synthesis

• ECMO
• Cardiopulmonary bypass
• DIC

Question 5

What causes coagulation factor dysfunction or inhibition

Answer 5

Vitamin K deficiency (2, 7, 9, 10)
Warfarin
Other anticoagulant

Question 6

What are the causes of fibrinogen deficiency

Answer 6

1. Liver disease or congestion
2. DIC
3. Abruptio-placentae
4. Hemodilution

Question 7

Can TEG analysis distinguish between platelet deficiency and platelet dysfunction

Answer 7

NO

Question 8

What is the clinical effect of low MA (platelet abnormality)

Answer 8

Low clot strength, insufficient to stop vascular bleeding

Question 9

What determines stability on a lateral neck x-ray for a patient with rheumatoid arthritis

Answer 9

ADI: Atlantodens Index < 3.5 mm

If ADI > 3.5 mm –> manual inline C-spine immobilization during intubation and likely will need fibreoptic laryngoscopy and intubation.

PADI (Posterior atlanto-dens interval) = Space Available for Cord (SAC) < 14mm requires surgery