Mock20 Polytrauma

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Stem: A known hepatitis C patient suffered a traumatic splenic rupture with massive blood loss. Splenectomy done and the patient received a massive blood transfusion. Later, the patient developed epistaxis, bleeding in the NG tube and oozing from the surgical wound. Investigations showed severe thrombocytopenia and low fibrinogen with increased fibrin degradation products.

Blood tests
Platelet count (low)
FDP, D-dimer (high)
Fibrinogen (low)
PT (high)
APTT (high)

What's your diagnosis?

DIC

Define DIC?

It is a pathological consumptive coagulopathy.
Occurs due to activation of the coagulation and fibrinolytic systems → formation of micro thrombi in many organs with the consumption of the clotting factors and platelets.

How to correct DIC?

By Blood, FFP, platelets, cryoprecipitate.

What is massive transfusion?

Replacement one blood volume in 24h
or Replacement of 50% of blood volume in 4 hours.

What's massive transfusion protocol?

Fixed ratio of transfusion, for e.g. RBC, FFP, platelets of 1:1:1 (or according to trust guidelines)

What are the complications of massive blood transfusion?

Acid base disturbance
Hyperkalaemia
Hypocalcaemia
Transfusion related Acute Lung
Hypothermia
Multi-organ failure
Fluid overload

How to minimize the need for blood transfusion?
Pre-operative measures

Correction of anaemia, e.g. by iron supplement, erythropoietin, haematinics
TXA
Intraoperative measures
!Cell salvage, autologous transfusion
Hypotensive technique.
Good haemostasis
Plasma expanders like crystalloids and colloids

How platelets are formed?

From megakaryocytes in bone marrow by fragmentation

What's its shelf life?

5 days

What's the percentage of WBCs in packed RBCs?

< 5x10^6 cells/L (Leukoreduced packed RBC)

Percentage of Platelet in packed RBCs?

0%

What's the life span of RBCs?

120 days

What would do before giving blood?

Grouping and cross matching (CXM)

What's cross matching?

Testing donor red cells against recipient serum to detect any potential incompatibility through which antibodies in recipient cause haemolysis to donor cells.

Which antigens are tested?

ABO and RH

What is meant by group and save?

Analysis of Recipient blood alone to detect:

Patient's blood group

Presence of atypical red cell antibodies in their blood (if atypical antibodies are present the laboratory will do additional work to identify them).

Why does this patient have bleeding tendency?

Because of the liver affection (Hep C positive)

What are the late manifestations of HCV?

Cirrhosis
HCC
Portal hypertension

What activates intrinsic and extrinsic pathways? How can you test each?
Intrinsic pathway

Activated by vessel injury which will lead to activation of factor 12
Tested by APTT

Extrinsic pathway

Activated by tissue thromboplastin released by the damaged cells
Tested by PT and INR

The patient developed a hypersensitivity reaction during blood transfusion, what is the definition of hypersensitivity?

Exaggerated or inappropriate immunologic responses occurring in response to an antigen or allergen.

What are its types?

Type I Type II Type III Type IV
Anaphylactic - IgE
Cytotoxic - IgG, IgM
Immune complex - IgG, IgA, IgM
Delayed type - T-cells
:Type V is autoimmune, e.g. Myasthenia gravis

The patient has sustained a long bone fracture, can you mention the different stages of bone healing?

Haematoma formation1 week
Fibrocartilaginous callus (soft callus)2-3 weeks
Bony callus1-4 months
RemodellingAfter union (months)

What are the effects of prolonged immobility on bone healing?

Loss of bone mass (Wolff's law)
Decrease in gravitational forces superimposed in bones → which will lead to demineralisation of bones and lose of trabeculae volume (bone will become thin and pores and fragile due to a relative increase in osteoclast activity).

Fracture was treated with ORIF; then the wound started oozing yellow fluid. What's the first test to be done to the fluid?

Wound swab for culture and sensitivity

Wound swab and culture revealed PVL. What does PVL stand for?

Panton-Valentine leucocidin (PVL)

What's the effect of its cytotoxin?

It is a pore forming toxin. It is produced by Staphylococcus aureus mostly in MRSA → leukocyte destruction and tissue necrosis.
PVL creates pores in the membranes of infected cells → necrotic lesions involving the skin or mucosa. (e.g. necrotizing pneumonia).

What would you like to do with the implant? Why?

I will remove the implant because
Become loose
Form a biofilm
Septic focus

What are the contents of cryoprecipitate?

Fibrinogen
Factor VIII
Factor XIII
Von Willebrand factor (VWF)

isurg

Mock20 Polytrauma