Haematology Flashcards
Which of the following are first line treatments for tumour lysis syndrome?
- Allopurinol
- Sodium Bicarbonate
- Renal replacement therapy
- Rasburicase
- Intravenous potassium
- Rasburicase
The treatment priorities for tumour lysis syndrome are
- Aggressive fluid resuscitation
- Correction of hyperkalaemia
- Intravenous rasburicase
- CVVHF if no improvement
Allopurinol can be given as prophylaxis but not immediate treatment.
Bicarbonate will only temporarily improve pH, but won’t correct the underlying issue.
Which bleeding disorder frequently presents for the first time following surgery?
Von Willebrand disease
It usually has normal FBC and Coagulation tests
What are the indications for splenectomy?
Open technique
- Trauma
- Massive splenomegaly
Laparoscopic
- Idiopathic Thrombocytopenic Purpura
- Hereditary spherocytosis
- Thalassaemia
- Hodgkin lymphoma
- Leukaemia
- Myeloproliferative disease
- Felty syndrome
How long before and after thrombolysis can an epidural catheter be sited or removed?
AAGBI advice is:
- 10 days after cessation of thrombolysis before performing a neuraxial block
- 10 days after block (or epidural catheter removal) before thrombolysis should be given
When talking about TEG, what is the R time?
Time from when test starts, to when clot starts to form
Normal is 5-10mins
Determined by clotting factors
If prolonged, give FFP
For ROTEM this is clotting time
When talking about TEG, what is the K time?
The time from the beginning of the clot forming, until the width or deviation of the graph is 20mm on the screen
Normal is 3-5mins
Determined by fibrinogen
If prolonged, give cryoprecipitate
For ROTEM this is clot formation time
When talking about TEG, what is the alpha angle?
This tells you the rate at which the clot is forming
Normal is around 50-70 degrees
Determined again by fibrinogen
If lower then give cryoprecipitate
This is the same in ROTEM
When talking about TEG, what is MA?
Maximum Amplitude
A measure of how big the clot gets
Normal is 50-70mm
Determined largely by platelets
Unsurprisingly - Give platelets if low
For ROTEM this is Maximum Clot Firmness
When talking about TEG, whas it CL30 or LY30?
A measure of how rapidly the clot is breaking down
Should be less than 8% by 30 minutes after maximum amplitude
If more than this, give tranexamic acid
TEG is CL30, ROTEM is LY30
What are the benefits of point of care coagulation testing?
Faster results
Tests in vivo function, rather than in vitro function
More judicious use of blood transfusion
Information about platelet function
Information about fibrinolysis
Tiny volume of blood required
Easy to use with correct training
What is the difference between TEG and ROTEM?
Thromboelastography
Blood added to cup, with pin suspended in the blood
Cup rotates
Rotational and shear forces exerted on the pin are recorded via a torsion wire
Rotational Thromboelastometry
Cup stays still, pin rotates
Optical system detects increased impedence corresponding to rotational forces
Describe the changes in TEG parameters you would see in early and late disseminated intravascular coagulopathy
Early
Shortened R time and K time
Increased alpha angle and MA
Increased LY30
This is due to an excessive consumptive coagulopathy with rapid fibrinolysis
Late
R and K prolonged
MA and alpha angle decreased
This is due to consumption of clotting factors and platelets, resulting in delayed and ineffective coagulation
What are the features of tumour lysis syndrome?
Hyperkalaemia
Hyperphosphataemia
Hypocalcaemia
Hyperuricaemia
High creatinine
High urea
Low bicarbonate
High lactate dehydrogenase
Which drugs are safe in porphyria?
Antacids
Propofol
Nitrous oxide
Suxamethonium, pancuronium, vecuronium
Atropine, glycopyrulate, neostigmine
Opioids
Bupivacaine
Midazolam and lorazepam
Droperidol
Adrenaline and Phenylephrine
Salbutamol
Magnesium
Beta blockers
Which drugs should be avoided in porphyria?
Ropivacaine
Phenytoin
Barbiturates
Sulphonamides
Chlordiazepoxide
Diazepam
Halothane
Steroids
Ketamine
Etomidate
Lidocaine
Atracurium
What are your management priorities for an acute attack of porphyria?
There are three main aims for management of an acute attack:
- Stop the triggering factor
- Adequate analgesia
- Reduce haem production (via ALA synthase activity)
As always, begin by resuscitating the patient as required with an A to E approach:
Call for assistance if needed
A - may require intubation if low GCS or unmanageable agitation
B - weakness or low GCS may require respiratory support
C - tachycardia and hypertension common - consider beta blockade*
D – agitation, low GCS, seizures - consider magnesium or midazolam
E - abdominal pain - rule out other causes, ensure IV access and analgesia
F - likely hyponatraemia manageable with fluid restriction or hypertonic sailine
G - ensure hypoglycaemia corrected as required
H - haem arginate
The specific treatment for a porphyric crisis is haem arginate:
- 3mg/kg once per day for 3-4 days
- Plasmapheresis can also be considered
As always - try and remove the triggering agent or factor where possible
You may also want to contact the patient’s haematologist if they’re known to have recurrent attacks.
*Beta blockers also reduce ALA synthase activity which is helpful to reduce haem production
What are the signs and symptoms of acute porphyria?
Abdominal pain - diffuse, recurrent and severe
Nausea and vomiting
No fever or leucocytosis
Cardiovascular - tachycardia, hypertension and arrhythmias
Weakness - proximal more than distal, up to 1 in 5 develop respiratory failure
Psychiatric features - confusion and psychosis
Pain and sensory disturbance - in limbs, back and trunk
Constipation
Gastroparesis
Postural hypotension
Cutaneous lesions - Only in VP and HCP
Hyponatraemia and other electrolyte derangement
What are the types of von Willebrand disease?
Type 1 - 75% - partial quantitative deficiency of VWF
Type 2 - 20% - functional deficiency of VWF*
Type 3 - 5% - complete lack of VWF
*This is further classified depending on whether the deficiency is in binding to platelets, factor 8 or collagen.
What is the risk of epidural haematoma with low platelets?
The estimated risk of an epidural haematoma
0.2% for platelets of 70 - 100
3% for 50 - 69
11% for 0 - 49
Tell me about haemophilia
X linked congenital bleeding disorder
Deficiency of factor 8 (Haemophilia A) or 9 (Haemophilia B)
Males affected, females can be carriers with a reduction in factor levels
80% of cases are haemophilia A
Mild = clotting level 0.05-0.5 IU/ml - bleeds with major surgery
Moderate = 0.01 - 0.05 - gets some spontaneous bleeds
Severe = <0.01 - spontaneous joint and muscle bleeding
Desmopressin can be used to increase levels of Factor 8 but not 9
