Clinical Approach to Anaemia SA Flashcards
CLinical signs seen with anaemia?
- none/vague if mild or chronic
- non-specific lethargy, anorexia, collapse
- specific = pale mms, ^ HR, ^RR, murmur, hyperdynamic pulses
- severity of signs reflects cause, chronicity and severity of anaemia
What are ddx for pale mms?
> poor perfusion - probably prolonged CRT - weak pulses > anaemia (euvolaemic) - normal CRT - strong pulses (^CO so greater difference betweend iastolic and systolic)
What does ^ HR and RR indicate in an anaemic patient?
- attempting to compoensate
= severe anaemia
How does chronic and acute anaemia present differnetly?
- chronic animal can adapt so cat with chronic anaemia 8% PCV can appear more stable than
- dog with aute onset PCV 18%
Is signalment ver relevant to anaemia?
YES > young - lower PCV normal, pale mm - parasites > older - neoplastic - renal > breeds - cocker IMHA
Important hx points with anaemia?
- lifestyle
- stable or deteriorating
- site of bleeding (melana and haematuria, epistaxis)
- access to drugs or toxins
- travel hx
PE points important for anaemia?
- stable
- HR, RR, demarnour
- icturys
- pleural and peritoneal space (auscultation and fluid thrill)
- concurrent disease
- masses/pain
- rectal (meleana)
Diagnostic approach to pale mms?
> poor perfusion v anaemia
- PCV/TP
- TP v haemorrhage, ^~ haemolysis or non-regenerative anaemia
regenerative v non-regenerative
- time scale
- measure reticulocyte count (correct for PCV or use absolute count better)
* >60,000/ul dog or >40,000/ul cats = regenerative
- blood smear evaluation in house (polychromasia, nRBC)
evidence of underlying cause on smear?
- immune-mediated destruction
- mechanical destruction
- infectious agent
Reasons for regenerative anaemia?
> haemorrhage
- internal (spleen dogs, thorax, trauma, amyloidosis hepatic in cats)
- external (epistaxis, parasites, meleana, UT)
Why may the spleen be enlarged in anaemia?
Help to regenerate RBCs
What might you want to check with haemorhaging patients?
> TP always \+- -coagulation - platelet count always - feacal lungworm (angiostrongylus vasorum) - ACTH (Addisons s-> GIT Ulceration) - search body cavities
Tx blood loss anaemia?
> Tx/remove underlying cause
- remove spleen/gut
- gastro-protectant if ulcerated but not surgical
- remove cause of ulceration
- tx lungworm
- blood transfusion?
Types of haemolysis
> intravascular - complement and IgM mediated - haemalgobinaemia and haemoglobinuria > extravascular - mcrophages in spleen liver etc. IgG mediated
what signs may help you to differentiate the type of haemolysis
- autoagglutination?
- Coombs test?
- Haemaglobinuria
- Bilirubinuria
4 main cauases of haemolytic anaemia
> IMHA - 1* idiopathic - 2* > inherited haemolytic anaemia - PK deficinecy - PFK deficiency > Infectious causes > Misc
Signalment and findings for IMAH
> spaniels - regenerative anaemia - no sign of blood loss - suggestion of haemolysis (jaundice, auto-agglutination (in-saline) spherocyte, ghost cells - R/O underlying dz > babesia, ehrlichia, non-blood cells
Tx IMHA?
- IV fluid tx/blood tranfusion/hboc - oxyglobin not available)
- immunosupressive tx
- ? aspirin, clopidogrel
- ? gastroprotectant
- nursing (IV catheter, gentle walks)
Main immunosuppressives to tx IMHA?
> Prednisolone
- suppresses macorphages, complement and Ab binding, suppresses IgG
+ Azathioprine (NOT CATS)
- cyclosporine, mycophenolate, chlorambucil (CATS)
Prognosis IMHA?
> guarded
- intravascualr worse
- icterus, haemaglobinaemia/uria, poor regeneration, all poor prognostic indicators
common cause of death PTE (thromboembolism)
may relapse
monitor
- regular PCV/TP and haem prior to each dose reduction
- regular biochem drug toxicity
What type of IMHA is most common in cats?
1* (despite old literature)
Why is IMHA in cats more difficult?
- Dx hard
- giving blood products mroe challenging ni cats (often give more volume watch for overload)
How does Babesia differ from IMHA?
- looks very similar
- more sick with babesia
- more intravasc ?
Specieis of babesia. How is this spread controlled?
- B. Canis in europe
- B. Gibsoni other areas
> travel scheme
Which species does mycoplasma affect?
- cats mainly
- dogs too after splenectomy
Which infections can act as an immunological trigger for IMHA?
- Any theoretically -> 2* IMHA
Miscellaneous causes of haemolysis
> oxidative damage - paracetamol (cats) - onions, garlic, Zn, Cu > hypophosphataemia (DKA) > shear injury (microangiopathic) d/t damaged endothelium
How do non-regenerative anaemia patients present?
- mild/severe
- may be o nvious on PE or not
- variable!!
> reticulocytes
-
Most common cause fo non-regenerative anaemia?
- anaemia of chronic inflammation
Mild - moderate anaemia (dogs 25-36%, cats 18-26%) - chronic infections and non-infectious disorders
- d/t poor iron storage/utilisation and shortened red cell survival, imparied erythrocyte production
k
-
What type of anaemia does renal dz cause?
- normocytic, normochromic
> not always obviuos on PE
Pathogenesis of renal dz anaemia?
- inadequate EPO production
- decreased erythrocyte lifespan
- decreased marrow response to EPO
- other factors (haemorrhage caused by uraemic ulcers etc.)
What should always be tested for in anaemic cats?
- FeLV
What type of anaemia does FeLV cause?
- macrocytic normochromic or normocytic normochromix in chronic dz
- may induce IMHA/1* BM dz
- > 75% anaemic cats found to be FeLV+ in past studies
3 main miscellaneous non-regenerative anaemia
> nutrient - iron deficieny - copper def (Cu associated hepatitis in labs) - folate/cobalamin deficiency (neutropenia, severe non-regen anaemia,s tunted growth, inherited dz in some breeds) > endocrine - hypothyroid - hypoadrenocorticism - hyperestrogen - mild-mod anaemia, severe pancytopenia poss with hyperestrogenism > liver - young dogs with PSS - mild-mod - iron metabolism affected
Types of BM dz? What type of anaemia would this cause?
> non-regenerative
- pure reed cell aplasia
- aplastic anaemia (pancytopenic)
- neoplaisa (myelophthisis)
- myelodysplasia (abnormal development RBC)
- myelofibrosis (fibrosis replaces BM)
Approach to non-regenerative anamiea
- depends on severity
- similar investigation path to regenerative anaeia but Ddx different (look for dz)
- if severe and no cause found on screening tests - BM
- Bi-pancytopenia - BM
Where are BM samples taken?
- humerus or iliac crest
Outline BM sampling technique
- sedation + local/GA
- clip and prepare aseptically
- aspirate (once obtained smear quickly as clots in seconds)
- core-roll preparations then into formalin
Tx BM dz -> non-regenerative anaemia?
- pure red cell aplasia (= IMHA Tx)
- aplastic anaemia (?)
- neoplasia (myelpthisis)
- myelodysplasia (NO tx)
- myelofibrosis (revesible, tx underlying dz)
What is anaemia?
- NOT a clinical sign/dx
= v PCV, HCT, Hb, RBC
may or may not be obvious on PE
