SA haematology Flashcards
1
Q
what is anaemia?
A
reduction in RBC mass (clinical sign not disease)
2
Q
what are ways of measuring RBC mass?
A
PCV/haematocrit
RBC count
total haemoglobin
3
Q
what are the three causes of anaemia?
A
inadequate production
increased destruction
loss (haemorrhage)
4
Q
what is the typical appearance of RBCs in anaemia caused by inadequate production by bone marrow?
A
normocytic normochromic
5
Q
what is the typical appearance of RBCs in anaemia caused by increased destruction?
A
macrocytic hypochromic
6
Q
what is the typical appearance of RBC in anaemia caused by loss (haemorrhage)?
A
microcytic hypochromic
7
Q
how can red blood cell size be described?
A
microcytic
normocytic
macrocytic
8
Q
is anaemia due to loss (haemorrhage) regenerative?
A
not regenerative enough (lack of iron)
9
Q
what increases in erythrocytes in animals with anaemia?
A
2,3-DPG
10
Q
what does an increase in 2-3-DPG in erythrocytes of anaemic animals do?
A
lowers the oxygen-haemoglobin affinity so more oxygen is delivered to tissue
11
Q
what does reduced tissue perfusion simulate?
A
increase erythropoietin levels stimulating erythropoiesis
12
Q
what are the three ways of classifying anaemia?
A
severity
erythrocyte index
regenerate response
13
Q
what is the PCV of a dog with mild anaemia?
A
30-36%
14
Q
what is the PCV of a cat with mild anaemia?
A
20-24%
15
Q
what is the PCV of a dog with moderate anaemia?
A
18-29%
16
Q
what is the PCV of a cat with moderate anaemia?
A
15-19%
17
Q
what is the PCV of a dog with severe anaemia?
A
<18%
18
Q
what is the PCV of a cat with severe anaemia?
A
<15%
19
Q
how can the erythrocyte index be described?
A
microcytic, normocytic, macrocytic
hypochromic, normochromic
20
Q
what is used to determine if nan anaemia is regenerative or not?
A
reticulocyte count
21
Q
what stain is used to visualise reticulocytes?
A
new methylene blue (blue speckles)
22
Q
how long does it take to see an increase in reticulocytes in regenerative anaemia?
A
2-3 days (peaks at 7 days)
23
Q
are all polychromatophils reticulocytes?
A
yes (not all reticulocytes are polychromatophilic)
24
Q
what are the main causes of regenerative anaemia?
A
haemorrhage
haemolysis
25
what are the two types of feline reticulocytes?
aggregate
| punctate
26
when are aggregate reticulocytes seen?
first 24 hours after being released from bone marrow
27
which feline reticulocyte should be counted when assessing if an anaemia is regenerative or not?
aggregate
28
how long does it take for iron stores to deplete in cases of chronic bleeding?
>1 month
29
what is the cause of anaemia in chronic bleeding patients?
iron deficiency (initially regenerative but becomes less and less)
30
how do RBCs appear in iron deficiency anaemias?
hypochromic (less iron)
| microcytic
31
what is used to treat iron deficiency anaemia?
```
iron supplement (ferrous sulphate)
blood transfusion (packed red cell)
```
32
what are the two classes of haemolysis?
immune mediated
| non immune mediated
33
what are some examples of non immune mediated haemolysis?
```
oxidative damage (onions, paracetamol...)
intra-erythrocytic parasites
mechanical damage
```
34
how does extravascular haemolysis occur?
antibody binds to RBC and macrophage causes phagocytosis/lysis
35
what is formed from partial phagocytosis of a RBC?
spherocyte
36
what system is activated during intravascular haemolysis?
complement (extensive inflammation)
37
why does intravascular haemolysis lead to renal compromise?
free haemoglobin in blood (haemoglobinaemia) which is toxic to the tubular epithelium
38
do animals with intravascular or extravascular haemolysis appear sicker?
intravascular
39
what is typically seen on haematology of a patient with immune mediated haemolytic anaemia?
regenerative anaemia
autoagglutination
spherocytes
40
how do spherocytes appear compared to RBCs?
smaller, rounder and denser
41
where should be looked on a blood smear for spherocytes?
monolayer
42
what are ghost cells?
lysed RBCs
43
what can cause autoagglutination of RBC in cases of immune mediated haemolytic anaemia?
anti-erythrocyte IgM
| high levels of anti-erythrocyte IgG
44
how does autoagglutination of RBCs appear?
cluster of grapes
45
what causes rouleaux formations?
increased plasma proteins coating RBCs (stacking of RBCs)
46
what type of blood should be used for the saline agglutination test?
anticoagulated
47
what is the Coombs test used for?
detect presence of antierythrocyte antibodies (can't be done if agglutination present)
48
what will be seen on biochemistry of animals with immune mediated haemolytic anaemia?
elevated ALT and AP
hyperbilirubinaemia
azotaemia
49
what is seen on urinalysis of animals with immune mediated haemolytic anaemia?
haemoglobinuria
bilirubinuria
proteinuria
50
what are the three treatments needed immune mediated haemolytic anaemia?
immunosuppression
antithrombotics
supportive
51
what is the first choice drug for immunosuppression in immune mediated haemolytic anaemia cases?
prednisolone
| dexamethasone, ciclosporin, azathioprine
52
what are some side effects of corticosteroids?
PU/PD
muscle wasting
GI (ulcers and gastritis)
53
when is a second like immunosuppressant used in immune mediated haemolytic anaemia cases?
life threatening disease
no response to first
severe corticosteroid side effects
54
what type of drug is prednisolone?
corticosteroid
55
what can be used if an immune mediated haemolytic anaemia patient hasn't responded to two immunosuppressants?
immunoglobulins (one off treatment)
56
how long does treatment of immune mediated haemolytic anaemia with immunosuppressants typically last?
4-8 months (some lifelong) - some can relapse
57
what immune mediated haemolytic anaemia patients is antithrombotic therapy used in?
severe intravascular haemolysis
58
are blood transfusions indicated for immune mediated haemolytic anaemia?
no - often haemolyse the donor RBCs
59
what is neonatal isoerythrolysis?
destruction of neonates RBCs by maternal antibodies (antibodies in colostrum)
60
what cat breed is neonatal isoerythrolysis seen in?
British shorthair
61
what is microangiopathic haemolytic anaemia?
RBCs damaged/fragmented as they pass through fibrin meshwork of microvasculature
62
what are some examples of causes of microangiopathic anaemia?
```
fibrin clots (DIC)
glomerulonephritis
congenital defects
```
63
what are formed from mechanical damage to RBCs (microangiopathic anaemia)?
schistocytes (sheared RBC)
64
what are acanthocytes?
RBCs with multiple rounded projections
65
what occurs due to oxidative damage of RBCs?
methaemoglobinaemia
heinz body formation
RBC membrane oxidation
66
what can cause oxidative injury to RBCs?
onions and zinc (dogs)
| paracetamol (cats)
67
what are Heinz bodies?
round pale inclusions on the inner surface of RBC membranes (aggregates of denatured haemoglobin)
68
what stain is used to visualise Heinz bodies?
methylene blue
69
what are three causes of intrinsic haemolytic anaemias?
pyruvate kinase deficiency
phosphofructokinase deficiency
osmotic fragility
70
what mycoplasma is associated with regenerative anaemia?
Mycoplasma haemofelis
71
what is used to treat Mycoplasma haemofelis?
doxycycline
prednisolone
(no cure - remain carriers)
72
what is the characteristic feature of non-regenerative anaemias?
absence of reticulocytes
73
what causes non-regenertive anaemia?
marrow disease
| lack of erythropoietin
74
what are some causes of intramarrow disease?
drug reactions
oestrogen toxcitiy
pure red cell aplasia
75
what does oestrogen toxicity cause?
thrombocytopenia
neutropenia
anaemia
(pancytopenia)
76
what cells are effected by red cell aplasia?
just erythrocytes
77
what cells are effected by aplastic anaemia?
all cell lines (pancytopenia)
78
what is myelofibrosis?
proliferation of collagen and reticulin fibres in bone marrow
79
what type of anaemia is anaemia of chronic disease?
non-regenerative normocytic and normochromic
80
what is the cause of anaemia in chronic kidney disease?
reduced erythropoietin production
81
what type of anaemia can FIV/FeLV cause?
non-regenerative
82
what are the five major leucocytes?
```
neutrophil
monocyte
lymphocyte
eosinophil
basophil
```
83
what are the three granulocytes? (polymorphonuclear)
neutrophil
eosinophil
basophil
84
as an estimate on low power, how many leukocytes would you class as a leukopenia?
<15
85
as an estimate on low power, how many leukocytes would you class as a leukocytosis??
>45
86
what is the morphology of mature neutrophils?
lobed nucleus with clear/pink cytoplasm
87
what is the morphology of a banded neutrophil?
U shaped parallel nucleus
88
what is the most abundant leucocyte?
neutrophil
89
what are the functions of neutrophils?
kill/inactivate bacteria, yeast, fungi, parasites
| regulate haemopoiesis
90
what are the three pools of neutrophils within bone marrow?
proliferative
maturation
storage
91
what regulate the production of neutrophils?
cytokines
| growth factors
92
what is the average time a neutrophil spends in blood?
6-10 hours
93
what blood cell has the shortest lifespan?
neutrophils (6-10 hours)
94
what happens to the number of neutrophils in circulation when there is a strong inflammatory stimulus?
increase in banded neutrophils
95
what is left shift?
increase in the number of immature cells in circulation
96
what is a degenerative left shift?
normal/low mature neutrophil count with increased immature cells (marrow not coping)
97
what are the common causes a neutrophilia?
physiological (stress)
acute inflammatory response
stress/corticosteroid induced
98
what mediates physiological neutrophilia?
adrenalin
99
what species is a physiological neutrophilia commonly seen in?
cats
100
in cats what is often also seen with a physiological neutrophilia?
marked lymphocytosis
101
what is the mediator of a stress leukogram?
cortisol/corticosteroid
102
what are the features of a stress leukogram?
neutrophilia
lymphopenia
eosinophilia
103
what is often seen with a neutrophilia in an acute inflammatory response?
left shift
104
what is toxic change of neutrophils due to?
reduced maturation time in bone marrow due to intense stimulation of myelopoiesis
105
how do neutrophils undergoing toxic change appear?
blue cytoplasm and granules
foamy vacuoles
less condensed chromatin
106
what are some causes of neutrophil dysfunction?
immunodeficiency syndromes
diabetes mellitus
neoplasia
FeLV
107
what are the two general causes of neutropenia?
overwhelming demand/decreased survival
| reduced/ineffective granulopoiesis
108
when is there overwhelming demand of neutrophils?
severe bacterial infection - prothorax, pyometra, peritonitis...
109
what are the main functions of eosinophils?
kill parasites
control hypersensitivity
allergic disease and inflammation
110
why is it hard to have an eosinopenia?
most normal levels extend to zero
111
what are the functions of basophils?
potentiate inflammation
histamine release
respond with eosinophils
112
what is the function of monocytes?
circulating precursor of macrophage
113
when does a monocytosis occur?
```
chronic inflammation
acute inflammatory response
tissue necrosis
immune mediated disease
stress leukogram
```
114
what are the majority of the circulating lymphocytes?
memory T cells
115
when is a lymphocytosis seen?
```
physiological stress
prolonged immune stimualtion
youth
lymphoproliferative disease
hypoadrenocorticism
```
116
when is a lymphopenia seen?
```
corticosteroids
viral disease
loss of lymphocyte rich lymph (chylothorax)
sepsis
lymphoma
```
117
what are the three most likely clincopathological abnormalities seen in a frightened kitten?
hyperglycaemic
neutrophilia
lymphocytosis
118
what is polycytaemia also known as?
erythrocytosis
119
what is erythrocytosis?
increase in PCV/hct, RBC count of haemoglobin
120
what is a relative erythrocytosis?
increased RBC numbers due to decreased plasma volume or RBC redistribution
121
what is an absolute erythrocytosis?
true increase in RBC numbers due to erythropoiesis
122
what breeds is it normal to have a high PCV?
greyhounds (sighthounds)
123
what can cause a decrease in plasma volume leading to relative erythrocytosis?
dehydration
| fluid shift
124
what causes RBC redistribution leading to a relative erythrocytosis?
splenic contraction (exercise/adrenalin)
125
what is absolute erythrocytosis secondary to?
increased erythropoietin
126
what is an appropriate reason for increased erythropoietin?
generalised hypoxia and hypoxaemia
127
what can cause an appropriate secondary absolute erythrocytosis?
severe heart disease
high altitude
alveolar hypoventilation
128
what can cause inappropriate secondary absolute erythrocytosis?
renal tumors/lesions (localised renal hypoxia)
| non-renal tumors (producing erythropoietin)
129
what disorder causes primary absolute polycytaemia?
myeloproliferative (leukaemia)
130
how is absolute erythrocytosis treated?
phlebotomy
| treat underlying disease
131
what percentage blood volume loss can most health animals withstand?
15-25%
132
what is done to stabilise a bleeding patient?
control haemorrhage
| fluid replacement
133
if hypovolaemic what kind of fluid should be used as a volume replacer?
crystalloid
134
what is the shock rate bolus volume?
1/5 to 1/4 of animals normal blood volume (40-50ml/kg)
135
what percentage blood loss is an indication a blood transfusion is needed?
>25%
136
what are the steps of haemostasis?
```
vessel injury
vascular contraction
primary haemostasis
secondary haemostasis
tertiary haemostasis
```
137
what happens during primary haemostasis?
platelet plug forms
138
what is platelet plug formation dependant on?
platelets
von Willebrand factor (for binding)
endothelium exposure
139
what is involved in secondary haemostasis?
coagulation cascade resulting in thrombin generation
140
what is the role of thrombin?
stabilises the blood clot
141
what happens during tertiary haemostasis?
fibrinolysis (ensures clot doesn't get too big)
142
what are the clinical signs of a primary haemostasis defect?
```
small hole (petechiae) - lack of platelet
melena
```
143
if an animal is suspected of having a clotting disorder, where should you not take blood from?
jugular - difficult to stop and apply pressure
144
what biochemistry test are done to assess disorders of haemostasis?
whole blood clotting time
activated clotting time
buccal mucosal bleeding time
145
what must be excluded before carrying out a buccal mucosal bleeding time?
thrombocytopenia (don't do if present)
146
what is being assessed when looking for a primary coagulopathy?
platelet function and number
147
what are the main tests done for secondary haemoostasis disorders?
prothrombin time
| activated partial thromboplastin time
148
what are some disorders of primary haemostasis?
thrombocytopenia
von Willebrand disease
(thrombocytopathia and vascular disorders)
149
what are the causes of thrombocytopenia?
lack of production (bone marrow disorder)
increased consumption (DIC)
increased destruction (immune mediated)
increased sequestration (splenic torsion)
spurious (lab error)
150
what breeds have inherited thrombocytopenia?
King Charles cavaliers
cairn terriers
(don't need to be worried)
151
what causes primary immune mediated thrombocytopenia?
IgG binding to platelets
152
what causes secondary immune mediated thrombocytopenia?
drugs, infectious disease, neoplasia, antibiotics
153
what is the main treatment option for primary immune mediated thrombocytopenia?
immunosuppression (glucocorticoids)
154
what are common causes of thrombocytopathia?
hepatic and renal disease
cancers
von Willebrand disease
155
what is thrombocytopathia?
normal platelets count and coagulation but still excessive bleeding
156
how long should a buccal mucosal bleed time be?
2-4 minutes
157
where is von Willebrands factor synthesised and stored?
endothelial cells
158
what is von Willebrand factor needed for?
platelet adherence
159
what is done to test for von Willebrand disease?
antigenic test
| genetic testing
160
what can be done to treat von Willebrand disease?
cryoprecipitate (rich in vWF and factor VIII)
161
what are the most common causes of acquired disorders of secondary haemostasis?
vitamin K deficiency (rodenticides)
liver disease
DIC
162
what are inherited disorders of secondary haemostasis?
```
haemophilia A (VIII deficiency)
haemophilia B (IX deficiency)
```
163
what are the clinical signs of vitamin K deficiency?
```
epistaxis
melaena
haematoma
haematuria
gingival bleeding
```
164
what is the best way to administer vitamin K therapy?
orally
165
what is DIC?
widespread activation of coagulation leading to microthrombi in organs (consumptive coagulopathy)
166
what is the most common cause of DIC?
septicaemia
| immune mediated disease
167
what lab abnormalities are found in animals with DIC?
```
prolonged clotting times
thrombocytopenia
schistocytes
decreased fibrinogen
increased D-dimers
```
168
what is done to treat DIC?
treat underlying disease
heparin
whole blood
169
what are D-dimers?
specific product of breakdown of cross linked fibrin (from clot)
170
what should whether a patient needs a blood transfusion or not be based on?
clinical signs (reduced tissue perfusion)
171
what must you ensure before deciding to give a transfusion?
the patient in normovolaemic
172
what blood product should blood loss be replaced with?
whole blood (or packed red cells)
173
what blood product should be used to replace low PCV due to haemolysis?
packed red cells
174
if the patient has a coagulopathy, what blood product should be used if a transfusion if required?
fresh frozen plasma
regular plasam
cryoprecipitate
175
if in doubt what blood type should be given to dogs?
DEA 1 negative
176
what type of blood is it imperative to give to cats?
type-matched
177
what is the pathophysiology of naive exposure in regards to transfusion medicine?
DEA 1 positive blood given to a DEA 1 negative recipient
178
what is sensitised exposure in regards to transfusion medicine?
DEA 1 negative dog has previously been given DEA 1 positive blood so now has antigens for them (haemolysis)
179
what does DEA stand for?
dog erythrocyte antigen
180
can a DEA 1 positive dog receive DEA 1 negative blood?
yes (and won't become sensitised)
181
why is it imperative to type match acts?
have naturally occurring auto-antibodies against other blood types
182
can type B cats be given type A blood?
no - severe haemolytic reaction (BAd)
183
can type A cats be given type B blood?
has a mild delayed reaction (not As Bad)
184
what can be used to boot type cats/dogs?
card or cassette (wash blood in saline first - auto-agglutination)
185
what does crossmatching do?
detect the majority of antibody-antigen incompatibilities in blood
186
what is a major crossmatch?
recipient has antibodies against donor RBCs (don't give)
187
what is a minor crossmatch?
donor has antibodies against recipient RBCs (can give)
188
when do patients need crossmatching?
if they have had a previous transfusion
189
why should blood transfusions be started at a slow rate?
to see if there is any reaction
190
what is used to administer blood transfusions?
transfusion set with in-line filter (stop microthrombi)
191
what speed is a blood transfusion initially given at?
0.5-1ml/kg/hr
192
what should the IV line of blood transfusions be flushed with?
NaCl (not Ca)
193
should blood be warmed prior to a transfusions?
no (sepsis risk) - give at room temperature
194
how fast do haemolytic reactions to a transfusion occur?
acute (rapid)
| delayed (days) - mild reaction or formation of new antibodies
195
how do non-haemolytic transfusion reactions present?
pyrexia
anaphylaxis
(can be citrate toxicity)
sepsis
196
how does citrate toxicity transfusion reaction present?
similar to hypocalcaemia
197
do plasma products need typing/crossmatching?
no (most DEA 1 negative)
