Clinical pathology AI Flashcards
What are the disadvantages of using in-house analyzers in laboratory testing?
The disadvantages of using in-house analyzers in laboratory testing include poor Quality Control/Quality Assurance, longer time to detect analytical errors, and the absence of regulations regarding POCT QA/QC.
What are the advantages of using external or reference laboratories in laboratory testing?
The advantages of using external or reference laboratories include tight QA/QC controls, a wider range of available tests, qualified interpretation and discussion of cases, and established reference ranges for the laboratory.
What are some biological factors that can influence laboratory test results?
Some biological factors that can influence laboratory test results include species, breed, age, gender/reproductive state, fasting/non-fasting status, stress/excitement, exercise, and drugs.
What are some non-biological factors that can affect laboratory test results?
Some non-biological factors that can affect laboratory test results include clots in the sample, haemolysis, lipaemia, and icterus of the sample.
What is haemolysis and what can cause it in laboratory samples?
Haemolysis is the red discoloration of serum/plasma caused by the leakage of hemoglobin from damaged red blood cells. It can be caused by intravascular haemolysis or in vitro factors such as the use of fine gauge needles, excessive suction, or failure to separate serum/plasma.
What is lipaemia and what can cause it in laboratory samples?
Lipaemia is the milky opacification of serum caused by increased lipids, mainly triglycerides, in the sample. It can be caused by post prandial factors or pathological conditions such as hypothyroidism, diabetes mellitus, hyperadrenocorticism, or pancreatitis.
What are the renal parameters used to assess kidney function?
Urea, creatinine, and urinalysis (USG and UPC).
Which parameter is used to evaluate kidney function specifically in cats?
SDMA (Symmetric Dimethylarginine).
Name the liver enzymes commonly measured in a liver function test.
ALT (Alanine Aminotransferase), AST (Aspartate Aminotransferase), ALP (Alkaline Phosphatase), and GGT (Gamma-Glutamyltransferase).
Which compound is measured to assess liver function related to bile flow?
Bilirubin, specifically Total Bilirubin.
What enzymes are measured to evaluate pancreatic function?
Amylase and Lipase.
What pancreatic test is used to assess exocrine function in dogs?
TLI (Trypsin-Like Immunoreactivity).
What pancreatic test is used to assess exocrine function in cats?
PLI (Pancreatic Lipase Immunoreactivity).
What parameters are measured to assess glucose metabolism?
Glucose and Fructosamine.
What parameters are measured to assess lipid metabolism?
Cholesterol and Triglycerides.
What are the muscle enzymes measured in the case of muscle damage?
CK (Creatine Kinase), AST (Aspartate Aminotransferase), and ALT (Alanine Aminotransferase) (only with marked damage).
Why should a patient be starved for 12 hours before collecting samples to prevent lipaemia?
To prevent lipaemia, and when possible, the patient should be starved for 12 hours before collecting the samples.
What causes the yellow/orange coloration of serum known as icterus?
The yellow/orange coloration of serum known as icterus is caused by the presence of increased bilirubin in the serum.
When can icterus be clinically appreciated in the sclera and skin?
Jaundice detection is usually only apparent in the sclera with TBIL > 25umol/l and in the skin with TBIL > 45 umol/L.
What factors should be considered when looking at a result?
When looking at a result, factors that should be considered include: Was the technique/analyser working correctly? Was the test done properly and with the right sample? Were there any potential sources of error? Is this result normal, or abnormal? And specifically, for this animal/patient?
How can pattern recognition be useful in interpreting biochemistry results?
Pattern recognition can give a systematic and thorough approach to interpretation of biochemistry results, especially in complicated cases.
What are the potential drawbacks of pattern recognition?
The potential drawbacks of pattern recognition include: lack of experience with the particular disease/pattern, only considering limited list of differentials, limited information, performing pattern recognition subconsciously without critical analysis.
What is organ profiling and how can it assist in interpreting biochemistry results?
Organ profiling is the use of pattern recognition to assist in recognizing patterns in biochemistry results, rather than focusing on individual tests/markers.
How should biochemistry tests be grouped?
One way to group biochemistry tests is as follows: Electrolytes - Na, K and Cl; Minerals - Calcium, Phosphate and Magnesium; Proteins - Total proteins, Albumin, Globulins and A/G ratio.
What are the learning objectives of this course module?
The learning objectives are to identify factors that may affect the results of laboratory tests, explain the advantages and disadvantages of in-house and external laboratory testing, understand the rationale behind selection of appropriate tests, identify biological and non-biological factors that can affect test results, and explain the benefits and drawbacks of pattern recognition.
What is the purpose of laboratory tests in veterinary medicine?
Laboratory tests are used to diagnose disease, monitor disease progression or response to therapy, and screen apparently healthy animals.
What factors can affect laboratory test results?
Factors that can affect laboratory test results include pre-analytical factors, analytical factors, and post-analytical factors.
What are pre-analytical factors and how do they affect test results?
Pre-analytical factors are associated with the patient, sample collection, handling, and quality. They can affect the quality of the sample and therefore the results. It is important to prevent or take into account these factors when interpreting the results.
What are the advantages of in-house haematology and biochemistry analysers?
The advantages of in-house analysers include fast turn-around time for patients, smaller volume of samples required, availability for out-of-hours testing, and availability everywhere.
What are the disadvantages of in-house haematology and biochemistry analysers?
The principal disadvantages are the requirement for a steady throughput of samples to justify initial outlay and wastage of materials/reagents, and the need for a cost/benefit analysis of the number of samples being run.
What is pattern recognition in laboratory testing?
Pattern recognition refers to recognizing patterns of results associated with certain pathologies. It can aid in the interpretation of laboratory test results.
What are the characteristics of the cytoplasm of band neutrophils compared to segmented neutrophils?
The cytoplasm of band neutrophils may be more diffusely basophilic when compared to that of segmented neutrophils.
How can nuclear chromatin help differentiate between segmented and band neutrophils?
A segmented neutrophil will have dense nuclear chromatin, while a band neutrophil will have a lighter nucleus with less dense chromatin.
What is a regenerative left shift and what does it indicate?
A regenerative left shift is an absolute increase in neutrophil numbers with immature cells in the circulation. It indicates an adequate response.
What is a degenerative left shift and what does it indicate?
A degenerative left shift occurs when the bone marrow is unable to maintain an adequate response. It is characterized by the release of increasingly immature bands and metamyelocytes. The total neutrophil count is reduced or normal, with low numbers of mature neutrophils.
What is a leukemoid reaction and what are its characteristics?
A leukemoid reaction is marked leucocytosis, usually neutrophilia and monocytosis, that mimics neoplasia (leukemia). It is associated with a wide spectrum of infectious, immune-mediated, inflammatory, and paraneoplastic processes. It is usually accompanied by a left shift and toxic changes. In eosinophils, it can be seen in hypereosinophilic syndromes.
What are the toxic changes observed in neutrophils during overwhelming demand?
Toxic changes in neutrophils during overwhelming demand include cytoplasmic basophilia, Dohle bodies, cytoplasmic vacuolation, persistent primary granules (toxic granulation), ring form nuclei, and giant forms.
What are the possible causes of neutrophilia?
Neutrophilia can be caused by increased production due to increased demand (infections, immune-mediated diseases, neoplasia, haemolysis, etc.), increased production independent of demand (neoplastic transformation), redistribution (stress/excitement), or may be accompanied by or without lymphocytosis.
What are the potential causes of neutropenia and how can it be approached?
Neutropenia can result from failure of bone marrow production or excessive neutrophil consumption. It can be associated with overwhelming demand, reduced or ineffective granulopoiesis, bone marrow disease, cytotoxic drug therapy, idiosyncratic drug reactions, immune-mediated destruction, cyclic neutropenia, and cobalamin deficiency. The approach to a neutropenic patient depends on the degree of neutropenia and persistence.
What are some factors that may adversely affect the quality of CBC data?
Some factors that may adversely affect the quality of CBC data are clots, platelet clumps, macroplatelets, agglutination of RBC, Heinz bodies and nRBC, and lipemia.
According to ASVCP, when should a blood smear be examined?
According to ASVCP, a blood smear should be examined when reviewing all critically ill patients and when CBCs with unusual or suspicious results are presented.
What is the recommended stepwise approach for examining a blood smear?
The recommended stepwise approach for examining a blood smear includes starting small, going deeper, going bigger, and finishing to the side.
How is the platelet count estimated from a blood smear?
The platelet count can be estimated from a blood smear by examining the smear for evidence of platelet clumping and counting the numbers of platelets in 10 consecutive fields under oil immersion.
What are some RBC morphologies to look out for?
Some RBC morphologies to look out for include rouleaux, agglutination, macrocytosis, microcytosis, polychromasia, hypochromasia, anisocytosis, crenated RBCs, acanthocytes, schistocytes, keratocytes, blister cells, and target cells.
What is the significance of rouleaux formation in cats and horses?
Rouleaux formation is normal in cats and horses, but in other species, it is associated with hyperviscosity, most often hyperproteinaemia.
What can cause microcytosis and poikilocytosis in RBCs?
Microcytosis and poikilocytosis in RBCs can be caused by iron deficiency (often alongside hypochromasia) and myeloproliferative disease (e.g., FeLV related in cats).
What is the most likely significance of crenated RBCs with spiky projections?
Crenated RBCs with spiky projections, also known as echinocytes, can indicate renal disease, neoplasms, lipid disorders, hyperthyroidism, or shear damage injury.
What are some morphological abnormalities that can be seen in red blood cells?
Morphological abnormalities that can be seen in red blood cells include codocyte, Eccentrocyte, Heinz bodies, spherocyte, ovalocyte, dacrocyte, and Howell Jolly bodies.
How are Heinz bodies formed in red blood cells?
Heinz bodies are formed in red blood cells due to oxidative damage to the sulfhydryl (-SH) chain of the hemoglobin, leading to its precipitation.
What is the significance of Howell Jolly bodies in red blood cells?
Howell Jolly bodies are round, dark, relatively large bodies that are nuclear remnants. They are of no clinical significance when present in low numbers.
How can reticulocyte counts determine if an anemia is regenerative or non-regenerative?
Reticulocyte counts are the best way to determine whether an anemia is regenerative or non-regenerative. Increased numbers of reticulocytes indicate a regenerative response.
How can reticulocyte counts be performed manually?
Reticulocyte counts can be performed manually by using supra vital stains such as new methylene blue or brilliant cresyl green. The procedure involves making a blood smear, evaluating it under an oil lens, and counting a minimum of 300 cells to determine the percentage of reticulocytes.
What are the different types of reticulocytes in dogs and cats?
In dogs, all reticulocytes are aggregate reticulocytes. In cats, there are two types of reticulocytes: aggregate reticulocytes and punctate reticulocytes.
What do punctate reticulocytes indicate in cats?
Punctate reticulocytes in cats indicate a regenerative response that occurred 2-4 weeks earlier, as they have undergone a degree of maturation and can remain in the bloodstream for up to 4 weeks after the anemia has resolved.
What are the causes of non-regenerative anaemia?
The causes of non-regenerative anaemia include anaemia of chronic disease, iron deficiency anaemia (chronic blood loss), chronic renal failure, chronic liver disease, hypoadrenocortisolism/hypothyroidism, drug-induced anaemia, infectious causes (e.g. FeLV), toxins (e.g. lead toxicity), primary bone marrow diseases (such as IMHA/maturation arrest, aplastic anaemia, myelophthisis, myelofibrosis, myelodysplasia, and myelonecrosis).
What are the haematological features observed in anaemia of chronic disease?
Haematological features observed in anaemia of chronic disease include normocytic/normochromic or microcytic/hypochromic anemia with or without an inflammatory leukogram.
What are the possible causes of iron deficiency anaemia?
Iron deficiency anaemia can be caused by chronic blood loss, such as gastrointestinal bleeding , inadequate dietary iron intake, or malabsorption disorders.
What are the possible causes of non-regenerative anaemia in cats?
In cats, non-regenerative anaemia can be caused by infectious diseases like FeLV, exposure to drugs or toxins, or primary bone marrow diseases.
What is the first step in investigating polycythaemia?
The first step in investigating polycythaemia is to determine if it is persistent or transient.
How can polycythaemia be classified?
Polycythaemia can be classified as relative (due to loss of plasma or splenic contraction) or absolute (increased red blood cell mass due to increased marrow production).
What are the major types of leucocytosis?
The major types of leucocytosis are inflammatory, glucocorticoid-associated, catecholamine-associated, and neoplastic leucocytosis.
What leucogram findings indicate a poor prognosis?
Leucogram findings indicating a poor prognosis include degenerative left shift, leucopenia, leukemoid reaction, toxic neutrophils, severe or persistent lymphopenia, and left shift.
