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What percentage of total errors in diagnostic laboratories are due to preanalytical errors?
What percentage of total errors in diagnostic laboratories are due to preanalytical errors?
What is the primary purpose of proper patient identification in the preanalytical phase?
What is the primary purpose of proper patient identification in the preanalytical phase?
What is the effect of traumatic venipuncture on the quality of the blood sample?
What is the effect of traumatic venipuncture on the quality of the blood sample?
Why is it important to avoid carryover of anticoagulants or other additives when collecting multiple blood tubes from the same patient?
Why is it important to avoid carryover of anticoagulants or other additives when collecting multiple blood tubes from the same patient?
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What is the primary reason for the intense focus on the preanalytical phase in the last decade?
What is the primary reason for the intense focus on the preanalytical phase in the last decade?
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Which of the following is an example of an uncontrollable preanalytical variable?
Which of the following is an example of an uncontrollable preanalytical variable?
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What is the effect of preanalytical errors on the health and safety of patients?
What is the effect of preanalytical errors on the health and safety of patients?
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What is the purpose of proper handling and storage of specimens in the preanalytical phase?
What is the purpose of proper handling and storage of specimens in the preanalytical phase?
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Which of the following is an example of a preanalytical variable that can be controlled?
Which of the following is an example of a preanalytical variable that can be controlled?
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What is the primary reason for the development of recommendations and standards for the preanalytical phase?
What is the primary reason for the development of recommendations and standards for the preanalytical phase?
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What is the main reason for the importance of the preanalytical phase in laboratory medicine?
What is the main reason for the importance of the preanalytical phase in laboratory medicine?
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The preanalytical phase only includes specimen collection and handling.
The preanalytical phase only includes specimen collection and handling.
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What is the purpose of proper patient identification in the preanalytical phase?
What is the purpose of proper patient identification in the preanalytical phase?
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The label on the tube must match exactly the _________ of the patient.
The label on the tube must match exactly the _________ of the patient.
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Match the following preanalytical variables with their descriptions:
Match the following preanalytical variables with their descriptions:
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Why is it important to perform venipuncture in the most atraumatic way possible?
Why is it important to perform venipuncture in the most atraumatic way possible?
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The preanalytical phase is responsible for the majority of errors in diagnostic laboratories.
The preanalytical phase is responsible for the majority of errors in diagnostic laboratories.
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What is an example of a specimen variable that can be controlled in the preanalytical phase?
What is an example of a specimen variable that can be controlled in the preanalytical phase?
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The preanalytical phase includes all those steps that occur in the practice such as specimen collection, handling, storage, and ____________ to the laboratory.
The preanalytical phase includes all those steps that occur in the practice such as specimen collection, handling, storage, and ____________ to the laboratory.
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What is the purpose of knowing uncontrollable preanalytical variables in the preanalytical phase?
What is the purpose of knowing uncontrollable preanalytical variables in the preanalytical phase?
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What is a common consequence of removing the needle while the tourniquet is still on during venipuncture?
What is a common consequence of removing the needle while the tourniquet is still on during venipuncture?
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What is the primary concern when collecting blood specimens from a patient with an IV line?
What is the primary concern when collecting blood specimens from a patient with an IV line?
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Which of the following can cause a rapid increase in the ratio of blood cells to plasma?
Which of the following can cause a rapid increase in the ratio of blood cells to plasma?
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What is the consequence of mixing blood specimens too vigorously?
What is the consequence of mixing blood specimens too vigorously?
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Why is it essential to wipe away the first blood drop in capillary collection?
Why is it essential to wipe away the first blood drop in capillary collection?
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What is the consequence of improper fit of the needle to the syringe during blood collection?
What is the consequence of improper fit of the needle to the syringe during blood collection?
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Why is it important to avoid probing during venipuncture?
Why is it important to avoid probing during venipuncture?
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What is the effect of dehydration on certain blood test results?
What is the effect of dehydration on certain blood test results?
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What is the consequence of squirting blood from a syringe during collection?
What is the consequence of squirting blood from a syringe during collection?
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Why is it essential to follow proper procedures for transportation and storage of blood specimens?
Why is it essential to follow proper procedures for transportation and storage of blood specimens?
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Which of the following is affected by a patient's diet?
Which of the following is affected by a patient's diet?
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What is the consequence of collecting blood specimens in partially filled tubes?
What is the consequence of collecting blood specimens in partially filled tubes?
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What is the effect of crying on WBC in infants?
What is the effect of crying on WBC in infants?
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What is the effect of exercise on certain blood test results?
What is the effect of exercise on certain blood test results?
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What is the effect of fever on certain hormones?
What is the effect of fever on certain hormones?
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What is the effect of smoking on WBC?
What is the effect of smoking on WBC?
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What is the effect of body position on certain blood test results?
What is the effect of body position on certain blood test results?
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What is the effect of pregnancy on RBC count?
What is the effect of pregnancy on RBC count?
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What should be done if a patient has a history of fainting?
What should be done if a patient has a history of fainting?
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What should be avoided when drawing blood from a patient who has had a mastectomy?
What should be avoided when drawing blood from a patient who has had a mastectomy?
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What is the ideal time frame for processing and examining hematology samples?
What is the ideal time frame for processing and examining hematology samples?
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What is the primary purpose of collecting blood samples in the basal state?
What is the primary purpose of collecting blood samples in the basal state?
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Which of the following physiological variables can affect RBC counts?
Which of the following physiological variables can affect RBC counts?
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What is the effect of dehydration on blood samples?
What is the effect of dehydration on blood samples?
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Which of the following can affect cortisol levels in blood samples?
Which of the following can affect cortisol levels in blood samples?
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What is the purpose of refrigerating serum/plasma samples?
What is the purpose of refrigerating serum/plasma samples?
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Which of the following is an example of a physiological variable that can affect TSH levels?
Which of the following is an example of a physiological variable that can affect TSH levels?
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What is the effect of IM injections on blood samples?
What is the effect of IM injections on blood samples?
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Which of the following is a characteristic of the basal state?
Which of the following is a characteristic of the basal state?
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What is the effect of altitude on RBC counts?
What is the effect of altitude on RBC counts?
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What happens to blood results when a patient is dehydrated?
What happens to blood results when a patient is dehydrated?
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Circadian variations can affect cortisol levels.
Circadian variations can affect cortisol levels.
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What is the effect of exercise on glucose levels?
What is the effect of exercise on glucose levels?
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Fever can affect certain ______________, such as insulin levels.
Fever can affect certain ______________, such as insulin levels.
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Match the following patient conditions with their effects on blood tests:
Match the following patient conditions with their effects on blood tests:
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Smoking can affect cholesterol levels.
Smoking can affect cholesterol levels.
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What should be done if a patient has a history of fainting?
What should be done if a patient has a history of fainting?
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What should be avoided when drawing blood from a patient who has had a mastectomy?
What should be avoided when drawing blood from a patient who has had a mastectomy?
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Body position can affect certain blood tests, such as __________________ and Fe.
Body position can affect certain blood tests, such as __________________ and Fe.
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Seizures can occur during blood collection.
Seizures can occur during blood collection.
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What is the consequence of removing the needle while the tourniquet is still on during venipuncture?
What is the consequence of removing the needle while the tourniquet is still on during venipuncture?
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Drawing blood through a hematoma can cause hemolysis.
Drawing blood through a hematoma can cause hemolysis.
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What is the primary concern when collecting blood specimens from a patient with an IV line?
What is the primary concern when collecting blood specimens from a patient with an IV line?
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The ratio of blood cells to plasma can increase rapidly due to ________ application.
The ratio of blood cells to plasma can increase rapidly due to ________ application.
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Match the following errors with their consequences:
Match the following errors with their consequences:
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What can cause a false high potassium and low calcium levels in blood samples?
What can cause a false high potassium and low calcium levels in blood samples?
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Partially filled tubes can affect the accuracy of coagulation tests only.
Partially filled tubes can affect the accuracy of coagulation tests only.
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Specimens should be stored according to the recommended ________ and duration to preserve their integrity until analysis.
Specimens should be stored according to the recommended ________ and duration to preserve their integrity until analysis.
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What can happen if the tourniquet is left on for more than 1 minute during venipuncture?
What can happen if the tourniquet is left on for more than 1 minute during venipuncture?
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What can prevent reflux of additive in blood collection?
What can prevent reflux of additive in blood collection?
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What is the ideal time frame for processing and examining hematology samples?
What is the ideal time frame for processing and examining hematology samples?
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The basal state is influenced by gender.
The basal state is influenced by gender.
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What is the effect of dehydration on blood samples?
What is the effect of dehydration on blood samples?
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The primary purpose of collecting blood samples in the _______________ state is to establish reference ranges on inpatients.
The primary purpose of collecting blood samples in the _______________ state is to establish reference ranges on inpatients.
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Match the following physiological variables with their effects on blood tests:
Match the following physiological variables with their effects on blood tests:
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Smoking can affect cortisol levels in blood samples.
Smoking can affect cortisol levels in blood samples.
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Which of the following physiological variables can affect TSH levels?
Which of the following physiological variables can affect TSH levels?
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What is the purpose of refrigerating serum/plasma samples?
What is the purpose of refrigerating serum/plasma samples?
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The basal state is defined as the resting state of the body early in the morning after _______________ hours of fasting.
The basal state is defined as the resting state of the body early in the morning after _______________ hours of fasting.
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IM injections can affect CK and LDH levels in blood samples.
IM injections can affect CK and LDH levels in blood samples.
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Study Notes
Importance of Preanalytical Phase
- The preanalytical phase is crucial in laboratory medicine, as errors in this phase can affect the analytical phase, jeopardizing patient health and safety, and increasing medical care costs.
- The preanalytical phase includes steps such as specimen collection, handling, storage, and shipping to the laboratory.
- Physiological variables (e.g., age, gender, pregnancy) and endogenous variables (e.g., medication, recent meals) can also impact laboratory results.
Preanalytical Errors
- Preanalytical errors account for 50% to 75% of total errors in diagnostic laboratories.
- The last decade has seen an increased focus on the preanalytical phase, leading to the development of recommendations and standards.
Controlling Preanalytical Variables
- Some preanalytical variables, such as specimen variables, can be controlled.
- A thorough knowledge of uncontrollable variables is necessary to separate their effects from disease-related changes affecting laboratory results.
Avoiding Errors
Patient Identification
- Proper patient identification is essential, requiring 100% accuracy.
- The label on the tube must match the patient's identification exactly.
Sample Collection
- Venipuncture should be performed in the most atraumatic way possible to obtain a blood sample of adequate quality.
- Traumatic venipuncture can cause sample artefacts, such as spurious hemolysis and formation of macro/micro clots.
Choice of Anticoagulant and Tube
- EDTA whole blood is the specimen of choice for most hematology variables.
- When collecting multiple blood tubes, carryover of anticoagulants or additives should be avoided.
- Follow the correct order of collection to avoid contamination by EDTA, which can cause false elevations of potassium and false decreases of calcium.
- Serum gel separator tubes can be used for most biochemical analysis, but should be avoided for hormones and drugs measurements.
Importance of Preanalytical Phase
- The preanalytical phase is crucial in laboratory medicine, as errors in this phase can affect the analytical phase, jeopardizing patient health and safety, and increasing medical care costs.
- The preanalytical phase includes steps such as specimen collection, handling, storage, and shipping to the laboratory.
- Physiological variables (e.g., age, gender, pregnancy) and endogenous variables (e.g., medication, recent meals) can also impact laboratory results.
Preanalytical Errors
- Preanalytical errors account for 50% to 75% of total errors in diagnostic laboratories.
- The last decade has seen an increased focus on the preanalytical phase, leading to the development of recommendations and standards.
Controlling Preanalytical Variables
- Some preanalytical variables, such as specimen variables, can be controlled.
- A thorough knowledge of uncontrollable variables is necessary to separate their effects from disease-related changes affecting laboratory results.
Avoiding Errors
Patient Identification
- Proper patient identification is essential, requiring 100% accuracy.
- The label on the tube must match the patient's identification exactly.
Sample Collection
- Venipuncture should be performed in the most atraumatic way possible to obtain a blood sample of adequate quality.
- Traumatic venipuncture can cause sample artefacts, such as spurious hemolysis and formation of macro/micro clots.
Choice of Anticoagulant and Tube
- EDTA whole blood is the specimen of choice for most hematology variables.
- When collecting multiple blood tubes, carryover of anticoagulants or additives should be avoided.
- Follow the correct order of collection to avoid contamination by EDTA, which can cause false elevations of potassium and false decreases of calcium.
- Serum gel separator tubes can be used for most biochemical analysis, but should be avoided for hormones and drugs measurements.
Hematology Samples
- Hematology samples should be processed and examined immediately, ideally within a few hours of collection.
- Samples sent to an external laboratory should be refrigerated.
Biochemistry Testing
- Serum/plasma should be separated and transferred into a plain tube and kept at refrigeration temperature until analysis.
- For longer storage, freezing is recommended.
Normal Range
- A range of normal values for healthy individuals.
- Influenced by age, gender, and body conditions.
Basal State
- Defines the resting state of the body early in the morning after fasting for 12 hours.
- Ideal for establishing reference ranges on inpatients.
- Minimizes effects of diet, exercise, etc. on test results.
Physiological Variables
- Factors that affect blood test results, including:
- Age: RBC, WBC, creatinine clearance
- Altitude: RBC
- Dehydration: Hemoconcentration, RBC, enzymes, Fe, Ca, Na
- Diet: Glucose, lipids, electrolytes
- Diurnal/circadian variation: TSH, cortisol, Fe
- Drug therapy: Enzymes, hormones
- Exercise: pH, PCO2, CK, LDH, glucose
- Fever: Hormones, cortisol
- Sex: RBC, Hgb, Hct
- IM injection: CK, LDH
- Jaundice: Yellow color interferes
- Position: Protein, K
- Pregnancy: RBC
- Smoking: Chol, cortisol, glucose, GH, triglyceride, WBC
- Stress: WBC, Fe, ACTH, catecholamine, cortisol
- Environmental factors: Hemoconcentration
Patient Complications and Conditions
- Factors that impact blood collection and test results, including:
- Adhesive allergy
- Excessive bleeding
- Fainting
- Pain
- Seizures
- Mastectomy
- Paralysis
Procedural Errors
- Mistakes during blood collection that can compromise sample quality, including:
- Hematoma
- Iatrogenic anemia
- Nerve damage
- Reflux of additive
- Vein damage
Specimen Quality Concerns
- Issues that affect the integrity and reliability of blood samples, including:
- Hemoconcentration
- Hemolysis
- Partially filled tubes
- Specimen contamination
- Wrong order
- Clotted anticoagulated specimens
- IV lines
- Wrong or expired collection tube
- Transportation delays
- Storage conditions
Importance of Education
- Educational programs can reduce sample errors and improve patient safety and health system outcomes.
Hematology Samples
- Hematology samples should be processed and examined immediately, ideally within a few hours of collection.
- Samples sent to an external laboratory should be refrigerated.
Biochemistry Testing
- Serum/plasma should be separated and transferred into a plain tube and kept at refrigeration temperature until analysis.
- For longer storage, freezing is recommended.
Normal Range
- A range of normal values for healthy individuals.
- Influenced by age, gender, and body conditions.
Basal State
- Defines the resting state of the body early in the morning after fasting for 12 hours.
- Ideal for establishing reference ranges on inpatients.
- Minimizes effects of diet, exercise, etc. on test results.
Physiological Variables
- Factors that affect blood test results, including:
- Age: RBC, WBC, creatinine clearance
- Altitude: RBC
- Dehydration: Hemoconcentration, RBC, enzymes, Fe, Ca, Na
- Diet: Glucose, lipids, electrolytes
- Diurnal/circadian variation: TSH, cortisol, Fe
- Drug therapy: Enzymes, hormones
- Exercise: pH, PCO2, CK, LDH, glucose
- Fever: Hormones, cortisol
- Sex: RBC, Hgb, Hct
- IM injection: CK, LDH
- Jaundice: Yellow color interferes
- Position: Protein, K
- Pregnancy: RBC
- Smoking: Chol, cortisol, glucose, GH, triglyceride, WBC
- Stress: WBC, Fe, ACTH, catecholamine, cortisol
- Environmental factors: Hemoconcentration
Patient Complications and Conditions
- Factors that impact blood collection and test results, including:
- Adhesive allergy
- Excessive bleeding
- Fainting
- Pain
- Seizures
- Mastectomy
- Paralysis
Procedural Errors
- Mistakes during blood collection that can compromise sample quality, including:
- Hematoma
- Iatrogenic anemia
- Nerve damage
- Reflux of additive
- Vein damage
Specimen Quality Concerns
- Issues that affect the integrity and reliability of blood samples, including:
- Hemoconcentration
- Hemolysis
- Partially filled tubes
- Specimen contamination
- Wrong order
- Clotted anticoagulated specimens
- IV lines
- Wrong or expired collection tube
- Transportation delays
- Storage conditions
Importance of Education
- Educational programs can reduce sample errors and improve patient safety and health system outcomes.
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Description
Learn about the preanalytical phase in laboratory medicine, its impact on patient health and safety, and the variables that can affect laboratory results.
