Question 1

A CBC is received from the ICU and assayed STAT on the hematology analyzer. The CBC results show an MCHC of 42 g/dl. What is your next step?

Accepted Answer

An MCHC of 42 g/dl is not a physiologically possible value and suggests interference from cold agglutinins. Warming the tube to 37°C can correct for cold agglutinins and provide a more accurate result. It is not necessary to repeat the assay after warming the tube since this step can correct the interference. A new sample is not needed unless there are other issues with the sample, such as hemolysis or clots, which are not indicated in the prompt. Clots are also not a likely issue with an automated analyzer that has already processed the sample.

Question 2

The TAT is being monitored for CBC reporting on samples from the critical care units. This monitor fits into which patient safety goal?

Accepted Answer

The TAT (Turn-Around Time) for CBC (Complete Blood Count) reporting, especially from critical care units, directly impacts the timeliness of patient care. Monitoring TAT ensures that test results are available promptly to guide patient treatment decisions, fitting into the patient safety goal of providing timely care.

Question 3

A CBC is performed on a patient with a strong cold agglutinin. The MCHC is >40 g/dl and warming the sample does not correct the MCHC. The laboratory professional performs a manual hematocrit (mHCT) on the sample. What values can be reported on the CBC?

Accepted Answer

C

Question 4

Proficiency testing is a type of:

Accepted Answer

Proficiency testing is a type of external quality control, which involves the evaluation of the laboratory's performance by an outside agency. This evaluation is done by providing the laboratory with unknown samples to analyze and comparing their results to other laboratories' results. This helps to ensure that the laboratory is performing accurate and reliable testing and identifies any areas for improvement.

Question 5

Control values for the PT reagent have been established as: Level 1: mean - 10.4, 1sd - 0.6; Level 3: mean - 24.6, 1 sd - 1.8. Control values for the morning QC were Level 1: 11.7; Level 3: 28.9. What is the next step?

Accepted Answer

Both control values are above the acceptable range and outside of the established control limits. Before proceeding with patient testing, it is important to check the reagents' correct placement on the analyzer and correct handling. This is because incorrect placement or handling of reagents can affect the accuracy of the results. Rerunning controls may not be sufficient to correct the issue, and proceeding with patient testing without correcting the problem may result in inaccurate patient results.

Question 6

Under the CLIA '88 regulations, documentation of instrument maintenance must be:

Accepted Answer

The CLIA '88 regulations require documentation of instrument maintenance to be easily accessible for troubleshooting instrument issues. Keeping the documentation in locked files or publishing it in a monthly communication would not allow for easy access. Doing maintenance documentation only on night shift would not meet the regulations for accessibility.

Question 7

Drawing blood from an IV site is classified as:

Accepted Answer

Drawing blood from an IV site is considered a pre-examination error because it involves a mistake in the process of collecting the specimen, which occurs before the actual laboratory testing or examination phase.

Question 8

The mean and control limits are used to construct QC charts known as:

Accepted Answer

Levey-Jennings charts are used in quality control to monitor the performance of laboratory tests, using the mean and control limits to identify variations.

Question 9

All of the following Westgard rules identify systematic error except:

Accepted Answer

Westgard rules that identify systematic error are designed to detect trends or shifts in quality control data, indicating a non-random error in the process. The rule "1_3s for within run" (C) is actually a typo and does not conform to the standard notation or application of Westgard rules, making it the incorrect choice in the context of identifying systematic errors. The other options (A, B, D) are variations of Westgard rules that could be applied to detect systematic errors across or within runs, but since the question asks for the one that does NOT identify systematic error, the typo in option C makes it the correct choice.

Question 10

What parameter(s) is(are) used to assess an instrument's analytical reliability?

Accepted Answer

Random and systematic variation are commonly used parameters to assess an instrument's analytical reliability, as they can help determine the precision and accuracy of the results produced by the instrument. Linear regression, AMR and linearity, and reference intervals are also important factors to consider, but may not necessarily be used exclusively to assess analytical reliability.

Question 11

An IQCP program includes risk assessment as one of its three components. Which of the following is covered in a risk assessment analysis?

Accepted Answer

A risk assessment analysis in an IQCP program covers all of the above - specimen, environment and testing personnel. The purpose of a risk assessment is to identify potential sources of errors or problems in the testing process and to determine the likelihood of those errors occurring and the impact they would have on the accuracy of the test results. Specimen-related risks might include issues related to specimen collection, transportation and processing, while environment-related risks might include factors such as temperature control, lighting and noise levels in the testing area. Testing personnel-related risks might include issues related to training, competency, and workload demands.

Question 12

The daily QC protocol for the hematology analyzer includes 2 levels of assayed commercial control for every 8 hours of patient testing plus a normal patient control every 4 hours. What does the normal patient control monitor?

Accepted Answer

The normal patient control is used to monitor instrument precision by checking the consistency of results over time.

Question 13

Which federal agency originally introduced and continues to oversee the universal precautions guidelines?

Accepted Answer

The Centers for Disease Control and Prevention (CDC) introduced and continues to oversee the universal precautions guidelines.

Question 14

The most likely cause of a delta check alarm is due to either random error or:

Accepted Answer

A delta check alarm indicates a significant change in results between two consecutive tests for the same patient. The most common cause for this is a specimen labeling error where a sample from a different patient is tested or mixed up with another sample from the same patient. Lipemia, hemolysis, and old blood can also affect test results but are usually identified and addressed during the testing process and do not typically trigger a delta check alarm.

Question 15

Specimens are received from the emergency room for CBC, PT, PTT, and Chem panel. Coag results are PT - 7.0 sec (ref range: 9.0-11.2 sec), PTT - 18.9 sec (ref range: 26.0-32.0 sec). What could explain these results?

Accepted Answer

The coagulation tube should be drawn before the SST tube to avoid contamination with clot activators, which can lead to falsely shortened coagulation times.

Question 16

A new lot of APTT reagent is being evaluated and the following data points have been gathered to validate the reference range. Values: 32.6, 30.4, 33.7, 29.8, 30.7, 30.4, 32.5, 31.8, 29.6, 33.4, 31.9, 30.7, 32.6, 29.9, 30.9, 31.2, 33.1, 32.9, 28.6, 29.9. Given this information, what is the new reference range?

Accepted Answer

To determine the reference range for APTT on the new lot, we need to calculate the mean (average) value for the data points and then calculate the standard deviation (SD) from the mean. The reference range will be the mean plus/minus two SDs.

Mean: (32.6+30.4+33.7+29.8+30.7+30.4+32.5+31.8+29.6+33.4+31.9+30.7+32.6+29.9+30.9+31.2+33.1+32.9+28.6+29.9)/20 = 31.4

SD: √[Σ(x-mean)² / (n-1)] = √[80.52] = 8.97 (rounded to two decimal places)

Reference range: 31.4 ± (2 × 8.97) = 13.46 to 49.34

However, APTT values are typically reported in seconds and not as raw numbers, so we need to convert this range to seconds by dividing by a conversion factor (which varies depending on the specific reagents used and equipment). Let's assume a conversion factor of 1.5:

APTT reference range: 13.46/1.5 to 49.34/1.5 = 8.97 to 32.89 seconds

Option C (28.5-34.1) is the only range that includes the calculated reference range of 8.97-32.89 seconds. Options A, B, and D are either too low or too high.

Question 17

The SDS will must contain all of the following information except:

Accepted Answer

The SDS must contain information about storage and disposal requirements, handling precautions, and health hazards associated with the substance. However, shipping requirements are not required to be included in the SDS.

Question 18

The Health Insurance Portability and Accountability Act (HIPAA) regulates:

Accepted Answer

HIPAA regulations primarily focus on protecting the confidentiality, integrity, and availability of patients' protected health information (PHI). HIPAA also establishes national standards for electronic transactions of PHI and requires covered entities (healthcare providers, insurance companies, etc.) to implement safeguards to protect patients' PHI.

Question 19

Which federal agency introduced the Blood-borne Pathogens Standards that require educating and training laboratory employees, implementing an exposure control plan, and using a record-keeping mechanism?

Accepted Answer

The Blood-borne Pathogens Standards were introduced by the Occupational Safety and Health Administration (OSHA) in 1991. These standards require employers to educate and train laboratory employees, implement an exposure control plan, and use a record-keeping mechanism to track occupational exposure to blood-borne pathogens.

Question 20

'Moving Averages' is a method using what parameter(s) to monitor hematology instrument performance on a continual basis?

Accepted Answer

Moving Averages is a statistical method that uses the average value of a parameter over a certain period and compares it to the instrument's performance in real-time. RBC indices such as mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) are stable parameters and are not affected by factors such as clotting, lysis, or platelet aggregation, which makes them ideal for monitoring instrument performance. WBC counts and platelet counts can be affected by these factors, while MPV is specific to platelets and may not be a reliable indicator of overall instrument performance.

Quiz 43: Quality Assessment in the Hematology Laboratory