MLPAO - Medical Laboratory Professionals Association of Ontario Laboratory Safety and Quality Questions and Answers — Questions and Answers
Question 1: A medical laboratory professional is reviewing the daily quality control data for a glucose assay on a Levey-Jennings chart. The last five consecutive control values have all plotted on the same side of the mean, but are still within ±2 standard deviations. Which of the following does this pattern most likely indicate?
- A random error has occurred.
- The control material is contaminated.
- A systematic error is developing. (Correct answer)
- The instrument is functioning optimally.
Correct answer: A systematic error is developing.
This pattern, where consecutive data points are distributed on one side of the mean, is known as a 'shift' or 'trend'. It is indicative of a systematic error, suggesting a consistent bias in the measurement process. This could be due to issues like deteriorating reagents, a change in instrument calibration, or a new lot of controls. A random error would result in unpredictable data points, not a consistent pattern.
Question 2: Which of the following activities is considered part of Quality Assurance (QA) but not Quality Control (QC) in a clinical laboratory setting?
- Running daily control samples on an analyzer.
- Performing preventative maintenance on an instrument.
- Reviewing and updating the laboratory's standard operating procedures (SOPs). (Correct answer)
- Calibrating a new reagent lot before use.
Correct answer: Reviewing and updating the laboratory's standard operating procedures (SOPs).
Quality Assurance (QA) is a broad, proactive process that encompasses all systems and procedures to ensure quality results, including documentation and training. [2, 3] Reviewing and updating SOPs is a key QA activity that ensures processes are current and correct. [2] In contrast, Quality Control (QC) refers to the specific, operational techniques and activities used to fulfill requirements for quality, such as running controls, performing maintenance, and calibrating reagents, which are all part of the analytical process. [2, 4]
Question 3: According to the Canadian Biosafety Standard (CBS), a laboratory routinely handling clinical specimens containing Mycobacterium tuberculosis, an agent that can cause serious disease and is transmissible by inhalation, must operate at which minimum Containment Level (CL)?
- Containment Level 1 (CL1)
- Containment Level 4 (CL4)
- Containment Level 2 (CL2)
- Containment Level 3 (CL3) (Correct answer)
Correct answer: Containment Level 3 (CL3)
Mycobacterium tuberculosis is a Risk Group 3 (RG3) human pathogen, defined as having a high individual risk and low community risk. [5] Work with indigenous or exotic agents that can cause serious or potentially lethal disease through the inhalation route must be conducted in a Containment Level 3 (CL3) laboratory. [21] This level requires specific engineering controls and operational practices to protect personnel and the community. [5, 12]
Question 4: A medical laboratory assistant receives an unlabeled tube of blood for a complete blood count (CBC). The requisition form is present and correctly filled out. What is the most appropriate immediate action?
- Label the tube with the patient's information from the requisition and process the sample.
- Ask a coworker for their opinion on what to do with the specimen.
- Reject the specimen and request a new, properly labeled sample be collected. (Correct answer)
- Process the sample and add a note to the report that the initial specimen was unlabeled.
Correct answer: Reject the specimen and request a new, properly labeled sample be collected.
Specimen integrity and correct patient identification are paramount for patient safety. An unlabeled specimen is a critical pre-analytical error that cannot be corrected after the fact. [23] The only acceptable action is to reject the specimen and notify the appropriate personnel to recollect a new, properly labeled sample to ensure the results are linked to the correct patient. [22]
Question 5: While unpacking a shipment of chemicals, a laboratory professional encounters a container with this WHMIS 2015 pictogram: a skull and crossbones. What type of hazard does this symbol represent?
- Flammability Hazard
- Biohazardous Infectious Materials
- Corrosion Hazard
- Acute Toxicity (Fatal or Toxic) (Correct answer)
Correct answer: Acute Toxicity (Fatal or Toxic)
The skull and crossbones pictogram under the Workplace Hazardous Materials Information System (WHMIS) 2015 indicates a product that can cause death or toxicity with short exposure to small amounts. [16] This falls under the Acute Toxicity hazard class and signifies a severe and immediate health hazard. [13]
Question 6: During the total testing process, the majority of laboratory errors occur in which phase?
- Analytical phase
- Pre-analytical phase (Correct answer)
- Post-analytical phase
- Reporting phase
Correct answer: Pre-analytical phase
Numerous studies have consistently shown that the pre-analytical phase is the most error-prone stage of the total testing process, accounting for up to 70% of all laboratory mistakes. [20, 25, 22] This phase includes patient identification, specimen collection, handling, and transport—all steps that occur before the sample is actually tested. [25, 27]
MLPAO - Medical Laboratory Professionals Association of Ontario Laboratory Safety and Quality Questions and Answers
A medical laboratory professional is reviewing the daily quality control data for a glucose assay on a Levey-Jennings chart.
The last five consecutive control values have all plotted on the same side of the mean, but are still within ±2 standard deviations.
Which of the following does this pattern most likely indicate?