Effective management of laboratory testing is only possible through consistent application of a continuous quality improvement approach to all processes involved. This approach depends on three factors: laboratory processes are closely monitored; there is an operational and functional error detection system in place; and root-cause analysis is performed whenever there is an increase in error frequency, as a part of continuous quality improvement.
In recent years, the concept of quality monitoring for laboratory testing has evolved beyond the analytic phase of testing to encompass the total testing process. Beginning with test ordering and ending with result reporting, this concept encompasses the pre-analytical, analytical, and post-analytical phases of testing. The impetus for total testing process (TTP) quality monitoring has been the realization that errors occur throughout all phases of testing, not just during the analytic phase.
In fact, as stated in Quality Indicators To Detect Pre-Analytical Errors In Laboratory Testing, “up to 70% of all errors made in laboratory testing occurs during the pre-analytic phase”. This phase encompasses patient preparation, specimen collection, transport, storage, and processing, as well as the maintenance of adequate inventory and proper storage conditions for reagents and related testing supplies.
Since specimen integrity is dependent upon proper performance of pre-analytical processes, compromises to specimen integrity can give erroneous results and compromise the care of the patient. This article covers some of the key steps in handling patient samples to provide optimal specimens for testing, combined with the usage of an automated real-time data-acquisition system to ensure safeguarding specimen integrity.
Challenges of maintaining specimen integrity
An essential requirement for quality testing is to maintain the integrity of the patient samples, reagents, and test systems utilized. This is best achieved by the laboratory having a reliable, real time environmental monitoring system that protects these items, maintains complete records and documentation, as well as meeting all regulatory and institutional requirements.
Ensuring proper patient preparation is one of the most challenging requirements of the pre-analytical phase because it encompasses variables that typically occur before the individual arrives for his or her sample collection. Patient preparation factors include:
Food consumption is a significant source of pre-analytical variability. This effect varies based on the analyte(s) to be measured, and the time between meal ingestion and sample collection. An overnight fasting period of 10 to 14 hours prior to collection is optimal for minimizing variations. However, some meals may have longer-lasting effects and particular foods should be prohibited before performing certain tests. Communicating these requirements to patients is important to ensure appropriate preparation for testing.
Timing of sample collection
Blood concentrations of various analytes change during the course of the day. These cyclical variations can be significant, so the timing of sample collection should be strictly controlled. For example, serum iron increases by as much as 50% from morning to afternoon, hormones such as cortisol, renin, aldosterone, and corticotropin are especially impacted by this circadian variation. The timing of sample collection is especially critical for therapeutic drug monitoring, which requires trough levels for most analytes. Protocols must specify an ideal time of sampling for each test and the actual time of draw must be carefully documented.
Specimen collection poses several opportunities for errors. Important factors to consider for reducing variability during this phase of testing include positive patient identification, correct collection tube type and order, and sample volume and mixing.
Improper patient identification is a major concern due to the possible severe consequences from mislabeling a specimen. When collecting samples, two unique identifiers are required for positive identification. When implemented, wristband barcodes, and barcode scanners have significantly reduced rates of misidentification.
Collection tube type
Several types of tubes are available for specimen collection depending on the different additives and barriers used for distinct applications. For example, additives may promote or inhibit clotting to produce serum or plasma, respectively. As a result, the order of collecting multiple tubes through the same needle is important, and should proceed from tubes with no additives to tubes with very strong additives.
Barriers are typically gel-barriers that separate plasma/serum from cells after centrifugation. This helps stabilize the specimen for transport and storage without the need to aliquot. However, some analytes react or bind to the gels and should therefore be tested using gel-free tubes.
Specimen volume and proper tube mixing
All sample collection tubes need to be filled with the appropriate volume. This ensures the proper amount of specimen to amount of additive in the tube. In addition, all tubes with additives need to be gently inverted to mix the additive evenly with the blood. Excessive shaking will rupture cells and cause hemolysis.
Specimen Processing, Transport and Storage
Transport can be a significant source of specimen problems. The main variables to consider include agitation, light exposure, temperature, transport time, and placement of samples within the proper transport container. Specimens should be delivered to the laboratory promptly after collection, and the time between sampling and analysis reduced to a minimum. In addition, samples should be transported and stored under proper temperature and light conditions. Storage of samples for follow up add-on testing should be monitored and validated for each analyte, for the specific storage temperatures used in the laboratory.
The time between collection and centrifugation affects some analytes more than others. When plasma or serum are required, labs should centrifuge samples (and aliquot, if necessary) prior to transportation if the sample is traveling > 1-2 hours to the central lab. Labs need standardized protocols for centrifugation time and speed, because these variables impact specimen integrity. Re-centrifugation should be avoided because it can cause hemolysis and affects gel-barrier integrity.
Summary of specimen collection and handling factors that can affect specimen integrity:
|❖ Patient Identification||❖ Requests with errors in patient ID|
|❖ Sample labeling||❖ Inappropriate sample type|
|❖ Needle size||❖ Inappropriate collection containers|
|❖ Sample volume||❖ Insufficient sample volume|
|❖ Sample collection tube||❖ Clotted samples|
|❖ Inadequate tube filling||❖ Hemolyzed samples|
|❖ IV contamination||❖ Lipemic samples|
|❖ Order of specimen draw||❖ Contaminated samples|
|❖ Specimen clotting||❖ Fist-clenching during phlebotomy|
|❖ Inappropriate sample volume to anticoagulant ratio|
|Sample Processing, Transportation and Storage||❖ Samples stored or not received||❖ Damaged samples|
|❖ Delayed specimen processing||❖ Add-on testing|
|❖ Samples transported at inappropriate time for processing||❖ Agitation|
|❖ Exposure of samples to environment||❖ Re-centrifugation|
|❖ Samples transported under inappropriate temperature conditions||❖ Improperly stored samples|
Personnel Training and Competency
Unlike the analytic phase, the processes of the pre-analytic phase, including test ordering, patient preparation, specimen collection, identification, handling, and transport, often involve personnel that are not under the direct supervision of the laboratory, such as phlebotomists, nurses, administrative personnel, even receptionists and other office staff. This makes it more challenging to control quality performance and address errors.
Proper training of personnel who collect and handle specimens is the key to ensuring sample integrity. Improper training can lead to high sample rejection volume and/or compromised patient results, which can affect the outcome of patient care. Thus, all personnel involved with “pre-laboratory” as well as laboratory-centered pre-analytical processes must have their training documented and their competency evaluated by qualified laboratory professionals.
Being proactive to ensure sample integrity
● Properly train and perform competency assessments on all personnel that collect patient samples.
● When collecting samples, ensure that the proper container is used. If in doubt, consult the laboratory manual or call the laboratory.
● Provide a detailed specimen collection procedure to all sites that submit samples to the laboratory. Include a section for rejecting specimens.
● Properly store all samples per manufacturer’s recommendations. If the laboratory performs laboratory-developed tests (LDT), specimen stability studies for specimen age, storage and transport must be performed.
● Ensure that all samples contain at least 2 unique identifiers and the information on the sample matches the information on the requisition.
Monitoring the Laboratory Environment to Maintain Specimen Integrity
In the clinical laboratory setting, proper environmental monitoring is an integral part of a clinical laboratory’s daily operations. The vast majority of medical laboratories are required by their institutions and regulatory bodies to maintain and monitor proper temperatures within the entire laboratory environment. These requirements are largely driven by the need to ensure the integrity of testing systems and reagents, and to protect test samples and products. While monitoring temperature is important, the total laboratory environment (beyond temperature) must also be monitored continuously. To handle this task, the laboratory must ensure system accuracy, and maintain required records.
Laboratory monitoring can be challenging
It is often difficult to determine the best methods and practices for implementing and maintaining a robust monitoring platform, especially considering the need to do so 24 hours a day, 7 days a week, in real-time. Facilities and Laboratory Managers must keep constant vigilance over all laboratory conditions and functionality. This task alone can be incredibly time consuming and painstaking. With a laboratory’s valuable research and reputation on the line, it is important to acknowledge all the challenges of monitoring the laboratory’s equipment and ambient parameters.
….no-one wants to go into a laboratory and find a freezer, refrigerator, incubator or any temperature controlled storage unit that has failed overnight and ruined or jeopardized precious samples, specimens, tissues, or products, not to mention the loss of countless hours of research. Or the need to contact patients for redraws, and the delay in patient testing. The repercussions could extend even further, damaging the reputation of the laboratory, significantly add to the expense of replacing lost inventory, and the added labor cost to duplicate what had been lost.
While many monitoring systems do alert staff, many stop at a certain point and don’t have automated measures to continue alerting until a confirmation is received and corrective action is taken. Therefore, when choosing the proper monitoring for your laboratory, it is imperative that the system is robust, reliable, and flexible to fit the needs of your organization.
There are important effects of temperature fluctuation on specimen integrity
Among the range of environmental parameters that must be accounted for are air pressure and flow, humidity, and, most important, temperature. However, this is not all encompassing for all laboratories and often other parameters are also necessary to ensure an overall holistic environment. These parameters include, but are not limited to, particle counting and VOCs, measurement of specific gases, and even light intensity. Accurate and precise recording over time is essential for many analytical measurements. Because most in vitro testing systems are biological in nature, the heightened sensitivity inherent to these practices requires stable and reliable ambient parameter control conditions. The physical properties of certain products can change depending on temperature, and aspects such as the stability of reagents or the viscosity of aqueous liquids will vary if temperature ranges are not maintained.
Equally important is maintaining proper calibration of equipment
The process of recording and documenting temperatures and other elements in the lab is essential to both internal protocols and external regulatory mandates. Therefore, it is prudent to employ devices that provide a constant recording graph or computer data recording system with minimum/maximum thermometer capabilities in order to alert designated laboratory personnel to any temperature variances in real time.
As well, all temperature measuring devices must go through calibration verification against a current National Institute of Standards and Technology (NIST) traceable thermometer or equivalent certified instrument when implemented and at least once a year thereafter. Any thermometers or recording devices that fail calibration should be removed from service.
Manually recording refrigeration temperatures and conditions can result in inconsistent data and inaccuracy. Automated real time environmental monitoring systems are easy to use and customizable, allowing the user to monitor and document a range of information such as temperature, humidity, CO₂, Oxygen and LN₂ levels in tank rooms, and other important conditions. At the application-level, users can view equipment groups and environmental conditions, as well as receive alerts when units are outside of their monitored threshold.
These systems can also generate a variety of useful reports on multiple units for compliance, display an example of the report before printing or exporting and provide alerts such as low battery warnings to prevent transmission interruptions. Customizable alert notifications allow the user to set the parameters and designate the alert method used.
Laboratory and facility monitoring systems should be robust, flexible, reliable, and allow remote monitoring of all parameters, while also securely capturing data and offering immediate alerting whenever conditions exceed pre-defined thresholds. In today’s modern world, the convenience, flexibility, and importance of cloud-based monitoring and mobile application access to system statistics cannot be overemphasized.
The benefits of an automated data-acquisition system are more than evident
As technology continues to evolve, the rudimentary manual recording of data is becoming more problematic. Error prone manual tasks, outdated IT systems, and lack of documentation are all factors that affect the specimen integrity, by not knowing how the sample was stored. A comprehensive, reliable, and 24/7 data-acquisition system is critical to ensure the safeguarding of samples, to not only measure how the samples were stored, but to also ensure working conditions are as they should be. The benefits of a data-acquisition system also include the organization and accessibility to documentation and record keeping. Additionally, the enhanced ability of facilities to ensure equipment health and functionality.
This blog was written in collaboration with LabUniversity. Here are some of they're applicable courses:
How does your lab currently handle patient samples and utilizes automation to ensure safeguarding specimen integrity?
Leave a comment below!