Keeping patients safe

Amazingly no governmental regulation exists in the UK for the labelling of pathology specimens, leaving the decision of how these should be managed to the individual NHS trusts. Peter Brooks tells Laboratory News why this is one of the most important decisions they can make

The misidentification of samples in the pathology laboratory poses a risk of misdiagnosis to thousands of patients annually. Figures obtained by the Freedom of Information act reveal that between 2008 and 2009 almost 366,000 NHS specimens were mislabelled or ‘mixed-up’ in pathology laboratories. A total of 46 recorded cases during this time period were uncovered where mislabelling was found to have been related to patient death or a serious delay in treatment¹.

The common occurrence of specimen misidentification can be a consequence of the insufficient protocols that many health service trusts have in place for labelling patient specimens. Errors can occur as a result of ineffective processes for identifying and tracking specimen cassettes and slides, leading to patients receiving incorrect diagnoses. This can result in patients undergoing unnecessary treatments or a failure to treat unreported conditions. To overcome this trusts and pathology laboratories must implement more advanced procedures for labelling and tracking specimens as they progress through laboratory workflows. Recently, there have been great improvements in reliable and effective technology that guarantees accuracy through automatic quality assurance and documentation to remove any potential error points during the process of specimen collection, grossing, staining, analysis and archiving.

Currently no governmental regulation exists in the UK for the labelling of pathology specimens, leaving the decision of how these should be managed to the individual NHS trusts. Many trust’s guidelines still only require specimens to be labelled manually. This prevalent practice of labelling samples by hand and lack of official policy results in a huge potential for error across the health service and the widespread incidence of specimen misidentification.

Misidentification of specimens in pathology laboratories can have significant consequences for patients through inaccurately matching slides to patient samples. In addition, a failure to treat unreported conditions can cause serious harm to patients who may also be subjected to unnecessary procedures as a result of misdiagnosis. A 2010 NHS report detailed that a pathology mix-up resulted in a patient with a benign breast condition receiving a malignant diagnosis and undergoing surgery, while another patient was wrongly given the all clear². The cause was identified as a pathology mix-up as a consequence of specimen misidentification. The manual labelling of tissue containers and microscopic slides is still common practice today while batching of specimens and printed labels for multiple patients is also widespread. This means that although they are rare, incidences such as this can still occur.

It has been recognised by laboratory technicians for decades that the current process for identifying and tracking specimen cassettes and slides is not an accurate science. Many technicians have no option but to write identification information on the slide label by hand in order to match specimens with the right tissue block or patient, simply because they have no other means of doing so.

Highly inefficient and time-consuming, manual methods are unsurprisingly prone to potential errors, whether from illegible handwriting, incomplete sample details or the inability to track the processes that a sample has been through. Deciphering somebody else’s handwriting can be in itself problematic and prone to error. The amount of space that is designated to labelling on a slide or cassette can also be very limited meaning that vital information may be abbreviated or even omitted.

Durability of labelling is of great concern. Tissue cassettes and specimens can become unreadable after contact with chemicals or solvents or even just routine handling within a laboratory which can easily smudge text that has been handwritten. Unsatisfactory labelling is also likely to use poor quality adhesive that is not strong enough to withstand harsh chemicals, solvents or extreme temperatures. As a consequence there is a risk that labels will be removed during processing making it impossible for samples to be matched to a patient and wasting valuable time and money.

Long-term storage can also present challenges to label preservation and the ability to track specimens for long periods. Traditional methods are ineffective as handwritten labelling can be susceptible to fading over time, causing particular challenges if specimens are being stored for legal reasons or for future testing. To overcome the issues faced on a day-to-day basis it is vital that pathology laboratories implement advanced means of labelling and tracking samples to ensure the risk of label illegibility and sample misidentification is minimal.

Accurate sample labelling is the best defence for pathology laboratories against misidentification errors and their consequences. In recent years, new innovative technology has emerged that makes safety a priority and recognises the importance of satisfactory identification and traceability. Labelling specimens using automated cassette printing at the time they are required is a proven method to reduce errors while improving processes and enabling laboratories to work more efficiently. Misidentification errors can be further prevented by using barcodes to identify samples and by scanning them to record transfers and to support test entry result, enabling sample data to be tracked as it proceeds through the laboratory workflow.

To address the risks associated with sample misidentification, new labelling and tracking solutions and devices have been developed by companies (for example Thermo Fisher Scientific) to ensure that the integrity of tissue samples is preserved. By removing the risk of sample mix-up, these solutions ensure that patients receive a quick and accurate diagnosis of diseases such as cancer. This new technology enables pathology laboratories to develop “closed-loop” specimen identification and tracking systems that use advanced labelling and barcode technology to significantly reduce errors and increase the efficiency of laboratory workflows.

By implementing printing at the workstation, pathology laboratories can automatically label cassettes and ensure samples can be identified accurately by offering instantly legible type and improved information content. High-quality printing capabilities now enable cassettes to be clearly marked with a 2D barcode that provides improved clarity for laboratory staff and significantly reduces the possibility for human error. By printing barcodes and text directly onto microscope slides, the slide is resistant to chemicals, protecting barcodes and text so they always remain readable, helping to avoid sample mix-up and misdiagnosis. Furthermore, barcode sample identification and data entry saves time, enabling staff to spend more time on diagnostic procedures rather than administrative work.

An inclusive workflow removes the possibility of errors caused through the manual labelling of slides and cassettes and ensures that when a sample is taken and processed through a laboratory, it is the same sample that is collected at the other end and the correct results that are passed on to the patient. The enhanced durability offered by new technologies mean that a sample can then be archived and retrieved without any risk of deterioration to the label or fading of the text, even under extreme conditions. This not only avoids irretrievable sample loss but also offers complete confidence to the technician and the patient that the correct sample has been identified. New technologies also enable laboratories to benefit from having records that prove that samples have been through specific workflow processes without any allowance for error or mix-up.

In addition to improving efficiency at every stage of sample processing, emerging identification and traceability systems also assist laboratories in meeting Good Lab Practice (GLP) standards by providing compatibility with LIMS and other data systems.

Sample misidentification poses a significant threat to thousands of patients annually and in the most severe cases, results in individuals receiving incorrect or unnecessary treatment or failed diagnoses. Over recent years, patient safety and patient care have increasingly become the focus for healthcare trusts in the UK. Pathology laboratories play a vital role in eliminating the likelihood of identification and traceability incidences and preventing the adverse events associated with specimen misidentification.

The traditional methods of sample identification widely used in pathology laboratories are not always effective, resulting in a significant risk to patients. New technology is assisting laboratories and healthcare trusts to implement solutions that guarantee the accurate labelling of specimens, enabling laboratory staff to identify samples and significantly reduce the prevalence of misidentified, lost or unusable samples and their related consequences. This means that patients can be confident that disease processes are diagnosed correctly and as rapidly as possible.