Effect of Time Interval between Collection, Plasma Separation and Analysis and the Effect of Temperature on the Laboratory Results of Plasma Glucose Estimation

Introduction:In a clinical laboratory, consistency of test results cannot be solely achieved by controlling the accuracy in the analytical phase of glucose estimation alone. Considering the high chances of pre-analytical errors, due consideration has to be given for storage criteria as well.Aims: Aim is to find out the quantitative alterations and the useful time interval between collection and analysis and the effect of temperature on the laboratory results of plasma glucose.Study Design:Cross sectional study.Place and Duration of Study:Study was conducted at Department of Biochemistry, Kasturba Medical College Hospitals, Mangaluru between 2015 and 2016.Methodology:In this study, 17 apparently healthyvolunteers aged 20-30 years wereenrolled with their consent.Plasma glucose levels were estimated by glucose oxidase-peroxidase kit method in semi-autoanalyzer at different temperatures and at different time intervals after collection and at room temperature but separating plasma at different time intervals and correlating it with the initial value.Results:The mean of plasma glucose when estimated immediately after separation of plasma was 78.16 ± 13.28 mg/dL. Only when glucose was estimated within 2hrs when stored at 2-8° Celsius after plasma separation (71.57 ±12.64), non-significant difference was noted(p value –0.696) otherwise as the temperature and time interval for estimation increases, the value of glucose decreases significantly. The effect of delayed separation of plasma showed that as the time of separation increases the value of glucose decreases significantly in the sample.Conclusion:Most mistakes occur before the samples are analysed, either during sampling or preparation for analysis. Thus, proper storage temperature and time must be considered for plasma glucose estimation, if measurement cannot be done immediately

An Analysis of Preanalytical Errors and Turnaround Time in Emergency Biochemistry Laboratory in a Tertiary Care Hospital in New Delhi

In modern diagnostics, it is extremely important to maintain and ensure quality of laboratory results dispatched. It is part of the total quality management and an essential criterion for accreditation of the laboratory. The analysis of biochemistry samples can be broadly divided into three phases: pre-analytical, analytical and post-analytical phase. We wanted to identify the commonly occurring pre-analytical errors and determine the turnaround time in the emergency biochemistry laboratory at a tertiary care hospital in Delhi.METHODSA cross-sectional study was done on a total of 2,73,111 samples received in the emergency biochemistry laboratory from September 2018 to August 2019 and an analysis of occurrence of pre-analytical errors was done, retrospectively. Additionally, the turnaround time of the laboratory was evaluated over a period of two months from July 2019 to August 2019 and average time was recorded. Data was collected from entry registers and rejected samples registers.RESULTSIn this study it was found that 10.58 % of the total samples received were rejected. Moreover, overall turnaround time was found to be 108 minutes (median value). In the present study, haemolysis was the most common reason for sample rejection. (63.14% of total rejections). Additionally, the second most common error was inadequate samples. 6570 samples were rejected due to this reason (22.73%).CONCLUSIONSHaemolysis was the most common cause of rejection in the emergency biochemistry laboratory. Also, it was seen that the most time-consuming step was analysis in auto-analyser with respect to contribution to turnaround time. As a matter of fact, Pre-analytical errors can adversely affect the treatment of patients. However, most of the errors can be reduced by proper training of the staff and checking competency thoroughly by conduction of practical and theory assessment of laboratory personnel at frequent intervals

A Study of Analysis of Critical Values at Emergency Biochemistry Laboratory in a Tertiary Care Hospital in India.

One of the important functions of a clinical biochemistry laboratory is clear, accurate, and rapid communication of a critical value to clinicians1. Critical value reporting is one of the requirements for laboratory accreditation. This study aimed to analyse the critical values data at a tertiary care hospital in New Delhi, India in the emergency laboratory setting and compare it with the available data from previous studies.METHODSThis is a retrospective study of emergency biochemistry samples done over a period of two months from July 2019 to September 2019. The critical values data of several biochemical parameters generated from the testing of samples on Beckman Coulter Olympus AU 480 during three months period were analysed. Statistical analysis was conducted using Microsoft Excel 2016 program.RESULTS183056 tests were analysed, and 11875 critical alerts were generated the incidence of which varied from 0.8% for glucose (children) to 10.6% for serum potassium in children. Frequency of critical values for serum potassium is highest followed by serum sodium. Also, critical values for serum potassium in paediatric patients is higher than in adults. It can be stated that there is a need to study of frequency of critical values in emergency as well as routine laboratories to identify the parameters with maximum critical values and also recognize the underlying causes for the same and take suitable measures.CONCLUSIONSThe frequency of critical value for serum potassium, is highest followed by serum sodium, in case of samples received from adult patients. Also, frequency of critical values for serum potassium in paediatric patients is even higher than adults. These values show that these critical biochemical values can be detrimental to these patients and timely notification to the clinician is very important so that necessary actions could be taken to correct them. Further studies of critical values in emergency labs is required to observe trends and identify the underlying causes and suggest suitable remedial measures if any.

Pre-analytical errors in clinical chemistry laboratory of a tertiary care hospital

Background: Pre-analytical errors account for up to 70% of all mistakes made in laboratory diagnostics, most of which arise from problems in patient preparation, sample collection, transportation, and preparation for analysis and storage. Pre-analytical errors influence the total error thus hindering TQM in laboratory, consequently decreasing the accuracy and reliability of the results generated. This study was conducted with the aim to determine nature and frequency of the occurrence of pre-analytical errors.Methods: This prospective analytical study was designed to evaluate the pre-analytical errors observed in a total of 13,892 out-patient and inpatient samples. Samples received for routine clinical chemistry analysis were screened for pre-analytical errors. Samples received for other investigations were excluded. We recorded all nonconformities and errors occurring over a 3-month period and corrective measures were suggested to minimise them. Laboratory personnel were asked to register rejections, and pre-analytical causes for rejection of ward as well as out-patient samples collected in the laboratory. Types of inappropriateness were evaluated as follows: hemolyzed, blood collection in wrong tubes, clotted blood, inappropriate timing of collection, improperly labelled samples, insufficient volume of specimen and lipemic samples.Results: A total of 13,892 samples from the outpatient department and in-house patients were received by our clinical biochemistry laboratory during the period from April 2019 to June 2019. Out of these 404 samples were found unsuitable for further processing. This accounted for 2.9% of all samples collected in the laboratory and pre-analytical errors were responsible for these samples to be rejected over a period of 3 months. Rejections arose as a result of the following reasons: 0.92% were rejected due to hemolysis; 0.58% were blood collected in wrong tubes; 0.55% were clotted blood; 0.26% had inappropriate timing of collection; 0.24% were mislabeled samples; 0.20% had insufficient sample quantity and 0.14% were lipemic samples.Conclusions: Of all the samples received in the lab, the overall percentage of rejection is 2.9%. Substantial number of samples undergo repeated testing because of rejection owing to pre-analytical errors. The efforts should be aimed to reduce the rates of rejected samples can provide to improve the quality of laboratory based health care processes.

Evaluation of laboratory request forms submitted to clinical pathology department in tertiary health care hospital

Background: Laboratory diagnostics is the fast-growing field which contributes 70% of clinical diagnosis. Laboratory information has a profound impact on patient diagnosis. Research has demonstrated most of the laboratory errors occur in the pre-analytical phase. Incorrect and incomplete filling of information on the laboratory request forms can significantly impact the quality of laboratory results, and it affects patient outcome and resources. We, therefore, evaluated the extent of incomplete laboratory forms in our center.Methods: The study was a retrospective study conducted on all request forms received over 1 month from June 15, 2018, to July 15, 2018, in the Clinical Pathology Department of ESI hospital, Coimbatore, during working hours were analyzed for the frequency of incomplete data.Results: Only the patient’s name appeared in all the forms. Consultant in charge of requesting laboratory tests (99%) was the most omitted parameter. No clinical details or location/ward details of the patient was provided in 90.7% and 7% of the cases. Age and gender did not appear in 21.9% and 22%, respectively. Date of request, doctor’s signature, and hospital number were missing on 8.4%, 27.6%, and 4.4%, respectively.Conclusions: The study has demonstrated the level completion of laboratory request forms was suboptimal. This may be responsible for many pre-analytical errors. There should be closer interaction between clinicians and laboratory physician to improve the quality of laboratory services and resource management.

Auditoría clínica: una herramienta para el seguimiento de errores preanalíticos en el laboratorio / Clinical audit: a tool to monitor pre-analytical errors in the laboratory

El objetivo del trabajo fue evaluar la efectividad de un programa de auditoría clínica para vigilar y reducir la magnitud de errores preanalíticos en el Laboratorio de Guardia de un hospital público de la provincia de Buenos Aires. En un período de 2004 y otro de 2005 se relevaron los diferentes tipos de errores en 11.949 recipientes de muestras de sangre y orina. Se calcularon los indicadores: porcentaje de errores preanalíticos totales en las muestras (% EP), de muestras coaguladas, de recipientes inadecuados, de volumen inadecuado, de muestras hemolizadas, de muestras batidas y de identificación inadecuada. Se capacitó al personal de enfermería. Se asignaron los costos correspondientes a las etapas de obtención y remisión de muestras de la fase preanalítica. El % EP no presentó modificaciones significativas en 2004, mientras que en 2005 sus variaciones acompañaron las de algunos de los restantes indicadores. Los costos correspondientes a errores preanalíticos constituyeron en promedio el 10% de los costos totales de obtención y remisión de muestras en los períodos estudiados. Se concluye que las actividades de capacitación deben realizarse en forma periódica y someterse a seguimiento continuo a fin de obtener disminuciones significativas y perdurables en la magnitud de los errores preanalíticos.

The aim of this study was to evaluate the effectiveness of a clinical audit program to monitor and reduce the magnitude of pre-analytical errors in the Emergency Laboratory of a Buenos Aires Province public hospital. During a 2004 period and another 2005 one, different types of errors were surveyed in 11.949 blood- and urine-sample flasks. The following indicators were calculated: sample pre-analytical error percentage (% PE), as well as percentages corresponding to coagulated samples, inadequate flask use, inadequate flask volume, samples that underwent haemolysis, shaken samples and poor sample identification. Nursing personnel were trained. Costs incurred were allocated to the extraction and delivery stages within the pre-analytical phase. PE % did not show any meaningful changes in 2004, while in 2005 its variations followed those of some of the other indicators. Costs attributed to pre-analytical error represented 10% of total cost of sample extraction and delivery in the periods that were studied. It can be concluded that training courses must be periodically offered and their results monitored on a permanent basis if any significant and long-lasting reduction in the magnitude of pre-analytical errors is to be achieved.