Estandarizacion en Uroanálisis - Fase Pre Analítica

Estandarización en Laboratorio Clínico

Objetivos de Estandarización

• El Instituto de Estandarización en Laboratorio Clínico tiene dos objetivos principales para 2019: estandarizar los procedimientos de euroanálisis y publicar una guía sobre el mismo.

Estrategia de Implementación

• La estrategia se divide en seis pasos, comenzando con una encuesta para realizar un análisis situacional de las prácticas actuales en laboratorios visitados y otros que participan a través de encuestas.

Capacitación y Formación

• Se han realizado capacitaciones presenciales y virtuales desde 2015, abarcando diversas ciudades peruanas como Lima, Trujillo, Arequipa, Piura y Huancayo. Estas capacitaciones son apoyadas por empresas privadas.

Colaboraciones Internacionales

• Se ha colaborado con instituciones como la Quality de Chile para abordar la estandarización en el área de euroanálisis.

Fase Preanalítica

• Enfocándose en la fase preanalítica, se están desarrollando instructivos para la recolección adecuada de muestras. Esto incluye evaluaciones sobre si los laboratorios proporcionan instrucciones claras a los pacientes.

Normativa ISO Relevante

• La norma ISO 20 658 del 2017 proporciona requisitos y recomendaciones sobre buenas prácticas para la toma, transporte, recepción y manejo de muestras. Esta norma es fundamental para mejorar las prácticas preanalíticas.

Proceso Detallado Preanalítico

• Un resumen del proceso preanalítico incluye pasos desde la generación de solicitudes hasta la preparación final antes del análisis. Cada paso está diseñado para asegurar calidad y precisión en el manejo de muestras.

Importancia del Transporte Adecuado

Sample Collection and Handling Procedures

Patient Preparation for Urine Sample Collection

• Not all patients will wake up at the same time; some may collect their urine samples as early as 3 or 5 AM. It is important to advise them to refrigerate the sample until they can deliver it to the lab.

Transporting Urine Samples

• If available, laboratories should use specialized tubes designed for transporting urine samples. This helps in maintaining sample integrity during transport.

Pre-Analytical Phase in Clinical Laboratories

• The pre-analytical phase includes procedures based on international and national guidelines for urine sample handling. Documentation of potential errors and their frequency is crucial.

Quality Indicators in Sample Handling

• Quality indicators should be documented throughout the pre-analytical phase, which consists of three parts: obtaining, transporting, and receiving the sample.

Recommendations for Urine Sample Collection

• Guidelines recommend documenting maximum transport times and conditions under which samples should be refrigerated. Clear criteria for rejecting samples must also be established.

Implementation of Standardized Procedures

Development of Standard Operating Procedures (SOP)

• In late 2018, a proposal was launched outlining ten steps for proper urine sample collection based on ISO standards. Input from laboratory professionals was solicited to enhance these guidelines.

Official Release of Guidelines

• By 2019, an official version of the urine collection guidelines was released, incorporating feedback and bibliographic support from specialists in clinical laboratories.

Key Steps in Urine Sample Collection

Important Pre-Sample Collection Instructions

• Patients are advised not to engage in sexual activity 24 hours prior to collection due to potential contamination that could lead to false positives in protein tests.

Specific Instructions for Emergency Patients

• Emergency patients may not follow standard instructions; thus, any urine they provide at that moment should be processed regardless of timing or conditions.

Detailed Procedure for Collecting Urine Samples

Recommended Equipment and Hygiene Practices

• Use sterile containers (120 mL recommended). Patients must label their containers with personal information clearly on the body rather than on the lid.

Hand Hygiene Protocol

• Patients should wash hands thoroughly before collecting samples. Paper towels are preferred over hand dryers due to concerns about bacterial proliferation from air drying methods.

Avoiding Contamination During Collection

• When opening containers, ensure that neither the inside of the container nor its lid touches any surfaces that could cause contamination during collection.

Proper Technique for Collecting Midstream Samples

How to Properly Collect and Handle Urine Samples

Steps for Collecting Urine Samples

• After the initial stream of urine, place the collection jar in a way that it captures more than half of the sample. Ensure proper closure of the jar to prevent leakage.

• Patients often place the jar in a bag for transport; if not sealed correctly, this can lead to loss of sample integrity, with more urine in the bag than in the jar.

• For infants, parents should purchase a sterile collection jar and use a collector bag. It's crucial to maintain hygiene by washing hands before handling.

• Parents should clean their baby properly after handwashing and ensure correct application of the urine collector bag.

• Check every 15 minutes if the baby has urinated; avoid leaving the collector on for over 30 minutes to minimize bacterial growth.

Handling Collected Samples

• Once collected, carefully remove the collector bag without spilling any sample.

• Transfer urine from the collector into a sterile jar while ensuring sterility is maintained throughout this process.

• Laboratory professionals must analyze samples immediately after collection; delays can alter results significantly due to temperature changes or light exposure.

Importance of Timely Analysis

• Ideally, samples should be processed within 45 minutes post-collection. However, transportation delays may extend this up to two hours.

• Clear instructions are essential for patients; misunderstandings can lead to improper handling or analysis of samples.

Effects of Improper Sample Storage

• Unpreserved urine samples can undergo changes affecting color, turbidity, odor, pH levels, glucose content, and bilirubin presence—leading to false negatives or positives during testing.

Understanding Test Parameters

• Each test parameter has specific reagents and sensitivity levels that need careful consideration during analysis.

• Laboratories must provide comprehensive information about test parameters including potential interferences that could affect results (false negatives/positives).

Laboratory Standards and Patient Awareness

• According to ISO 15189:2012 standards, laboratories are required to inform patients about acceptance criteria for samples they submit.

Challenges in Sample Collection and Processing

Issues with Sample Identification and Contamination

• Samples may lack proper labeling or have discrepancies between the label and request format, potentially due to inadequate collection techniques or improper sample preservation.

• Visible contamination in urine samples can occur, such as the presence of fecal material or toilet paper, which complicates analysis.

• If contamination is observed, it is crucial not to process the sample; however, alternatives should be considered if it's the only available sample from the patient.

Patient Communication and Information Delivery

• Monitoring indicators monthly helps assess whether information provided to patients is effective and understandable.

• Insufficient urine volume can lead to sample rejection; recommendations suggest using containers that hold 100 to 120 milliliters for adequate collection.

Common Laboratory Errors

• Laboratories often mistakenly require patients to drink water before urination, which can dilute urine samples and result in false negatives during analysis.

Quality Control in Laboratory Documentation

Importance of Document Management

• ISO 15189 emphasizes that document control is a critical aspect of quality management systems within laboratories.

• A structured documentation format should include essential details like title, code, date of issue, version number, and pagination for clarity.

Roles in Document Creation

• It’s important for all personnel involved in document creation to be identified clearly. This includes who authored it, reviewed it, and authorized its distribution.

Collaboration for Accuracy

• In small laboratories where one person may handle multiple roles (author/reviewer), seeking external review from colleagues is recommended to minimize errors.

Recommendations for Review Process