Pre-Examination Processes & Sample Acceptance/ Rejection Part-3

Yes, patient consent is generally required for any clinical or biochemistry research project, regardless of whether it's considered routine. This is because research involves using patient data or samples for a specific purpose, which requires the patient's informed agreement.

However, for routine clinical or biochemical investigations in a medical laboratory setting, written consent may not be necessary if the patient directly visits the laboratory with a requisition form and pays the required fees.

Consent is crucial for invasive procedures such as bone marrow sampling or Pap smear because they are not routine processes like phlebotomy. These procedures can carry risks, such as bleeding or other complications, and obtaining written consent ensures that the patient is fully informed and agrees to proceed.

The criteria for sample acceptance should be clearly defined and must include ensuring that the specimen request form is complete as per the established guidelines. This includes factors such as the type of sample, the correct labelling, and the completion of the necessary information.

Sample rejection should be based on significant omissions or errors that compromise the quality or integrity of the sample. Minor errors like a missing signature should not automatically result in sample rejection, especially if the sample is precious. Judgment should be used in such cases, and the sample should not be rejected for very minor issues.

The type of tube required for flu sample testing depends on the test type. In general, it is recommended to use sterile tubes without any preservatives for flu testing to ensure sample integrity.

No, histopathology tissues should not be rejected solely because of minor omissions on the request form, such as a missing signature. These specimens are often irreplaceable, such as tissues collected during surgeries like appendix removal. Therefore, it is important to be judgmental and consider the criticality of the specimen before deciding to reject it based on minor clerical errors.

Laboratories should retain rejected specimens because it may not always be possible to obtain the specimen again. Retaining these specimens allows for accountability and provides an opportunity for cross-checking the reason for rejection. Additionally, there may be cases where the rejected specimen, such as a hemolyzed or compromised sample, still needs to be examined due to the unavailability of a replacement. It is recommended to keep rejected specimens for a specific period, such as 6 to 8 hours, or as per your lab’s policy. 

Yes, routine clinical biochemistry tests can be performed in both red tubes and lithium heparin tubes. However, it's important to follow the manufacturer’s guidelines for specific tests. If the test requires a plain serum sample, a red tube should be used. For tests that require lithium heparin, use the appropriate tube. Keep in mind that lithium heparin tubes are more expensive, so consider the cost factor when choosing tubes.

Yes, informed consent is generally required even when blood is collected by trainees for training purposes. Since training may involve procedures not strictly adhering to the standard protocol, resampling could be required. If an additional tube is collected beyond what was initially requested for the patient's clinical test, a signed consent form is necessary to ensure the patient is informed and consents to the extra sample collection.

No, it's not practical to list all criteria on the TRF. Instead, laboratories should have a detailed Standard Operating Procedure (SOP) for sample collection. This SOP should be made available to everyone involved in the sample collection process to ensure they follow the proper protocols when collecting samples.

Yes, hemolysis can occur during transportation if samples are not properly packaged. To prevent this, laboratories should use appropriate packaging materials for sample transport.

Employ triple-layer packaging containers with absorbent material to protect samples from damage and spills. By adhering to these packaging protocols, you can minimize the risk of sample deterioration and ensure that samples remain stable during transport, whether by two-wheeler or any other mode of public transport.

Yes, while collecting the specimens with the closed system of collection there is a specific order which needs to be followed. The standard order of tube collection is as follows:

• Blood Culture Tubes (Aerobic first, then Anaerobic)
• Citrate Tube
• Plain Tube
• Heparin Tube
• EDTA Tube
• Fluoride Tube 

According to GCLP (Good Clinical Laboratory Practice) and international patient safety goals, two identifiers are required. This is crucial for ensuring patient safety and accurate identification. One identifier should be related to the patient’s identity (such as a unique identification number), and the other can be the patient’s name or another distinguishing factor.

Arterial and venous blood have distinct compositions, leading to slight differences in electrolyte levels. Oxygen levels, in particular, will be higher in arterial blood. Ensure that your testing protocols account for these differences. Clearly define and document the expected ranges for both arterial and venous blood electrolytes in your lab procedures.

It can be challenging to obtain the recommended ABG sample volume using routine syringes in neonates, especially preterm babies. Use micro tubes or other specialized collection devices designed for small volumes. These devices often work on microfluidic principles and are better suited for collecting samples from very small infants. Microtubes and specialized ABG collection devices are designed to handle the small volumes of blood that can be obtained from neonates and preterm babies. They can be effective for collecting samples even from very small infants, such as those weighing 500 grams to 2 kilograms.

If obtaining a new sample is not possible, the laboratory should process the existing sample, and use any available techniques or methods to make the most of the sample volume. Document any difficulties encountered during sample processing in your final report. Include details such as insufficient sample volume and any steps taken to handle the limited volume, dilution of the sample or use of alternative test methods or any issues like hemolysis. By documenting and communicating any issues encountered with small samples, you ensure accurate interpretation of results and maintain transparency in your analysis.

While a 12-hour fast is often recommended for lipid profiles, it's not always strictly necessary. Guidelines from organizations like the Lipid Association and Heart Association recognize that fasting may not be feasible in all cases.

If a 12-hour fast is not possible, collecting samples within an 8-hour fasting window is generally acceptable. You can also consider collecting samples for glucose and lipid profiles simultaneously.