CAP Blood Gas Checklist

CAP is the College of American Pathologists. As an organization, CAP encourages pathologists and laboratories to maintain high standards for quality and accuracy. To that end, CAP documents and accredits labs that meet quality and performance standards. Labs performing blood gas workups receive a CAP checklist every other year to help maintain quality control. The lab must complete the checklist to maintain CAP accreditation between CAP inspections. The questions on the blood gas checklist cover a wide variety of situations.

Labeling

• Arterial blood gas samples can be unstable, requiring lab technicians to analyze them as soon as possible after capturing the sample. Sometimes, this urgency leads to sloppy habits, the most notable of which is to wait to label samples. Many lab technicians will line up samples to keep track of them rather than taking the time to label them properly. This is a dangerous and unacceptable practice. Two questions on the CAP blood gas checklist address labeling. Labs must verify that each sample is labeled to identify the patient and to avoid mix-ups. Labs must also describe their labeling and documentation processes.

QC Requirements

• Quality control is another important topic covered by the CAP blood gas checklist. CAP requires that labs do a quality control check on pH, pCO2 and pO2 every eight hours. CAP requires two quality control checks each day for calculated values, co-oximetry analytes and measured analytes, such as sodium, potassium or glucose. The checklist has questions to verify that lab personnel are properly performing these QC checks.

Calibration

• Properly calibrated instruments and reagents are critical to performing accurate blood gas tests. Therefore the CAP blood gas checklist includes questions to verify that instruments are calibrated at least every six months or according to manufacturers' recommended schedules. In addition, the checklist verifies that labs calibrate instruments after a major maintenance or service event, after reagents in the instrument are changed over completely or if the reagents used in the instrument are changed.

Procedure Reviews

• In order to maintain quality and accuracy, a lab director should regularly review and sign off on procedures. The lab should also document the review process so that it has records showing that reviews are regularly performed. The CAP blood gas checklist addresses this requirement.