College of American Pathologists
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  Q & A





cap today



May 2007

Q: Q. Regarding the critical values guidelines noted in CAP laboratory general checklist items GEN.41320, GEN.41330, and GEN.41340, is it necessary to include the entire first and last name of the individual contacted in reporting a critical value, or is it acceptable to use the first initial and full last name?

A. The CLIA ’88 regulations (42CFR493.1109[f]) state:

The laboratory must develop and follow written procedures for reporting imminent life-threatening laboratory results or panic values. In addition, the laboratory must immediately alert the individual or entity requesting the test or the individual responsible for utilizing the test results when any test result indicates an imminent life-threatening condition.

The lab must notify the individual caring for the patient or the designee of test results that indicate an imminent life-threatening condition. However, if the patient’s physician cannot be reached or refuses to take calls, then these details should be documented as part of the laboratory’s quality improvement activities and assessed by the laboratory director.

As stated in the note in laboratory general checklist item GEN. 41330, the laboratory must maintain records documenting that it promptly notified the appropriate clinician after obtaining results in the critical range. These records should include date, time, responsible laboratorian, person notified, and test results. It is up to the laboratory medical director whether to include the entire first and last name of the individual contacted. As indicated in the CLIA regulations noted here, the laboratory must develop a policy regarding critical value notification and follow it.

If a critical value is transmitted from the lab to the nursing unit by computer or fax, the lab should phone the unit administrators to inform them that a critical value was sent. It is not acceptable to leave results on an answering machine or in a voicemail message because someone other than the physician may have access to the confidential information. It is acceptable to leave a message asking a physician to call the laboratory to obtain a critical message about a patient.

Deborah A. Miller-Jones, MPH, MT(ASCP)
Senior Technical Specialist
Laboratory Accreditation Program
College of American Pathologists
Northfield, Ill.

Q. As our laboratory tries to strengthen its specimen rejection policy, we are stuck on the issue of hemolysis in blood samples. At what level of hemolysis, based on a colored reference chart with examples of hemolysis levels, should all specimens be rejected? Should this threshold be reduced for potassium and other analytes?

A. It’s difficult, and probably misguided, to come up with a single value for the level of hemolysis at which all samples should be rejected. In the end, it is a judgment call. Different laboratory directors in different settings will come up with different answers. Thus, there is no—and should be no—single CAP guideline on rejecting samples.

However, as reflected in CAP laboratory general checklist question GEN.20348, every laboratory needs to monitor preanalytical processes, including specimen acceptability rates.1 In a CAP Q-Probes study,2 the most frequent cause for rejection was hemolysis, even though specimen rejection was very infrequent (0.35 percent of chemistry samples).

The analytes that are adversely affected by hemolysis can vary considerably with each method. The amount of interference, as well as the level at which it occurs, is also method-specific. (For interested laboratories, the CAP offers the Interfering Substances Survey, which can help laboratories assess the degree to which their methods for many analytes are affected by hemoglobin and bilirubin.)

You should indicate the degree of hemolysis, when present, on the laboratory report. In addition, if there is interference for a specific test, include a comment to that effect with the report, such as “Sample is mildly hemolyzed” or “Hemolysis increases LD values.”

For example, our major spectrophotometric chemistry analyzer estimates the level of hemolysis, icterus, and turbidity on each sample. When hemolysis reaches various levels, our computer system adds comments about the degree of hemolysis as well as comments specific to each analyte measured.

With potassium measurement, you could argue that even a grossly hemolyzed sample should be analyzed, which is consistent with the CAP chemistry and toxicology checklist question CHM.11900. Assuming that the degree of hemolysis and its effect on potassium are prominently indicated in the report, the potassium value can be helpful. A low or low-normal level suggests the patient may be severely hypokalemic. A high level encourages the physician to obtain a new sample.

Keep in mind, too, that in some cases hemolysis is an in vivo phenomenon. You obviously would not want to reject a sample from a patient with acute hemolytic anemia because it was grossly hemolyzed. It probably makes more sense to comment on the degree of hemolysis, suggest that the values be interpreted with caution, and run the requested tests. If the number of hemolyzed samples from some practices is inordinately high, then it would be worthwhile to investigate and try to correct the problem.


  1. Dale JC, Novis DA. Outpatient phlebotomy success and reasons for specimen rejection. Arch Pathol Lab Med. 2002;126:416–419.
  2. Jones BA, Calam RR, Howanitz PJ. Chemistry specimen acceptability: a College of American Pathologists Q-Probes study of 453 laboratories. Arch Pathol Lab Med. 1997;121:19–26.

Gary L. Horowitz, MD
Director of Clinical Chemistry
Beth Israel Deaconess Medical Center

Chair, CAP Chemistry
Resource Committee