Laboratory Medicine Updates - September 30, 2005

University of Virginia Health System

Medical Laboratories

“Quality You Expect, Service You Deserve”

 

LABORATORY MEDICINE UPDATE

September 30, 2005

Discontinuation of 21 Days Incubation for Fastidious Organisms and Suspected Infectious Endocarditis

Based on the data summarized below from our institution and similar reports from other institutions, the Clinical Microbiology lab has discontinued the practice of holding blood cultures for 21 days when the diagnosis of endocarditis is noted on the request form.  We have additional information from the manufacturer of the blood culture instrument, BioMerieux, documenting that fastidious organisms including the HACEK group were shown to grow and be detected by the system in less than 7 days.

We will continue to provide incubation for 21 days if specifically requested for particular organisms when a request is made to the laboratory.  Please contact the Clinical Microbiology division at 434-924-8052 if you have questions.

University of Virginia Data :

Time of study:

24 months

# of bottles held 21 days:

550

# of positive bottles:

19

Time to positive:

<7 days (standard hold time)

17

>7 days

2*

*8.1 days (fungi; bone marrow aspirate) and 9.6 days (fungi; vitreous fluid)

 

2006 ICD-9 Codes

October 1, 2005 begins the use of the new 2006 ICD-9 codes.  There are a number of changes this year but the most significant for the laboratory appears to be with the Renal Codes.  ICD-9 code 585 (Chronic Renal Disease) has been expanded and now requires a 4th digit.

ICD-9 Code

Description

585

Chronic kidney disease (note description change)

585.1

Chronic kidney disease, Stage I

585.2

Chronic kidney disease, Stage II (mild)

585.3

Chronic kidney disease, Stage III (moderate)

585.4

Chronic kidney disease, Stage IV (severe)

585.5

Chronic kidney disease, Stage V

585.6

End stage renal disease

585.9

Chronic kidney disease, unspecified

 

 

 

 

 

 

Adrenocorticotropin Hormone (ACTH)

The ACTH assay is once again being performed in the Davis Laboratory, although on a different instrument than the previous in-house assay.   The methodology remains chemiluminescence with an analytical measurement range of 5 – 1250 pg/mL.  The reference interval (<50 pg/mL), specimen requirement (EDTA tube) and handling conditions (priority transport and processing) have not changed.

Reference Interval Change – Alkaline Phosphatase

The Division of Clinical Chemistry has expanded the reference intervals for Alkaline Phosphatase to include age and sex specific reference intervals.  The following reference intervals are now in effect:

Females Males

0d – 12Y:         <500 U/L                     0d – 12Y :        <500 U/L

13Y-15Y:        <300 U/L                     13Y-15Y :       <750 U/L

>15Y:              40-150 U/L                  16Y-20Y:        >250 U/L

>20Y:              40-150 U/L

ReferenceIntervalChange – SerumProteinElectrophoresis

The Medical Laboratories has updated the reference interval for serum protein electrophoresis fractions after an internal review of patient values on the new electrophoresis system.  The new ranges are as follows:

Albumin

Alpha-1

Alpha-2

Beta

Gamma

mg/dL

3.4 – 5.0

0.1 – 0.3

0.5 – 1.1

0.65 – 1.15

0.65 – 1.25

%

49 – 69

1.6 – 3.8

8.8 – 15

9.5 – 15.5

8.5 – 17.5

Change to Fibrinogen Critical Value

The Coagulation Laboratory has changed the Fibrinogen critical value from less than 100 mg FEU/mL to less than 120 mg/mL. Any questions regarding this change may be directed to the Special Coagulation Laboratory at 924-8007 or page the Pathology Resident at 1663.

Critical Value Call-Back

The Customer Service staff have recently assumed responsibility for calling most critical lab values to ordering physicians.   The exceptions are blood gas results and Microbiology results.  We have adopted a computerized system for alerting Customer Service staff of pending critical results and they are establishing effective call back procedures with the many different services and physician clients.

Medical Laboratories is pleased to offer this enhanced call back service and further simplify access to critical information.   Incoming calls should be made to the Customer Service area, 434-924-LABS (5227).