CHANGE TO REPORTING RETICULOCYTE COUNT

On April 5, 1999 we changed our reporting of reticulocyte counts to exclude provision of a reticulocyte percentage and report only an absolute reticulocyte count (in giga/L).

The absolute reticulocyte count is calculated from the percentage reticulocytes multiplied by the red cell count. Our reference range is 35 - 120 giga/L. If one looks at reticulocyte percentage in isolation, there is a possibility of being misled by a raised reticulocyte percentage in the presence of significant anemia. The following example serves to illustrate this problem:

Hemoglobin = 60 g/L
Red Cell Count = 2.8 tera/L
Reticulocyte % = 3.5

Since the reticulocyte percentage is increased at 3.5% (normal 0.2 - 2.0), it might be considered that there is a fair marrow response to the anemia. In fact, the absolute reticulocyte count is 87.5 giga/L which is clearly a very poor response to this degree of anemia.

CONFIDENTIALITY, PRIVACY AND FREEDOM-OF-INFORMATION

MDS Metro has updated its policies regarding confidentiality, privacy and freedom-of-information. The revised policy assures that we are in compliance with a variety of new codes in this area (including the CMA Guidelines). Of interest to medical practitioners is the requirement that we must provide a patient with a copy of his or her laboratory results if requested by the patient. Our usual approach to such requests will be to send copies of reports to the patient by mail (or have them available for pickup). Suitable precautions will be taken to ensure the individual's identity. We will not provide results any faster than this unless there is a medical indication for such a service that has been agreed upon by the patient's physician. Historical searches for results at the request of a patient may require the payment of a fee. Questions regarding any aspect of confidentiality and privacy may be referred to Dr. Michael McNeely at 250-881-3109.

CARDIAC TESTING SERVICES

We have recently implemented some changes to our cardiac testing services, including ECG and Holter tracings. The changes are designed to achieve a uniformly high quality of tracings and to ensure prompt turnaround.

We have made arrangements with specialist groups to interpret undesignated ECG and Holter tracings on a regional basis. If you wish to have a specific reading physician interpret your patient's tracing, we ask that you write this on the requisition form and we will ensure the tracing is passed along. Tracings on children younger than 16 years are referred to a pediatric cardiologist or internist for interpretation.

In addition, we have limited the number of locations providing Holter hook ups, recognizing this requires a special expertise. Holter hook ups are done by appointment and we have one or more locations in each area we serve, to ensure good patient access. The Patient Service Centers that provide Holter and ECG services are identified on the back of our requisition form.

For further information regarding these changes, please contact the Cardiac Resources Department at 604-412-4503.

COMPLETE SEMEN ANALYSIS - VICTORIA

A reminder for Victoria doctors. The only Patient Service Center where samples for Complete Semen Analysis can be delivered is in the Royal Oak Shopping Plaza at 106-4480 West Saanich Road. The sample must be received between 7:30 am and 9:30 am.

UTILIZATION HINT: SERUM MAGNESIUM

An MDS Metro review of serum magnesium ordering by Family Practitioners reveals that 22% are requested by 5% of the GPs who use our services. Over 90% of physicians order between zero and three magnesiums each month. If you are ordering more than 5 per month it would be prudent to review your clinical indications for the test. Listed below are many of the accepted reasons for ordering a serum magnesium.

• The administration of certain cardiac drugs which cause adverse effects in the presence of low magnesium (i.e., Quinidine, Procainamide). Patients taking these drugs should have their magnesium checked approximately once every six months.
  
• Long term parenteral nutrition.
  
• Malabsorption syndromes: The frequency should depend on the severity of the syndrome, but once the patient's level is stabilized, a monthly check should be adequate.
  
• Renal loss secondary to diuretic use should be followed on a six-month basis.
  
• Chronic alcoholism, diabetic acidosis, and renal tubular acidosis. These patients should be followed on an as needed basis according to their symptomatology. Without symptoms, they should be checked no more than annually.
  
• Chronic diarrhea otherwise unexplained and persistent, should have a magnesium check once it is stabilized on a 2-3 month basis.
  Prolonged nasogastric suction greater than five days should have a magnesium check every two to three weeks.
  
• Cisplatin treatment- checked on a regular basis during the therapeutic regimen.
  
• Patients receiving IV magnesium therapy for a low serum level
  
• Patients with hypocalcemia not due to albumin deficiency should have a magnesium check.
  
• Lethargy and confusion which are not otherwise explained. Once a patient has been diagnosed with processes such as Alzheimer or psychotic depression, etc., there is no indication to follow their magnesium level on a regular basis.
  
• Patients receiving oral magnesium in the face of impaired renal function should have their magnesium level checked on a monthly basis.
  
• Other conditions that may warrant a magnesium evaluation are: pre-eclampsia, unexplained muscular paralysis, neuromuscular irritability, blood clotting disorders (not a first line test), supraventricular and ventricular arrhythmias, not otherwise classified.
  

CLINICAL OUTCOMES HINT: URINARY MICROALBUMIN

An analysis of our computer database was undertaken to see how often Urinary Microalbumin testing is being carried out in diabetic patients. It would appear that the use of microalbumin is only about 60% of ideal and many diabetics are not being provided the advantage of this test.

The CMA 1998 Clinical Practice Guideline for the Management of Diabetes in Canada (CMAJ 1998;159:8 Suppl S21) suggests:

"In people with either type 1 or type 2 diabetes, screening for microalbuminuria is recommended in those with dipstick-negative or trace proteinuria. Frequency of screening is annual for people over 15 years of age with a 5-year history of type I diabetes and for all people after the diagnosis of type 2 diabetes. The recommended screening method is measurement of an albumin:creatinine ratio in a random, daytime urine sample. If values are greater than 2.8 for females and 2.0 for males, the test should be repeated (and confirmed in 2 out of 3 measurements over three months); if uncertainty about elevation still exists, it should be confirmed with a timed urine collection to measure the rate of microalbuminuria."