A FUNNY THING HAPPENED ON THE WAY TO THE LABORATORY

1. A FUNNY THING HAPPENED ON THE WAY TO THE LABORATORY GEOFFREY M KELLERMAN HUNTER AREA PATHOLOGY SERVICE

2. WHERE CAN THINGS GO WRONG? • The patient • The collection • The transport • The storage • The data entry • Places we have never imagined – SOD’s law triumphs

3. COMMENT • I use these alerts to identify many of the unexpected results - they have been developed over the years as needed. • There is NO way that such alerts can pick up all errors. • Alertness of machine operators for delta check failures is an essential part of the necessary surveillance.

6. PATIENT IDENTIFICATION • THE CASE OF ROBYN SMITH • “WHY DO THEY WANT A PSA ON A WOMAN?” WHICH TURNED OUT TO BE BECAUSE TWO PATIENTS IN THE SAME PRACTICE HAD IDENTICAL SOUNDING NAMES – ONE MAN, ONE WOMAN • THE UNEXPECTED INCREASE OF 240 uMOL/L IN CREATININE IN 12 HOURS WITH K OF 7.2 • (FOLLOWED UP BY WARD VISIT AND FINDING THAT MAN IN NEXT BED HAD HIGH CREA AND K) • NOT SO FUNNY FOR THE FIRST MAN WHO HAD HAD ANTI - K THERAPY AND WAS THEN ON REPLACEMENT K DRIP FOR 2 DAYS • THE UNEXPECTED DECREASE IN CREATININE TO 60 IN OUTPATIENT – SEE NEXT SLIDES

10. COMMENT WHILE THERE IS NOTHING IN THE 0940 SAMPLE ON 1 SEPT TO INDICATE A PROBLEM THERE WAS AN ALERT WITH THE NEXT SAMPLE THAT THE CREATININE HAD RISEN FROM 60 TO 133. IT CAN BE SEEN THAT ALL RECENT SAMPLES FROM THIS PATIENT HAD A CREATININE ROUND 120-140 SUBSEQUENT INQUIRY WITH THE MEDICAL OFFICER IN CHARGE ELICITED THE INFORMATION THAT THE PATIENT HAD NOT HAD A SAMPLE TAKEN ON 1 SEPT THE APPROPRIATE DISCLAIMER WAS ADDED TO THE REPORT

12. PROBLEMS WITH COLLECTIONAND TRANSPORT • HAEMOLYSED SAMPLES • TOO COLD STORAGE LEADS TO PARALYSIS OF Na-K PUMP IN CELL MEMBRANES SO THAT K LEAKS OUT OF CELLS WITHOUT ANY HAEMOLYSIS • TOO WARM STORAGE AND/OR TRANSPORT LEADS TO RAPID GLYCOLYSIS WITH LOW GLUCOSE AND LOW BICARBONATE • DELAY IN TRANSPORT (WE ALLOW NOT > 8 HOURS FROM COLLECTION TO ANALYSIS, PREFER NOT > 6 HOURS) LEADS TO HIGH K, LOW GLUCOSE AND BICARBONATE EVEN WITHOUT OBVIOUS HAEMOLYSIS • PROBLEM WORSE IF WHITE CELL COUNT HIGH • INCORRECT ANTICOAGULANT – Li HEPARIN FOR Li • SEE NEXT SLIDES FOR AN EXAMPLE • COLLECTION FROM DRIP ARMS – SEE NEXT SLIDES

21. COMMENT • THREE DIFFERENT CONTAMINATIONS • 1. K2EDTA, INCREASED K, LOW Ca • 2. INTRAVENOUS IRON INFUSION • 3. HYDROCORTISONE INJECTION BEFORE SAMPLING • 4. NOT ALL ODD RESULTS ARE WRONG – CORTISOL FROM ADRENAL VEIN CANNULATION FOR TUMOUR

31. COMMENT • SEVERAL SAMPLES WITH NORMAL SALINE CONTAMINATION FROM DRIP ARM COLLECTION • MAIN CLUE IS RELATIVELY NORMAL Na WITH ELEVATED Cl, AND OTHER ANALYTES VARIABLY LOW DEPENDING ON PROPORTION OF CONTAMINATION

35. COMMENT • DRIP ARM CONTAMINATION WITH A LOW NaCl SOLUTION – 5% GLUCOSE, N/5 SALINE + 4% GLUCOSE OR N/2 SALINE + 2.5% GLUCOSE AS SOMETIMES USED IN YOUNG CHILDREN • YOU CAN CONFIRM THE SUSPICION BY RUNNING A GLUCOSE, WHICH WILL BE VERY HIGH, BUT BEWARE OF REPORTING THE GLUCOSE AS IT COULD RESULT IN ERRONEOUS DIAGNOSIS OF,TREATMENT FOR, DIABETES MELLITUS!!

39. COMMENT • DRIP ARM CONTAMINATION WITH A KCl SUPPLEMENT IN NORMAL SALINE • BOTH K AND Cl ARE HIGH

44. COMMENT • A SUSPECTED DRIP ARM, BECAUSE THIS WAS A PATIENT WHO HAD AN ABDOMINAL AORTIC ANEURYSM REPAIRED WITH LARGE BLOOD LOSS AND MUCH SALINE INFUSION • POST OPERATION ALBUMIN HALF PREOP LEVEL BUT THIS SAMPLE VERY MUCH LOWER • BLOOD GAS RECORD SHOWS HIGH K WAS CORRECT (SEE NEXT SLIDE) • SUSPICION RAISED BY HIGH Cl AND LOW ALBUMIN

50. COMMENT • CLEARLY SOME CONTAMINATION FROM DRIP – WHERE THIS WAS DONE THEY USE HARTMANN’S SOLUTION RATHER THAN NORMAL SALINE FOR RESUSCITATION. • HARTMANN’S SOLUTION HAS LACTATE (METABOLISED TO BICARBONATE) WHICH DOES NOT SHOW UP ON ROUTINE ANALYSIS AND THE Cl IS ONLY ABOUT 100, NOT 154 AS IN NORMAL SALINE