Question

What happens if you draw a lavender tube before a green tube when performing a venipuncture?

Answer 1

LAVENDER - TOP TUBE ( EDTA )

THIS TUBE CONTAINS EDTA AS AN ANTICOAGULANT USED FOR MOST HEMATOLOGICAL PROCEDURES.THESE TUBES ARE PREFERRED FOR MOLECULAR TESTS .

NOTE : AFTER THE TUBE HAS BEEN FILLED WITH BLOOD, IMMEDIATELY INVERT THE TUBE 8-10 TIMES TO MIX AND ENSURE ADEQUATE ANTICOAGULATION OF THE SPECIMEN. TO AVOID RBC SHRINKAGE DUE TO EXCESS EDTA ( WITH RESULTING CHANGES IN HCT AND RBC INDICES VALUES ) AND POSSIBLE DILUTIONAL EFFECT , THE TUBES SHOULD BE FILLED WITH THE PROPER AMOUNT OF BLOOD FOR THE SIZE OF TUBE USED.TUBES WITH VARIOUS DRAW VOLUMES ARE AVAILABLE ( 2.0ml, 3.0ml,5.0ml AND 0.75ml MICROVETTES ); TO ASSURE PROPER RATIO OF EDTA TO BLOOD , IT IS RECOMMENDED THAT THE TUBES CONTAIN NO LESS THAN ONE-HALF OF THE STATED VOLUME.

DARK GREEN - TOP TUBE     ( SODIUM HEPARIN )

THIS TUBE CONTAINS SODIUM HEPARIN USED FOR THE COLLECTION OF HEPARINIZED PLASMA OR WHOLE BLOOD FOR SPECIAL TESTS.

NOTE: AFTER THE TUBE HAS BEEN FILLED WITH BLOOD, IMMEDIATELY INVERT THE TUBE 8-10 TIMES TO MIX AND ENSURE ADEQUATE ANTICOAGULATION OF THE SPECIMEN.

ORDER OF DRAW : YELLOW TOP TUBE ( OR ANAEROBIC / AEROBIC BOTTLES )

BLUE

RED

SST ( AKA AS GOLD OR TIGER TOP )

GREEN ( EITHER DARK OR LIGHT )

LAVENDER

GREY

IF TWO DIFFERENT TYPES OF TUBE ARE USED ( e.g. using lavender tube before green tube ) NOT FOLLOWING THE ORDER OF DRAW CONTAMINATION FROM OTHER ADDITIVES COULD INTERFERE WITH TEST RESULTS. TO AVOID CROSS - CONTAMINATION OF ADDITIVES BETWEEN TUBES,BLOOD MUST BE DRAWN IN A SPECIFIC ORDER.THE PROCEDURE IS THE SAME FOR ALL TYPES OF TUBES BEING USED. IT IS VITAL THAT THE ORDER OF DRAW IS FOLLOWED NOT ONLY TO AVOID.CONTAMINATION ,BUT ALSO TO MAKE SURE THAT THE RESULTS ARE ACCURATE.IF LAVENDER TUBE USED FIRST THEN GREEN BOTTLE ,THEN  EDTA MAY WILL CONTAMINATED WITH SODIUM HEPARIN BOTTLE THE TEST RESULT WILL ALTERED.

IF WE DRAW EDTA BOTTLE FIRST THEN GREEN TUBE; THEN EDTA CONTAIN HIGH IN POTTASSIUM AND ALSO BIND CALCIUM WILL ALTER THE RESULT.AND END WITH RESULT OF HYPERKALEMIA OF PATIENTS HAVING HYPOKALEMIA.THE RESULT WILL MASK BY ALTERING THE ORDER OF DRAW.

SO DON'T DRAW LAVENDER BOTTLE FIRST WE HAVE TO DRAW GREEN BOTTLE. IF WE DONE THAT THE RESULT WILL PATIENT HAVE WRONG RESULT OF HYPERKALEMIA.