Measuring Blood Lactate Concentration

Note: You are required to wear latex gloves any time you draw or analyze blood!

Preparation for drawing and analyzing blood

• The analyzer should be turned on at least 30 minutes before calibrating.
• Check to see that the buffer bottle (on right rear side with green solution) is at least 25% full. If not, inform instructor.
• Check to see that the waste bottle (second from right in back) is no more than 75% full. If so, inform instructor.
• Set out three of the small plastic cups in a vertical line along one side of the analyzer.
• In the first cup, pour only a few drops of the 5 mmol/L lactate standard
• Half fill the second cup with distilled deionized water from the squirt bottle by analyzer
• Use the third cup as a waste container

Calibrating YSI Sport 1500 Lactate Analyzer

• If analyzer window is not showing SAMPLE-0; CAL-1; PRIME-2, press MENU until this message is indicated
• Press 1 followed by ENTER to begin calibration procedure
• Fill pipette with lactate standard twice; eject standard into waste container
• Fill 25 mL-pipette with lactate standard and when prompted, inject standard in injection port on analyzer. Do NOT force the pipette tip into the analyzer!
• Refill pipette with lactate standard, and when prompted, inject standard a second time so that the analyzer can verify its calibration
• Rinse pipette at least three times with water; eject water into waste container

Drawing blood from a finger stick

• Set out everything that will, or could, be needed before getting ready to draw blood. This includes at least: 2-3 alcohol swaps, several gauze pads, 2-3 lancet needles, 3-4 heparinized capillary tubes, and the autolancet fitted with a clean needle and platform. Leave the needle tip in place until just before lancing the subject. Have all the materials placed so that they can be reached easily and quickly!
• Keep in mind that many subjects are uncomfortable being stuck, so instill confidence in them by knowing-or at least acting like you know-what you are doing. When the time arrives to draw blood, do so quickly and efficiently.
• Position the subject's hand with the palm-side up on a stable object (e.g. the front safety bar of the treadmill). Select either the fourth or fifth fingertip as these are likely to have fewer calluses on them.
• Vigorously scrub the area with an alcohol swap. Allow the area to dry completely before lancing the finger. After disinfecting, don't contaminate the area by touching it. If this occurs, clean the area again.
• Twist off cap to the needle. While holding the subject's finger with one hand, firmly place the autolancet with the other hand against the finger tip and press the release button. Do not squeeze the finger yet. Place the autolancet aside.
• Grab a gauze pad, squeeze the fingertip and wipe off the first drops of blood.
• Again squeeze the fingertip and place an end of the capillary tube in the blood droplets at a slight angle to the fingertip surface-blood will be pulled up the tube through capillary action.
• After capillary tube is nearly filled, set aside and press a gauze pad on puncture site. Instruct subject to hold in place. Should subject begin feeling dizzy or lightheaded, immediately sit subject down and have him/her lean forward with the head over the legs.
• Place the needle, gauze pads, and anything else that touched blood into a sharps container!

Blood drawing tips

• Avoid lifting the capillary tube out of the blood, otherwise air bubbles will be introduced into the tube.
• If a bubble is introduced, it sometimes can be eliminated by holding the capillary tube in a vertical position and letting the blood drain out until the bubble is eliminated.
• If numerous bubbles have been drawn up, discard the tube and begin over with a fresh capillary tube.
• Many times the blood flow is not sufficient. If so, try "milking" the finger and forcing more blood out of the puncture.
• There will be times when the blood flow is inadequate despite efforts of milking the finger. In these instances, re-clean the site and lance the finger again.

Sampling blood for lactate concentration (units shown as mmol/L)

· If analyzer window is not showing SAMPLE-0; CAL-1; PRIME-2, press MENU until this message is indicated

· Press 0 followed by ENTER to begin sampling procedure

· Fill pipette with whole blood from capillary tube. Care must be taken not to take in any bubbles from capillary tube

· When prompted, inject blood in injection port of analyzer. Do NOT force the pipette tip into the analyzer!

· Rinse pipette at least three times with water; eject water into waste container

· If there is sufficient blood in capillary tube, repeat a duplicate analysis