Marker of severity of condition
When tissues lack oxygen, cells switch to the anaerobic pathway for energy production, the byproduct of which is lactate. Its level in the blood is one of the most informative indicators of the severity of the condition in shock, sepsis, severe cardiac and respiratory failure, and the dynamics of decrease during treatment serves as an objective criterion for the effectiveness of intensive care. A separate indication is monitoring when taking metformin in patients with diabetes and impaired renal function: a rare but dangerous complication is lactic acidosis. In sports medicine, lactate is used to determine the threshold of anaerobic metabolism. Important: blood is taken without prolonged application of a tourniquet or using a fist - otherwise the result will be overestimated.
Why preparation is so important
The laboratory result is a number, but the correct number can only be obtained if the rules are followed. Eating changes the levels of glucose, lipids and a number of enzymes significantly; physical activity the day before increases CK and AST; smoking affects hormones; time of day is critical for cortisol and testosterone.
Therefore, a “bad analysis” often turns out to be a consequence of impaired preparation, and not an illness, and leads to unnecessary examinations and prescriptions.
General rules for donating blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
- for hormones in women, take into account the day of the cycle
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important. It is up to the physician to interpret the analysis: an isolated indicator without a clinical context is often misleading.