Study for severe conditions
The acid-base balance shows whether the body is able to maintain acid-base balance and how effectively the lungs provide gas exchange. This is one of the key studies in intensive care and emergency conditions: severe pneumonia and respiratory failure, diabetic ketoacidosis, shock, renal failure, poisoning. Based on the combination of pH, pCO2 and bicarbonate, the doctor determines the type of disorder - respiratory or metabolic acidosis or alkalosis - and the degree of its compensation, which directly affects the tactics of intensive care. Blood for a full study is taken from the artery; the capillary version is used in pediatrics.
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.