Investigations: Essential clinical chemistry
Suneeta Kochhar and William Marshall kick off a new series on basic clinical investigations. They explain what biochemistry results can tell you and how you should interpret them
We have all seen the bits of paper that come back from the laboratory full of endless numbers referring to many different biochemical ions. But what are they used for and what can they tell us?
Clinical biochemistry is important to: help formulate a diagnosis or make treatment decisionsscreen for a conditionhelp with a prognosis and to follow the course of an illnessmonitor the response or side effects of treatment.
Biochemical tests can be done on blood plasma or serum, urine, or cerebrospinal fluid. Tests may be sent to a laboratory for analysis or be done at the bedside using reagent sticks--for example, monitoring blood glucose. The results are then compared with a reference range. If the results are wildly unexpected you may need to repeat the test or reconsider the diagnosis. If you need any advice about choosing the appropriate test, do not be afraid to ask someone more