Basic Concepts of Fluid and Electrolyte Therapy

Chloride
Despite the fact that serum chloride measurements do not increase
the cost of biochemical screening, many laboratories no longer report
serum Cl – . However, in the differential diagnosis of acidosis, particularly
in patients receiving 0.9% saline (with its high chloride content
in relation to plasma) intravenously, it may be an important parameter
to detect the development of hyperchloraemic acidosis in which
the plasma chloride is elevated and bicarbonate reduced.
Bicarbonate
Venous or arterial bicarbonate concentrations indicate acid-base
status as described above.
Serial data charts
The sticking of individual reports in the back of notes makes it difficult
to detect clinically important trends. The only satisfactory way of
monitoring patients with fluid and electrolyte problems is the use of
serial data charts on which, each day, important data are recorded, so
that changes and trends can be seen at a glance. Our own practice is
to record daily weight, serum biochemistry and haematology, etc., on
charts, which are kept by the patient’s bedside. Although transferring
data to such charts is time consuming, it reduces time taken in clinical
decision making as well as improving the accuracy of prescribing.
It also compels one to look at reports and think carefully about their
significance.
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