Dialysis-induced muscle cramps: treatment with hypertonic saline and theory as to etiology.

We postulate that plasma or muscle cell hypo-osmolality may be the major factor or co-factor causing muscle cramps during dialysis, rather than plasma volume contraction alone. The transient hyperosmolality induced with hypertonic saline is therapeutic because it reverses this abnormal state. We feel that the bolus administration of hypertonic saline is of great value in the therapy of dialysis-induced cramps and may be the treatment of choice. It is a rapid and effective means of relieving cramps at no risk to the patient, and without compromising ultrafiltration.