The drug of choice for the patient with bipolar disorder is lithium. Lithium toxicity can occur causing severe volume depletion resulting in lethargy, confusion, and decreased level of consciousness. Treatment involves aggressive fluid resuscitation to prevent circulatory collapse. Therefore, the nurse anticipates an order to provide 2 L of normal saline at 200 mL/h followed by 0.45% normal saline at 100 mL/h with diuretics. Hypertonic saline, lithium, and diuretics as initial treatment will all worsen the client’s symptoms.