Final answer:
To reach dry weight, the patient must lose approximately 498.7 mL/hour over a four-hour treatment.
Step-by-step explanation:
To calculate the mL/hour the patient must lose to reach dry weight, we need to find the difference between the pre-treatment weight and the dry weight, and divide it by the duration of the treatment.
The difference in weight is 158.4 lb - 154.0 lb = 4.4 lb. Since the treatment is for four hours, the patient must lose 4.4 lb / 4 hours = 1.1 lb/hour.
To convert the weight from pounds to mL, we need to know the density of water, which is approximately 1 g/mL. Therefore, 1.1 lb is equal to 1.1 lb * (454 g/1 lb) * (1 mL/1 g) = 498.7 mL. So, the patient must lose approximately 498.7 mL/hour to reach dry weight.