Final answer:
The best way to know how much fluid a patient is retaining is through urine osmolality testing, concentration tests, and the Mosenthal test. Intravenous fluid can be given to dehydrated patients to replenish lost fluids.
Step-by-step explanation:
The best way to know how much fluid your patient is retaining is through urine osmolality testing. This test measures the number of dissolved particles in the urine and provides a more precise measurement than specific gravity. In a concentration test, an injection of pituitrine is given and the specific gravity of the urine is measured. If the specific gravity is 1.020, the kidneys are functioning normally. If it is lower, there may be an abnormality in the kidneys' ability to concentrate urine.
The Mosenthal test is another method to evaluate renal concentrating ability. This test involves collecting urine samples every two hours during the ingestion of a controlled diet. The total volume of urine in a 12-hour period should not be less than 725 ml, and there should be a difference in specific gravity of 0.009 between successive samples.
Intravenous fluid can be given to a dehydrated human patient to replenish lost fluids. The type of fluid given depends on the patient's needs, such as isotonic fluids for mild dehydration or hypertonic fluids for severe dehydration.