Final answer:
For a patient in the oliguric phase of AKI with 400 mL of total output in 24 hours, the fluid allocation for the next 24 hours would be 1000 mL, taking into account the minimum requirement for kidney function and replacement of losses.
Step-by-step explanation:
The fluid allocation for a patient in the oliguric phase of acute kidney injury (AKI) who has excreted 300 mL of urine and 100 mL of other losses in the past 24 hours would be calculated by first replenishing the loss and then adding the minimum to maintain normal bodily functions. The daily fluid allocation thus can be determined as follows:
C. 1000 mL.
Since the patient excreted 300 mL of urine and 100 mL of other losses, the total output is 400 mL. Starting with this base, we would replace the losses. Additionally, the kidneys excrete a minimum of 500 mL/day to eliminate wastes efficiently. Therefore, the minimum fluid allocation should equal the output of 400 mL plus the minimum requirement of 500 mL, which totals to 900 mL. To round this up and account for any measurement errors or insensible losses, a safe fluid allowance would be 1000 mL over the next 24 hours.
This calculation maintains a balance that aims to prevent further dehydration without overwhelming the kidneys, considering the oliguric phase of AKI where the urine output is already low. The kidney function is preserved by avoiding an overload of fluids, which is crucial in managing AKI.