Final answer:
Passing a double-J ureteral stent is the most appropriate next step to manage the 18-year-old pregnant patient's ureteral obstruction caused by calculi, as it will relieve the obstruction and reduce the risk of further infection and kidney damage.
Step-by-step explanation:
The most appropriate next step in the management of an 18 year-old G1P0 patient at 16 weeks gestation with a right ureteral obstruction secondary to calculi and a persistent fever despite aggressive hydration and broad-spectrum antibiotics is D. Pass a double-J ureteral stent. The symptoms suggest the development of complications such as pyelonephritis, a serious kidney infection, which can arise from obstructions in the urinary tract. A ureteral stent is indicated here to relieve the obstruction, allowing urine to flow from the kidney to the bladder, thereby reducing the risk of further infection and damage to the kidneys.
It is crucial to address the obstruction to prevent damaging pressure to the kidneys and potential further infection. Despite the patient's fever suggesting an ongoing infection, solely changing or continuing with the current antibiotics (B. Change antibiotics and C. Continue present antibiotics) without addressing the physical obstruction may not be sufficient. E. Perform percutaneous nephrostomy may be considered in certain cases, but typically after less invasive methods such as stenting has been attempted or when stenting is not possible.
Given the patient's pregnancy and the importance of managing urological complications swiftly and safely, passing a double-J ureteral stent is often found to be a reliable and safe intervention.