Reasons for this patients pain could be recurrent UTIs, kidney stones, pyelonephritis, or cystitis. Her complaint of flank pain can be a sign of kidney stones or other issues with organs in that region. Flank pain with chills, blood noted in urine, feeling of frequent urination, an urgency to urinate, or fever can be signs of renal complications. Laboratory workup or tests for this patient would be CBC, CMP, H&H, renal ultrasound, blood cultures, and possibly CT scans and or MRI. Feasible causes of recurrent UTIs include reactions to medications, irritating soaps/hygiene products, and frequent sexual intercourse that is introducing bacteria. 
Prerenal acute renal failure is due to inadequate renal perfusion. This can be caused by sepsis, diarrheal illness, cardiovascular disease, decompensated liver disease, or inadequate fluid intake. (Malkina, 2020). 
Intrarenal acute renal failure is due to intrinsic kidney disease or damage caused by acute tubular necrosis, acute glomerulonephritis, and nephrotoxins. (Malkina, 2020). 
Postrenal acute renal failure is due to various types of obstruction in the voiding and collecting parts of the urinary system. (Malkina, 2020). Obstruction ultrafiltrate increases pressure in the urinary space of the glomerulus, reducing GFR. Obstruction affects renal blood flow increasing the flow and pressure in the glomerular capillary by reducing afferent arteriolar resistance. An example is when there is an enlarged prostate causing an obstruction reducing or eliminating the bladder to have an outlet to release urine. This can be a sudden onset and is common.  
As noted in announcements this week’s discussion will also include PDSA model schemata for case studies. For the PDSA for these cases, I would plan accordingly.  
Plan: Collect more information like labs, history, physical, studies, and a list of current medications. 
Do:  Use results to form a diagnosis and form a plan of care and patient education. This includes treatment with medications.  
Study:  See if treatment, plan of care, and education were able to work to treat the patient adequately.  
Act: If treatment was unsuccessful then reformulate with the second plan of care.  Reevaluate the first diagnosis and other possible new diagnoses. Retreat with alternative medications, plan of care, and patient education. If treatment was successful evaluate treatment positives with specifics as future resources.