Urinary tract infections (UTIs), including pyelonephritis

Pregnancy converts every urinary tract infection (UTI), including asymptomatic bacteriuria, into a condition warranting treatment, because untreated bacteriuria in pregnancy raises the risk of pyelonephritis, preterm labor, and low birth weight. Universal early-pregnancy urine culture screening, pregnancy-safe antibiotics (amoxicillin-clavulanate, cephalosporins, or second-trimester nitrofurantoin, never fluoroquinolones), and a lower threshold for hospitalization in pyelonephritis are the pillars of management.

Acute bacterial prostatitis is a sudden bacterial infection of the prostate presenting with local urinary symptoms plus fever, chills, and a tender boggy prostate on exam. Diagnosis is clinical, confirmed by urinalysis and culture, and treatment is empiric antibiotics chosen by patient age and risk, continued for 2-4 weeks.

Nephrolithiasis affects 7-11% of the US population, most often as calcium oxalate stones, and presents as colicky flank pain radiating to the groin with hematuria. Noncontrast CT confirms the diagnosis and stone size drives management: hydration, NSAID/opioid analgesia, and alpha-blocker expulsive therapy for stones under 10 mm, urologic intervention for larger, infected, or obstructing stones.

Benign prostatic hyperplasia is age-related epithelial and stromal growth of the prostate transition zone causing bladder outlet obstruction and lower urinary tract symptoms in older men. Diagnosis rests on history, the AUA/IPSS symptom score, and a symmetrically enlarged, smooth prostate on digital rectal exam; management is staged from observation to alpha-1-blockers, 5-alpha-reductase inhibitors, and surgery.

Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection, identified by an acute rise in SOFA score of 2 points or more in a patient with known or suspected infection. Survival depends on recognizing the pattern early and completing the hour-1 bundle: lactate, blood cultures before antibiotics, broad-spectrum antibiotics such as cefepime 2 g IV every 8 hours, and 30 mL/kg crystalloid for hypotension or a lactate of 4 mmol/L or higher.

Acute kidney injury is a sudden rise in serum creatinine or fall in urine output from prerenal, intrinsic, or postrenal causes, defined and staged by KDIGO criteria. Management targets the underlying cause, corrects volume and electrolyte derangements, and escalates to renal replacement therapy for refractory hyperkalemia, acidosis, volume overload, or uremia.

Renal abscess is a focal, pus-filled collection in the renal parenchyma (intrarenal) or perinephric space, most often complicating unresolved ascending pyelonephritis with gram-negative organisms or hematogenous staphylococcal seeding. Persistent fever and pyuria despite 5-7 days of appropriate antibiotics should prompt CT or ultrasound imaging, with percutaneous or surgical drainage required for perinephric collections and intrarenal abscesses larger than 5 cm.

Emphysematous pyelonephritis is a severe, life-threatening complication of acute pyelonephritis caused by gas-producing bacteria within the renal parenchyma and collecting system, occurring almost exclusively in patients with diabetes or immunocompromise. It requires emergency broad-spectrum antibiotics, aggressive resuscitation, and source control with percutaneous drainage or nephrectomy for extensive or refractory disease.

Urinary tract obstruction (obstructive uropathy) is mechanical blockage of urine flow anywhere from the renal pelvis to the urethral meatus, producing hydronephrosis and, when bilateral or affecting a solitary kidney, postrenal acute kidney injury. Diagnosis is by renal/bladder ultrasound showing hydronephrosis or an elevated post-void residual, and management is prompt decompression, urethral or suprapubic catheterization for bladder outlet obstruction or percutaneous nephrostomy/ureteral stenting for upper-tract obstruction, followed by definitive treatment of the underlying cause, with generally good renal recovery if relieved within 1 to 2 weeks.

Neurogenic bladder is dysfunction of bladder storage or emptying caused by disease or injury of the central or peripheral nervous system, producing either a spastic, high-pressure bladder with urgency incontinence or an atonic, high-volume bladder with retention and overflow incontinence depending on lesion location. Diagnosis rests on the neurologic history and exam with urodynamic testing, and management is centered on a regular, low-pressure emptying regimen, most often clean intermittent catheterization, to protect renal function and prevent infection.