This document discusses urinary tract disorders including urinary tract infections (UTIs) and nephrolithiasis (kidney stones). It describes the types and causes of UTIs, risk factors, clinical presentations, diagnostic methods, and treatment options. It also covers the risk factors, workup, and treatment approaches for nephrolithiasis including surgical interventions and preventative measures.

1. Urinary Tract Disorders

2. Objectives Distinguish types of UTI, including bacteriuria, urethritis, cystitis, and pyelonephritis Describe the pathophysiology related to UTI, such as organisms and host factors Describe pathophys of common forms of nephrolithiasis, including risk factors for development of nephrolithiasis Describe typical clinical presentations, and elicit a pertinent history, in a patient with UTI or nephrolithiasis Describe the diagnostic methods and diagnostic criteria for the various types of UTI Summarize the methods used for dx of nephrolithiasis Describe modes of therapy for acute, chronic, and complicated UTI, including prophylaxis for recurrent infection Summarize therapeutic options for nephrolithiasis, and strategies to prevent recurrence

3. Urinary Tract Infection Lower urethritis cystitis prostatitis Upper pyelonephritis intrarenal and perinephric abscess

4. Also categorized into Non-catheter associated (commum. acquired) Catheter associated (hosp. acquired) Any category may be sx or asx

5. Urinary Tract Infection Pathogenic microorganisms in urine, urethra, bladder, kidney, prostate Usually growth > 10 5 organisms per milliliter From midstream “ clean catch” urine sample If sx or from catheter specimen can be significant with 10 2 or 10 4 organisms per mL

6. Etiology Most common is Gram neg. bacteria E. coli = 80% of uncomp. acute UTI Proteus – assoc. with stones Klebsiella – assoc. with stones Enterobacter Serratia Pseudomonas

7. Etiology Gram pos. cocci Staphylococcus saprophyticus 10-15 % acute sx UTI in young females Enterococci – occas. in acute uncomp. cystitis Staphylococcus aureus – assoc. with renal stones, instrumentation, increased susp. of bacteremic kidney infection

8. Etiology Urethritis from chlamydia, gonorrhea, HSV – acute sx female with sterile pyuria Ureaplasma urealyticum Candida or other fungal species – commonly assoc. with cath. or DM Mycobacteria

9. Pathogenesis Usually ascent of bacteria from urethra to bladder to kidney Vaginal introitus, distal urethra colonized by normal flora Gram negative bacilli from bowel may colonize at introitus, periurethra

10. ? Predisposing conditions to UTI Female Short urethra, proximity to anus, termination beneath labia Sexual activity Pregnancy 2-3% have UTI in preg, 20-30% with asx bacteriuria  may lead to pyelo Increased risk of pyelo = decreased ureteral tone, decreased ureteral peristalsis, temp. incomp of vesicoureteral valves

11. ? Predisposing conditions Neurogenic bladder dysfunction or bladder diverticulum (incomplete emptying) Age - Postmenopausal women with uterine or bladder prolapse (incomplete emptying), lack of estrogen, decreased normal flora, concomitant medical conditions such as DM Vesicoureteral reflux Bacterial virulence Genetics Change in urine nutrients, DM, gout

12. Urethritis ? Acute dysuria, frequency Often need to suspect sexually transmitted pathogens esp. if sx more than 2 days, no hematuria, no suprapubic pain, new sexual partner, cervicitis

13. Cystitis Sx: frequency, dysuria, urgency, suprapubic pain Cloudy, malodorous urine (nonspec.) Leukocyte esterase positive = pyuria Nitrite positive (but not always) WBC (2-5 with sx) and bacteria on urine microscopy

14. Pyelonephritis Fever chills, N/V, diarrhea, tachycardia, gen. muscle tenderness CVAT or tenderness with deep abdominal tenderness Possibly signs of Gram neg. sepsis

15. ? Pyelonephritis Leukocytosis Pyuria with leukocyte casts, and bacteria and hematuria on microscopy Complications: sepsis, papillary necrosis, ureteral obstruction, abscess, decreased renal function if scarring from chronic infection, in pregnancy – may increase incidence of preterm labor

16. Catheter-Associated ? Urinary Tract Infections 10-15% of hosp. patients with indwelling catheter develop bacteriuria Risk of infection is 3-5% per day of catheterization UTI after one-time bladder cath approx. 2% Gram neg. bacteremia most significant complication of cath-induced UTI Greater antimicrobial resistance

17. Diagnosis of UTI History Physical exam Lab Urinalysis with micro = WBC, bacteria Urine culture Sensitivities of culture for tailored antibiotic therapy May dx acute uncomp. cystitis based on hx, PE, and UA alone, no need for culture to treat

18. Diagnosis Urinalysis Leuk. Esterase pos. = pyuria Nitrite pos. from urea prod. bact. (but not always) Micro – WBC (even 2-5 in patient with sx) Micro – Bacteria

19. Diagnosis Urine culture Once 10 5 colonies per mL considered standard for dx but misses up to 50% Now, 10 2 to 10 4 accepted as significant if patient symptomatic Needed in upper UTI, comp. UTI, and in failed treatment or reinfection Sensitivities for better tailoring of tx

20. Treatment ? Uncomp. cystitis with less than 48 hours of sx, non-pregnant, usu. 3 days tx sufficient Bactrim DS, Septra DS Cipro or other FQ (avoid in preg.) Nitrofurantoin (7 days) Augmentin Bladder analgesis, Pyridium

21. Treatment Uncomp. cystitis in pregnant patient Requires longer tx of 7-14 days Cephalosporin, nitrofurantoin, augmentin, sulfonamides (do not use near term, inc. kernicterus)

22. Asymptomatic ? Bacteriuria 10 5 org/mL growth Empiric treatment of all asymptomatic bacteriuria (ASB) in pregnancy. Screening at first visit. ASB if untreated = inc. PTD and LBW, 20-30% develop pyelo. Do TOC in 2 weeks and each trimester. Screen Sickle cell trait each trimester. Twofold inc. risk of ASB

23. Asymptomatic Bacteriuria Treatment failures: repeat tx based on sensitivities for 1 week, then prophylactic therapy for remainder of pregnancy Prophylaxis: Nitrofurantoin, Ampicillin, TMP/SMX

24. Treatment Recurrent uncomp. UTI 3 or more episodes in one year, 2 in 6 months Bactrim DS ( or septra DS) QD for 3-6 months once infection eradicated, self-admin. Single dose at symptom onset or one DS tab post-coitus Measures for prevention: voiding after intercourse, good hydration, frequent and complete voiding

25. Treatment of Pyelonephritis -- Outpatient Uncomp. Nonpreg pyelo Primary – any FQ x 7 days, cipro Alt. -- Augmentin, TMP/SMX, or oral CSP for 14 days

26. Treatment of Pyelonephritis – Inpatient ? Treat IV until patient is afebrile 24-48 hours. Then, complete 2 week course with PO meds Use FQ or amp/gent or ceftriaxone or piperacillin If no improvement on IV, consider imaging studies to look for abscess or obstruction All pregnant patients with pyelo get inpatient tx, appropriate IV antibiotics immediately

27. Treatment of Complicated UTI Catheter related Amp/gent or Zosyn or ticaricillin/clav or imipenem or meropenem x 2-3 weeks Switch to PO FQ or TMP/SMX when possible Rule out obstruction Watch out for enterococci and pseudomonas

28. Nephrolithiasis ? Supersat. of urine by stone forming constituents Crystals of foreign bodies act as nidi Freq. stone types: Calcium (most common), struvite, oxalate, uric acid, staghorn Risk factors: metabolic disturbances, previous UTI, gout, genetic

29. Nephrolithiasis Incidence = 2-3% Morbidity Obstruction  pain Chronic obstruction, may be asx  loss of renal function Hematuria (rarely dangerous by itself) Dangerous combo = obstruction + infection

30. Nephrolithiasis ? More prev. in Asians and whites Males > females, 3:1 Struvite stones – from infection, increased in females Ages 20-49 Recurrent Uncommon after 50 y.o.

31. Nephrolithiasis Patient History ? Often dramatic pain, poss. infection, hematuria Even nonobst. May cause sx Bladder irritating sx Renal colic because of stone in ureter Severe, undulating cramps because of ureter peristalsis, sever pain, N/V Pain may migrate

32. Nephrolithiasis Patient History Duration, char, location of pain Hx of stones? UTI? Loss of renal function? FHx of stones Solitary/ transplanted kidney

33. Nephrolithiasis Physical Exam Dramatic CVAT, may migrate as stone moves Usu. Lacking peritoneal signs Calculus often in area of maximum discomfort

34. Nephrolithiasis Workup Urinalysis Evid. Of hematuria and infection 24-hour urinalysis helpful in identifying cause CMP, uric acid, CBC Calcium, oxalate, uric acid in the 24 hour urine

35. Nephrolithiasis Workup Plain abd film (KUB) Renal USG IVP Helical CT without contrast (stone protocol)

36. Nephrolithiasis Treatment If no obstruction or infection, stones < 5-6mm may likely pass Restore fluid volume if dehyd. Analgesics – narcotics, nsaids Antiemetics Occasionally nifedipine (CCB) to relax ureteral smooth muscle and prednisone used Urology consult

37. Nephrolithiasis Treatment ? Surgical intervention (call urology) Extracorporeal shock-wave lithotrypsy (not in pregnancy) Ureteral stent Percutaneous nephrostomy Ureteroscopy Indications = pain, infection, obstruction Contraindications = active untx infection, uncorrected bleeding diathesis, pregnancy (relative)

38. Nephrolithiasis Prophylaxis ? Increase fluid intake (2 liters per day of UOP) 24 hour urine, eval calcium, oxalate, uric acid to determine dietary prevention metabolic tests to determine cause (Ex: hyperparathyroidism) Decrease salt intake

39. References Braunwald et al. (2002) Harrison’s Principals of Internal Medicine (15 th edition). New York: McGraw-Hill. Ling F., & Duff, P. () Obstetrics and Gynecology, Principles for Practice. 2001. New York: McGraw-Hill. www.emedicine.com ACOG Practice Bulletin, Clinical Mgmt Guidelines (No 23, Jan 2001). Antibiotic Prophylaxis for Gyn Procedures Brankowski et al. The Johns Hopkins Manual of Obstetrics and Gynecology. 2002. Philadelphia: LWW The Sanford Guide to Antibiotic Therapy