Urinary Tract Disorders

Urinary Tract Disorders May 12, 2005 Lolly Eldridge, M.D. 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 Urinary Tract Infection Lower urethritis cystitis prostatitis Upper pyelonephritis intrarenal and perinephric abscess Also categorized into  Non-catheter associated (commum. acquired)  Catheter associated (hosp. acquired)  Any category may be sx or asx Urinary Tract Infection  Pathogenic microorganisms in urine, urethra, bladder, kidney, prostate  Usually growth > 105 organisms per milliliter  From midstream “ clean catch” urine sample  If sx or from catheter specimen can be significant with 102 or 104 organisms per mL 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 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 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 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 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 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 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 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 Pyelonephritis  Fever  chills, N/V, diarrhea, tachycardia, gen. muscle tenderness  CVAT or tenderness with deep abdominal tenderness  Possibly signs of Gram neg. sepsis ? 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 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 ? 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 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 Diagnosis  Urine culture  Once 105 colonies per mL considered standard for dx but misses up to 50%  Now, 102 to 104 accepted as significant if patient symptomatic  Needed in upper UTI, comp. UTI, and in failed treatment or reinfection  Sensitivities for better tailoring of tx 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 Treatment  Uncomp. cystitis in pregnant patient  Requires longer tx of 7-14 days  Cephalosporin, nitrofurantoin, augmentin, sulfonamides (do not use near term, inc. kernicterus) Asymptomatic Bacteriuria  105 org/mL growth  Empiric treatment of all asymptomatic bacteriuria (ASB) in pregnancy. Screening at first visit.  ASB if untreated = inc. PTD and LBW, 2030% develop pyelo.  Do TOC in 2 weeks and each trimester.  Screen Sickle cell trait each trimester. Twofold inc. risk of ASB ? Asymptomatic Bacteriuria  Treatment failures: repeat tx based on sensitivities for 1 week, then prophylactic therapy for remainder of pregnancy  Prophylaxis: Nitrofurantoin, Ampicillin, TMP/SMX 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 postcoitus  Measures for prevention: voiding after intercourse, good hydration, frequent and complete voiding Treatment of Pyelonephritis - Outpatient  Uncomp. Nonpreg pyelo  Primary – any FQ x 7 days, cipro  Alt. -- Augmentin, TMP/SMX, or oral CSP for 14 days 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 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 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 ? 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 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. ? 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 ? Nephrolithiasis Patient History       Duration, char, location of pain Hx of stones? UTI? Loss of renal function? FHx of stones Solitary/ transplanted kidney Nephrolithiasis Physical Exam  Dramatic CVAT, may migrate as stone moves  Usu. Lacking peritoneal signs  Calculus often in area of maximum discomfort 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 Nephrolithiasis Workup     Plain abd film (KUB) Renal USG IVP Helical CT without contrast (stone protocol) 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 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) ? 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 References  Braunwald et al. (2002) Harrison’s Principals of Internal Medicine (15th 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