UTI Flashcards
Q: What is a urinary tract infection (UTI)?
A: UTI is an inflammatory response of the urothelium to bacterial invasion, usually associated with bacteriuria (presence of bacteria in urine) and pyuria (presence of white blood cells in urine).
Q: What is bacteriuria?
A: Bacteriuria is the presence of bacteria in urine, which is normally free of bacteria. It can be symptomatic or asymptomatic, and bacteriuria without pyuria indicates bacterial colonization rather than infection.
Q: What is pyuria?
A: Pyuria is the presence of white blood cells in the urine. Pyuria without bacteriuria warrants evaluation for tuberculosis, stones, or cancer.
Q: What is the difference between uncomplicated and complicated UTIs?
A:
- Uncomplicated UTI: Occurs in a healthy patient with a structurally and functionally normal urinary tract.
- Complicated UTI: Occurs in a patient with a compromised urinary tract or abnormalities that increase infection risk or reduce therapy efficacy.
Q: What are the three categories of UTIs?
A:
1. Isolated infections: First-time infections or those occurring 6 months after a previous infection.
2. Unresolved infections: Bacteria persist in the urine during or after treatment due to resistance to antibiotics.
3. Recurrent infections: Occur after previous infection clearance, caused by either reinfection or bacterial persistence.
Q: What is reinfection in recurrent UTIs?
A: Reinfection occurs when new bacteria from outside the urinary tract cause a recurrent UTI, accounting for more than 95% of all recurrent UTIs in females.
Q: What is bacterial persistence in recurrent UTIs?
A: Bacterial persistence refers to a recurrent UTI caused by the same bacteria from a focus within the urinary tract, such as an infection stone or the prostate.
Q: What are the three routes of UTI infection?
A:
1. Ascending Route: Bacteria enter the urinary tract from the fecal reservoir, ascending through the urethra to the bladder.
2. Hematogenous Route: Infection spreads to the kidney from the bloodstream, usually in patients with bacteremia (e.g., Staphylococcus aureus).
3. Lymphatic Route: Direct extension of bacteria from adjacent organs via lymphatics (e.g., from a severe bowel infection).
Q: What is the most common cause of community-acquired and hospital-acquired UTIs?
A: E. coli is responsible for 85% of community-acquired and 50% of hospital-acquired UTIs.
Q: What are other common pathogens responsible for UTIs?
A:
- Gram-negative Enterobacteriaceae (e.g., Proteus, Klebsiella).
- Gram-positive bacteria (e.g., Enterococcus faecalis, Staphylococcus saprophyticus).
Q: What pathogens commonly cause complicated or nosocomial UTIs?
A:
- E. coli and E. faecalis are frequent causes, along with Klebsiella, Enterobacter, Citrobacter, Serratia, Pseudomonas aeruginosa, and Providencia.
Q: What is acute pyelonephritis?
A: Acute pyelonephritis is inflammation of the kidney and renal pelvis, presenting with chills, fever, costovertebral angle tenderness, dysuria, and increased urinary frequency.
Q: What are the laboratory findings in acute pyelonephritis?
A:
- Increased white blood cells (WBCs), WBC casts, and red blood cells in urine.
- Bacteria (rods or cocci) visible under a microscope.
- Positive urine cultures.
- Polymorphonuclear leukocytosis and elevated C-reactive protein (CRP) in blood tests.
Q: What is the treatment for uncomplicated acute pyelonephritis that does not require hospitalization?
A:
- Oral fluoroquinolones for 7 days.
- TMP-SMX for 14 days.
- Amoxicillin or amoxicillin-clavulanic acid if gram-positive bacteria are suspected.
Q: What is the recommended treatment for complicated infections associated with hospitalization?
A: Aggressive broad-spectrum parenteral therapy, followed by oral therapy for an additional 7-14 days if the patient improves.
Q: What is chronic pyelonephritis?
A: Chronic pyelonephritis refers to a small, contracted, atrophic kidney or coarsely scarred kidney caused by recurrent or chronic bacterial infections.
Q: How is chronic pyelonephritis diagnosed?
A: Diagnosis is made radiologically and pathologically, often revealing a small, scarred, clubbed kidney associated with reflux nephropathy.
Q: What is emphysematous pyelonephritis?
A: Emphysematous pyelonephritis is a necrotizing infection caused by gas-forming uropathogens, usually occurring in diabetic patients and presenting with fever, vomiting, and flank pain.
Q: What is the management for emphysematous pyelonephritis?
A:
- Antimicrobial therapy.
- Treatment of diabetes.
- Surgical drainage or nephrectomy if antimicrobial therapy is ineffective.
Q: What is renal abscess?
A: A renal abscess is a collection of purulent material confined to the renal parenchyma, usually caused by gram-negative organisms and presenting with fever, chills, and flank pain.
Q: How is a renal abscess diagnosed and treated?
A: Diagnosis is made using CT scans, and treatment involves percutaneous or open incision and drainage, along with antimicrobial therapy.
Q: What is pyonephrosis?
A: Pyonephrosis refers to infected hydronephrosis with suppurative destruction of the kidney parenchyma, leading to nearly total loss of renal function.
Q: What is perinephric abscess?
A: A perinephric abscess is a collection of purulent material located within Gerota’s fascia, typically caused by hematogenous seeding or extension from a renal infection.
Q: How is perinephric abscess treated?
A: Treatment involves surgical drainage or nephrectomy if the kidney is nonfunctioning, combined with antimicrobial therapy to control infection.
