CC#4: Urinary Tract Infections in Pregnant Individuals Flashcards
Entities that comprise UTI (3)
ASB, symptomatic acute cystitis, pyelo
Percentage of pregnancies affected by UTI of some sort
~8%
Most common bacterial pathogen isolated from pregnant pts w/ UTI
E. coli
Pregnancy risks associated w/ presence of UTI (2)
PTD, LBW
Potential serious maternal complications of pyelo (3)
Sepsis, DIC, ARDS
Percentage of pregnant pts in whom ASB is identified
2-10%
Percentage of pregnant pts in whom acute cystitis is diagnosed; percentage of pregnant pts in whom pyelo is diagnosed
~1-2%; ~1-2%
When is pyelo most likely to occur?
2nd tri
Anatomic/Physiologic changes during pregnancy that can predispose pts to UTIs
Progesterone-induced ureteral dilation and mechanical compression of ureter by gravid uterus > increased residual volume in bladder and urinary stasis > VUR > increased risk of bacterial colonization and ascending infection
When should screening for ASB be performed; how should screening for ASB be performed?
At an early prenatal visit; w/ UCx
Why is screening for ASB indicated?
Because it has been shown to be associated w/ a decrease in pyelo
Are routine UDips at each PNV beneficial?
No (and also not sufficiently sensitive to detect ASB)
Reason that routine UDips are not beneficial/sensitive
Both midstream and midstream clean-catch specimens commonly have at least moderate contamination in pregnant pts (and because of increased risk of culture contamination w/ advancing gestational age, attempts at repeat collection may be futile)
Is additional screening indicated after initial negative screening UCx; why?
No; residual risk of pyelo is low
Maternal condition that may benefit from more frequent UTI screening; maternal conditions that do not merit additional screening for ASB beyond initial screen (2)
SCT; DM, SCI
Reason additional screening is not recommended for pts w/ SCI (3)
ASB seems to be protective against symptomatic UTI, tx can precipitate symptomatic UTI, tx can contribute to antimicrobial resistance
At what cutoff is ASB clinically significant; what do lower levels represent?
CFU >100,000 (ie 10^5); contamination from vulva/vagina
General tx recs for ASB
5-7 day course of abx that has demonstrated efficacy against most common bacteria in ASB/UTI (ie E. coli, Proteus, Klebsiella)
Abx exception to 5-7 day course rec for tx of ASB
Fosfomycin (has good efficacy as single-dose tx for both ASB and symptomatic acute cystitis)
When should tx be started for ASB?
Once bacteriuria is confirmed (and then altered if abx sensitivities show that isolated bacteria are not sensitive to initial choice of tx)
When should GBSbu be treated; what do lower levels indicate?
If CFU >100,000; do not require tx but should be noted as indication for intrapartum GBS ppx
Components of normal vulvovaginal flora that should not be treated (3)
Lactobacilli, Corynebacteria, coagulase-neg Staph)
Is TOC or repeat screening indicated s/p tx of ASB?
Evidence does not make rec
Common presenting sxs of acute cystitis (4)
Dysuria, hematuria, frequency, nocturia (which frequently overlap w/ common pregnancy sxs)
Most useful tool for triage of UTI sxs
UA
Definition of pyuria on UA
> 5 WBC/HPF, or presence of leuk esterase
Sensitivity of pyuria on UA; general specificity of pyuria on UA
97%; lower (because WBCs could be contaminants of vulva/vagina)
Specificity of nitrites on UA; general sensitivity of nitrites on UA
94-98%; lower (because not all bacteria produce nitrites)
NPV of UA w/ neither leuk esterase nor nitrites present
78-98%
Can UTI be excluded if UDip is entirely normal?
Yes
When can abx tx be initiated for symptomatic acute cystitis?
In presence of positive UA, for symptomatic relief
Situation in which empiric tx may be considered for symptomatic acute cystitis
When urine specimens cannot be collected and pt described new-onset dysuria and frequency
Should UCx be obtained in suspected symptomatic acute cystitis; why?
Ideally, yes; to confirm dx and direct abx therapy
Cutoff at which tx is indicated in symptomatic acute cystitis
Reasonable to treat CFU as low as 100 of a single organism (unlike in ASB) if sxs are present
Sensitivity of UDip w/ leuks; specificity of UDip w/ leuks; PPV of UDip w/ leuks; NPV of UDip w/ leuks
72-97%; 41-86%; 43-56; 82-91
Sensitivity of UDip w/ nitrites; specificity of UDip w/ nitrites; PPV of UDip w/ nitrites; NPV of UDip w/ nitrites
19-48%; 92-100%; 50-83; 70-88
Sensitivity of UDip w/ leuks or nitrites; specificity of UDip w/ leuks or nitrites; PPV of UDip w/ leuks or nitrites; NPV of UDip w/ leuks or nitrites
46-100%; 42-98%; 52-68; 78-98
Sensitivity of UDip w/ protein >3+; specificity of UDip w/ protein >3+
96%; 87%
Sensitivity of UDip w/ protein >1+; specificity of UDip w/ protein >1+
91-100%; 65-99%
Sensitivity of microscopy w/ >5 WBC/HPF; specificity of microscopy w/ >5 WBC/HPF; PPV of microscopy w/ >5 WBC/HPF; NPV of microscopy w/ >5 WBC/HPF
90-96%; 47-50%; 56-59; 83-95
Sensitivity of microscopy w/ >5 RBC/HPF; specificity of microscopy w/ >5 RBC/HPF; PPV of microscopy w/ >5 RBC/HPF; NPV of microscopy w/ >5 RBC/HPF
18-44%; 88-89%; 27; 82
Sensitivity of microscopy w/ bacteriuria; specificity of microscopy w/ bacteriuria; PPV of microscopy w/ bacteriuria; NPV of microscopy w/ bacteriuria
46-58%; 89-94%; 54-88; 77-86
How does PPV change in a low-prevalence population; how does NPV change in a low-prevalence population?
Decreases; increases
General tx recs for acute cystitis
5-7 day course of abx (w/ poss modification based on UCx sensitivities)
Macrobid tx regimen for ASB and acute cystitis
100mg PO q12h x5-7 days
Considerations for macrobid tx for UTI in pregnancy (2)
Reasonable to offer in 1st tri only if no appropriate alternative available, avoid for pyelo 2/2 inability to reach therapeutic levels in kidney
Keflex tx regimen for ASB and acute cystitis
250-500mg PO q6h x5-7 days
ASB/acute cystitis tx recs for pts w/ low-risk beta-lactam allergy; ASB/acute cystitis tx recs for pts w/ high-risk beta-lactam allergy
Tx w/ cephalosporins appropriate; alternative regimen recommended
Bactrim tx regimen for ASB and acute cystitis
800/160mg PO q12h x5-7 days
Considerations for Bactrim tx for UTI in pregnancy (2)
Reasonable to offer in 1st tri only if no appropriate alternative available, avoid initiating prior to UCx results available in areas w/ >20% resistance to Bactrim
Fosfomycin tx regimen for ASB and acute cystitis
3g PO once
Consideration for fosfomycin tx for UTI in pregnancy
Avoid for pyelo 2/2 inability to reach therapeutic levels in kidney
Amoxicillin tx regimens for ASB and acute cystitis (2)
500mg PO q8h x5-7 days, 875mg PO q12h x5-7 days
Consideration for amoxicillin/amoxicillin-clavulanate tx for UTI in pregnancy
High degree of resistance in E. coli, so avoid if initiating tx before UCx results available
Amoxicillin-clavulanate tx regimens for ASB and acute cystitis (2)
500mg PO q8h x5-7 days, 875mg PO q12h x5-7 days
Reasonable first-line option for tx of lower UTIs; advantages of this med (3)
Macrobid; low resistance rates, effective against many pathogens common in pregnancy, achieves therapeutic levels in bladder
Reason why Macrobid and Bactrim are ideally avoided in 1st tri (unless no appropriate alternatives available)
Some data suggest poss congenital anomalies
Pts in whom Macrobid should be avoided; why?
G6PD deficiency; use can be associated w/ pulm toxicity and hemolytic anemia
Is single-dose fosfomycin as effective as other longer tx regimens?
Yes
Appropriate surveillance strategies s/p tx for acute cystitis (2)
Repeat UCx in 1-2 weeks s/p abx tx, clinical monitoring (w/ UCx only if sxs recur)
Definition of recurrent UTI; percentage of pregnancies this occurs in
2+ UTIs diagnosed during pregnancy; 4-5% of pregnancies
Abx ppx strategies for recurrent UTI in pregnancy (2)
Continuous, postcoital
How to administer postcoital abx ppx
Abx taken only before or after vaginal intercourse (shown to have decrease in adverse events related to abx use)
How to administer continuous abx ppx
Abx taken once daily
Common continuous suppressive abx regimens (2)
Macrobid 100mg PO daily, Keflex 250-500mg PO daily
Definition of pyelo
Infection of kidney thought to arise from ascending bacteria from bladder to upper urinary tract
Presenting signs/sxs of pyelo (5)
Fever, N/V, flank pain, CVA tenderness, renal US abnormalities
Poss CBC findings during pyelo (4)
Elevated WBC, bandemia, thrombocytopenia, anemia
CBC finding highly correlated w/ adverse outcomes (ie ICU admission)
Abnormalities in multiple cell lines
Common pyelo presentation that should prompt timely abx tx
Abnormal UA w/ fever, flank pain, CVA tenderness
Poss alternative presentations of pyelo (4)
Preterm ctxs/PTL, sepsis, acute renal insufficiency, ARDS
Ddx for pyelo-like sxs in pregnancy (4)
Nephrolithiasis, renal abscess, urosepsis w/o pyelo, chorio
Recommended labs when evaluating pt w/ suspected pyelo (3)
Midstream/catheterized urine specimen for UA, microscopy, UCx prior to initiation of abx (though tx should not be delayed while awaiting UCx results)
Are BCx clinically useful in setting of suspected pyelo?
No
Initial inpatient management principles in tx of pyelo (2)
Fluid hydration, IV abx
What factors determine initial abx regimen for pyelo (2)?
Local susceptibility data, recent abx use by pt
First-line abx for pyelo (2)
Broad spectrum beta-lactams w/ consideration of adding aminoglycosides (ie ampt + gent), or single-agent cephalosporins (ie Rocephin or cefepime)
Pyelo tx recs for pts w/ low-risk beta-lactam allergy; pyelo tx recs for pts w/ high-risk beta-lactam allergy
Tx w/ cephalosporins appropriate; alternative regimen such as aztreonam an ID consult should be pursued
Amp + gent regimen for tx of pyelo
Amp 2g IV q6h + gent 1.5mg/kg IV q8h (or 5mg/kg IV q24h)
Rocephin regimen for tx of pyelo
1g IV q24h
Cefepime regimen for tx of pyelo
1g IV q24h
Aztreonam regimen for tx of pyelo
1g IV q8-12h
Percentage of pyelo pts w/ clinical improvement (afebrile >24h and improvement in sxs) within 48-72h after initiating IV abx
75-95%
Further evaluation principle for pts not demonstrating clinical improvement within 72h
R/o bacterial resistance and/or other urinary tract pathology
Most common reason for pyelo tx failure
Abx resistance
Ongoing tx recs after clinical improvement of pyelo w/ IV abx
Transition to appropriate PO abx (based on UCx sensitivity) for 14-day abx course
Is repeat UCx indicated after completion of abx for pyelo?
Yes, to confirm no residual infection
What should be pursued if antimicrobial-resistant organisms are identified?
ID consult in order to determine abx course and duration of tx
Percentage of pts who experience recurrence of pyelo prior to delivery
25%
Suppression abx regimens s/p pyelo tx (2); recommended duration of tx
Macrobid 100mg PO daily, Keflex 250-500mg PO daily; until 4-6 weeks PP
Lab testing consideration for pts w/ recurrent pyelo in pregnancy
Routine monthly UCx
