Agenda Background Pathophysiology Incidence Classifications Clinical Approach Workup

Agenda Background Pathophysiology Incidence Classifications Clinical Approach Workup Treatment

Background Hormonal and mechanical changes put even a woman who is not pregnant at risk for urinary stasis and ureterovesical reflux along with a short urethra and difficulty with hygiene due a distended, pregnant belly, cause urinary tract infections (UTIs) to become a common occurrence for pregnant women.

Background UTI is defined as the presence of at least 100, 000 organisms per milliliter of urine in an asymptomatic patient or as more than 100 organisms per milliliter of urine in a symptomatic patient with accompanying pyuria (>7 WBCs/m. L).

Background Vaginal infections can cause or mimic UTIs, which are common in women of reproductive years, affecting 25 -35% of women aged 20 -40 years. The main method of discriminating between the 2 depends upon vaginal and urinary cultures

Pathophysiology Hormonal Mechanical Hypertrophy of the kidney

Hormonal Progesterone relaxation of on smooth muscles of the whole tract dilatation of the pelvis & ureter & Vasicouretral reflux stasis of urine predispose to infection

Mechanical By gravid uterus, on : Bladder wall get pushed up into the abdomen : intravesical pr urine stasis frequency of urination Stress incontinence 50% in primigravida. Less in multigravida (unknown cause). ureter at pelvic brim obstruction of the ureters hydronephrosis. Hydronephrosis & hydro-ureter is more in right side (50%) b/c of dextro rotation of uterus to the right side.

Hypertrophy of the kidney Structural Hypertrophy Functional Hypertrophy: Renal Blood Flow GFR by 40% Renal plasma volume by 60% BUN & serum creatinine Glucosuria “sometimes due to filtration by the kid” RBF & GFR tubular re-absorption loss of glucose, amino-acids…etc Na and fluid retention. # All these changes return back to normal 4 months after delivery:

Incidence In the US: The prevalence of ASB in pregnant women is 2. 5 -11% Internationally: higher prevalence of bacteriuria in Caucasian women during pregnancy (6. 3%) when compared to Bangladeshi women (2%)

Incidence prevalence of UTI during pregnancy is 28. 7% in whites and Asians, 30. 1% in blacks, and 41. 1% in Hispanics. Prevalence increases with age, low socioeconomic status, sexual activity, multiparity, and untreated pathologies

Classifications Asymptomatic bacteriuria Cystitis Pyelonephritis

Asymptomatic bacteriuria Definition: Presence of actively multiplying bacteria (100000/ml) without symptoms Incidence: 5 – 10%. (2 -7%) 2 x more in sickle cell trait 3 x more in diabetes

Asymptomatic bacteriuria Most common organisms: Usually comes form the peri-anal area “G-ve “ E. coli 77% Klebsiella Proteus. Others: Pseudomonus, Staphylococcus aureus, enterobacter.

Asymptomatic bacteriuria Predisposing factors : DM Race Multiparous Sickle cell trait “not disease” chronic cystitis or chronic pyelonephritis

Asymptomatic bacteriuria Diagnosis: History of recurrent attacks & recurrent analgesics intake. Urine will show >/= 105/ml urine bacteria Isolation of organism

Asymptomatic bacteriuria Complications (if not treated) Symptomatic UTI “frank cystitis” Pyelonephritis “i. e. active infection” in 30% Preterm labor. in ¼ Anemia. IUGR. PET.

Cystitis Intro: Less benign than asymptomatic 40% if not treated will end up by Pyelonephritis Incidence 1% rare in pregnancy

Cystitis Presentation: Lower abdominal pain Dysuria Urgency Frequency No systemic manifestations

Cystitis Urinalysis: WBC RBC Micro & Macro Hematuria

General Management of Asymptomatic Bacteruria & Cystitis Hydration to wash the bacteria Antibiotics: Should do the culture first, otherwise the picture will be masked Types of Antibiotics given: Ampicllin Amoxacillin Augmentin Nitrofurantoin Regimens: Single dose regimen good for compliance 3 day regimen full coarse for 10 days If persists (i. e. +ve culture), continue Ab daily till delivery as Nitrofurantoin OD

Pyelonephritis Intro Most serious complication in pregnancy May cause renal dysfunction and even renal failure 40% is ascending Incidence 1 – 2%. Most common organisms G-ve organisms

Pyelonephritis Symptoms: Symptoms vary; it could be asymptomatic or patient present with septicemia and shock. Sudden onset 50% unilateral on the right side 25% bilateral

Pyelonephritis General 1. Fever, may reach 420 C, or even Hypothermia 2. Chills & rigors 3. N/V. 4. Malaise. 5. Anorexia *these are due to the endotoxin released in the blood Specific 1. 2. 3. 4. Flank Pain Dysurea Frequency Urgency. *Examination should include simple percussion on the costophrenic angle to elicit the pain

Pyelonephritis Investigations: CBC anemia , thrombocytopenia RFT GFR & Creatinine clearance, serum creatinine MSU Significant bacteruria, Proteinurea , RBC cast, Urine culture to isolate the organism (mostly E. coli).

Pyelonephritis Differential Diagnosis: Labour Chorioamnionitis Acute abdomen as Appendicitis Ectopic pregnancy “usually present early” Abruption placenta esp. Concealed type Fibroid

Pyelonephritis Effect on fetus: the incidence of abortion. the incidence of prematurity. the incidence of prenatal morbidity and mortality

Management Should be more aggressive Admit to hospital “ some pt can be managed as outpatients” & Bed rest. Rehydration. Antibiotics: Empirical treatment with IV antibiotics Types of Antibiotics given: Ampicllin Cloxacillin 3 rd generation cephalosporins Gentamycin Check RFT Nitrofurantoin Shift to oral Ab after 24 -48 hr when she is afebrile Repeat culture after 2 weeks , b/c it might persist If still no response then have to investigate the patient with IVP even when she’s pregnant (One x-ray will not harm her).

WORKUP Lab Studies. Imaging Studies. Other Tests. Histology

Lab Studies 1/4 Urine specimen collection midstream catheterization Urine culture A colony count of 100, 000 colony-forming units (CFUs) per milliliter historically has been used to define a positive culture result

Lab Studies 1/4 Urinalysis Positive results for nitrites, leukocyte esterase, WBCs, RBCs, and protein are suggestive of a UTI Urinalysis has a specificity of 97 -100%, but it has a sensitivity that ranges from 25 -67% when compared to culture in the diagnosis of ASB Urine dip Sensitivities 50 -92%, and specificity is 86 -97% compared to culture in the diagnosis of ASB. this is a useful and inexpensive test

Imaging Studies 2/4 Routine imaging studies are not indicated in the evaluation of pregnancy-related UTI. Renal ultrasound—or limited intravenous pyelography (IVP) may be helpful in patients with recurrent UTI or symptoms that are suggestive of nephrolithiasis

Other Tests 3/4 rarely are indicated Urine cytology may be useful in detecting rare upper urinary tract lesions ASO titer greater than 200 Todd units suggests recent group A streptococcal infection

Histologic Findings 4/4 Clumping WBCs and WBC casts pyelonephritis RBC casts are characteristic of acute glomerulonephritis

Antibiotics Oral antibiotics treatment of choice for ASB and cystitis Although antibiotic courses of 1, 3, and 7 days have been evaluated, 10 -14 days of treatment is usually recommended in order to eradicate the offending bacteria Intravenous treatment The standard course of treatment for pyelonephritis Patients with pyelonephritis can become dehydrated because of nausea and vomiting. However, patients are at high risk for development of pulmonary edema and adult respiratory distress syndrome (ARDS).

Antibiotics 1/6 Amoxillin Action: bactericidal against G+ve & G-ve Bacteria Dose: 1 -Day regimen: 3 g PO bid 3 -Day regimen: 500 mg PO qid 7 -Day regimen: 250 mg PO q 8 h

Antibiotics 2/6 Augmentin Action: Clavulanic acid is active against plasmid- mediated beta-lactamases Dose: 1 g PO q 12 h

Antibiotics 3/6 Ceftriaxone Action: Arrests bacterial growth. broad-spectrum gram-negative activity, lower efficacy against gram-positive organisms, and higher efficacy against resistant organisms Dose: 1 g IV/IM qd Precaution with breast feeding

Antibiotics 4/6 Vancomycin: Action: Potent antibiotic directed against gram-positive organisms and active against Enterococcus species Useful in the treatment of septicemia Dose: 500 mg/d to 2 g/d IV divided tid/qid for 7 -10 d S/E: red man syndrome is caused by too rapid IV infusion

Antibiotics 5/6 Nitrofurantoin: Action: Bactericidal in urine at therapeutic doses inactivates vital cellular biochemical processes of protein synthesis Dose: 1 tab PO bid for 3 -5 d S/E: irreversible peripheral neuropathy

Antibiotics 6/6 Trimethoprim & sulfamethoxazole Action: Sulfamethoxazole inhibits metabolism of dihydrofolic acid by competing with para-aminobenzoic acid trimethoprim blocks the production of tetrahydrofolic acid from dihydrofolic acid Dose: 2 tabs PO for 1 d 1 DS tab PO bid for 3 -5 d S/E: Trimethoprim decrease Folic Acid Sulphonamide kernicterus