III. Pathophysiology
- Pregnancy factors that increase Pyelonephritis risk
- Increased GFR (results in Glycosuria, alkaluria)
- Increased Serum Progesterone (results in dilation of renal calyces, ureteral peristalsis stagnation)
- Bladder compression
IV. Symptoms
- Fever
- Chills
- Nausea
- Contractions
- Preterm Labor
- Acute Cystitis Symptoms
V. Signs
- Fever
- Maternal Tachycardia
- Fetal Tachycardia
- Costovertebral Angle Tenderness to palpation
- Pelvic exam
VI. Labs
- Urinalysis
-
Urine Culture with Sensitivity
- Urinary Catheter sample not typically recommended
- Complete Blood Count
- Blood Cultures
- Chemistry Panel (basic metabolic panel)
- Consider straining urine for calculi
VII. Imaging
- Renal Ultrasound
VIII. Management: Inpatient
- Most pregnant patients with Pyelonephritis start with inpatient care
- Pregnant women have a higher risk of morbidity and mortality (Sepsis occurs in up to 17% of cases)
- Convert from IV to oral in first 48-72 hours
- Preferred Antibiotics: Patients at LOW risk for Bacterial resistance
- Ceftriaxone (Rocephin) 1 to 2 g IV q24 hours
- Avoid in the peripartum period due to risk of newborn Kernicterus
- Cefepime 2 g IV every 12 hours
- Unasyn 1.5-3g IV every 6 hours
- Other agents are preferred due to resistance rates
- Ceftriaxone (Rocephin) 1 to 2 g IV q24 hours
- Preferred Antibiotics: Patients at HIGH risk for multi-drug Bacterial resistance (or severe cases)
- Ertapenem 1 g IV every 24 hours
- Piperacillin-Tazobactam (Zosyn) 3.375 to 4.5 g IV every 6 hours
- Agents to AVOID
- Gentamicin had been historically used in combination with Ampicillin (no longer recommended)
- Ampicillin 2 g IV every 6 hours
- Gentamycin 1.5 mg/kg (Maximum 80-100 mg) q8 hours
- Adjust dosing per kinetics for >1-2 days use
- Gentamicin had been historically used in combination with Ampicillin (no longer recommended)
- Other Inpatient Therapy
- Transition to oral antibiotic timing
- Oral antibiotics when affebrile without CVA pain for 48 hours
- Complete a total of 7-14 days
- Consider Urinary Tract Infection prophylaxis
IX. Management: Outpatient antibiotics
- Typically follows inpatient initial antibiotics (see above)
- In uncommon stable pregnant patients, oral antibiotics may be started at outset
- Indications
- Tolerating oral antibiotics and oral fluids (with or without oral Antiemetics)
- No signs of Sepsis
- Compliant
- Close interval follow-up
- Give single dose of IV antibiotics while awaiting Urine Culture
- Ceftriaxone 1-2 g IV or
- Ertapenem (Invanz) 1 g IV
- Indications
- Oral agents (higher resistance rates, accompany with initial dose of a broad spectrum IV antibiotic)
- Amoxicillin-Clavulanate (Augmentin) 875 mg orally twice daily for 14 days
- Cefixime (Suprax) 400 mg orally daily for 14 days
- Cefpodoxime 200 mg orally twice daily for 14 days
- Cephalexin (Keflex) 500 mg orally twice daily for 14 days
- Precautions
- Do NOT use Nitrofurantoin or fosfomycin
- Inadequate renal penetration to treat Pyelonephritis
- Do NOT use Nitrofurantoin or fosfomycin
X. Complications
- Sepsis (17% of Pyelonephritis cases in pregnancy)
- Acute Respiratory Distress Syndrome (in up to 8% of cases of Pyelonephritis in Pregnancy)
- Acute Kidney Injury
- Anemia
- Recurrent Pyelonephritis (6-8% of cases)
- Consider prophylaxis
- Nitrofurantoin 50-100 mg orally at bedtime until 6 weeks postpartum or
- Cephalexin (Keflex) 250-500 mg orally at bedtime until 6 weeks postpartum
XI. References
- Swadron, Schmitz, Bridwell, Carius in Herbert (2019) EM:Rap 19(3): 12-4
- Herness (2020) Am Fam Physician 102(3): 173-80 [PubMed]
- Matuszkiewicz-Rowinska (2015) Arch Med Sci. 2015 Mar 16; 11(1): 67–77 +PMID: 25861291 [PubMed]