Sepsis with an Obstructing 8 mm Ureteral Stone and a Rising Creatinine
A 45-year-old woman presents with 36 hours of right loin pain, fever of 39.1 C, rigors and vomiting. She is tachycardic at 118/min, blood pressure 92/58 mmHg, respiratory rate 24/min, and confused. White cell count is 19.8 x 10^9/L, lactate 3.1 mmol/L, creatinine 210 micromol/L (baseline 70). Non-contrast CT shows an 8 mm stone at the right ureterovesical junction with moderate hydronephrosis and perinephric stranding. Urinalysis shows nitrites and leucocytes; blood cultures have been taken. She is 10 weeks pregnant.
1. What is your immediate management in the first 6 hours, and what changes because she is pregnant?
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This is obstructive pyelonephritis with sepsis (qSOFA-positive: hypotension, altered mentation, tachypnoea) in a pregnant patient. The obstructed, infected system is the source, and antibiotics alone will not control it.
First 6 hours:
- Sepsis bundle: oxygen to target saturation, two large-bore cannulae, blood and urine cultures before antibiotics, broad-spectrum intravenous antibiotics covering Gram-negatives (guided by local resistance patterns; in pregnancy avoid fluoroquinolones and aminoglycosides where alternatives exist), and fluid resuscitation with balanced crystalloid, reassessing response.
- Emergency decompression of the obstructed kidney is the single most important intervention, and it should not wait for antibiotic response. In pregnancy, ureteric stent insertion or percutaneous nephrostomy are both acceptable; a stent is often preferred under ultrasound or fluoroscopic guidance with abdominal shielding, but if the stone is at the UVJ and access is difficult, nephrostomy is a safe alternative. Definitive stone treatment (ureteroscopy) is deferred until after delivery or to the second trimester if decompression fails.
- Involve obstetrics for fetal monitoring and maternal-fetal medicine; involve intensive care if hypotension persists after fluids.
- Avoid nephrotoxic drugs, adjust antibiotic doses for renal function, and monitor urine output with a catheter if needed.
Pregnancy-specific changes: left lateral tilt to avoid caval compression, avoidance of ionising radiation where possible (ultrasound first), caution with vasopressors and fluid overload, and awareness that physiological hydronephrosis of pregnancy can mask or mimic obstruction. The diagnosis of obstruction should be based on stone visualisation and clinical picture, not dilatation alone.
2. She improves after decompression but the stone remains. How do you plan definitive management, and what are the risks of leaving the stent in situ until delivery?
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Definitive management options:
- Ureteroscopy with laser lithotripsy and stent placement is feasible in pregnancy, ideally in the second trimester, and is the preferred definitive option if the stone does not pass and the patient is stable. It avoids repeated stent changes and anaesthetic exposure later in pregnancy.
- Interval stent changes every 4-6 weeks until delivery is an alternative if the patient prefers to avoid a procedure in pregnancy or if ureteroscopy is not feasible.
- Observation with stent in situ and definitive treatment postpartum is acceptable for a small stone that may pass, but an 8 mm UVJ stone is unlikely to pass spontaneously.
Risks of leaving a stent until delivery:
- Encrustation and stone formation on the stent, which increases with duration, infection and pregnancy-related hypercalciuria; this can make later ureteroscopy much harder.
- Recurrent infection and sepsis, particularly with a history of obstructive pyelonephritis.
- Stent-related pain, haematuria and migration or obstruction.
- Difficulty in changing the stent if it becomes encrusted.
Plan: Book ureteroscopy in the second trimester with obstetric and anaesthetic cover, counsel about preterm labour and the small risk of ureteric injury, and arrange postpartum imaging to confirm stone clearance. If she declines, schedule stent changes every 4-6 weeks with urine cultures and a low threshold for earlier review.