Obstructing Ureteric Stone with Sepsis and a Mechanical Heart Valve
A 71-year-old woman is brought to the emergency department with a 3-day history of left flank pain, fever and rigors. She takes warfarin for a mechanical mitral valve and her last dose was two days ago. Temperature is 38.9°C, heart rate 118/min, blood pressure 92/54 mmHg and respiratory rate 24/min. Bloods show white cell count 19×10⁹/L, lactate 3.2 mmol/L, platelets 78×10⁹/L, INR 1.6 and creatinine 210 µmol/L (baseline 80). Non-contrast CT shows a 14 mm left proximal ureteric stone with moderate left hydronephrosis and no drainable collection. Bedside ultrasound confirms hydronephrosis. Urine dipstick is positive for leucocytes and nitrites. She has no rash and no known drug allergies. The on-call urology registrar asks whether to take her to theatre for ureteroscopy and stenting or to perform a bedside procedure.
1. What are the immediate management priorities in the first hour, and which investigations must not delay decompression?
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This is urosepsis with an obstructing stone until proven otherwise. The priorities are the sepsis bundle plus urgent source control: high-flow oxygen if needed, intravenous crystalloid resuscitation, blood cultures, urine culture, broad-spectrum intravenous antibiotics covering Gram-negative organisms, hourly urine output and lactate monitoring. Do not wait for culture results or for a contrast study before decompressing. The CT has already confirmed obstruction and excluded a drainable abscess. Antibiotics should be given within one hour, and blood cultures should be taken before antibiotics if this does not cause delay. Warn the cardiology team early because she has a mechanical valve and is anticoagulated. The key judgement is that the patient is haemodynamically unstable and thrombocytopenic; definitive ureteroscopy is not the priority and may be dangerous. Source control by percutaneous drainage should proceed as soon as it can be organised safely, ideally within 6–12 hours.
2. Which decompression method would you choose and why? Include how you would manage the coagulopathy.
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I would choose ultrasound-guided percutaneous nephrostomy under local anaesthetic. It avoids general anaesthesia, avoids ureteric instrumentation and can be performed with a platelet count of 78×10⁹/L and an INR of 1.6, accepting a small bleeding risk. A ureteric stent would require cystoscopy, often anaesthesia, and manipulation of an infected obstructed system; in an unstable patient with abnormal coagulation it carries a higher bleeding and sepsis risk. The nephrostomy should be performed by an experienced operator using a small calibre needle and catheter, with direct ultrasound guidance and post-procedure monitoring. I would not routinely reverse warfarin with vitamin K before a percutaneous procedure because of the risk of valve thrombosis, but I would discuss the case with cardiology. If bleeding occurs, hold warfarin, give vitamin K and consider prothrombin complex concentrate. Platelet transfusion is not routinely needed for a percutaneous procedure at this count unless there is active bleeding, but it should be available. Antibiotics continue after drainage.
3. Outline the definitive management of the stone and the anticoagulation plan after recovery.
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Definitive stone treatment is delayed until sepsis has resolved and the patient is stable. The nephrostomy is left in place and the patient is supported with antibiotics guided by cultures. Once afebrile, haemodynamically stable and with improving renal function, I would plan ureteroscopy and laser lithotripsy, usually after 4–6 weeks, with the nephrostomy providing access and drainage in the interim. A stone composition analysis and metabolic screen should follow. Anticoagulation is complex because of the mechanical mitral valve: warfarin should be restarted when bleeding risk allows, with a target INR determined by the valve type and cardiology advice. For elective ureteroscopy, I would use a bridging strategy only after multidisciplinary discussion; for many patients, continuing warfarin with a therapeutic INR may be acceptable for flexible ureteroscopy, but this depends on local protocols and anaesthetic assessment. The patient must understand that percutaneous drainage is a temporising measure, not definitive treatment.