Acute Pyelonephritis 08.05.13 Dr Andrew Stein Consultant in Acute and Renal Medicine Clinical Commissioning Director Coventry and Rugby CCGs Structure of Talk • Definition • Clinical Features • Investigation • Radiology • Treatment • Referrals • Quiz Choices • Renal US/not • Admit/not • Renal referral/not Definition and Diagnosis • Acute pyelonephritis = ascending bacterial infection of the renal pelvis and the renal parenchyma usually presenting with fever, loin pain and bacteriuria • 'Pyelonephritis': from Greek πήληξ – pyelum, meaning 'renal pelvis', νεφρός – nephros, meaning 'kidney' and -itis, meaning 'inflammation') • Clinical diagnosis; no single diagnostic clinical feature or investigation Risk Factors • DM • Female sex, pregnancy, intercourse • Stones, bladder catheter, structural renal tract abnormality • Chronic liver disease • IV drug use • Infective endocarditis Classification: Complicated vs Non-Complicated UTI • UTI can be 'complicated' eg acute pyelonephritis • This can be the first presentation of a (treatable) structural disease of the urinary tract, or diabetes mellitus • Assume all men, children, pregnant women and ill patients, have a complicated UTI; and exclude a structural cause • In a man, the diagnosis of UTI should be confirmed with a MSU, as it is an important diagnosis Structural Renal Disease Not requiring surgery • Reflux nephropathy • Polycystic kidney disease • Duplex system Requiring surgery (Obstruction) • Pelvi-ureteric junction (PUJ) obstruction • Renal stones • Prostatism Organisms • Escherichia coli is the commonest organism (80% communityacquired but <40% hospital-acquired) Note: other organisms (below) more associated with structural abnormalities: • Proteus mirabilis 20% • Staphylococcus saprophyticus 10% • Klebsiella 5% • Other organisms include: Streptococcus faecalis, Enterobacter, Acinetobacter, Pseudomonas aeruginosa, Serratia marascens, Candida albicans, Staphylococcus aureus Note: TB classically causes a sterile pyuria Symptoms • 75% have preceding lower urinary tract symptoms • Loin pain • Back pain • Fever/rigors • Other manifestation of severe sepsis Note: symptoms can develop over hours, or a day Signs • Pyrexia • Loin tenderness • Rarely, a palpable loin mass • Scoliosis concave towards the affected side • Of severe sepsis • Of AKI (rare) Note: in prostatitis, there may be a swollen and tender prostate Investigations (Blood and Urine) • FBC, ESR, CRP • U+E, LFT, Bone, Glucose (may be first presentation of DM) • BC (20% +ve) • Urinalysis: haematuria, proteinuria and be positive for nitrites and leucocytes; usually but not always positive • MSU: pure growth of >10x5 is diagnostic (60% +ve); pyuria = > 20 WC, on microscopy Investigations: Radiology • CXR (Erect: subdiaphragmatic gas?) • Renal Ultrasound (not unless male, pregnant, child, recurrent, unclear diagnosis or ill) • CT (Emphysematous Pyelonephritis) • CT-KUB (Stone?) Emphysematous Pyelonephritis • This is rare but life-threatening, mainly seen in patients with poorly controlled diabetes (90% have DM) • Necrotising infection of the renal parenchyma and its surrounding areas that results in the presence of gas in the renal parenchyma, collecting system, or perinephric tissue. • 50% mortality • 70% E Coli 70% • Classic finding is gas within the body of the kidney (CT) • Bilateral nephrectomy may be necessary (really!) CT abdomen Investigation – Urinary Dipstick 3 False beliefs • Protein – nil ≠ no proteinuria (= no albuminuria) • Protein + ≠ UTI • ‘Pos dip’ = UTI True belief • Protein ≥ +++ = glomerular/interstial disease, ++ might be Differential Diagnosis • Renal colic • Pelvic inflammatory disease • Acute appendicitis • Acute cholecystitis or diverticulitis • AAA Treatment: Antibiotics • Uncomplicated: PO TRIMETHOPRIM 200 mg bd • Complicated: IV GENTAMICIN 5 mg/kg od + IV CO-AMOXICLAV 1.2 g tds • ± Analgesia Treatment: Other • ABG/VBG • Sepsis Six • ICU Treatment: In or outpatient • IV Cetotaxime 1g OD • Follow-up • GP • Renal / not Who to Refer to Nephrology or Urology • Complicated (some) • Recurrent or unclear diagnosis • Pregnant woman • Young (child) • Male • Unwell Ie, considering diagnosis structural renal disease .. if doing Renal US, refer Complications + Indications for Surgery • Renal cortical abscess (renal carbuncle) • Renal corticomedullary abscess: Incision and drainage, nephrectomy • Perinephric abscess: Drainage, nephrectomy • Calculi-related urinary tract infection (UTI): Extracorporeal shockwave lithotripsy (ESWL) or endoscopic, percutaneous, or open surgery • Renal papillary necrosis: CT guided drainage or surgical drainage with debridement • Emphysematous pyelonephritis: Nephrectomy Quiz 1. 20% of patients have a positive BC 2. 20% pf patients have a positive MSU 3. Urinalysis: ‘protein – nil’ = no proteinuria 4. All patients need a Renal US 5. Klebsiella is the commonest organism Summary • Acute pyelonephritis is relatively easy diagnosis • 3 Big decisions .. • Renal US or not • Out vs Inpatient? • Refer to Renal/Urology or not Thankyou andrew.stein@uhcw.nhs.uk Acutemed.co.uk Renalmed.co.uk