Acute Pyelonephritis 08.05.13 Dr Andrew Stein Consultant in Acute and Renal Medicine Clinical...

Acute Pyelonephritis08.05.13

Dr Andrew SteinConsultant in Acute and Renal Medicine

Clinical Commissioning DirectorCoventry 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% community-acquired 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 TRIMETHOPRIM200 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