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emphysematous pyelonephritis ( epn ) is a urologic emergency , characterized by an acute necrotizing parenchymal and perirenal infection caused by gas - forming uropathogens .
it has been postulated that high tissue glucose levels in diabetic patients provide the substrate for microorganisms such as escherichia coli , which are able to produce carbon dioxide by fermenting the sugar .
a 48-year - old , premenopausal lady was admitted with constant and dull aching right sided flank pain of a week 's duration .
she had a fever for three days and three episodes of gross painless hematuria without clots .
she had decreased urine output for 5 days , but no lower urinary tract symptoms .
she was recently diagnosed to have diabetes mellitus but was not on any anti - diabetic measures . on examination , she was febrile , with pulse rate of 90/min and blood pressure of 120/80 mmhg .
abdomen was soft with no distension but tenderness was present in the right renal angle without any mass .
her laboratory results were notable for a raised total leukocyte count with increased polymorphs and the platelet count was 180,000cells / cu.mm .
urine examination revealed deposits showing plenty of wbc and 20 - 25 rbcs / hpf .
urine culture and sensitivity showed e. coli 10/hpf , sensitive to amikacin , piperacillin - tazobactum , and cefoperazone sulbactum .
renal functions showed blood urea of 120 mg / dl , serum creatinine of 5.4 mg / dl , serum sodium of 130meq / dl , serum potassium of 4.2meq / dl .
serum prothrombin time , activated partial thromboplastin time ( aptt ) , assay of antithrombin iii , proteinc , proteins , and anti - phospholipid antibodies were normal .
x - ray kub showed colonic shadows displaced downwards and the right renal area was occupied by gas shadows .
right kidney measured 14 cm  4.4 cm and hyperechogenic gas shadows were observed on the ultrasonogram ( usg ) .
( a ) usg kub : right kidney 14 cm 4.4 cm and hyperechogenic dirty gas shadows with normal cmd and pcs , ( b ) colordoppler usg : thrombus seen in right renal vein extending into ivc , ( c ) cect kub : right kidney enlarged with perinephric stranding , air pockets in pcs , parenchyma and deep to the gerota 's fascia , ( d ) reconstructed cect : thrombus in the right renal vein and extension into the ivc contrast enhanced computed tomographic scan of ( cect ) revealed right kidney enlargement with perinephric stranding , air pockets in the pelvicalyceal system , parenchyma , and deep to the gerota 's fascia . a thrombus was seen in the right renal vein , extending into the ivc .
diethylene triamine pentaacetic acid ( dtpa ) isotope study was deferred due to raised renal parameters .
the patient was started on injection piperacillin with tazobactum , 4.5 g iv twice daily for 7 days .
she was hemo - dialysed 4 times and her urine output improved to 1.5 - 2l / day .
her serum creatinine decreased to 2 mg / dl and blood urea of 62 mg / dl in a week 's time .
the patient improved symptomatically and repeat usg color doppler showed complete recanalization of the ivc thrombus and partial recanalization of the right renal vein thrombus .
as she was considered high risk for any other surgical procedure , cystoscopy and right sided double j stenting was performed under local anesthesia and her urine output improved to 3l / day .
a dtpa scan showed right differential function of 33% and total glomerular filtration rate ( gfr ) was 59 ml / min [ figure 2a ] .
( a ) tc-99 dtpa diuretic renogram : right kidney functioning 33% , ( b ) repeat cect kub : better functioning right kidney , ( c ) magnetic resonance imaging : right kidney in normal state the patient became symptom free and was discharged .
she is on regular follow up now and a repeat cect and magnetic resonance imaging ( mri ) showed the right kidney with improved function even after 3 months [ figure 2b and c ] .
epn is a urologic emergency characterized by an acute necrotizing parenchymal and perirenal infection caused by gas - forming uropathogens .
epn may be classified into four classes according to computed tomography ( ct ) findings , class 1 : gas in the collecting system , class 2 : gas confined to renal parenchyma alone , class 3a : perinephric extension of gas or abscess , class 3b : extension of gas beyond gerota 's fascia and class 4 : bilateral epn or epn in a solitary kidney .
there has been no grading for our peculiar situation of epn with renal vein and ivc thrombus .
we ruled out predisposing factors for inherited and acquired causes of thrombosis with investigations including antithrombiniii , protein c , protein s , and anti - phospholipid antibodieswhich were normal .
we believe that the release of inflammatory mediators such as endotoxin , il-6 could have resulted in thrombosis .
epn presenting with renal vein and ivc thrombus has been reported in the literature . in a similar case ,
another case was reported by bhatt et al . where a 53-year - old woman with bilateral epn and new - onset diabetes developed septic emboli to her brain , lungs , liver , and portal vein thrombosis and succumbed to the disease despite aggressive medical management . in the management protocol , if the kidney is obstructed , catheter drainage must be instituted .
nephrectomy is recommended for patients who do not improve after a few days of therapy and if the affected kidney is nonfunctioning , because medical treatment alone may not suffice . at the time of initial presentation in our patient
, we did not contemplate nephrectomy due to her poor general condition and the likelihood of dislodgement of the thrombus during surgery .
as she showed marked improvement in general condition and renal function with conservative management , a dtpa study was obtained which showed 33% split function in the affected kidney .
epn complicated by thrombus in the renal vein and ivc is a rare presentation . in our patient ,
emphysematous pyelonephritis ( epn ) is a rapidly progressive necrotizing infection characterized by gas in the kidneys . 
 we describe a 48-year - old woman , a newly diagnosed diabetic , who presented with clinical features of right sided pyelonephritis with hematuria of short duration . on further evaluation 
 , she was diagnosed to have right sided epn , with thrombus in the renal vein and inferior vena cava ( ivc ) . 
 she was managed conservatively with hydration , insulin , intravenous antibiotics , anticoagulants and ureteric stenting on the right side . on follow - up , the gas shadows resolved and the thrombus completely regressed .